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Martin TCS, Vinetz JM. Asymptomatic Plasmodium vivax parasitaemia in the low-transmission setting: the role for a population-based transmission-blocking vaccine for malaria elimination. Malar J 2018; 17:89. [PMID: 29466991 PMCID: PMC5822557 DOI: 10.1186/s12936-018-2243-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 02/17/2018] [Indexed: 12/21/2022] Open
Abstract
Plasmodium vivax remains an important cause of morbidity and mortality across the Americas, Horn of Africa, East and South East Asia. Control of transmission has been hampered by emergence of chloroquine resistance and several intrinsic characteristics of infection including asymptomatic carriage, challenges with diagnosis, difficulty eradicating the carrier state and early gametocyte appearance. Complex human-parasite-vector immunological interactions may facilitate onward infection of mosquitoes. Given these challenges, new therapies are being explored including the development of transmission to mosquito blocking vaccines. Herein, the case supporting the need for transmission-blocking vaccines to augment control of P. vivax parasite transmission and explore factors that are limiting eradication efforts is discussed.
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Affiliation(s)
- Thomas C S Martin
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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Mehrizi AA, Rezvani N, Zakeri S, Gholami A, Babaeekhou L. Poly(I:C) adjuvant strongly enhances parasite-inhibitory antibodies and Th1 response against Plasmodium falciparum merozoite surface protein-1 (42-kDa fragment) in BALB/c mice. Med Microbiol Immunol 2018; 207:151-166. [PMID: 29397427 DOI: 10.1007/s00430-018-0535-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 01/10/2018] [Indexed: 10/18/2022]
Abstract
Malaria vaccine development has been confronted with various challenges such as poor immunogenicity of malaria vaccine candidate antigens, which is considered as the main challenge. However, this problem can be managed using appropriate formulations of antigens and adjuvants. Poly(I:C) is a potent Th1 inducer and a human compatible adjuvant capable of stimulating both B- and T-cell immunity. Plasmodium falciparum merozoite surface protein 142 (PfMSP-142) is a promising vaccine candidate for blood stage of malaria that has faced several difficulties in clinical trials, mainly due to improper adjuvants. Therefore, in the current study, poly(I:C), as a potent Th1 inducer adjuvant, was evaluated to improve the immunogenicity of recombinant PfMSP-142, when compared to CFA/IFA, as reference adjuvant. Poly(I:C) produced high level and titers of anti-PfMSP-142 IgG antibodies in which was comparable to CFA/IFA adjuvant. In addition, PfMSP-142 formulated with poly(I:C) elicited a higher ratio of IFN-γ/IL-4 (23.9) and IgG2a/IgG1 (3.77) with more persistent, higher avidity, and titer of IgG2a relative to CFA/IFA, indicating a potent Th1 immune response. Poly(I:C) could also help to induce anti-PfMSP-142 antibodies with higher growth-inhibitory activity than CFA/IFA. Altogether, the results of the current study demonstrated that poly(I:C) is a potent adjuvant that can be appropriate for being used in PfMSP-142-based vaccine formulations.
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Affiliation(s)
- Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran.
| | - Niloufar Rezvani
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran.,Department of Biology, Islamshahr Branch, Islamic Azad University, Islamshahr, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
| | - Atefeh Gholami
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
| | - Laleh Babaeekhou
- Department of Biology, Islamshahr Branch, Islamic Azad University, Islamshahr, Tehran, Iran
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Pirahmadi S, Zakeri S, Mehrizi AA, Djadid ND. Analysis of genetic diversity and population structure of gene encoding cell-traversal protein for ookinetes and sporozoites (CelTOS) vaccine candidate antigen in global Plasmodium falciparum populations. INFECTION GENETICS AND EVOLUTION 2018; 59:113-125. [PMID: 29391203 DOI: 10.1016/j.meegid.2018.01.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/24/2017] [Accepted: 01/25/2018] [Indexed: 10/18/2022]
Abstract
Plasmodium falciparum cell-traversal protein for ookinetes and sporozoites (PfCelTOS) has been reported as one of the most attractive malaria vaccine candidate antigens. To design a broadly effective malaria vaccine based on this antigen, it is crucial to have adequate information on genetic diversity in global PfCelTOS. Therefore, the extent of sequence diversity at the full-length of the pfceltos was assessed among both natural P. falciparum isolates collected from Iran (n = 93) and from available global pfceltos sequence data retrieved from PlasmoDB database (n = 159). Also, recombination, natural selection, the degree of genetic differentiation as well as the predicted immunodominant regions in PfCelTOS were analyzed. In total, 40 SNPs (including 1 synonymous and 39 non-synonymous) were detected in 34 positions, as compared to 3D7 sequence, which led to 66 distinct haplotypes with different frequencies. Among those haplotypes, 34 (51.5%, excluded from further analysis) were singleton haplotype and mostly detected among Senegalese parasite isolates. PfCelt-1 was found as predominant haplotype (32.6% total frequency) that was only detected in Iranian P. falciparum isolates. Nucleotide diversity was low in French Guiana (0.00236 ± 0.00203) and Iranian (0.00259 ± 0.00048) P. falciparum isolates in comparison with African populations. Evidence for positive selection by host immunity and intragenic recombination were detected that are two key factors responsible for gene evolution and genetic diversity of pfceltos gene. The results of Fst analysis and haplotype network revealed that PfCelTOS antigen displayed evident genetic structure between geographical parasite populations. In conclusion, the present analysis demonstrates that there is a limited antigenic diversity and geographic variation in global PfCelTOS, and this finding may be associated with the critical function of this antigen in cell traversal of the parasite in sporozoite and ookinete. Besides, most of the predicted B- and T-cell epitopes were located in the conserved region of the gene, but most of the amino acid replacements were located at the C-terminal region of PfCelTOS. The obtained results in this investigation could provide knowledge for better design of PfCelTOS-based malaria vaccine.
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Affiliation(s)
- Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran, Pasteur Avenue, P.O. Box 1316943551, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran, Pasteur Avenue, P.O. Box 1316943551, Tehran, Iran.
| | - Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran, Pasteur Avenue, P.O. Box 1316943551, Tehran, Iran
| | - Navid Dinparast Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran, Pasteur Avenue, P.O. Box 1316943551, Tehran, Iran
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Poonam, Gupta Y, Gupta N, Singh S, Wu L, Chhikara BS, Rawat M, Rathi B. Multistage inhibitors of the malaria parasite: Emerging hope for chemoprotection and malaria eradication. Med Res Rev 2018; 38:1511-1535. [DOI: 10.1002/med.21486] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/09/2017] [Accepted: 12/26/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Poonam
- Department of Chemistry; Miranda House, University of Delhi; India
| | - Yash Gupta
- National Institute of Malaria Research (ICMR); New Delhi India
| | - Nikesh Gupta
- Special Centre for Nanosciences; Jawaharlal Nehru University; New Delhi India
| | - Snigdha Singh
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry; Hansraj College University Enclave, University of Delhi; Delhi India
| | - Lidong Wu
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA USA
- Key Laboratory of Control of Quality and Safety for Aquatic Products; Ministry of Agriculture, Chinese Academy of Fishery Sciences; Beijing China
| | | | - Manmeet Rawat
- Department of Internal Medicine; University of New Mexico School of Medicine; Albuquerque NM USA
| | - Brijesh Rathi
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry; Hansraj College University Enclave, University of Delhi; Delhi India
- Department of Chemistry; Massachusetts Institute of Technology; Cambridge MA USA
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Menon V, Kapulu MC, Taylor I, Jewell K, Li Y, Hill F, Long CA, Miura K, Biswas S. Assessment of Antibodies Induced by Multivalent Transmission-Blocking Malaria Vaccines. Front Immunol 2018; 8:1998. [PMID: 29403479 PMCID: PMC5780346 DOI: 10.3389/fimmu.2017.01998] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/22/2017] [Indexed: 01/20/2023] Open
Abstract
A malaria transmission-blocking vaccine would be a critical tool in achieving malaria elimination and eradication. By using chimpanzee adenovirus serotype 63 and modified vaccinia virus Ankara viral vectored vaccines, we investigated whether incorporating two antigens into one vaccine would result in higher transmission-reducing activity than one antigen. We demonstrated that when Pfs25 was administered with other antigens Pfs28 or Pfs230C, either concurrently as a mixed vaccine or co-expressed as a dual-antigen vaccine, the antibody response in mice to each antigen was comparable to a monoantigen vaccine, without immunological interference. However, we found that the transmission-reducing activity (functional activity) of dual-antigen vaccines was not additive. Dual-antigen vaccines generally only elicited similar transmission-reducing activity to monoantigen vaccines and in one instance had lower transmission-reducing activity. We found that despite the lack of immunological interference of dual-antigen vaccines, they are still not as effective at blocking malaria transmission as Pfs25-IMX313, the current leading candidate for viral vectored vaccines. Pfs25-IMX313 elicited similar quality antibodies to dual-antigen vaccines, but higher antibody titers.
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Affiliation(s)
- Vinay Menon
- Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Iona Taylor
- Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Kerry Jewell
- Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Yuanyuan Li
- Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD, United States
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD, United States
| | - Sumi Biswas
- Jenner Institute, University of Oxford, Oxford, United Kingdom
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Abstract
PURPOSE OF REVIEW Great progress has been made in reducing malaria morbidity and mortality, yet the parasite continues to cause a startling 200 million infections and 500 000 deaths annually. Malaria vaccine development is pushing new boundaries by steady advancement toward a licensed product. RECENT FINDINGS Despite 50 years of research, the complexity of Plasmoidum falciparum confounds all attempts to eradicate the organism. This very complexity has pushed the boundaries of vaccine development to new heights, yet it remains to be seen if an affordable vaccine can provide durable and high-level protection. Novel vaccines such as RTS,S/AS01E are on the edge of licensure, but old techniques have resurged with the ability to deliver vialed, whole organism vaccines. Novel adjuvants, multistage/multiantigen approaches and transmission blocking vaccines all contribute to a multipronged battle plan to conquer malaria. SUMMARY Vaccines are the most cost-effective tools to control infectious diseases, yet the complexity of malaria has frustrated all attempts to develop an effective product. This review concentrates on recent advances in malaria vaccine development that lend hope that a vaccine can be produced and malaria eradicated.
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Menezes RADO, Gomes MDSM, Mendes AM, Couto ÁARDA, Nacher M, Pimenta TS, de Sousa ACP, Baptista ARDS, de Jesus MI, Enk MJ, Cunha MG, Machado RLD. Enteroparasite and vivax malaria co-infection on the Brazil-French Guiana border: Epidemiological, haematological and immunological aspects. PLoS One 2018; 13:e0189958. [PMID: 29293589 PMCID: PMC5749708 DOI: 10.1371/journal.pone.0189958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/05/2017] [Indexed: 11/30/2022] Open
Abstract
Malaria-enteroparasitic co-infections are known for their endemicity. Although they are prevalent, little is known about their epidemiology and effect on the immune response. This study evaluated the effect of enteroparasite co-infections with malaria caused by Plasmodium vivax in a border area between Brazil and French Guiana. The cross sectional study took place in Oiapoque, a municipality of Amapá, on the Amazon border. Malaria was diagnosed using thick blood smears, haemoglobin dosage by an automated method and coproparasitology by the Hoffman and Faust methods. The anti-PvMSP-119 IgG antibodies in the plasma were evaluated using ELISA and Th1 (IFN-γ, TNF-α and IL-2), and Th2 (IL-4, IL-5 and IL-10) cytokine counts were performed by flow cytometry. The participants were grouped into those that were monoinfected with vivax malaria (M), vivax malaria-enteroparasite co-infected (CI), monoinfected with enteroparasite (E) and endemic controls (EC), who were negative for both diseases. 441 individuals were included and grouped according to their infection status: [M 6.9% (30/441)], [Cl 26.5% (117/441)], [E 32.4% (143/441)] and [EC 34.2% (151/441)]. Males prevailed among the (M) 77% (23/30) and (CI) 60% (70/117) groups. There was a difference in haemoglobin levels among the different groups under study for [EC-E], [EC-Cl], [E-M] and [Cl-M], with (p < 0.01). Anaemia was expressed as a percentage between individuals [CI-EC (p < 0.05)]. In terms of parasitaemia, there were differences for the groups [CI-M (p < 0.05)]. Anti-PvMSP-119 antibodies were detected in 51.2% (226/441) of the population. The level of cytokines evaluation revealed a large variation in TNF-α and IL-10 concentrations in the co-infected group. In this study we did not observe any influence of coinfection on the acquisition of IgG antibodies against PvMSP119, as well as on the profile of the cytokines that characterize the Th1 and Th2 patterns. However, co-infection increased TNF-α and IL-10 levels.
