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Ciubotariu II, Broyles BK, Xie S, Thimmapuram J, Mwenda MC, Mambwe B, Mulube C, Matoba J, Schue JL, Moss WJ, Bridges DJ, He Q, Carpi G. Diversity and selection analyses identify transmission-blocking antigens as the optimal vaccine candidates in Plasmodium falciparum. EBioMedicine 2024; 106:105227. [PMID: 39018754 DOI: 10.1016/j.ebiom.2024.105227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. METHODS We analysed 325 P. falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Database. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. FINDINGS Among the ten antigens analysed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. INTERPRETATION These findings offer valuable insights into the selection of optimal vaccine candidates against P. falciparum. Based on our results, we recommend prioritising conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. FUNDING Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).
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Affiliation(s)
- Ilinca I Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Bradley K Broyles
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, IN, USA
| | | | - Mulenga C Mwenda
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Brenda Mambwe
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Jessica L Schue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - William J Moss
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
| | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA; Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN, USA.
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Sadr S, Ahmadi Simab P, Niazi M, Yousefsani Z, Lotfalizadeh N, Hajjafari A, Borji H. Anti-inflammatory and immunomodulatory effects of mesenchymal stem cell therapy on parasitic drug resistance. Expert Rev Anti Infect Ther 2024; 22:435-451. [PMID: 38804866 DOI: 10.1080/14787210.2024.2360684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
INTRODUCTION The emergence of antiparasitic drug resistance poses a concerning threat to animals and humans. Mesenchymal Stem Cells (MSCs) have been widely used to treat infections in humans, pets, and livestock. Although this is an emerging field of study, the current review outlines possible mechanisms and examines potential synergism in combination therapies and the possible harmful effects of such an approach. AREAS COVERED The present study delved into the latest pre-clinical research on utilizing MSCs to treat parasitic infections. As per investigations, the introduction of MSCs to patients grappling with parasitic diseases like schistosomiasis, malaria, cystic echinococcosis, toxoplasmosis, leishmaniasis, and trypanosomiasis has shown a reduction in parasite prevalence. This intervention also alters the levels of both pro- and anti-inflammatory cytokines. Furthermore, the combined administration of MSCs and antiparasitic drugs has demonstrated enhanced efficacy in combating parasites and modulating the immune response. EXPERT OPINION Mesenchymal stem cells are a potential solution for addressing parasitic drug resistance. This is mainly because of their remarkable immunomodulatory abilities, which can potentially help combat parasites' resistance to drugs.
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Affiliation(s)
- Soheil Sadr
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Pouria Ahmadi Simab
- Department of Pathobiology, Faculty of Veterinary Medicine, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
| | - Mahta Niazi
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Zahra Yousefsani
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Narges Lotfalizadeh
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ashkan Hajjafari
- Department of Pathobiology, Faculty of Veterinary Medicine, Islamic Azad University, Science and Research Branch, Tehran, Iran
| | - Hassan Borji
- Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
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Ciubotariu II, Broyles BK, Xie S, Thimmapuram J, Mwenda MC, Mambwe B, Mulube C, Matoba J, Schue JL, Moss WJ, Bridges DJ, He Q, Carpi G. Diversity and selection analyses identify transmission-blocking antigens as the optimal vaccine candidates in Plasmodium falciparum. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.11.24307175. [PMID: 38766239 PMCID: PMC11100930 DOI: 10.1101/2024.05.11.24307175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Background A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. Methods We analyzed 325 P. falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Rdatabase. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. Findings Among the ten antigens analyzed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. Interpretations These findings offer valuable insights into the selection of optimal vaccine candidates against P. falciparum. Based on our results, we recommend prioritizing conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. Funding Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).