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Affiliation(s)
- Rubens Alex de Oliveira Menezes
- Postgraduate Program in the Biology of Infectious and Parasitic Agents, Federal University of Pará (UFPA), Belém, Pará State, Brazil
- Laboratory of morphofunctional and parasitic studies with impact on health (LEMPIS), Federal University of Amapá (UNIFAP), Macapa, Amapá State, Brazil
- * E-mail:
| | | | - Anapaula Martins Mendes
- UNIFAP/Oiapoque Binational Campus, Federal University of Amapá, Oiapoque, Amapá State, Brazil
| | | | - Mathieu Nacher
- Centre d’Investigation Clinique, CIC INSERM 1424, Centre Hospitalier de Cayenne, Cayenne, French Guiana
| | - Tamirys Simão Pimenta
- Postgraduate Program in Neuroscience and Cell Biology, UFPA, Belém, Pará State, Brazil
- Evandro Chagas Institute/Brazilian Secretariat of Health Surveillance (SVS)/Brazilian Ministry of Health (MS), Ananindeua, Pará State, Brazil
| | - Aline Collares Pinheiro de Sousa
- Evandro Chagas Institute/Brazilian Secretariat of Health Surveillance (SVS)/Brazilian Ministry of Health (MS), Ananindeua, Pará State, Brazil
| | | | - Maria Izabel de Jesus
- Evandro Chagas Institute/Brazilian Secretariat of Health Surveillance (SVS)/Brazilian Ministry of Health (MS), Ananindeua, Pará State, Brazil
| | - Martin Johannes Enk
- Evandro Chagas Institute/Brazilian Secretariat of Health Surveillance (SVS)/Brazilian Ministry of Health (MS), Ananindeua, Pará State, Brazil
| | - Maristela Gomes Cunha
- Postgraduate Program in the Biology of Infectious and Parasitic Agents, Federal University of Pará (UFPA), Belém, Pará State, Brazil
- Laboratory of Microbiology and Immunology, Federal University of Pará (UFPA), Belém, Pará State, Brazil
| | - Ricardo Luiz Dantas Machado
- Postgraduate Program in the Biology of Infectious and Parasitic Agents, Federal University of Pará (UFPA), Belém, Pará State, Brazil
- Evandro Chagas Institute/Brazilian Secretariat of Health Surveillance (SVS)/Brazilian Ministry of Health (MS), Ananindeua, Pará State, Brazil
- Fluminense Federal University, Niterói, Rio de Janeiro State, Brazil
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Wang J, Zheng W, Liu F, Wang Y, He Y, Zheng L, Fan Q, Luo E, Cao Y, Cui L. Characterization of Pb51 in Plasmodium berghei as a malaria vaccine candidate targeting both asexual erythrocytic proliferation and transmission. Malar J 2017; 16:458. [PMID: 29132428 PMCID: PMC5683326 DOI: 10.1186/s12936-017-2107-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 11/02/2017] [Indexed: 11/10/2022] Open
Abstract
Background A vaccine that targets multiple developmental stages of malaria parasites would be an effective tool for malaria control and elimination. Methods A conserved gene in Plasmodium, the Plasmodium berghei gene (PBANKA_020570) encoding a 51 kDa protein (pb51 gene), was identified through search of the PlasmoDB database using a combination of expression and protein localization criteria. A partial domain of the Pb51 protein was expressed in a prokaryotic expression system (rPb51) and used for immunization in mice. The protein expression profile and localization were studied by Western blot and indirect immunofluorescence assay (IFA), respectively. The inhibitory effect of the anti-rPb51 antibodies on parasite proliferation was evaluated in erythrocytes in vivo. The transmission-blocking activity of the immune sera was determined by in vitro ookinete conversion assay and by direct mosquito feeding assay (DFA). Results The rPb51 elicited specific antibodies in mice. Western blot confirmed Pb51 expression in schizonts, gametocytes and ookinetes. IFA showed localization of Pb51 on the outer membranes of schizonts, gametocytes, zygotes, retorts, ookinetes and sporozoites of P. berghei. Mice immunized with the rPb51 protein significantly reduced parasite proliferation and gametocyte conversion in vivo. Moreover, the rPb51 antisera also significantly reduced the in vitro ookinete conversion when added into the ookinete culture medium. In DFA, mice immunized with the rPb51 reduced the prevalence of mosquito infection by 21.3% and oocyst density by 54.8%. Conclusions In P. berghei, P51 was expressed in both asexual erythrocytic and sexual stages and localized on the surface of these stages with the exception of the ring stage. The anti-rPb51 antibodies inhibited both P. berghei proliferation in mice and transmission of the parasite to mosquitoes. Electronic supplementary material The online version of this article (10.1186/s12936-017-2107-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jian Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Wenqi Zheng
- Laboratory of Surgery, The Affiliated Hospital, Inner Mongolia Medical University, Hohhot, 010050, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Yaru Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Yiwen He
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Li Zheng
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Enjie Luo
- Department of Pathogen Biology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China.
| | - Liwang Cui
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110001, Liaoning, China.,Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
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Comparative functional potency of DNA vaccines encoding Plasmodium falciparum transmission blocking target antigens Pfs48/45 and Pfs25 administered alone or in combination by in vivo electroporation in rhesus macaques. Vaccine 2017; 35:7049-7056. [PMID: 29132995 DOI: 10.1016/j.vaccine.2017.10.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 09/26/2017] [Accepted: 10/13/2017] [Indexed: 02/07/2023]
Abstract
Antibodies recognizing conformational epitopes in Pfs48/45, an antigen expressed on the surface of Plasmodium falciparum gametes and zygotes, have firmly established Pfs48/45 as a promising transmission blocking vaccine (TBV) candidate. However, it has been difficult to reproducibly express Pfs48/45 in a variety of recombinant expression systems. The goal of our studies was to evaluate functional immunogenicity of Pfs48/45 using DNA vaccine format in rhesus macaques. An additional goal was to ensure that when used in combination with another malarial antigen, specific immunity to both antigens was not compromised. For testing combination vaccines, we employed Pfs25 DNA plasmids that have previously undergone evaluations in rodents and nonhuman primates. Pfs25 is expressed on the surface of parasites after fertilization and is also a lead TBV candidate. DNA plasmids based on codon-optimized sequences of Pfs48/45 and Pfs25 were administered by in vivo electroporation, followed by a final recombinant protein boost. Our studies demonstrate that Pfs48/45 encoded by DNA plasmids is capable of inducing potent transmission blocking antibody responses, and such transmission blocking immune potency of Pfs48/45 was not compromised when tested in combination with Pfs25, These findings provide the evidence in favor of further studies on Pfs48/45 and Pfs25, either alone or in combination with other known malaria vaccine candidates for developing effective vaccines capable of interrupting malaria transmission.
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The potential use of melatonin to treat protozoan parasitic infections: A review. Biomed Pharmacother 2017; 97:948-957. [PMID: 29136773 DOI: 10.1016/j.biopha.2017.11.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/01/2017] [Accepted: 11/03/2017] [Indexed: 01/09/2023] Open
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) is a circadian hormone produced in vertebrates by the pineal gland and other organs. Melatonin is believed to influence immune cells leading to modulation of the proliferative response of stimulated lymphocytes as well as cytokine production. Due to the antioxidant and immunomodulatory effects of melatonin, it is suggested that this molecule could be a therapeutic alternative agent to fight bacterial, viral, and parasitic infections by a variety of mechanisms. Herein, we review the effects of melatonin on the cell biology of protozoan parasites and host's immune response. In toxoplasmosis, African trypanosomiasis and Chagas' disease, melatonin enhances host's immune response against the parasite via regulating the secretion of inflammatory mediators. In amoebiasis, melatonin reduces the amoebic lesions as well as increasing the leukophagocytosis and the number of dead amoebae. In giardiasis, serum melatonin levels are elevated in these patients; this suggests a positive correlation between the level of melatonin and phagocytic activity in the G. duodenalis infected patients, possibly related to melatonin's immunomodulatory effect. In leishmaniasis, melatonin arrests parasite replication accompanied by releasing mitochondrial Ca2+ into the cytosol, increasing the level of mitochondrial nitrites as well as reducing superoxide dismutase (SOD) activity. In malaria, melatonin synchronizes the Plasmodium cell cycle via modulating cAMP-PKA and IP3-Ca2+ pathways. Thus, simultaneous administration of melatonin agonists or giving pharmacological doses of melatonin may be considered a novel approach for treatment of malarial infection.
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Abstract
Since the turn of the century, a remarkable expansion has been achieved in the range and effectiveness of products and strategies available to prevent, treat, and control malaria, including advances in diagnostics, drugs, vaccines, and vector control. These advances have once again put malaria elimination on the agenda. However, it is clear that even with the means available today, malaria control and elimination pose a formidable challenge in many settings. Thus, currently available resources must be used more effectively, and new products and approaches likely to achieve these goals must be developed. This paper considers tools (both those available and others that may be required) to achieve and maintain malaria elimination. New diagnostics are needed to direct treatment and detect transmission potential; new drugs and vaccines to overcome existing resistance and protect against clinical and severe disease, as well as block transmission and prevent relapses; and new vector control measures to overcome insecticide resistance and more powerfully interrupt transmission. It is also essential that strategies for combining new and existing approaches are developed for different settings to maximise their longevity and effectiveness in areas with continuing transmission and receptivity. For areas where local elimination has been recently achieved, understanding which measures are needed to maintain elimination is necessary to prevent rebound and the reestablishment of transmission. This becomes increasingly important as more countries move towards elimination.
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Rabinovich RN, Drakeley C, Djimde AA, Hall BF, Hay SI, Hemingway J, Kaslow DC, Noor A, Okumu F, Steketee R, Tanner M, Wells TNC, Whittaker MA, Winzeler EA, Wirth DF, Whitfield K, Alonso PL. malERA: An updated research agenda for malaria elimination and eradication. PLoS Med 2017; 14:e1002456. [PMID: 29190300 PMCID: PMC5708604 DOI: 10.1371/journal.pmed.1002456] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Achieving a malaria-free world presents exciting scientific challenges as well as overwhelming health, equity, and economic benefits. WHO and countries are setting ambitious goals for reducing the burden and eliminating malaria through the "Global Technical Strategy" and 21 countries are aiming to eliminate malaria by 2020. The commitment to achieve these targets should be celebrated. However, the need for innovation to achieve these goals, sustain elimination, and free the world of malaria is greater than ever. Over 180 experts across multiple disciplines are engaged in the Malaria Eradication Research Agenda (malERA) Refresh process to address problems that need to be solved. The result is a research and development agenda to accelerate malaria elimination and, in the longer term, transform the malaria community's ability to eradicate it globally.
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Affiliation(s)
- Regina N. Rabinovich
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- * E-mail: ,
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - B. Fenton Hall
- National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health (NIH), Bethesda, Maryland, United States of America
| | - Simon I. Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
| | - Janet Hemingway
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - David C. Kaslow
- PATH Essential Medicines and PATH Center for Vaccine Innovation and Access, Seattle, Washington, United States of America
| | - Abdisalan Noor
- KEMRI Wellcome Trust Research Programme, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Fredros Okumu
- Ifakara Health Institute, Ifakara, Tanzania
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Parktown, South Africa
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Richard Steketee
- PATH Malaria Control and Elimination Partnership in Africa, Seattle, Washington, United States of America
| | - Marcel Tanner
- Swiss TPH, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Maxine A. Whittaker
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Australia
| | - Elizabeth A. Winzeler
- University of California, San Diego, School of Medicine, La Jolla, California, United States of America
| | - Dyann F. Wirth
- Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Kate Whitfield
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Pedro L. Alonso
- World Health Organization (WHO), Global Malaria Programme (GMP), Geneva, Switzerland
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Eldering M, Bompard A, Miura K, Stone W, Morlais I, Cohuet A, van Gemert GJ, Brock PM, Rijpma SR, van de Vegte-Bolmer M, Graumans W, Siebelink-Stoter R, Da DF, Long CA, Morin MJ, Sauerwein RW, Churcher TS, Bousema T. Comparative assessment of An. gambiae and An. stephensi mosquitoes to determine transmission-reducing activity of antibodies against P. falciparum sexual stage antigens. Parasit Vectors 2017; 10:489. [PMID: 29041962 PMCID: PMC5646129 DOI: 10.1186/s13071-017-2414-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 10/01/2017] [Indexed: 01/08/2023] Open
Abstract
Background With the increasing interest in vaccines to interrupt malaria transmission, there is a demand for harmonization of current methods to assess Plasmodium transmission in laboratory settings. Potential vaccine candidates are currently tested in the standard membrane feeding assay (SMFA) that commonly relies on Anopheles stephensi mosquitoes. Other mosquito species including Anopheles gambiae are the dominant malaria vectors for Plasmodium falciparum in sub-Saharan Africa. Methods Using human serum and monoclonal pre-fertilization (anti-Pfs48/45) and post-fertilization (anti-Pfs25) antibodies known to effectively inhibit sporogony, we directly compared SMFA based estimates of transmission-reducing activity (TRA) for An. stephensi and An. gambiae mosquitoes. Results In the absence of transmission-reducing antibodies, average numbers of oocysts were similar between An. gambiae and An. stephensi. Antibody-mediated TRA was strongly correlated between both mosquito species, and absolute TRA estimates for pre-fertilisation monoclonal antibodies (mAb) showed no significant difference between the two species. TRA estimates for IgG of naturally exposed individuals and partially effective concentrations of anti-Pfs25 mAb were higher for An. stephensi than for An. gambiae. Conclusion Our findings support the use of An. stephensi in the SMFA for target prioritization. As a vaccine moves through product development, better estimates of TRA and transmission-blocking activity (TBA) may need to be obtained in epidemiologically relevant parasite-species combination. Electronic supplementary material The online version of this article (10.1186/s13071-017-2414-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maarten Eldering
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anaïs Bompard
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Kazutoyo Miura
- National Institute of Allergy and Infectious Diseases, Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD, USA
| | - Will Stone
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Isabelle Morlais
- Institut de Recherche pour le Développement, UMR MIVEGEC UM-CNRS 5290-IRD 224, Montpellier, France
| | - Anna Cohuet
- Institut de Recherche pour le Développement, UMR MIVEGEC UM-CNRS 5290-IRD 224, Montpellier, France
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Patrick M Brock
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sanna R Rijpma
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rianne Siebelink-Stoter
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | - Carole A Long
- National Institute of Allergy and Infectious Diseases, Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD, USA
| | | | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK.
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65
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França CT, White MT, He WQ, Hostetler JB, Brewster J, Frato G, Malhotra I, Gruszczyk J, Huon C, Lin E, Kiniboro B, Yadava A, Siba P, Galinski MR, Healer J, Chitnis C, Cowman AF, Takashima E, Tsuboi T, Tham WH, Fairhurst RM, Rayner JC, King CL, Mueller I. Identification of highly-protective combinations of Plasmodium vivax recombinant proteins for vaccine development. eLife 2017; 6:28673. [PMID: 28949293 PMCID: PMC5655538 DOI: 10.7554/elife.28673] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/25/2017] [Indexed: 12/22/2022] Open
Abstract
The study of antigenic targets of naturally-acquired immunity is essential to identify and prioritize antigens for further functional characterization. We measured total IgG antibodies to 38 P. vivax antigens, investigating their relationship with prospective risk of malaria in a cohort of 1–3 years old Papua New Guinean children. Using simulated annealing algorithms, the potential protective efficacy of antibodies to multiple antigen-combinations, and the antibody thresholds associated with protection were investigated for the first time. High antibody levels to multiple known and newly identified proteins were strongly associated with protection (IRR 0.44–0.74, p<0.001–0.041). Among five-antigen combinations with the strongest protective effect (>90%), EBP, DBPII, RBP1a, CyRPA, and PVX_081550 were most frequently identified; several of them requiring very low antibody levels to show a protective association. These data identify individual antigens that should be prioritized for further functional testing and establish a clear path to testing a multicomponent P. vivax vaccine.
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Affiliation(s)
- Camila Tenorio França
- Division of Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Michael T White
- Division of Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Australia.,MRC Center for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Wen-Qiang He
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Jessica B Hostetler
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom.,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Jessica Brewster
- Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Gabriel Frato
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, United States
| | - Indu Malhotra
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, United States
| | - Jakub Gruszczyk
- Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Christele Huon
- Malaria Parasite Biology and Vaccines Unit, Institut Pasteur, Paris, France
| | - Enmoore Lin
- Malaria Immuno-Epidemiology Unit, PNG Institute of Medical Research, Yagaum, Papua New Guinea
| | - Benson Kiniboro
- Malaria Immuno-Epidemiology Unit, PNG Institute of Medical Research, Yagaum, Papua New Guinea
| | - Anjali Yadava
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, United States
| | - Peter Siba
- Malaria Immuno-Epidemiology Unit, PNG Institute of Medical Research, Yagaum, Papua New Guinea
| | - Mary R Galinski
- International Center for Malaria Research, Education, and Development, Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, United States.,Infectious Diseases Division, Department of Medicine, Emory University, Atlanta, United States
| | - Julie Healer
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Chetan Chitnis
- Malaria Parasite Biology and Vaccines Unit, Institut Pasteur, Paris, France.,International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Alan F Cowman
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Eizo Takashima
- Malaria Vaccine Branch, Walter Reed Army Institute of Research, Silver Spring, United States
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Wai-Hong Tham
- Department of Medical Biology, University of Melbourne, Parkville, Australia.,Division of Infection and Immunity, Walter and Eliza Hall Institute, Parkville, Australia
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, United States
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, United States
| | - Ivo Mueller
- Division of Population Health and Immunity, Walter and Eliza Hall Institute, Parkville, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Australia.,Malaria Parasites and Hosts Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France.,Barcelona Institute of Global Health, Barcelona, Spain
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66
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Canavati SE, Quintero CE, Haller B, Lek D, Yok S, Richards JS, Whittaker MA. Maximizing research study effectiveness in malaria elimination settings: a mixed methods study to capture the experiences of field-based staff. Malar J 2017; 16:362. [PMID: 28893264 PMCID: PMC5594431 DOI: 10.1186/s12936-017-2016-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 09/06/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND In a drug-resistant, malaria elimination setting like Western Cambodia, field research is essential for the development of novel anti-malarial regimens and the public health solutions necessary to monitor the spread of resistance and eliminate infection. Such field studies often face a variety of similar implementation challenges, but these are rarely captured in a systematic way or used to optimize future study designs that might overcome similar challenges. Field-based research staff often have extensive experience and can provide valuable insight regarding these issues, but their perspectives and experiences are rarely documented and seldom integrated into future research protocols. This mixed-methods analysis sought to gain an understanding of the daily challenges encountered by research field staff in the artemisinin-resistant, malaria elimination setting of Western Cambodia. In doing so, this study seeks to understand how the experiences and opinions of field staff can be captured, and used to inform future study designs. METHODS Twenty-two reports from six field-based malaria studies conducted in Western Cambodia were reviewed using content analysis to identify challenges to conducting the research. Informal Interviews, Focus Group Discussions and In-depth Interviews were also conducted among field research staff. Thematic analysis of the data was undertaken using Nvivo 9® software. Triangulation and critical case analysis was also used. RESULTS There was a lack of formalized avenues through which field workers could report challenges experienced when conducting the malaria studies. Field research staff faced significant logistical barriers to participant recruitment and data collection, including a lack of available transportation to cover long distances, and the fact that mobile and migrant populations (MMPs) are usually excluded from studies because of challenges in follow-up. Cultural barriers to communication also hindered participant recruitment and created unexpected delays. Field staff often paid a physical, emotional and financial cost, going beyond their duty in order to keep the study running. CONCLUSIONS Formal monthly reports filled out by field study staff could be a key tool for capturing field study staff experiences effectively, but require specific report fields to encourage staff to outline their challenges and to propose potential solutions. Forging strong bonds with communities and their leaders may improve communication, and decrease barriers to participant recruitment. Study designs that make it feasible for MMPs to participate should be pursued; in addition to increasing the potential participant pool, this will ensure that the most malaria-endemic demographic is taken into account in research studies. Overlaps between clinical care and research create ethical dilemmas for study staff, a fact that warrants careful consideration. Lessons learned from study field staff should be used to create a set of locally-relevant recommendations to inform future study designs.
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Affiliation(s)
- Sara E. Canavati
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Vysnova Partners Inc., Washington, DC USA
| | - Cesia E. Quintero
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
| | | | - Dysoley Lek
- The National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Sovann Yok
- Provincial Health Department, Pailin City, Pailin Province Cambodia
| | - Jack S. Richards
- Centre for Biomedical Research, Burnet Institute, Melbourne, Australia
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Australia
| | - Maxine Anne Whittaker
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, Australia
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67
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Natural immune response to Plasmodium vivax alpha-helical coiled coil protein motifs and its association with the risk of P. vivax malaria. PLoS One 2017. [PMID: 28651021 PMCID: PMC5484505 DOI: 10.1371/journal.pone.0179863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Protein α-helical coiled coil structures are known to induce antibodies able to block critical functions in different pathogens. In a previous study, a total of 50 proteins of Plasmodium vivax erythrocytic asexual stages containing α-helical coiled coil structural motifs were identified in silico, and the corresponding peptides were chemically synthesized. A total of 43 peptides were recognized by naturally acquired antibodies in plasma samples from both Papua New Guinea (PNG) and Colombian adult donors. In this study, the association between IgG antibodies to these peptides and clinical immunity was further explored by measuring total IgG antibody levels to 24 peptides in baseline samples from a longitudinal study of children aged 1–3 years (n = 164) followed for 16 months. Samples were reactive to all peptides tested. Eight peptides were recognized by >50% of individuals, whereas only one peptide had < 20% reactivity. Children infected at baseline were seropositive to 23/24 peptides. No significant association was observed between antibody titers and age or molecular force of infection, suggesting that antibody levels had already reached an equilibrium. There was a strong association between antibody levels to all peptides and protection against P. vivax clinical episodes during the 16 months follow-up. These results suggest that the selected coiled coil antigens might be good markers of both exposure and acquired immunity to P. vivax malaria, and further preclinical investigation should be performed to determine their potential as P. vivax vaccine antigens.
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Mehrizi AA, Torabi F, Zakeri S, Djadid ND. Limited genetic diversity in the global Plasmodium vivax Cell traversal protein of Ookinetes and Sporozoites (CelTOS) sequences; implications for PvCelTOS-based vaccine development. INFECTION GENETICS AND EVOLUTION 2017; 53:239-247. [PMID: 28600217 DOI: 10.1016/j.meegid.2017.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 06/04/2017] [Accepted: 06/05/2017] [Indexed: 01/04/2023]
Abstract
Cell traversal protein of Ookinetes and Sporozoites (CelTOS) is a new malaria vaccine candidate antigen. Since one of the main challenges in malaria vaccine development is the extensive antigenic diversity of this parasite, local and global gene diversity analysis is of particular importance. Therefore, in this study, the genetic diversity of pvceltos gene was investigated among Iranian P. vivax isolates (n=46) and compared with available worldwide pvceltos sequences. One synonymous (C109A) and three amino acid replacements (V118L, K178T, and G179R) were observed in Iranian pvceltos sequences in compare with Sal-1 sequence leading to five haplotypes including PvCelt-A (GSVKGL, 13%), PvCelt-B (GSLKGL, 50%), PvCelt-C (GSLTGL, 17.4%), PvCelt-D (GSVTGL, 13%) and PvCelt-E (GSLTRL, 6.5%). However, amino acid replacements were observed in six positions (G10S, S40N, V118L/M, K178T, G179R/D and L181R) in PvCelTOS antigen of global isolates leading to 11 distinct haplotypes. PvCelt-A and PvCelt-B haplotypes were the most common haplotypes in the world. The overall nucleotide diversity for Iranian isolates was 0.00169, while, the level of nucleotide diversity was ranged from 0.00252 for Thailand to 0.00022 for Peru populations in the world. The analysis of SNPs in relation with the predicted immunodominant regions revealed that only K178T and G179R SNPs are located in putative B-cell epitopes. All replacements were located in CD4+ and/or CD8+ T-cell epitopes. However, the majority of epitopes are located in conserved regions. Knowing whether these changes may alter the affinity of the epitopes for antibodies and/or MHC molecules remains to be investigated in experimental studies. In conclusion, the present study showed a very limited genetic diversity in pvceltos gene among the global clinical isolates that can be regarded as a potential candidate antigen to apply for vivax-based malaria vaccine development.
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Affiliation(s)
- Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran.
| | - Fatemeh Torabi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran; Department of Genetics, Tehran Medical Branch, Islamic Azad University, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
| | - Navid Dinparast Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
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69
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Matuschewski K. Vaccines against malaria-still a long way to go. FEBS J 2017; 284:2560-2568. [DOI: 10.1111/febs.14107] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/09/2017] [Accepted: 05/10/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Kai Matuschewski
- Department of Molecular Parasitology; Institute of Biology; Humboldt University Berlin; Germany
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70
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Niu G, Franc A C, Zhang G, Roobsoong W, Nguitragool W, Wang X, Prachumsri J, Butler NS, Li J. The fibrinogen-like domain of FREP1 protein is a broad-spectrum malaria transmission-blocking vaccine antigen. J Biol Chem 2017; 292:11960-11969. [PMID: 28533429 DOI: 10.1074/jbc.m116.773564] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/15/2017] [Indexed: 01/01/2023] Open
Abstract
FREP1 in mosquito midguts facilitates Plasmodium falciparum parasite transmission. The fibrinogen-like (FBG) domain of FREP1 is highly conserved (>90% identical) among Anopheles species from different continents, suggesting that anti-FBG antibodies may block malaria transmission to all anopheline mosquitoes. Using standard membrane-feeding assays, anti-FREP1 polyclonal antibodies significantly blocked transmission of Plasmodium berghei and Plasmodium vivax to Anopheles gambiae and Anopheles dirus, respectively. Furthermore, in vivo studies of mice immunized with FBG achieved >75% blocking efficacy of P. berghei to A. gambiae without triggering immunopathology. Anti-FBG serum also reduced >81% of P. falciparum infection to A. gambiae Finally, we showed that FBG interacts with Plasmodium gametocytes and ookinetes, revealing the molecular mechanism of its antibody transmission-blocking activity. Collectively, our data support that FREP1-mediated Plasmodium transmission to mosquitoes is a conserved pathway and that targeting the FBG domain of FREP1 will limit the transmission of multiple Plasmodium species to multiple Anopheles species.
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Affiliation(s)
- Guodong Niu
- Department of Biological Sciences, Florida International University, Miami, Florida 33199
| | - Caio Franc A
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019
| | - Genwei Zhang
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Center, Mahidol University Faculty of Tropical Medicine, Bangkok 10400, Thailand
| | - Wang Nguitragool
- Mahidol Vivax Research Center, Mahidol University Faculty of Tropical Medicine, Bangkok 10400, Thailand
| | - Xiaohong Wang
- Department of Biological Sciences, Florida International University, Miami, Florida 33199
| | - Jetsumon Prachumsri
- Mahidol Vivax Research Center, Mahidol University Faculty of Tropical Medicine, Bangkok 10400, Thailand
| | - Noah S Butler
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa 52242
| | - Jun Li
- Department of Biological Sciences, Florida International University, Miami, Florida 33199; Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019.
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Bauer WS, Kimmel DW, Adams NM, Gibson LE, Scherr TF, Richardson KA, Conrad JA, Matakala HK, Haselton FR, Wright DW. Magnetically-enabled biomarker extraction and delivery system: towards integrated ASSURED diagnostic tools. Analyst 2017; 142:1569-1580. [PMID: 28386613 PMCID: PMC5674985 DOI: 10.1039/c7an00278e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diagnosis of asymptomatic malaria poses a great challenge to global disease elimination efforts. Healthcare infrastructure in rural settings cannot support existing state-of-the-art tools necessary to diagnose asymptomatic malaria infections. Instead, lateral flow immunoassays (LFAs) are widely used as a diagnostic tool in malaria endemic areas. While LFAs are simple and easy to use, they are unable to detect low levels of parasite infection. We have developed a field deployable Magnetically-enabled Biomarker Extraction And Delivery System (mBEADS) that significantly improves limits of detection for several commercially available LFAs. Integration of mBEADS with leading commercial Plasmodium falciparum malaria LFAs improves detection limits to encompass an estimated 95% of the disease reservoir. This user-centered mBEADS platform makes significant improvements to a previously cumbersome malaria biomarker enrichment strategy by improving reagent stability, decreasing the processing time 10-fold, and reducing the assay cost 10-fold. The resulting mBEADS process adds just three minutes and less than $0.25 to the total cost of a single LFA, thus balancing sensitivity and practicality to align with the World Health Organization's ASSURED criteria for point-of-care (POC) testing.
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Affiliation(s)
- Westley S Bauer
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA.
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Mordmüller B, Surat G, Lagler H, Chakravarty S, Ishizuka AS, Lalremruata A, Gmeiner M, Campo JJ, Esen M, Ruben AJ, Held J, Calle CL, Mengue JB, Gebru T, Ibáñez J, Sulyok M, James ER, Billingsley PF, Natasha KC, Manoj A, Murshedkar T, Gunasekera A, Eappen AG, Li T, Stafford RE, Li M, Felgner PL, Seder RA, Richie TL, Sim BKL, Hoffman SL, Kremsner PG. Sterile protection against human malaria by chemoattenuated PfSPZ vaccine. Nature 2017; 542:445-449. [PMID: 28199305 PMCID: PMC10906480 DOI: 10.1038/nature21060] [Citation(s) in RCA: 284] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Accepted: 12/14/2016] [Indexed: 12/26/2022]
Abstract
A highly protective malaria vaccine would greatly facilitate the prevention and elimination of malaria and containment of drug-resistant parasites. A high level (more than 90%) of protection against malaria in humans has previously been achieved only by immunization with radiation-attenuated Plasmodium falciparum (Pf) sporozoites (PfSPZ) inoculated by mosquitoes; by intravenous injection of aseptic, purified, radiation-attenuated, cryopreserved PfSPZ ('PfSPZ Vaccine'); or by infectious PfSPZ inoculated by mosquitoes to volunteers taking chloroquine or mefloquine (chemoprophylaxis with sporozoites). We assessed immunization by direct venous inoculation of aseptic, purified, cryopreserved, non-irradiated PfSPZ ('PfSPZ Challenge') to malaria-naive, healthy adult volunteers taking chloroquine for antimalarial chemoprophylaxis (vaccine approach denoted as PfSPZ-CVac). Three doses of 5.12 × 104 PfSPZ of PfSPZ Challenge at 28-day intervals were well tolerated and safe, and prevented infection in 9 out of 9 (100%) volunteers who underwent controlled human malaria infection ten weeks after the last dose (group III). Protective efficacy was dependent on dose and regimen. Immunization with 3.2 × 103 (group I) or 1.28 × 104 (group II) PfSPZ protected 3 out of 9 (33%) or 6 out of 9 (67%) volunteers, respectively. Three doses of 5.12 × 104 PfSPZ at five-day intervals protected 5 out of 8 (63%) volunteers. The frequency of Pf-specific polyfunctional CD4 memory T cells was associated with protection. On a 7,455 peptide Pf proteome array, immune sera from at least 5 out of 9 group III vaccinees recognized each of 22 proteins. PfSPZ-CVac is a highly efficacious vaccine candidate; when we are able to optimize the immunization regimen (dose, interval between doses, and drug partner), this vaccine could be used for combination mass drug administration and a mass vaccination program approach to eliminate malaria from geographically defined areas.