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Affiliation(s)
- Ilinca I. Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Bradley K. Broyles
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, Indiana, USA
| | | | - Mulenga C. Mwenda
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Brenda Mambwe
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Jessica L. Schue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - William J. Moss
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, Indiana, USA
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Plaza DF, Zerebinski J, Broumou I, Lautenbach MJ, Ngasala B, Sundling C, Färnert A. A genomic platform for surveillance and antigen discovery in Plasmodium spp. using long-read amplicon sequencing. CELL REPORTS METHODS 2023; 3:100574. [PMID: 37751696 PMCID: PMC10545912 DOI: 10.1016/j.crmeth.2023.100574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 06/18/2023] [Accepted: 08/07/2023] [Indexed: 09/28/2023]
Abstract
Many vaccine candidate proteins in the malaria parasite Plasmodium falciparum are under strong immunological pressure and confer antigenic diversity. We present a sequencing and data analysis platform for the genomic surveillance of the insertion or deletion (indel)-rich antigens merozoite surface protein 1 (MSP1), MSP2, glutamate-rich protein (GLURP), and CSP from P. falciparum using long-read circular consensus sequencing (CCS) in multiclonal malaria isolates. Our platform uses 40 PCR primers per gene to asymmetrically barcode and identify multiclonal infections in pools of up to 384 samples. With msp2, we validated the method using 235 mock infections combining 10 synthetic variants at different concentrations and infection complexities. We applied this strategy to P. falciparum isolates from a longitudinal cohort in Tanzania. Finally, we constructed an analysis pipeline that streamlines the processing and interpretation of epidemiological and antigenic diversity data from demultiplexed FASTQ files. This platform can be easily adapted to other polymorphic antigens of interest in Plasmodium or any other human pathogen.
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Affiliation(s)
- David Fernando Plaza
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden.
| | - Julia Zerebinski
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden
| | - Ioanna Broumou
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden
| | - Maximilian Julius Lautenbach
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden
| | - Billy Ngasala
- Muhimbili University of Health and Allied Sciences, Dar es Salaam 57RF+V8, Tanzania
| | - Christopher Sundling
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden
| | - Anna Färnert
- Division of Infectious Diseases, Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Infectious Diseases, Karolinska University Hospital, 17176 Stockholm, Sweden
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Ciubotariu II, Monroe A, Williams NA, Ogoma SB, Okumu F. Ifakara MasterClasses: lessons from leading experts on the battle against malaria. Trends Parasitol 2023; 39:607-614. [PMID: 37331883 DOI: 10.1016/j.pt.2023.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 05/24/2023] [Indexed: 06/20/2023]
Affiliation(s)
- Ilinca I Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA; Ifakara Health Institute, Ifakara, Tanzania.
| | - Nana Aba Williams
- MESA Alliance, Barcelona Institute for Global Health (ISGlobal), Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.
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High-level production of recombinant HBcAg virus-like particles in a mathematically modelled P. pastoris GS115 Mut + bioreactor process under controlled residual methanol concentration. Bioprocess Biosyst Eng 2022; 45:1447-1463. [PMID: 35939139 PMCID: PMC9358087 DOI: 10.1007/s00449-022-02754-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/04/2022] [Indexed: 11/08/2022]
Abstract
Recombinant hepatitis B core antigen (HBcAg) molecules, produced in heterologous expression systems, self-assemble into highly homogenous and non-infectious virus-like particles (VLPs) that are under extensive research for biomedical applications. HBcAg production in the methylotrophic yeast P. pastoris has been well documented; however, productivity screening under various residual methanol levels has not been reported for bioreactor processes. HBcAg production under various excess methanol levels of 0.1, 1.0 and 2.0 g L−1 was investigated in this research. Results indicate that, under these particular conditions, the total process and specific protein yields of 876–1308 mg L−1 and 7.9–11.2 mg gDCW−1, respectively, were achieved after 67–75 h of cultivation. Produced HBcAg molecules were efficiently purified and the presence of highly immunogenic, correctly formed and homogenous HBcAg-VLPs with an estimated purity of 90% was confirmed by electron microscopy. The highest reported HBcAg yield of 1308 mg L−1 and 11.2 mg gDCW−1 was achieved under limiting residual methanol concentration, which is about 2.5 times higher than the next highest reported result. A PI-algorithm-based residual methanol concentration feed rate controller was employed to maintain a set residual methanol concentration. Finally, mathematical process models to characterise the vegetative, dead and total cell biomass (Xv, Xd and X), substrate (Glycerol and Methanol) concentration, reactor volume (V), and product (HBcAg) dynamics during cultivation, were identified. A rare attempt to model the residual methanol concentration during induction is also presented.