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Affiliation(s)
- Benjamin Mordmüller
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Güzin Surat
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Heimo Lagler
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, 1090 Vienna, Austria
| | | | - Andrew S Ishizuka
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, Maryland 20892, USA
| | - Albert Lalremruata
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Markus Gmeiner
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | | | - Meral Esen
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | | | - Jana Held
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Carlos Lamsfus Calle
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Juliana B Mengue
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Tamirat Gebru
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Javier Ibáñez
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | - Mihály Sulyok
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
| | | | | | - K C Natasha
- Sanaria Inc., Rockville, Maryland 20850, USA
- Protein Potential, LLC, Rockville, Maryland 20850, USA
| | - Anita Manoj
- Sanaria Inc., Rockville, Maryland 20850, USA
| | | | | | | | - Tao Li
- Sanaria Inc., Rockville, Maryland 20850, USA
| | - Richard E Stafford
- Sanaria Inc., Rockville, Maryland 20850, USA
- Protein Potential, LLC, Rockville, Maryland 20850, USA
| | - Minglin Li
- Sanaria Inc., Rockville, Maryland 20850, USA
- Protein Potential, LLC, Rockville, Maryland 20850, USA
| | - Phil L Felgner
- Department of Medicine, University of California Irvine, Irvine, California 92697, USA
| | - Robert A Seder
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, Maryland 20892, USA
| | | | - B Kim Lee Sim
- Sanaria Inc., Rockville, Maryland 20850, USA
- Protein Potential, LLC, Rockville, Maryland 20850, USA
| | | | - Peter G Kremsner
- Institute of Tropical Medicine, University of Tübingen and German Center for Infection Research, partner site Tübingen, 72074 Tübingen, Germany
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Requena P, Arévalo-Herrera M, Menegon M, Martínez-Espinosa FE, Padilla N, Bôtto-Menezes C, Malheiro A, Hans D, Castellanos ME, Robinson L, Samol P, Kochar S, Kochar SK, Kochar DK, Desai M, Sanz S, Quintó L, Mayor A, Rogerson S, Mueller I, Severini C, Del Portillo HA, Bardají A, Chitnis CC, Menéndez C, Dobaño C. Naturally Acquired Binding-Inhibitory Antibodies to Plasmodium vivax Duffy Binding Protein in Pregnant Women Are Associated with Higher Birth Weight in a Multicenter Study. Front Immunol 2017; 8:163. [PMID: 28261219 PMCID: PMC5313505 DOI: 10.3389/fimmu.2017.00163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/31/2017] [Indexed: 12/11/2022] Open
Abstract
A vaccine to eliminate malaria would need a multi-stage and multi-species composition to achieve robust protection, but the lack of knowledge about antigen targets and mechanisms of protection precludes the development of fully efficacious malaria vaccines, especially for Plasmodium vivax (Pv). Pregnant women constitute a risk population who would greatly benefit from a vaccine preventing the adverse events of Plasmodium infection during gestation. We hypothesized that functional immune responses against putative targets of naturally acquired immunity to malaria and vaccine candidates will be associated with protection against malaria infection and/or poor outcomes during pregnancy. We measured (i) IgG responses to a large panel of Pv and Plasmodium falciparum (Pf) antigens, (ii) the capacity of anti-Pv ligand Duffy binding protein (PvDBP) antibodies to inhibit binding to Duffy antigen, and (iii) cellular immune responses to two Pv antigens, in a subset of 1,056 pregnant women from Brazil, Colombia, Guatemala, India, and Papua New Guinea (PNG). There were significant intraspecies and interspecies correlations for most antibody responses (e.g., PfMSP119 versus PfAMA1, Spearman’s rho = 0.81). Women from PNG and Colombia had the highest levels of IgG overall. Submicroscopic infections seemed sufficient to boost antibody responses in Guatemala but not antigen-specific cellular responses in PNG. Brazil had the highest percentage of Duffy binding inhibition (p-values versus Colombia: 0.040; Guatemala: 0.047; India: 0.003, and PNG: 0.153) despite having low anti-PvDBP IgG levels. Almost all antibodies had a positive association with present infection, and coinfection with the other species increased this association. Anti-PvDBP, anti-PfMSP1, and anti-PfAMA1 IgG levels at recruitment were positively associated with infection at delivery (p-values: 0.010, 0.003, and 0.023, respectively), suggesting that they are markers of malaria exposure. Peripheral blood mononuclear cells from Pv-infected women presented fewer CD8+IFN-γ+ T cells and secreted more G-CSF and IL-4 independently of the stimulus used in vitro. Functional anti-PvDBP levels at recruitment had a positive association with birth weight (difference per doubling antibody levels: 45 g, p-value: 0.046). Thus, naturally acquired binding-inhibitory antibodies to PvDBP might confer protection against poor outcomes of Pv malaria in pregnancy.
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Affiliation(s)
- Pilar Requena
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | | | | | - Flor E Martínez-Espinosa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil; Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazonia), Amazonia, Brazil
| | - Norma Padilla
- Centro de Estudios en Salud, Universidad del Valle de Guatemala , Guatemala City , Guatemala
| | - Camila Bôtto-Menezes
- Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazonia), Amazonia, Brazil; Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
| | - Adriana Malheiro
- Instituto de Ciências Biológicas, Universidade Federal do Amazonas , Manaus , Brazil
| | - Dhiraj Hans
- International Center for Genetic Engineering and Biotechnology , Delhi , India
| | | | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea; Macfarlane Burnet Institute of Medical Research, Melbourne, VIC, Australia; Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | - Paula Samol
- Papua New Guinea Institute of Medical Research , Madang , Papua New Guinea
| | - Swati Kochar
- Medical College Bikaner , Bikaner, Rajasthan , India
| | | | | | - Meghna Desai
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Malaria Branch , Atlanta, GA , USA
| | - Sergi Sanz
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Llorenç Quintó
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | | | - Ivo Mueller
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia, Spain; Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | | | - Hernando A Del Portillo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia, Spain; ICREA, Barcelona, Spain
| | - Azucena Bardají
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Chetan C Chitnis
- International Center for Genetic Engineering and Biotechnology , Delhi , India
| | - Clara Menéndez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Carlota Dobaño
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
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Huang YM, Shi LW, She R, Bai J, Jiao SY, Guo Y. Domestic trends in malaria research and development in China and its global influence. Infect Dis Poverty 2017; 6:4. [PMID: 28069075 PMCID: PMC5223349 DOI: 10.1186/s40249-016-0222-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 12/15/2016] [Indexed: 11/17/2022] Open
Abstract
Background Though many countries, including China, are moving towards malaria elimination, malaria remains a major global health threat. Due to the spread of antimalarial drug resistance and the need for innovative medical products during the elimination phase, further research and development (R&D) of innovative tools in both epidemic and elimination areas is needed. This study aims to identify the trends and gaps in malaria R&D in China, and aims to offer suggestions on how China can be more effectively involved in global malaria R&D. Methods Quantitative analysis was carried out by collecting data on Chinese malaria-related research programmes between 1985 and 2014, invention patents in China from 1985 to 2014, and articles published by Chinese researchers in PubMed and Chinese databases from 2005 to 2014. All data were screened and extracted for numerical analysis and were categorized into basic sciences, drug/drug resistance, immunology/vaccines, or diagnostics/detection for chronological and subgroup comparisons. Results The number of malaria R&D activities have shown a trend of increase during the past 30 years, however these activities have fluctuated within the past few years. During the past 10 years, R&D on drug/drug resistance accounted for the highest percentages of research programmes (32.4%), articles (55.0% in PubMed and 50.6% in Chinese databases) and patents (45.5%). However, these R&D activities were mainly related to artemisinin. R&D on immunology/vaccines has been a continuous interest for China’s public entities, but the focus remains on basic science. R&D in the area of high-efficiency diagnostics has been rarely seen or reported in China. Conclusions China has long been devoted to malaria R&D in multiple areas, including drugs, drug resistance, immunology and vaccines. R&D on diagnostics has received significantly less attention, however, it should also be an area where China can make a contribution. More focus on malaria R&D is needed, especially in the area of diagnostics, if China would like to contribute in a more significant way to global malaria control and elimination. Electronic supplementary material The online version of this article (doi:10.1186/s40249-016-0222-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang-Mu Huang
- School of Public Health, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191, China
| | - Lu-Wen Shi
- School of Pharmaceutical Science, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191, China
| | - Rui She
- School of Public Health, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191, China
| | - Jing Bai
- Department of Health Policy and Management, School of Public Health, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191, China
| | - Shi-Yong Jiao
- Patent Examination Cooperation Center of the Patent Office, SIPO, Beijing, China
| | - Yan Guo
- School of Public Health, Peking University Health Science Center, Xueyuan Road 38, Haidian District, Beijing, 100191, China.
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75
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Zheng W, Liu F, He Y, Liu Q, Humphreys GB, Tsuboi T, Fan Q, Luo E, Cao Y, Cui L. Functional characterization of Plasmodium berghei PSOP25 during ookinete development and as a malaria transmission-blocking vaccine candidate. Parasit Vectors 2017; 10:8. [PMID: 28057055 PMCID: PMC5217559 DOI: 10.1186/s13071-016-1932-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 12/06/2016] [Indexed: 12/23/2022] Open
Abstract
Background Plasmodium ookinete surface proteins as post-fertilization target antigens are potential malaria transmission-blocking vaccine (TBV) candidates. Putative secreted ookinete protein 25 (PSOP25) is a highly conserved ookinete surface protein, and has been shown to be a promising novel TBV target. Here, we further investigated the TBV activities of the full-length recombinant PSOP25 (rPSOP25) protein in Plasmodium berghei, and characterized the potential functions of PSOP25 during the P. berghei life-cycle. Methods We expressed the full-length P. berghei PSOP25 protein in a prokaryotic expression system, and developed polyclonal mouse antisera and a monoclonal antibody (mAb) against the recombinant protein. Indirect immunofluorescence assay (IFA) and Western blot were used to test the specificity of antibodies. The transmission-blocking (TB) activities of antibodies were evaluated by the in vitro ookinete conversion assay and by direct mosquito feeding assay (DFA). Finally, the function of PSOP25 during Plasmodium development was studied by deleting the psop25 gene. Results Both polyclonal mouse antisera and anti-rPSOP25 mAb recognized the PSOP25 proteins in the parasites, and IFA showed the preferential expression of PSOP25 on the surface of zygotes, retorts and mature ookinetes. In vitro, these antibodies significantly inhibited ookinetes formation in an antibody concentration-dependent manner. In DFA, mice immunized with the rPSOP25 and those receiving passive transfer of the anti-rPSOP25 mAb reduced the prevalence of mosquito infection by 31.2 and 26.1%, and oocyst density by 66.3 and 63.3%, respectively. Genetic knockout of the psop25 gene did not have a detectable impact on the asexual growth of P. berghei, but significantly affected the maturation of ookinetes and the formation of midgut oocysts. Conclusions The full-length rPSOP25 could elicit strong antibody response in mice. Polyclonal and monoclonal antibodies against PSOP25 could effectively block the formation of ookinetes in vitro and transmission of the parasites to mosquitoes. Genetic manipulation study indicated that PSOP25 is required for ookinete maturation in P. berghei. These results support further testing of the PSOP25 orthologs in human malaria parasites as promising TBV candidates. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1932-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wenqi Zheng
- Department of Pathogen Biology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China.,Laboratory of Surgery, The Affiliated Hospital, Inner Mongolia Medical University, Hohhot, 010050, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China
| | - Yiwen He
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China
| | - Qingyang Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China
| | - Gregory B Humphreys
- Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Takafumi Tsuboi
- Cell-free Science and Technology Research Center, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Enjie Luo
- Department of Pathogen Biology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning, 110001, China.
| | - Liwang Cui
- Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA
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Datta D, Bansal GP, Gerloff DL, Ellefsen B, Hannaman D, Kumar N. Immunogenicity and malaria transmission reducing potency of Pfs48/45 and Pfs25 encoded by DNA vaccines administered by intramuscular electroporation. Vaccine 2017; 35:264-272. [PMID: 27912985 PMCID: PMC5192010 DOI: 10.1016/j.vaccine.2016.11.072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 11/03/2016] [Accepted: 11/22/2016] [Indexed: 01/06/2023]
Abstract
Pfs48/45 and Pfs25 are leading candidates for the development of Plasmodium falciparum transmission blocking vaccines (TBV). Expression of Pfs48/45 in the erythrocytic sexual stages and presentation to the immune system during infection in the human host also makes it ideal for natural boosting. However, it has been challenging to produce a fully folded, functionally active Pfs48/45, using various protein expression platforms. In this study, we demonstrate that full-length Pfs48/45 encoded by DNA plasmids is able to induce significant transmission reducing immune responses. DNA plasmids encoding Pfs48/45 based on native (WT), codon optimized (SYN), or codon optimized and mutated (MUT1 and MUT2), to prevent any asparagine (N)-linked glycosylation were compared with or without intramuscular electroporation (EP). EP significantly enhanced antibody titers and transmission blocking activity elicited by immunization with SYN Pfs48/45 DNA vaccine. Mosquito membrane feeding assays also revealed improved functional immunogenicity of SYN Pfs48/45 (N-glycosylation sites intact) as compared to MUT1 or MUT2 Pfs48/45 DNA plasmids (all N-glycosylation sites mutated). Boosting with recombinant Pfs48/45 protein after immunization with each of the different DNA vaccines resulted in significant boosting of antibody response and improved transmission reducing capabilities of all four DNA vaccines. Finally, immunization with a combination of DNA plasmids (SYN Pfs48/45 and SYN Pfs25) also provides support for the possibility of combining antigens targeting different life cycle stages in the parasite during transmission through mosquitoes.
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Affiliation(s)
- Dibyadyuti Datta
- Department of Tropical Medicine, School of Public Health and Tropical Medicine and Vector-Borne Infectious Disease Research Center, Tulane University, New Orleans, LA, United States
| | - Geetha P Bansal
- Department of Tropical Medicine, School of Public Health and Tropical Medicine and Vector-Borne Infectious Disease Research Center, Tulane University, New Orleans, LA, United States
| | | | - Barry Ellefsen
- ICHOR Medical Systems Inc., San Diego, CA, United States
| | - Drew Hannaman
- ICHOR Medical Systems Inc., San Diego, CA, United States
| | - Nirbhay Kumar
- Department of Tropical Medicine, School of Public Health and Tropical Medicine and Vector-Borne Infectious Disease Research Center, Tulane University, New Orleans, LA, United States.
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77
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Jimah JR, Salinas ND, Sala-Rabanal M, Jones NG, Sibley LD, Nichols CG, Schlesinger PH, Tolia NH. Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption. eLife 2016; 5. [PMID: 27906127 PMCID: PMC5132341 DOI: 10.7554/elife.20621] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/14/2016] [Indexed: 01/02/2023] Open
Abstract
Apicomplexan parasites contain a conserved protein CelTOS that, in malaria parasites, is essential for traversal of cells within the mammalian host and arthropod vector. However, the molecular role of CelTOS is unknown because it lacks sequence similarity to proteins of known function. Here, we determined the crystal structure of CelTOS and discovered CelTOS resembles proteins that bind to and disrupt membranes. In contrast to known membrane disruptors, CelTOS has a distinct architecture, specifically binds phosphatidic acid commonly present within the inner leaflet of plasma membranes, and potently disrupts liposomes composed of phosphatidic acid by forming pores. Microinjection of CelTOS into cells resulted in observable membrane damage. Therefore, CelTOS is unique as it achieves nearly universal inner leaflet cellular activity to enable the exit of parasites from cells during traversal. By providing novel molecular insight into cell traversal by apicomplexan parasites, our work facilitates the design of therapeutics against global pathogens.
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Affiliation(s)
- John R Jimah
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Monica Sala-Rabanal
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Paul H Schlesinger
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, United States
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Utilizing direct skin feeding assays for development of vaccines that interrupt malaria transmission: A systematic review of methods and case study. Vaccine 2016; 34:5863-5870. [PMID: 27789147 DOI: 10.1016/j.vaccine.2016.10.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/23/2016] [Accepted: 10/11/2016] [Indexed: 01/29/2023]
Abstract
Shifting the malaria priorities from a paradigm of control and elimination to a goal of global eradication calls for renewed attention to the interruption of malaria transmission. Sustained progress toward eradication will require both improved understanding of infectious reservoirs and efficient development of novel transmission-blocking interventions, such as rapidly acting and highly efficacious therapeutics and vaccines. Here, we review the direct skin feeding assay (DSF), which has been proposed as a valuable tool for measuring the in natura transmission of malaria parasites from human hosts to mosquito vectors across heterogeneous populations. To capture the methodological breadth of this assay's use, we first systematically review and qualitatively synthesize previously published investigations using DSFs to study malaria transmission in humans. Then, using a recent Phase 1 trial in Mali of the Pfs25H-EPA/Alhydrogel® vaccine candidate (NCT01867463) designed to interrupt Plasmodium falciparum transmission as a case study, we describe the potential opportunities and current limitations of utilizing the endpoints measured by DSF in making early clinical decisions for individually randomized transmission-interrupting intervention candidates. Using simulations based on the data collected in the clinical trial, we demonstrate that the capacity of the DSF to serve as an evaluative tool is limited by the statistical power constraints of the "effective sample size" (i.e. the number of subjects that are capable of transmitting at the time of feeding). Altogether, our findings suggest DSFs have great potential utility for assessing the public health impacts of emerging antimalarial tools, but additional research is needed to address issues of scalability and to establish correlation with community-wide clinical endpoints as well as complementary in vitro measures, such as standard membrane feeding assays.
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79
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Safety and Immunogenicity of EBA-175 RII-NG Malaria Vaccine Administered Intramuscularly in Semi-Immune Adults: A Phase 1, Double-Blinded Placebo Controlled Dosage Escalation Study. PLoS One 2016; 11:e0163066. [PMID: 27644034 PMCID: PMC5028127 DOI: 10.1371/journal.pone.0163066] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 08/29/2016] [Indexed: 02/03/2023] Open
Abstract
The erythrocyte binding antigen region II (EBA-175 RII) is a Plasmodium falciparum ligand that mediates erythrocyte invasion and is considered an important malaria vaccine candidate. A phase Ia trial in malaria naïve adults living in the United States found the recombinant non-glycosylated vaccine antigen, EBA-175 RII-NG adjuvanted with aluminium phosphate to be safe, immunogenic and capable of inducing biologically active antibodies that can inhibit parasite growth in vitro. The aim of the current study was to assess the safety and immunogenicity of this vaccine in malaria exposed semi-immune healthy adults living in a malaria endemic country, Ghana. In this double-blinded, placebo controlled, dose escalation phase I trial, eighteen subjects per group received ascending dose concentrations (5 μg, 20 μg or 80 μg) of the vaccine intramuscularly at 0, 1 and 6 months, while 6 subjects received placebo (normal saline). The primary end point was the number of subjects experiencing Grade 3 systemic or local adverse events within 14 days post-vaccination. Serious adverse events were assessed throughout the study period. Blood samples for immunological analyses were collected at days 0, 14, 28, 42, 180 and 194. A total of 52 subjects received three doses of the vaccine in the respective groups. No serious adverse events were reported. The majority of all adverse events reported were mild to moderate in severity, with local pain and tenderness being the most common. All adverse events, irrespective of severity, resolved without any sequelae. Subjects who received any of the EBA-175 RII-NG doses had high immunoglobulin G levels which moderately inhibited P. falciparum growth in vitro, compared to those in the placebo group. In conclusion, the EBA-175 RII-NG vaccine was safe, well tolerated and immunogenic in malaria semi-immune Ghanaian adults. Its further development is recommended.
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80
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Miura K, Stone WJR, Koolen KM, Deng B, Zhou L, van Gemert GJ, Locke E, Morin M, Bousema T, Sauerwein RW, Long CA, Dechering KJ. An inter-laboratory comparison of standard membrane-feeding assays for evaluation of malaria transmission-blocking vaccines. Malar J 2016; 15:463. [PMID: 27612458 PMCID: PMC5016893 DOI: 10.1186/s12936-016-1515-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/02/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An effective malaria transmission-blocking vaccine may play an important role in malaria elimination efforts, and a robust biological assay is essential for its development. The standard membrane-feeding assay (SMFA) for Plasmodium falciparum infection of mosquitoes is considered a "gold standard" assay to measure transmission-blocking activity of test antibodies, and has been utilized widely in both non-clinical and clinical studies. While several studies have discussed the inherent variability of SMFA within a study group, there has been no assessment of inter-laboratory variation. Therefore, there is currently no assurance that SMFA results are comparable between different studies. METHODS Mouse anti-Pfs25 monoclonal antibody (mAb, 4B7 mAb), rat anti-Pfs48/45 mAb (85RF45.1 mAb) and a human polyclonal antibody (pAb) collected from a malaria-exposed adult were tested at the same concentrations (6-94 μg/mL for 4B7, 1.2-31.3 μg/mL for 85RF45.1 and 23-630 μg/mL for human pAb) in two laboratories following their own standardized SMFA protocols. The mAbs and pAb, previously shown to have strong inhibition activities in the SMFA, were tested at three or four concentrations in two or three independent assays in each laboratory, and percent inhibition in mean oocyst intensity relative to a control in the same feed was determined in each feeding experiment. RESULTS Both monoclonal and polyclonal antibodies dose-dependently reduced oocyst intensity in all experiments performed at the two test sites. In both laboratories, the inter-assay variability in percent inhibition in oocyst intensity decreased at higher levels of inhibition, regardless of which antibody was tested. At antibody concentrations that led to a >80 % reduction in oocyst numbers, the inter-laboratory variations were in the same range compared with the inter-assay variation observed within a single laboratory, and the differences in best estimates from multiple feeds between the two laboratories were <5 percentage points. CONCLUSIONS This study confirms previous reports that the precision of the SMFA increases with increasing percent inhibition. Moreover, the variation between the two laboratories is not greater than the variation observed within a laboratory. The findings of this study provide guidance for comparison of SMFA data from different laboratories.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, USA.
| | - Will J R Stone
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Karin M Koolen
- TropIQ Health Science, Transistorweg 5, 6534 AT, Nijmegen, The Netherlands
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, USA
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, USA
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Emily Locke
- PATH Malaria Vaccine Initiative, 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Merribeth Morin
- PATH Malaria Vaccine Initiative, 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Nijmegen Medical Center, 6500 HB, Nijmegen, The Netherlands
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, USA
| | - Koen J Dechering
- TropIQ Health Science, Transistorweg 5, 6534 AT, Nijmegen, The Netherlands.
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Reiner RC, Guerra C, Donnelly MJ, Bousema T, Drakeley C, Smith DL. Estimating malaria transmission from humans to mosquitoes in a noisy landscape. J R Soc Interface 2016; 12:20150478. [PMID: 26400195 PMCID: PMC4614487 DOI: 10.1098/rsif.2015.0478] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the ‘colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine.
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Affiliation(s)
- Robert C Reiner
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA Department of Entomology, University of California, Davis, CA, USA Department of Epidemiology and Biostatistics, Indiana University, Bloomington, IN, USA
| | - Carlos Guerra
- Center for Disease Dynamics, Economics and Policy, Washington, DC, USA
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK Malaria Programme, Wellcome Trust Sanger Institute, Cambridge, UK
| | - Teun Bousema
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
| | - David L Smith
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA Sanaria Institute for Global Health and Tropical Medicine, Rockville, MD, USA Department of Zoology, University of Oxford, Oxford, UK Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
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82
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Miura K, Swihart BJ, Deng B, Zhou L, Pham TP, Diouf A, Burton T, Fay MP, Long CA. Transmission-blocking activity is determined by transmission-reducing activity and number of control oocysts in Plasmodium falciparum standard membrane-feeding assay. Vaccine 2016; 34:4145-4151. [PMID: 27372156 PMCID: PMC4958521 DOI: 10.1016/j.vaccine.2016.06.066] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/27/2016] [Accepted: 06/23/2016] [Indexed: 01/01/2023]
Abstract
Malaria transmission-blocking vaccines (TBVs) are potentially helpful tools for malaria eradication. The standard membrane-feeding assay (SMFA) is considered one of the "gold standard" assays for TBV development. However, lack of consensus in reporting results from SMFA has made it very challenging to compare results from different studies. Two main readouts, % inhibition in mean oocyst count per mosquito (TRA) and % inhibition in prevalence of infected mosquitoes (TBA), have been used widely. In this study, we statistically modeled the oocyst data in SMFA using data from 105 independent feeding experiments including 9804 mosquitoes. The model was validated using an independent data set that included 10,790 mosquitoes from 110 feeding studies. The model delineates a relationship between TRA, the mean oocyst count in the control mosquitoes (mo-contl), and TBA. While TRA was independent from mo-contl, TBA values changed depending on mo-contl. Regardless of monoclonal or polyclonal antibodies tested, there were strong concordances between observed TBA and predicted TBA based on the model using mo-contl and observed TRA. Simulations showed that SMFA with lower true control means had increased uncertainty in TRA estimates. The strong linkage between TBA, TRA and mo-contl inspired creation of a standardized TBA, a model-based TBA standardized to a target control mean, which allows comparison across multiple feeds regardless of mo-contl. This is the first study showing that the observed TBA can be reasonably predicted by mo-contl and the TRA of the test antibody using independent experimental data. This study indicates that TRA should be used to compare results from multiple feeds with different levels of mo-contl. If a measure of TBA is desired, it is better to report standardized TBA rather than observed TBA. These recommendations support rational comparisons of results from different studies, thus benefiting future TBV development.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Bruce J. Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD 20852, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Thao P. Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Timothy Burton
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Michael P. Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD 20852, USA
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
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83
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Liu J, Liu Y, Nie K, Du S, Qiu J, Pang X, Wang P, Cheng G. Flavivirus NS1 protein in infected host sera enhances viral acquisition by mosquitoes. Nat Microbiol 2016; 1:16087. [PMID: 27562253 PMCID: PMC5003325 DOI: 10.1038/nmicrobiol.2016.87] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 05/05/2016] [Indexed: 11/12/2022]
Abstract
The arbovirus life cycle involves viral transfer between a vertebrate host and an arthropod vector, and acquisition of virus from an infected mammalian host by a vector is an essential step in this process. Here, we report that flavivirus nonstructural protein-1 (NS1), which is abundantly secreted into the serum of an infected host, plays a critical role in flavivirus acquisition by mosquitoes. The presence of dengue virus (DENV) and Japanese encephalitis virus NS1s in the blood of infected interferon-α and γ receptor-deficient mice (AG6) facilitated virus acquisition by their native mosquito vectors because the protein enabled the virus to overcome the immune barrier of the mosquito midgut. Active immunization of AG6 mice with a modified DENV NS1 reduced DENV acquisition by mosquitoes and protected mice against a lethal DENV challenge, suggesting that immunization with NS1 could reduce the number of virus-carrying mosquitoes as well as the incidence of flaviviral diseases. Our study demonstrates that flaviviruses utilize NS1 proteins produced during their vertebrate phases to enhance their acquisition by vectors, which might be a result of flavivirus evolution to adapt to multiple host environments.