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Vah L, Medved T, Grošelj U, Klemenčič M, Podlipnik Č, Štefane B, Wagger J, Novinec M, Svete J. Regioselective Synthesis of 5- and 3-Hydroxy- N-Aryl-1 H-Pyrazole-4-Carboxylates and Their Evaluation as Inhibitors of Plasmodium falciparum Dihydroorotate Dehydrogenase. Molecules 2022; 27:4764. [PMID: 35897941 PMCID: PMC9332393 DOI: 10.3390/molecules27154764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/15/2022] [Accepted: 07/17/2022] [Indexed: 02/05/2023] Open
Abstract
In silico evaluation of various regioisomeric 5- and 3-hydroxy-substituted alkyl 1-aryl-1H-pyrazole-4-carboxylates and their acyclic precursors yielded promising results with respect to their binding in the active site of dihydroorotate dehydrogenase of Plasmodium falciparum (PfDHODH). Consequently, four ethyl 1-aryl-5-hydroxy-1H-pyrazole-4-carboxylates and their 3-hydroxy regioisomers were prepared by two-step syntheses via enaminone-type reagents or key intermediates. The synthesis of 5-hydroxy-1H-pyrazoles was carried out using the literature protocol comprising acid-catalyzed transamination of diethyl [(dimethylamino)methylene]malonate with arylhydrazines followed by base-catalyzed cyclization of the intermediate hydrazones. For the synthesis of isomeric methyl 1-aryl-3-hydroxy-1H-pyrazole-4-carboxylates, a novel two-step synthesis was developed. It comprises acylation of hydrazines with methyl malonyl chloride followed by cyclization of the hydrazines with tert-butoxy-bis(dimethylamino)methane. Testing the pyrazole derivatives for the inhibition of PfDHODH showed that 1-(naphthalene-2-yl)-5-hydroxy-1H-pyrazole-4-carboxylate and 1-(naphthalene-2-yl)-, 1-(2,4,6-trichlorophenyl)-, and 1-[4-(trifluoromethyl)phenyl]-3-hydroxy-1H-pyrazole-4-carboxylates (~30% inhibition) were slightly more potent than a known inhibitor, diethyl α-{[(1H-indazol-5-yl)amino]methylidene}malonate (19% inhibition).
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Affiliation(s)
| | | | | | | | | | | | | | - Marko Novinec
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia; (L.V.); (T.M.); (U.G.); (M.K.); (Č.P.); (B.Š.); (J.W.)
| | - Jurij Svete
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000 Ljubljana, Slovenia; (L.V.); (T.M.); (U.G.); (M.K.); (Č.P.); (B.Š.); (J.W.)
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Knowledge, Attitudes, and Practices in Relation to Mosquito-Borne Diseases in Bangladesh. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19148258. [PMID: 35886105 PMCID: PMC9324993 DOI: 10.3390/ijerph19148258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023]
Abstract
Mosquito-borne diseases (MBDs) such as dengue, malaria, and chikungunya are common in Bangladesh, with frequent outbreaks in the rainy season. Analysis of the knowledge, attitudes, and practices of people toward any crisis is fundamental to addressing any gap. Here, we conducted a cross-sectional study mainly focusing on the northern, southern and central parts of Bangladesh to understand the level of knowledge, attitudes, and practices of people regarding MBDs, mosquito habitats, or control measures. A total of 1720 participants were involved in the study from 33 out of 64 districts of Bangladesh, of which 56.9% were male. While most of them knew about dengue (97.1%), chikungunya (81.4%), and malaria (85.2%), only half of them were aware of filaria (53.3%), which is endemic to the northern region. A knowledge score (0−8, low), (9−16, moderate), (17−24, high), and attitude score (0−4, poor), (5−8, moderate), and (9−13, high) were assigned. While poor and moderate attitudes were considered negative, good attitudes were considered positive. About 45% of the respondents had a moderate knowledge score (50−70); however, about 67.9% of participants showed a good attitude score (>70) towards the control of MBDs. It was found that the knowledge and attitude of the responders were related to their profession (knowledge p < 0.001; attitude, p = 0.002), residential area (knowledge p < 0.001; attitude, p < 0.001), and education level (knowledge p < 0.001; attitude p = 0.004). A mosquito is a kind of nuisance bug, and about 79.8% of responders admitted that they kill mosquitoes as soon as they notice them. They also use bed nets (93.7%) followed by mosquito coils (85.7%) as a preventive method. Interestingly, 73.2% of the responders were reluctant to contact the local government during an increase in mosquito numbers. Overall, the people of Bangladesh have a positive attitude towards the prevention of mosquito-borne diseases. It is highly recommended that the government creates more knowledge regarding this issue and develops collaborative approaches with local people to implement robust preventive measures against mosquito-borne diseases.