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Affiliation(s)
- Jianying Liu
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yang Liu
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
- School of Life Science, Tsinghua University, Beijing, P.R. China, 100084
| | - Kaixiao Nie
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Senyan Du
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jingjun Qiu
- Department of Health Statistics, School of Preventive Medicine, Fourth Military Medical University, Shaanxi, P.R. China, 710032
| | - Xiaojing Pang
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Penghua Wang
- Department of Microbiology and Immunology, School of Medicine, New York Medical College, Valhalla, NY, the United States, 10595
| | - Gong Cheng
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, Tsinghua University, Beijing 100084, China
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84
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Blagborough AM, Musiychuk K, Bi H, Jones RM, Chichester JA, Streatfield S, Sala KA, Zakutansky SE, Upton LM, Sinden RE, Brian I, Biswas S, Sattabonkot J, Yusibov V. Transmission blocking potency and immunogenicity of a plant-produced Pvs25-based subunit vaccine against Plasmodium vivax. Vaccine 2016; 34:3252-9. [PMID: 27177945 PMCID: PMC4915602 DOI: 10.1016/j.vaccine.2016.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/06/2016] [Accepted: 05/03/2016] [Indexed: 01/18/2023]
Abstract
Malaria transmission blocking (TB) vaccines (TBVs) directed against proteins expressed on the sexual stages of Plasmodium parasites are a potentially effective means to reduce transmission. Antibodies induced by TBVs block parasite development in the mosquito, and thus inhibit transmission to further human hosts. The ookinete surface protein P25 is a primary target for TBV development. Recently, transient expression in plants using hybrid viral vectors has demonstrated potential as a strategy for cost-effective and scalable production of recombinant vaccines. Using a plant virus-based expression system, we produced recombinant P25 protein of Plasmodium vivax (Pvs25) in Nicotiana benthamiana fused to a modified lichenase carrier protein. This candidate vaccine, Pvs25-FhCMB, was purified, characterized and evaluated for immunogenicity and efficacy using multiple adjuvants in a transgenic rodent model. An in vivo TB effect of up to a 65% reduction in intensity and 54% reduction in prevalence was observed using Abisco-100 adjuvant. The ability of this immunogen to induce a TB response was additionally combined with heterologous prime-boost vaccination with viral vectors expressing Pvs25. Significant blockade was observed when combining both platforms, achieving a 74% and 68% reduction in intensity and prevalence, respectively. This observation was confirmed by direct membrane feeding on field P. vivax samples, resulting in reductions in intensity/prevalence of 85.3% and 25.5%. These data demonstrate the potential of this vaccine candidate and support the feasibility of expressing Plasmodium antigens in a plant-based system for the production of TBVs, while demonstrating the potential advantages of combining multiple vaccine delivery systems to maximize efficacy.
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Affiliation(s)
- A M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK.
| | - K Musiychuk
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - H Bi
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - R M Jones
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - J A Chichester
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - S Streatfield
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - K A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - S E Zakutansky
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - L M Upton
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - R E Sinden
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - I Brian
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - S Biswas
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - J Sattabonkot
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - V Yusibov
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
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85
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Ishizuka AS, Lyke KE, DeZure A, Berry AA, Richie TL, Mendoza FH, Enama ME, Gordon IJ, Chang LJ, Sarwar UN, Zephir KL, Holman LA, James ER, Billingsley PF, Gunasekera A, Chakravarty S, Manoj A, Li M, Ruben AJ, Li T, Eappen AG, Stafford RE, K C N, Murshedkar T, DeCederfelt H, Plummer SH, Hendel CS, Novik L, Costner PJM, Saunders JG, Laurens MB, Plowe CV, Flynn B, Whalen WR, Todd JP, Noor J, Rao S, Sierra-Davidson K, Lynn GM, Epstein JE, Kemp MA, Fahle GA, Mikolajczak SA, Fishbaugher M, Sack BK, Kappe SHI, Davidson SA, Garver LS, Björkström NK, Nason MC, Graham BS, Roederer M, Sim BKL, Hoffman SL, Ledgerwood JE, Seder RA. Protection against malaria at 1 year and immune correlates following PfSPZ vaccination. Nat Med 2016; 22:614-23. [PMID: 27158907 PMCID: PMC11294733 DOI: 10.1038/nm.4110] [Citation(s) in RCA: 254] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/15/2016] [Indexed: 02/07/2023]
Abstract
An attenuated Plasmodium falciparum (Pf) sporozoite (SPZ) vaccine, PfSPZ Vaccine, is highly protective against controlled human malaria infection (CHMI) 3 weeks after immunization, but the durability of protection is unknown. We assessed how vaccine dosage, regimen, and route of administration affected durable protection in malaria-naive adults. After four intravenous immunizations with 2.7 × 10(5) PfSPZ, 6/11 (55%) vaccinated subjects remained without parasitemia following CHMI 21 weeks after immunization. Five non-parasitemic subjects from this dosage group underwent repeat CHMI at 59 weeks, and none developed parasitemia. Although Pf-specific serum antibody levels correlated with protection up to 21-25 weeks after immunization, antibody levels waned substantially by 59 weeks. Pf-specific T cell responses also declined in blood by 59 weeks. To determine whether T cell responses in blood reflected responses in liver, we vaccinated nonhuman primates with PfSPZ Vaccine. Pf-specific interferon-γ-producing CD8 T cells were present at ∼100-fold higher frequencies in liver than in blood. Our findings suggest that PfSPZ Vaccine conferred durable protection to malaria through long-lived tissue-resident T cells and that administration of higher doses may further enhance protection.
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Affiliation(s)
- Andrew S Ishizuka
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Kirsten E Lyke
- Institute for Global Health, Center for Vaccine Development and Division of Malaria Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Adam DeZure
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Andrea A Berry
- Institute for Global Health, Center for Vaccine Development and Division of Malaria Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Floreliz H Mendoza
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Mary E Enama
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Ingelise J Gordon
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Lee-Jah Chang
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Uzma N Sarwar
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Kathryn L Zephir
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - LaSonji A Holman
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | | | | | | | | | | | - MingLin Li
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential, LLC, Rockville, Maryland, USA
| | | | - Tao Li
- Sanaria Inc., Rockville, Maryland, USA
| | | | - Richard E Stafford
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential, LLC, Rockville, Maryland, USA
| | - Natasha K C
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential, LLC, Rockville, Maryland, USA
| | | | - Hope DeCederfelt
- Pharmaceutical Development Section, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Sarah H Plummer
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Cynthia S Hendel
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Laura Novik
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Pamela J M Costner
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Jamie G Saunders
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Matthew B Laurens
- Institute for Global Health, Center for Vaccine Development and Division of Malaria Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Christopher V Plowe
- Institute for Global Health, Center for Vaccine Development and Division of Malaria Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Barbara Flynn
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - William R Whalen
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - J P Todd
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Jay Noor
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Srinivas Rao
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Kailan Sierra-Davidson
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Geoffrey M Lynn
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Judith E Epstein
- Naval Medical Research Center (NMRC), Malaria Department, Silver Spring, Maryland, USA
| | - Margaret A Kemp
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Gary A Fahle
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | | | | | - Brandon K Sack
- Center for Infectious Disease Research, Seattle, Washington, USA
| | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, Washington, USA
| | - Silas A Davidson
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Lindsey S Garver
- Entomology Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Niklas K Björkström
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Martha C Nason
- Biostatistics Research Branch, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Barney S Graham
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Mario Roederer
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - B Kim Lee Sim
- Sanaria Inc., Rockville, Maryland, USA
- Protein Potential, LLC, Rockville, Maryland, USA
| | | | - Julie E Ledgerwood
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
| | - Robert A Seder
- Vaccine Research Center (VRC), National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda (NIH), Maryland, USA
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86
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Quispe AM, Llanos-Cuentas A, Rodriguez H, Clendenes M, Cabezas C, Leon LM, Chuquiyauri R, Moreno M, Kaslow DC, Grogl M, Herrera S, Magill AJ, Kosek M, Vinetz JM, Lescano AG, Gotuzzo E. Accelerating to Zero: Strategies to Eliminate Malaria in the Peruvian Amazon. Am J Trop Med Hyg 2016; 94:1200-1207. [PMID: 30851016 PMCID: PMC4889734 DOI: 10.4269/ajtmh.15-0369] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
AbstractIn February 2014, the Malaria Elimination Working Group, in partnership with the Peruvian Ministry of Health (MoH), hosted its first international conference on malaria elimination in Iquitos, Peru. The 2-day meeting gathered 85 malaria experts, including 18 international panelists, 23 stakeholders from different malaria-endemic regions of Peru, and 11 MoH authorities. The main outcome was consensus that implementing a malaria elimination project in the Amazon region is achievable, but would require: 1) a comprehensive strategic plan, 2) the altering of current programmatic guidelines from control toward elimination by including symptomatic as well as asymptomatic individuals for antimalarial therapy and transmission-blocking interventions, and 3) the prioritization of community-based active case detection with proper rapid diagnostic tests to interrupt transmission. Elimination efforts must involve key stakeholders and experts at every level of government and include integrated research activities to evaluate, implement, and tailor sustainable interventions appropriate to the region.
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Affiliation(s)
- Antonio M. Quispe
- *Address correspondence to Antonio M. Quispe, Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205. E-mail:
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87
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França CT, Hostetler JB, Sharma S, White MT, Lin E, Kiniboro B, Waltmann A, Darcy AW, Li Wai Suen CSN, Siba P, King CL, Rayner JC, Fairhurst RM, Mueller I. An Antibody Screen of a Plasmodium vivax Antigen Library Identifies Novel Merozoite Proteins Associated with Clinical Protection. PLoS Negl Trop Dis 2016; 10:e0004639. [PMID: 27182597 PMCID: PMC4868274 DOI: 10.1371/journal.pntd.0004639] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 03/29/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Elimination of Plasmodium vivax malaria would be greatly facilitated by the development of an effective vaccine. A comprehensive and systematic characterization of antibodies to P. vivax antigens in exposed populations is useful in guiding rational vaccine design. METHODOLOGY/PRINCIPAL FINDINGS In this study, we investigated antibodies to a large library of P. vivax entire ectodomain merozoite proteins in 2 Asia-Pacific populations, analysing the relationship of antibody levels with markers of current and cumulative malaria exposure, and socioeconomic and clinical indicators. 29 antigenic targets of natural immunity were identified. Of these, 12 highly-immunogenic proteins were strongly associated with age and thus cumulative lifetime exposure in Solomon Islanders (P<0.001-0.027). A subset of 6 proteins, selected on the basis of immunogenicity and expression levels, were used to examine antibody levels in plasma samples from a population of young Papua New Guinean children with well-characterized individual differences in exposure. This analysis identified a strong association between reduced risk of clinical disease and antibody levels to P12, P41, and a novel hypothetical protein that has not previously been studied, PVX_081550 (IRR 0.46-0.74; P<0.001-0.041). CONCLUSION/SIGNIFICANCE These data emphasize the benefits of an unbiased screening approach in identifying novel vaccine candidate antigens. Functional studies are now required to establish whether PVX_081550 is a key component of the naturally-acquired protective immune response, a biomarker of immune status, or both.
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Affiliation(s)
- Camila T. França
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Jessica B. Hostetler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Sumana Sharma
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Michael T. White
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Center for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Enmoore Lin
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Benson Kiniboro
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Andreea Waltmann
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Andrew W. Darcy
- National Health Training & Research Institute, Ministry of Health, Honiara, Solomon Islands
| | - Connie S. N. Li Wai Suen
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Peter Siba
- Vector Borne Diseases Unit, PNG Institute of Medical Research, Madang, Papua New Guinea
| | - Christopher L. King
- Center for Global Health & Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- * E-mail: (JCR); (RMF); (IM)
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (JCR); (RMF); (IM)
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
- * E-mail: (JCR); (RMF); (IM)
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88
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Mehrizi AA, Dodangeh F, Zakeri S, Djadid ND. Worldwide population genetic analysis and natural selection in the Plasmodium vivax Generative Cell Specific 1 (PvGCS1) as a transmission-blocking vaccine candidate. INFECTION GENETICS AND EVOLUTION 2016; 43:50-7. [PMID: 27180894 DOI: 10.1016/j.meegid.2016.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/11/2016] [Accepted: 05/11/2016] [Indexed: 11/28/2022]
Abstract
GENERATIVE CELL SPECIFIC 1 (GCS1) is one of the Transmission Blocking Vaccine (TBV) candidate antigens, which is expressed on the surface of male gametocytes and gametes of Plasmodium species. Since antigenic diversity could inhibit the successful development of a malaria vaccine, it is crucial to determine the diversity of gcs1 gene in global malaria-endemic areas. Therefore, gene diversity and selection of gcs1 gene were analyzed in Iranian Plasmodium vivax isolates (n=52) and compared with the corresponding sequences from worldwide clinical P. vivax isolates available in PlasmoDB database. Totally 12 SNPs were detected in the pvgcs1 sequences as compared to Sal-1 sequence. Five out of 12 SNPs including three synonymous (T797C, G1559A, and G1667T) and two amino acid replacements (Y133S and Q634P) were detected in Iranian pvgcs1 sequences. According to four amino acid replacements (Y133S, N575S, Q634P and D637N) observed in all world PvGCS1 sequences, totally 5 PvGCS1 haplotypes were detected in the world, that three of them observed in Iranian isolates including the PvGCS-A (133S/634Q, 92.3%), PvGCS-B (133Y/634Q, 5.8%), and PvGCS-C (133S/634P, 1.9%). The overall nucleotide diversity (π) for all 52 sequences of Iranian pvgcs1 gene was 0.00018±0.00006, and the value of dN-dS (-0.00031) were negative, however, it was not statistically significant. In comparison with global isolates, Iranian and PNG pvgcs1 sequences had the lowest nucleotide and haplotype diversity, while the highest nucleotide and haplotype diversity was observed in China population. Moreover, epitope prediction in this antigen showed that all B-cell epitopes were located in conserved regions. However, Q634P (in one Iranian isolate) and D637N (observed in Thailand, China, Vietnam and North Korea) mutations are involved in predicted IURs. The obtained results in this study could be used in development of PvGCS1 based malaria vaccine.
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Affiliation(s)
- Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran.
| | - Fatemeh Dodangeh
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran; Department of Genetics, Tehran Medical Branch, Islamic Azad University, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
| | - Navid Dinparast Djadid
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, P.O. Box 1316943551, Tehran, Iran
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Bronner IF, Otto TD, Zhang M, Udenze K, Wang C, Quail MA, Jiang RHY, Adams JH, Rayner JC. Quantitative insertion-site sequencing (QIseq) for high throughput phenotyping of transposon mutants. Genome Res 2016; 26:980-9. [PMID: 27197223 PMCID: PMC4937560 DOI: 10.1101/gr.200279.115] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 05/04/2016] [Indexed: 01/06/2023]
Abstract
Genetic screening using random transposon insertions has been a powerful tool for uncovering biology in prokaryotes, where whole-genome saturating screens have been performed in multiple organisms. In eukaryotes, such screens have proven more problematic, in part because of the lack of a sensitive and robust system for identifying transposon insertion sites. We here describe quantitative insertion-site sequencing, or QIseq, which uses custom library preparation and Illumina sequencing technology and is able to identify insertion sites from both the 5′ and 3′ ends of the transposon, providing an inbuilt level of validation. The approach was developed using piggyBac mutants in the human malaria parasite Plasmodium falciparum but should be applicable to many other eukaryotic genomes. QIseq proved accurate, confirming known sites in >100 mutants, and sensitive, identifying and monitoring sites over a >10,000-fold dynamic range of sequence counts. Applying QIseq to uncloned parasites shortly after transfections revealed multiple insertions in mixed populations and suggests that >4000 independent mutants could be generated from relatively modest scales of transfection, providing a clear pathway to genome-scale screens in P. falciparum. QIseq was also used to monitor the growth of pools of previously cloned mutants and reproducibly differentiated between deleterious and neutral mutations in competitive growth. Among the mutants with fitness defects was a mutant with a piggyBac insertion immediately upstream of the kelch protein K13 gene associated with artemisinin resistance, implying mutants in this gene may have competitive fitness costs. QIseq has the potential to enable the scale-up of piggyBac-mediated genetics across multiple eukaryotic systems.
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Affiliation(s)
- Iraad F Bronner
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Thomas D Otto
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Min Zhang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA
| | - Kenneth Udenze
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA
| | - Chengqi Wang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA
| | - Michael A Quail
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Rays H Y Jiang
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA
| | - John H Adams
- Center for Global Health and Infectious Diseases, Department of Global Health, University of South Florida, Tampa, Florida 33612, USA
| | - Julian C Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
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90
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Lecona-Valera AN, Tao D, Rodríguez MH, López T, Dinglasan RR, Rodríguez MC. An antibody against an Anopheles albimanus midgut myosin reduces Plasmodium berghei oocyst development. Parasit Vectors 2016; 9:274. [PMID: 27165123 PMCID: PMC4863318 DOI: 10.1186/s13071-016-1548-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/27/2016] [Indexed: 11/13/2022] Open
Abstract
Background Malaria parasites are transmitted by Anopheles mosquitoes. Although several studies have identified mosquito midgut surface proteins that are putatively important for Plasmodium ookinete invasion, only a few have characterized these protein targets and demonstrated transmission-blocking activity. Molecular information about these proteins is essential for the development of transmission-blocking vaccines (TBV). The aim of the present study was to test three monoclonal antibodies (mAbs), A-140, A-78 and A-10, for their ability to recognize antigens and block oocyst infection of the midgut of Anopheles albimanus, a major malaria vector in Latin America. Method Western-blot of mAbs on antigens from midgut brush border membrane vesicles was used to select antibodies. Three mAbs were tested by membrane feeding assays to evaluate their potential transmission-blocking activity against Plasmodium berghei. The cognate antigens recognized by mAbs with oocyst-reducing activity were determined by immunoprecipitation followed by liquid chromatography tandem mass spectrometry. Results Only one mAb, A-140, significantly reduced oocyst infection intensity. Hence, its probable protein target in the Anopheles albimanus midgut was identified and characterized. It recognized three high-molecular mass proteins from a midgut brush border microvilli vesicle preparation. Chemical deglycosylation assays confirmed the peptide nature of the epitope recognized by mAb A-140. Immunoprecipitation followed by proteomic identification with tandem mass spectrometry revealed five proteins, presumably extracted together as a complex. Of these, AALB007909 had the highest mascot score and corresponds to a protein with a myosin head motor domain, indicating that the target of mAb A-140 is probably myosin located on the microvilli of the mosquito midgut. Conclusion These results provide support for the participation of myosin in mosquito midgut invasion by Plasmodium ookinetes. The potential inclusion of this protein in the design of new multivalent vaccine strategies for blocking Plasmodium transmission is discussed. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1548-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alba N Lecona-Valera
- Center of Research on Infectious Diseases, National Institute of Public Health, Av. Universidad 655, Col. Santa María Ahuacatitlán, Cuernavaca, Morelos, C. P. 62508, Mexico
| | - Dingyin Tao
- W. Harry Feinstone Department of Molecular Microbiology & Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland, 21205, USA
| | - Mario H Rodríguez
- Center of Research on Infectious Diseases, National Institute of Public Health, Av. Universidad 655, Col. Santa María Ahuacatitlán, Cuernavaca, Morelos, C. P. 62508, Mexico
| | - Tomás López
- Instituto de Biotecnología, Universidad Nacional Autónoma de Méxic006F, Av. Universidad 2001, Colonia Chamilpa, Cuernavaca, Morelos, 62210, Mexico
| | - Rhoel R Dinglasan
- W. Harry Feinstone Department of Molecular Microbiology & Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, Maryland, 21205, USA
| | - María C Rodríguez
- Center of Research on Infectious Diseases, National Institute of Public Health, Av. Universidad 655, Col. Santa María Ahuacatitlán, Cuernavaca, Morelos, C. P. 62508, Mexico.
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91
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Vallejo AF, Martinez NL, Tobon A, Alger J, Lacerda MV, Kajava AV, Arévalo-Herrera M, Herrera S. Global genetic diversity of the Plasmodium vivax transmission-blocking vaccine candidate Pvs48/45. Malar J 2016; 15:202. [PMID: 27067024 PMCID: PMC4828788 DOI: 10.1186/s12936-016-1263-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 03/31/2016] [Indexed: 12/17/2022] Open
Abstract
Background Plasmodium vivax 48/45 protein is expressed on the surface of gametocytes/gametes and plays a key role in gamete fusion during fertilization. This protein was recently expressed in Escherichia coli host as a recombinant product that was highly immunogenic in mice and monkeys and induced antibodies with high transmission-blocking activity, suggesting its potential as a P. vivax transmission-blocking vaccine candidate. To determine sequence polymorphism of natural parasite isolates and its potential influence on the protein structure, all pvs48/45 sequences reported in databases from around the world as well as those from low-transmission settings of Latin America were compared. Methods Plasmodium vivax parasite isolates from malaria-endemic regions of Colombia, Brazil and Honduras (n = 60) were used to sequence the Pvs48/45 gene, and compared to those previously reported to GenBank and PlasmoDB (n = 222). Pvs48/45 gene haplotypes were analysed to determine the functional significance of genetic variation in protein structure and vaccine potential. Results Nine non-synonymous substitutions (E35K, Y196H, H211N, K250N, D335Y, E353Q, A376T, K390T, K418R) and three synonymous substitutions (I73, T149, C156) that define seven different haplotypes were found among the 282 isolates from nine countries when compared with the Sal I reference sequence. Nucleotide diversity (π) was 0.00173 for worldwide samples (range 0.00033–0.00216), resulting in relatively high diversity in Myanmar and Colombia, and low diversity in Mexico, Peru and South Korea. The two most frequent substitutions (E353Q: 41.9 %, K250N: 39.5 %) were predicted to be located in antigenic regions without affecting putative B cell epitopes or the tertiary protein structure. Conclusions There is limited sequence polymorphism in pvs48/45 with noted geographical clustering among Asian and American isolates. The low genetic diversity of the protein does not influence the predicted antigenicity or protein structure and, therefore, supports its further development as transmission-blocking vaccine candidate.
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Affiliation(s)
| | | | | | - Jackeline Alger
- Facultad de Ciencias Médicas, Hospital Escuela Universitario, Universidad Nacional Autónoma de Honduras, Tegucigalpa, Honduras
| | - Marcus V Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Andrey V Kajava
- Centre de Recherches Biochimie Macromoléculaire (CRBM), Institut de Biologie Computationnelle (IBC), CNRS, University of Montpellier, Montpellier, France.,Institute of Bioengineering, University ITMO, Saint Petersburg, Russia
| | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center, Cali, Colombia.,School of Health, Universidad del Valle, Cali, Colombia
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92
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Okamoto KW, Gould F, Lloyd AL. Integrating Transgenic Vector Manipulation with Clinical Interventions to Manage Vector-Borne Diseases. PLoS Comput Biol 2016; 12:e1004695. [PMID: 26962871 PMCID: PMC4786096 DOI: 10.1371/journal.pcbi.1004695] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 12/07/2015] [Indexed: 11/24/2022] Open
Abstract
Many vector-borne diseases lack effective vaccines and medications, and the limitations of traditional vector control have inspired novel approaches based on using genetic engineering to manipulate vector populations and thereby reduce transmission. Yet both the short- and long-term epidemiological effects of these transgenic strategies are highly uncertain. If neither vaccines, medications, nor transgenic strategies can by themselves suffice for managing vector-borne diseases, integrating these approaches becomes key. Here we develop a framework to evaluate how clinical interventions (i.e., vaccination and medication) can be integrated with transgenic vector manipulation strategies to prevent disease invasion and reduce disease incidence. We show that the ability of clinical interventions to accelerate disease suppression can depend on the nature of the transgenic manipulation deployed (e.g., whether vector population reduction or replacement is attempted). We find that making a specific, individual strategy highly effective may not be necessary for attaining public-health objectives, provided suitable combinations can be adopted. However, we show how combining only partially effective antimicrobial drugs or vaccination with transgenic vector manipulations that merely temporarily lower vector competence can amplify disease resurgence following transient suppression. Thus, transgenic vector manipulation that cannot be sustained can have adverse consequences—consequences which ineffective clinical interventions can at best only mitigate, and at worst temporarily exacerbate. This result, which arises from differences between the time scale on which the interventions affect disease dynamics and the time scale of host population dynamics, highlights the importance of accounting for the potential delay in the effects of deploying public health strategies on long-term disease incidence. We find that for systems at the disease-endemic equilibrium, even modest perturbations induced by weak interventions can exhibit strong, albeit transient, epidemiological effects. This, together with our finding that under some conditions combining strategies could have transient adverse epidemiological effects suggests that a relatively long time horizon may be necessary to discern the efficacy of alternative intervention strategies. Despite decades of attempted vector control, several vector-borne diseases remain endemic. Recent high-profile studies suggest that candidate vaccines, particularly for dengue, may be less than completely effective as public health interventions. Nevertheless, the epidemiological consequences of using other novel approaches (e.g., transgenic strategies to reduce or replace vector populations) remain highly uncertain. Faced with unclear prospects of any one strategy succeeding in isolation, there is increasing interest in designing a comprehensive public health response to manage vector-borne diseases. Here we use a relatively simple model to study how combining vaccines, transgenic vector manipulation and antimicrobial medications can facilitate disease management. We explain why the epidemiological consequences for combining strategies are not expected to merely sum their effects. Contrary to the prevailing assumption that comprehensive disease management always yields public health benefits, we find integrating transgenic vector manipulation with clinical interventions can, in some cases, temporarily exacerbate the adverse consequences of any one strategy failing. These results highlight the need for system-specific modeling efforts aimed at assessing whether our conclusions apply to specific vector-borne diseases. We outline the implications for proceeding with public health responses integrating currently available products, as well as assessing their efficacy.
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Affiliation(s)
- Kenichi W. Okamoto
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
- Yale Institute for Biospheric Studies, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| | - Fred Gould
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Alun L. Lloyd
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Mathematics and Biomathematics, Graduate Program, North Carolina State University, Raleigh, North Carolina, United States of America
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93
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Canavati SE, Lawford HLS, Fatunmbi BS, Lek D, Top-Samphor N, Leang R, Dondorp AM, Huy R, Kazadi WM. Establishing research priorities for malaria elimination in the context of the emergency response to artemisinin resistance framework-the Cambodian approach. Malar J 2016; 15:120. [PMID: 26916933 PMCID: PMC4766599 DOI: 10.1186/s12936-016-1117-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 01/22/2016] [Indexed: 11/10/2022] Open
Abstract
Background Countries of the greater Mekong subregion have made a transition from malaria control to an aim for falciparum and vivax malaria elimination. The elimination of falciparum malaria will have to be achieved against a background of increasing artemisinin and multi-drug resistance. This ambitious goal requires an operational research (OR) agenda that addresses the dynamic challenges encountered on the path to elimination, which will need to be flexible and developed in close relation with the cambodian national programme for parasitology, entomology and malaria control (CNM). In Cambodia, a number of meetings with stakeholders were convened by the CNM and emergency response to artemisinin resistance (ERAR) hub, producing an initial list of priority OR topics. The process and outcome of these meetings are described, which could serve as a template for other countries in the region. Methods A landscaping exercise was conducted to gather all past, on-going and planned malaria focussed OR activities conducted by the cambodian research consortium in Cambodia and categorized according to research theme. The six themes included (1) malaria epidemiology, surveillance and response, (2) malaria case management, (3) malaria vector control, (4) malaria behavioural issues, (5) malaria clinical studies, and (6) other vector-borne diseases (dengue, neglected tropical diseases, soil-transmitted helminths). The different themes were discussed in small focus groups, which made an initial prioritization list which was then presented to a plenary group for further discussion. This produced a list of research questions ranked according to priority. Results OR priorities produced by the thematic groups were discussed in the plenary meeting and given a priority score by group voting. A list of 17 OR questions were developed, finalized and listed, which included questions on surveillance, active case detection and treatment efficacy. Conclusion This paper describes ERAR’s work on supporting Cambodia’s transition to malaria elimination by identifying national operational research priorities. ERAR has initiated and currently plays a critical role in the development of country specific research agendas for malaria elimination. The first example of this has been the described exercise in Cambodia, which could serve a template for setting OR priorities in the wider region.