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Nava-Lausón C, Spencer LM, Sajo-Bohus L, Dávila J, Tellkamp MP. Evaluation of X-ray ionizing radiation on Plasmodium berghei invasion of erythrocytes. BIONATURA 2022. [DOI: 10.21931/rb/2022.07.01.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Developing new strategies for designing effective vaccines has become a priority for parasitologists worldwide. There is high interest in designing a vaccine against malaria since it is considered one of the most prevalent infectious diseases in the tropics. We evaluated the effects of X-rays irradiation on the erythrocytic stage of Plasmodium berghei ANKA merozoites and schizonts using doses of ionizing radiation ranging between 10 and 300 Gy on parasitized red blood cells (PRBC) to study the attenuating effects of radiation on the merozoites. Parasitic activity diminution was observed starting at 50 Gy, and the dose for complete attenuation was established at 200 Gy, corresponding with a 100% survival rate of mice. In vivo invasion experiments and immunofluorescence assays (IFA) showed inhibition of merozoite invasion of the host red blood cells (RBC). Nonetheless, immunization with irradiated parasitized red blood cells (IPRBC) was ineffective in protective assays. We perform cytoadherence and inhibition of cytoadhesion assays on irradiated merozoites. The results showed that high irradiation doses caused an unspecific cellular adhesion phenomenon independent of the ICAM-1 and CD36 interaction, which was determined by Cytoadhesion assays.
Our results show that, even though X-ray irradiation is an effective method to induce complete parasite attenuation, it might affect the parasite's membrane surface structures triggering unspecific adhesion.
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Affiliation(s)
- Carina Nava-Lausón
- Cell Biology Department, Simón Bolívar University, Valle de Sartenejas, Caracas - Venezuela
| | - Lilian M. Spencer
- Cell Biology Department, Simón Bolívar University, Valle de Sartenejas, Caracas - Venezuela School of Biological Sciences and Engineering, Yachay Tech University, San Miguel de Urcuquí - Ecuador
| | - Laszlo Sajo-Bohus
- Physics Department, Simón Bolívar University, Valle de Sartenejas, Caracas - Venezuela
| | - Jesús Dávila
- Radiotherapy Service Gurve, La Trinidad. Caracas, Venezuela
| | - Markus P. Tellkamp
- School of Biological Sciences and Engineering, Yachay Tech University, San Miguel de Urcuquí - Ecuador
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Global diversity and balancing selection of 23 leading Plasmodium falciparum candidate vaccine antigens. PLoS Comput Biol 2022; 18:e1009801. [PMID: 35108259 PMCID: PMC8843232 DOI: 10.1371/journal.pcbi.1009801] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 02/14/2022] [Accepted: 01/03/2022] [Indexed: 12/30/2022] Open
Abstract
Investigation of the diversity of malaria parasite antigens can help prioritize and validate them as vaccine candidates and identify the most common variants for inclusion in vaccine formulations. Studies of vaccine candidates of the most virulent human malaria parasite, Plasmodium falciparum, have focused on a handful of well-known antigens, while several others have never been studied. Here we examine the global diversity and population structure of leading vaccine candidate antigens of P. falciparum using the MalariaGEN Pf3K (version 5.1) resource, comprising more than 2600 genomes from 15 malaria endemic countries. A stringent variant calling pipeline was used to extract high quality antigen gene 'haplotypes' from the global dataset and a new R-package named VaxPack was used to streamline population genetic analyses. In addition, a newly developed algorithm that enables spatial averaging of selection pressure on 3D protein structures was applied to the dataset. We analysed the genes encoding 23 leading and novel candidate malaria vaccine antigens including csp, trap, eba175, ama1, rh5, and CelTOS. Our analysis shows that current malaria vaccine formulations are based on rare haplotypes and thus may have limited efficacy against natural parasite populations. High levels of diversity with evidence of balancing selection was detected for most of the erythrocytic and pre-erythrocytic antigens. Measures of natural selection were then mapped to 3D protein structures to predict targets of functional antibodies. For some antigens, geographical variation in the intensity and distribution of these signals on the 3D structure suggests adaptation to different human host or mosquito vector populations. This study provides an essential framework for the diversity of P. falciparum antigens to be considered in the design of the next generation of malaria vaccines.
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Mwamlima TG, Mwakasungula SM, Mkindi CG, Tambwe MM, Mswata SS, Mbwambo SG, Mboya MF, Draper SJ, Silk SE, Mpina MG, Vianney JM, Olotu AI. Understanding the role of serological and clinical data on assessing the dynamic of malaria transmission: a case study of Bagamoyo district, Tanzania. Pan Afr Med J 2022; 43:60. [PMID: 36578806 PMCID: PMC9755714 DOI: 10.11604/pamj.2022.43.60.35779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 09/01/2022] [Indexed: 12/30/2022] Open
Abstract
Introduction naturally acquired blood-stage malaria antibodies and malaria clinical data have been reported to be useful in monitoring malaria change over time and as a marker of malaria exposure. This study assessed the total immunoglobulin G (IgG) levels to Plasmodium falciparum schizont among infants (5-17 months), estimated malaria incidence using routine health facility-based surveillance data and predicted trend relation between anti-schizont antibodies and malaria incidence in Bagamoyo. Methods 252 serum samples were used for assessment of total IgG by enzyme-linked immunosorbent assay and results were expressed in arbitrary units (AU). 147/252 samples were collected in 2021 during a blood-stage malaria vaccine trial [ClinicalTrials.gov NCT04318002], and 105/252 were archived samples of malaria vaccine trial conducted in 2012 [ClinicalTrials.gov NCT00866619]. Malaria incidence was calculated from outpatient clinic data of malaria rapid test or blood smear positive results retrieved from District-Health-Information-Software-2 (DHIS2) between 2013 and 2020. Cross-sectional data from both studies were analysed using STATA version 14. Results this study demonstrated a decline in total anti-schizont IgG levels from 490.21AU in 2012 to 97.07AU in 2021 which was related to a fall in incidence from 58.25 cases/1000 person-year in 2013 to 14.28 cases/1000 person-year in 2020. We also observed a significant difference in incidence when comparing high and low malaria transmission areas and by gender. However, we did not observe differences when comparing total anti-schizont antibodies by gender and study year. Conclusion total anti-schizont antibody levels appear to be an important serological marker of exposure for assessing the dynamic of malaria transmission in infants living in malaria-endemic regions.
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Affiliation(s)
- Tunu Guntram Mwamlima
- Ifakara Health Institute, Bagamoyo, Tanzania
- Department of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
- Corresponding author: Tunu Guntram Mwamlima, Ifakara Health Institute, Bagamoyo, Tanzania.
| | | | | | | | | | | | | | - Simon John Draper
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | | | | | - John-Mary Vianney
- Department of Life Science and Bio-Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
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Nateghpour M, Etemadi S, Motevalli Haghi A, Eslami H, Mohebali M, Farivar L. Serological responses to a soluble recombinant circumsporozoite protein-VK210 of Plasmodium vivax (rPvCSP-VK210) among Iranian malaria patients. Eur J Med Res 2021; 26:134. [PMID: 34823591 PMCID: PMC8620637 DOI: 10.1186/s40001-021-00607-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 11/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Circumsporozoite protein (CSP) has a central immune domain that includes short regions of repeating amino acid sequences. This immunodynamic region is an epitope of B cells that can elicit an immune response in human and laboratory animals. The aim of the present study was to express the recombinant PvCSP-VK210 antigen and evaluate it for assaying antibodies obtained during human P. vivax infection by Western blotting and indirect ELISA (enzyme-linked immunosorbent assay). METHOD Genomic DNA of P. vivax was isolated from a blood sample of an Iranian person with vivax malaria, and by PCR, the fragment of the PvCSP-VK210 gene was amplified. The gene fragment was cut after gel purification by BamHI and HindIII enzymes and then cloned into pET28a expression vector. Finally, the recombinant pET28a was transformed into the E. coli BL21 (DE3) as the expression host. In order to produce His-tagged protein, the expression host was cultured in LB medium. The protein was purified by Ni-NTA columns and immobilized metal affinity chromatography, and after confirmation by Western blotting technique, was used as the antigen in the indirect ELISA test. RESULTS The recombinant protein was expressed and purified as a 32-kDa protein. The sensitivity and specificity of the indirect ELISA test with the recombinant PvCSP-VK210 antigen were 61.42% and 97.14%, respectively, based on OD = 0.313. Between the results of the microscopic test and the indirect ELISA test with the recombinant PvCSP-VK210 antigen there was a Kappa coefficient of 0.586. The positive and negative predictive value and validity of the ELISA test with the recombinant PvCSP-VK210 antigen were 95.55%, 71.57%, 79.28%, respectively. CONCLUSION The sensitivity of the indirect ELISA method with the recombinant PvCSP-VK210 antigen was 61.42%, which is the first report from Iran.