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Affiliation(s)
- Sara E Canavati
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Rajthevee, Bangkok, Thailand.
| | - Harriet L S Lawford
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
| | - Bayo S Fatunmbi
- Emergency Response to Artemisinin Resistance, WHO Representative Office in Cambodia, Penh Phnom Penh, Cambodia.
| | - Dysoley Lek
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
| | - Narann Top-Samphor
- Emergency Response to Artemisinin Resistance, WHO Representative Office in Cambodia, Penh Phnom Penh, Cambodia.
| | - Rithea Leang
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Rekol Huy
- The National Center for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia.
| | - Walter M Kazadi
- Emergency Response to Artemisinin Resistance, WHO Representative Office in Cambodia, Penh Phnom Penh, Cambodia.
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94
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Li F, Bounkeua V, Pettersen K, Vinetz JM. Plasmodium falciparum ookinete expression of plasmepsin VII and plasmepsin X. Malar J 2016; 15:111. [PMID: 26911483 PMCID: PMC4765185 DOI: 10.1186/s12936-016-1161-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 02/10/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Plasmodium invasion of the mosquito midgut is a population bottleneck in the parasite lifecycle. Interference with molecular mechanisms by which the ookinete invades the mosquito midgut is one potential approach to developing malaria transmission-blocking strategies. Plasmodium aspartic proteases are one such class of potential targets: plasmepsin IV (known to be present in the asexual stage food vacuole) was previously shown to be involved in Plasmodium gallinaceum infection of the mosquito midgut, and plasmepsins VII and plasmepsin X (not known to be present in the asexual stage food vacuole) are upregulated in Plasmodium falciparum mosquito stages. These (and other) parasite-derived enzymes that play essential roles during ookinete midgut invasion are prime candidates for transmission-blocking vaccines. METHODS Reverse transcriptase PCR (RT-PCR) was used to determine timing of P. falciparum plasmepsin VII (PfPM VII) and plasmepsin X (PfPM X) mRNA transcripts in parasite mosquito midgut stages. Protein expression was confirmed by western immunoblot and immunofluorescence assays (IFA) using anti-peptide monoclonal antibodies (mAbs) against immunogenic regions of PfPM VII and PfPM X. These antibodies were also used in standard membrane feeding assays (SMFA) to determine whether inhibition of these proteases would affect parasite transmission to mosquitoes. The Mann-Whitney U test was used to analyse mosquito transmission assay results. RESULTS RT-PCR, western immunoblot and immunofluorescence assay confirmed expression of PfPM VII and PfPM X in mosquito stages. Whereas PfPM VII was expressed in zygotes and ookinetes, PfPM X was expressed in gametes, zygotes, and ookinetes. Antibodies against PfPM VII and PfPM X decreased P. falciparum invasion of the mosquito midgut when used at high concentrations, indicating that these proteases play a role in Plasmodium mosquito midgut invasion. Failure to generate genetic knockouts of these genes limited determination of the precise role of these proteases in parasite transmission but suggests that they are essential during the intraerythrocytic life cycle. CONCLUSIONS PfPM VII and PfPM X are present in the mosquito-infective stages of P. falciparum. Standard membrane feeding assays demonstrate that antibodies against these proteins reduce the infectivity of P. falciparum for mosquitoes, suggesting their viability as transmission-blocking vaccine candidates. Further study of the role of these plasmepsins in P. falciparum biology is warranted.
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Affiliation(s)
- Fengwu Li
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0760, USA.
| | - Viengngeun Bounkeua
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0760, USA.
| | - Kenneth Pettersen
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0760, USA.
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0760, USA.
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95
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Vallejo AF, García J, Amado-Garavito AB, Arévalo-Herrera M, Herrera S. Plasmodium vivax gametocyte infectivity in sub-microscopic infections. Malar J 2016; 15:48. [PMID: 26822406 PMCID: PMC4730736 DOI: 10.1186/s12936-016-1104-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/14/2016] [Indexed: 01/07/2023] Open
Abstract
Background The use of molecular techniques has put in the spotlight the existence of a large mass of malaria sub-microscopic infections among apparently healthy populations. These sub-microscopic infections are considered an important pool for maintained malaria transmission. Methods In order to assess the appearance of Plasmodium vivax gametocytes in circulation, gametocyte density and the parasite infectivity to Anopheles mosquitoes, a study was designed to compare three groups of volunteers either experimentally infected with P. vivax sporozoites (early infections; n = 16) or naturally infected patients (acute malaria, n = 16 and asymptomatic, n = 14). In order to determine gametocyte stage, a quantitative reverse transcriptase PCR (RT-qPCR) assay targeting two sexual stage-specific molecular markers was used. Parasite infectivity was assessed by membrane feeding assays (MFA). Results In early infections P. vivax gametocytes could be detected starting at day 7 without giving rise to infected mosquitoes during 13 days of follow-up. Asymptomatic carriers, with presumably long-lasting infections, presented the highest proportion of mature gametocytes and were as infective as acute patients. Conclusions This study shows the potential role of P. vivax asymptomatic carriers in malaria transmission should be considered when new policies are envisioned to redirect malaria control strategies towards targeting asymptomatic infections as a tool for malaria elimination. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1104-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrés F Vallejo
- Malaria Vaccine and Drug Development Centre (MVDC), Cali, Colombia.
| | - Jhon García
- Malaria Vaccine and Drug Development Centre (MVDC), Cali, Colombia.
| | | | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Centre (CSRC)/Centro Latino Americano de Investigación en Malaria (CLAIM), Cali, Colombia. .,Facultad de Salud, Universidad del Valle, Cali, Colombia.
| | - Sócrates Herrera
- Malaria Vaccine and Drug Development Centre (MVDC), Cali, Colombia. .,Caucaseco Scientific Research Centre (CSRC)/Centro Latino Americano de Investigación en Malaria (CLAIM), Cali, Colombia.
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Mukherjee D, Mishra P, Joshi M, Thakur PK, Hosur RV, Jarori GK. EWGWS insert in Plasmodium falciparum ookinete surface enolase is involved in binding of PWWP containing peptides: Implications to mosquito midgut invasion by the parasite. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 68:13-22. [PMID: 26592350 DOI: 10.1016/j.ibmb.2015.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/12/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
There are multiple stages in the life cycle of Plasmodium that invade host cells. Molecular machinery involved is such host-pathogen interactions constitute excellent drug targets and/or vaccine candidates. A screen using a phage display library has previously demonstrated presence of enolase on the surface of the Plasmodium ookinete. Phage-displayed peptides that bound to the ookinete contained a conserved motif (PWWP) in their sequence. Here, direct binding of these peptides with recombinant Plasmodium falciparum enolase (rPfeno) was investigated. These peptides showed specific binding to rPfeno, but failed to bind to other enolases. Plasmodium spp enolases are distinct in having an insert of five amino acids ((104)EWGWS(108)) that is not found in host enolases. The possibility of this insert being the recognition motif for the PWWP containing peptides was examined, (i) by comparing the binding of the peptides with rPfeno and a deletion variant Δ-rPfeno lacking (104)EWGWS(108), (ii) by measuring the changes in proton chemical shifts of PWWP peptides on binding to different enolases and (iii) by inter-molecular docking experiment to locate the peptide binding site. Results from these studies showed that the pentapeptide insert of Pfeno indeed constitutes the binding site for the PWWP domain containing peptide ligands. Search for sequences homologous to phage displayed peptides among peritrophic matrix proteins resulted in identification of perlecan, laminin, peritrophin and spacran. The possibility of these PWWP domain-containing proteins in the peritrophic matrix of insect gut to interact with ookinete cell surface enolase and facilitate the invasion of mosquito midgut epithelium is discussed.
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Affiliation(s)
- Debanjan Mukherjee
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Pushpa Mishra
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Mamata Joshi
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Prasoon Kumar Thakur
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisbon, 1649- 028 Lisbon, Portugal
| | - R V Hosur
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
| | - Gotam K Jarori
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India.
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Osterholm M, Moore K, Ostrowsky J, Kimball-Baker K, Farrar J. The Ebola Vaccine Team B: a model for promoting the rapid development of medical countermeasures for emerging infectious disease threats. THE LANCET. INFECTIOUS DISEASES 2016; 16:e1-e9. [PMID: 26526664 PMCID: PMC7106346 DOI: 10.1016/s1473-3099(15)00416-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 10/26/2015] [Indexed: 12/04/2022]
Abstract
In support of accelerated development of Ebola vaccines from preclinical research to clinical trials, in November, 2014, the Wellcome Trust and the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota established the Wellcome Trust-CIDRAP Ebola Vaccine Team B initiative. This ongoing initiative includes experts with global experience in various phases of bringing new vaccines to market, such as funding, research and development, manufacturing, determination of safety and efficacy, regulatory approval, and vaccination delivery. It also includes experts in community engagement strategies and ethical issues germane to vaccination policies, including eight African scientists with direct experience in developing and implementing vaccination policies in Africa. Ebola Vaccine Team B members have worked on a range of vaccination programmes, such as polio eradication (Africa and globally), development of meningococcal A disease vaccination campaigns in Africa, and malaria and HIV/AIDS vaccine research. We also provide perspective on how this experience can inform future situations where urgent development of vaccines is needed, and we comment on the role that an independent, expert group such as Team B can have in support of national and international public health authorities toward addressing a public health crisis.
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Affiliation(s)
- Michael Osterholm
- Center for Infectious Disease Research and Policy, University of Minnesota, Minneapolis, MN, USA.
| | - Kristine Moore
- Center for Infectious Disease Research and Policy, University of Minnesota, Minneapolis, MN, USA
| | - Julie Ostrowsky
- Center for Infectious Disease Research and Policy, University of Minnesota, Minneapolis, MN, USA
| | - Kathleen Kimball-Baker
- Center for Infectious Disease Research and Policy, University of Minnesota, Minneapolis, MN, USA
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Abstract
In 2013 there were an estimated 584,000 deaths and 198 million clinical illnesses due to malaria, the majority in sub-Saharan Africa. Vaccines would be the ideal addition to the existing armamentarium of anti-malaria tools. However, malaria is caused by parasites, and parasites are much more complex in terms of their biology than the viruses and bacteria for which we have vaccines, passing through multiple stages of development in the human host, each stage expressing hundreds of unique antigens. This complexity makes it more difficult to develop a vaccine for parasites than for viruses and bacteria, since an immune response targeting one stage may not offer protection against a later stage, because different antigens are the targets of protective immunity at different stages. Furthermore, depending on the life cycle stage and whether the parasite is extra- or intra-cellular, antibody and/or cellular immune responses provide protection. It is thus not surprising that there is no vaccine on the market for prevention of malaria, or any human parasitic infection. In fact, no vaccine for any disease with this breadth of targets and immune responses exists. In this limited review, we focus on four approaches to malaria vaccines, (1) a recombinant protein with adjuvant vaccine aimed at Plasmodium falciparum (Pf) pre-erythrocytic stages of the parasite cycle (RTS,S/AS01), (2) whole sporozoite vaccines aimed at Pf pre-erythrocytic stages (PfSPZ Vaccine and PfSPZ-CVac), (3) prime boost vaccines that include recombinant DNA, viruses and bacteria, and protein with adjuvant aimed primarily at Pf pre-erythrocytic, but also asexual erythrocytic stages, and (4) recombinant protein with adjuvant vaccines aimed at Pf and Plasmodium vivax sexual erythrocytic and mosquito stages. We recognize that we are not covering all approaches to malaria vaccine development, or most of the critically important work on development of vaccines against P. vivax, the second most important cause of malaria. Progress during the last few years has been significant, and a first generation malaria candidate vaccine, RTS,S/AS01, is under review by the European Medicines Agency (EMA) for its quality, safety and efficacy under article 58, which allows the EMA to give a scientific opinion about products intended exclusively for markets outside of the European Union. However, much work is in progress to optimize malaria vaccines in regard to magnitude and durability of protective efficacy and the financing and practicality of delivery. Thus, we are hopeful that anti-malaria vaccines will soon be important tools in the battle against malaria.
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Bijker EM, Borrmann S, Kappe SH, Mordmüller B, Sack BK, Khan SM. Novel approaches to whole sporozoite vaccination against malaria. Vaccine 2015; 33:7462-8. [PMID: 26469716 PMCID: PMC6858867 DOI: 10.1016/j.vaccine.2015.09.095] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 08/22/2015] [Accepted: 09/22/2015] [Indexed: 12/15/2022]
Abstract
The parasitic disease malaria threatens more than 3 billion people worldwide, resulting in more than 200 million clinical cases and almost 600,000 deaths annually. Vaccines remain crucial for prevention and ultimately eradication of infectious diseases and, for malaria, whole sporozoite based immunization has been shown to be the most effective in experimental settings. In addition to immunization with radiation-attenuated sporozoites, chemoprophylaxis and sporozoites (CPS) is a highly efficient strategy to induce sterile protection in humans. Genetically attenuated parasites (GAP) have demonstrated significant protection in rodent studies, and are now being advanced into clinical testing. This review describes the existing pre-clinical and clinical data on CPS and GAP, discusses recent developments and examines how to transform these immunization approaches into vaccine candidates for clinical development.
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Affiliation(s)
- Else M Bijker
- Radboud University Medical Center, Department of Medical Microbiology, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Steffen Borrmann
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stefan H Kappe
- Seattle Biomedical Research Institute, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA
| | - Benjamin Mordmüller
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany; German Centre for Infection Research, University of Tübingen, Tübingen, Germany; Centre de Recherches Médicales de Lambaréné, Alberts Schweitzer Hospital, BP 118 Lambaréné, Gabon
| | | | - Shahid M Khan
- Leiden University Medical Center, Department of Parasitology, PO Box 9600, 2300 RC Leiden, The Netherlands
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100
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Birkett AJ. Building an effective malaria vaccine pipeline to address global needs. Vaccine 2015; 33:7538-43. [PMID: 26469721 DOI: 10.1016/j.vaccine.2015.09.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/25/2015] [Accepted: 09/29/2015] [Indexed: 02/08/2023]
Abstract
Despite impressive gains over the last 15 years in reducing the mortality associated with malaria, it remains a public health emergency. New interventions, such as vaccines, are needed to ensure that previous gains serve as a foundation for future progress. Vaccines have the potential to prevent severe disease and death in those most vulnerable, and to accelerate elimination and eradication by breaking the cycle of parasite transmission. The pipeline is as healthy as it has ever been, with approaches targeting different stages of the parasite lifecycle using an array of technologies. This article reviews recent progress and reviews key considerations in the quest to develop products that are aligned with the unmet medical need.
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Affiliation(s)
- Ashley J Birkett
- PATH Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC 20001-2621, USA.
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