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Affiliation(s)
- Mehdi Nateghpour
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Soudabeh Etemadi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. .,Infectious Disease and Tropical Medicine Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran. .,Department of Parasitology and Mycology, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
| | - Afsaneh Motevalli Haghi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamid Eslami
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Leila Farivar
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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13
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Bonam SR, Rénia L, Tadepalli G, Bayry J, Kumar HMS. Plasmodium falciparum Malaria Vaccines and Vaccine Adjuvants. Vaccines (Basel) 2021; 9:1072. [PMID: 34696180 PMCID: PMC8541031 DOI: 10.3390/vaccines9101072] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 12/02/2022] Open
Abstract
Malaria-a parasite vector-borne disease-is a global health problem, and Plasmodium falciparum has proven to be the deadliest among Plasmodium spp., which causes malaria in humans. Symptoms of the disease range from mild fever and shivering to hemolytic anemia and neurological dysfunctions. The spread of drug resistance and the absence of effective vaccines has made malaria disease an ever-emerging problem. Although progress has been made in understanding the host response to the parasite, various aspects of its biology in its mammalian host are still unclear. In this context, there is a pressing demand for the development of effective preventive and therapeutic strategies, including new drugs and novel adjuvanted vaccines that elicit protective immunity. The present article provides an overview of the current knowledge of anti-malarial immunity against P. falciparum and different options of vaccine candidates in development. A special emphasis has been made on the mechanism of action of clinically used vaccine adjuvants.
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Affiliation(s)
- Srinivasa Reddy Bonam
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
| | - Laurent Rénia
- A*STAR Infectious Diseases Labs, 8A Biomedical Grove, Singapore 138648, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore 308232, Singapore
| | - Ganesh Tadepalli
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
| | - Jagadeesh Bayry
- Institut National de la Santé et de la Recherche Médicale, Centre de Recherche des Cordeliers, Equipe-Immunopathologie et Immunointervention Thérapeutique, Sorbonne Université, Université de Paris, F-75006 Paris, France;
- Biological Sciences & Engineering, Indian Institute of Technology Palakkad, Palakkad 678623, India
| | - Halmuthur Mahabalarao Sampath Kumar
- Vaccine Immunology Laboratory, Organic Synthesis and Process Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India;
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14
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Production and Immunogenicity of a Tag-Free Recombinant Chimera Based on PfMSP-1 and PfMSP-3 Using Alhydrogel and Dipeptide-Based Hydrogels. Vaccines (Basel) 2021; 9:vaccines9070782. [PMID: 34358198 PMCID: PMC8310097 DOI: 10.3390/vaccines9070782] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/23/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
A fusion chimeric vaccine comprising multiple protective domains of different blood-stage Plasmodium falciparum antigens is perhaps necessary for widening the protective immune responses and reducing the morbidity caused by the disease. Here we continue to build upon the prior work of developing a recombinant fusion chimera protein, His-tagged PfMSP-Fu24, by producing it as a tag-free recombinant protein. In this study, tag-free recombinant PfMSPFu24 (rFu24) was expressed in Escherichia coli, and the soluble protein was purified using a three-step purification involving ammonium sulphate precipitation followed by 2-step ion exchange chromatography procedures and shown that it was highly immunogenic with the human-compatible adjuvant Alhydrogel. We further investigated two dipeptides, phenylalanine-α, β-dehydrophenylalanine (FΔF) and Leucine-α, β-dehydrophenylalanine (LΔF) based hydrogels as effective delivery platforms for rFu24. These dipeptides self-assembled spontaneously to form a highly stable hydrogel under physiological conditions. rFu24 was efficiently entrapped in both the F∆F and L∆F hydrogels, and the three-dimensional (3D) mesh-like structures of the hydrogels remained intact after the entrapment of the antigen. The two hydrogels significantly stimulated rFu24-specific antibody titers, and the sera from the immunized mice showed an invasion inhibitory activity comparable to that of Alhydrogel. Easily synthesized dipeptide hydrogels can be used as an effective antigen delivery platform to induce immune responses.
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15
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Raissi V, Etemadi S, Getso MI, Mehravaran A, Raiesi O. Structure-genetic diversity and recombinant protein of circumsporozoite protein (CSP) of vivax malaria antigen: A potential malaria vaccine candidate. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Zhang R, Dong X, Wang J, Guo Y, Dai Y. A protocol for systematic review and meta-analysis of optimizing treatment for malaria. Medicine (Baltimore) 2020; 99:e22044. [PMID: 32899064 PMCID: PMC7478701 DOI: 10.1097/md.0000000000022044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 08/04/2020] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Malaria remains a global health threat for centuries. In recent years, a rising resistance of Plasmodium falciparum to current standard artemisinin-based combination therapies (ACTs) leads to increasing treatment failures and requires for optimized treatment. Here, we intend to make a systematic review and meta-analysis of optimizing treatment for malaria, so as to find a potential optimal treatment. METHODS We will search electronic databases: the Cochrane Infectious Diseases Group (CIDG) Specialized Register, the Cochrane Central Register of Controlled Trials (CEN-TRAL), PubMed, Embase, Web of Science from their inception to 1 July, 2020. We will also search International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov, and contact with authors when necessary. Two authors will independently collect and select data, and the statistical analyses will be conducted by Revman V.5.3 software. RESULTS We will evaluate efficacy and safety of modified ACTs for uncomplicate malaria, comparing with standard ACTs in all eligible clinical studies. CONCLUSION In this study, we will offer clinical evidence for optimizing treatment for malaria. REGISTRATION NUMBER INPLASY202070115.
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17
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Opuni KFM, Koy C, Russ M, Reepmeyer M, Danquah BD, Weresow M, Alef A, Lorenz P, Thiesen HJ, Glocker MO. ITEM-THREE analysis of a monoclonal anti-malaria antibody reveals its assembled epitope on the pfMSP1 19 antigen. J Biol Chem 2020; 295:14987-14997. [PMID: 32848020 DOI: 10.1074/jbc.ra120.014802] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/18/2020] [Indexed: 11/06/2022] Open
Abstract
Rapid diagnostic tests are first-line assays for diagnosing infectious diseases, such as malaria. To minimize false positive and false negative test results in population-screening assays, high-quality reagents and well-characterized antigens and antibodies are needed. An important property of antigen-antibody binding is recognition specificity, which best can be estimated by mapping an antibody's epitope on the respective antigen. We have cloned a malarial antigen-containing fusion protein, MBP-pfMSP119, in Escherichia coli, which then was structurally and functionally characterized before and after high pressure-assisted enzymatic digestion. We then used our previously developed method, intact transition epitope mapping-targeted high-energy rupture of extracted epitopes (ITEM-THREE), to map the area on the MBP-pfMSP119 antigen surface that is recognized by the anti-pfMSP119 antibody G17.12. We identified three epitope-carrying peptides, 386GRNISQHQCVKKQCPQNSGCFRHLDE411, 386GRNISQHQCVKKQCPQNSGCFRHLDEREE414, and 415CKCLLNYKQE424, from the GluC-derived peptide mixture. These peptides belong to an assembled (conformational) epitope on the MBP-pfMSP119 antigen whose identification was substantiated by positive and negative control experiments. In conclusion, our data help to establish a workflow to obtain high-quality control data for diagnostic assays, including the use of ITEM-THREE as a powerful analytical tool. Data are available via ProteomeXchange: PXD019717.
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Affiliation(s)
- Kwabena F M Opuni
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany; Department of Pharmaceutical Chemistry, School of Pharmacy, College of Health, University of Ghana, Legon, Ghana
| | - Cornelia Koy
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany
| | - Manuela Russ
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany
| | - Maren Reepmeyer
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany
| | - Bright D Danquah
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany
| | | | | | - Peter Lorenz
- Institute for Immunology, University Medicine Rostock, Rostock, Germany
| | | | - Michael O Glocker
- Proteome Center Rostock, University Medicine Rostock and University of Rostock, Rostock, Germany.
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18
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Skwarczynski M, Chandrudu S, Rigau-Planella B, Islam MT, Cheong YS, Liu G, Wang X, Toth I, Hussein WM. Progress in the Development of Subunit Vaccines against Malaria. Vaccines (Basel) 2020; 8:vaccines8030373. [PMID: 32664421 PMCID: PMC7563759 DOI: 10.3390/vaccines8030373] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 12/02/2022] Open
Abstract
Malaria is a life-threatening disease and one of the main causes of morbidity and mortality in the human population. The disease also results in a major socio-economic burden. The rapid spread of malaria epidemics in developing countries is exacerbated by the rise in drug-resistant parasites and insecticide-resistant mosquitoes. At present, malaria research is focused mainly on the development of drugs with increased therapeutic effects against Plasmodium parasites. However, a vaccine against the disease is preferable over treatment to achieve long-term control. Trials to develop a safe and effective immunization protocol for the control of malaria have been occurring for decades, and continue on today; still, no effective vaccines are available on the market. Recently, peptide-based vaccines have become an attractive alternative approach. These vaccines utilize short protein fragments to induce immune responses against malaria parasites. Peptide-based vaccines are safer than traditional vaccines, relatively inexpensive to produce, and can be composed of multiple T- and B-cell epitopes integrated into one antigenic formulation. Various combinations, based on antigen choice, peptide epitope modification and delivery mechanism, have resulted in numerous potential malaria vaccines candidates; these are presently being studied in both preclinical and clinical trials. This review describes the current landscape of peptide-based vaccines, and addresses obstacles and opportunities in the production of malaria vaccines.
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Affiliation(s)
- Mariusz Skwarczynski
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Saranya Chandrudu
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Berta Rigau-Planella
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Md. Tanjir Islam
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Yee S. Cheong
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Genan Liu
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
| | - Xiumin Wang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Woolloongabba, QLD 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
- Correspondence: (I.T.); (W.M.H.)
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia; (M.S.); (S.C.); (B.R.-P.); (M.T.I.); (Y.S.C.); (G.L.); (X.W.)
- Correspondence: (I.T.); (W.M.H.)
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19
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Hou N, Jiang N, Ma Y, Zou Y, Piao X, Liu S, Chen Q. Low-Complexity Repetitive Epitopes of Plasmodium falciparum Are Decoys for Humoural Immune Responses. Front Immunol 2020; 11:610. [PMID: 32351503 PMCID: PMC7174639 DOI: 10.3389/fimmu.2020.00610] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/17/2020] [Indexed: 01/18/2023] Open
Abstract
Induction of humoural immunity is critical for clinical protection against malaria. More than 100 malaria vaccine candidates have been investigated at different developmental stages, but with limited protection. One of the roadblocks constrains the development of malaria vaccines is the poor immunogenicity of the antigens. The objective of this study was to map the linear B-cell epitopes of the Plasmodium falciparum erythrocyte invasion-associated antigens with a purpose of understanding humoural responses and protection. We conducted a large-scale screen using overlapping peptide microarrays of 37 proteins from the P. falciparum parasite, most of which are invasion-associated antigens which have been tested in clinical settings as vaccine candidates, with sera from individuals with various infection episodes. Analysis of the epitome of the antigens revealed that the most immunogenic epitopes were predominantly located in the low-complexity regions of the proteins containing repetitive and/or glutamate-rich motifs in different sequence contexts. However, in vitro assay showed the antibodies specific for these epitopes did not show invasion inhibitory effect. These discoveries indicated that the low-complexity regions of the parasite proteins might drive immune responses away from functional domains, which may be an instructive finding for the rational design of vaccine candidates.
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Affiliation(s)
- Nan Hou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
| | - Yu Ma
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yang Zou
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xianyu Piao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shuai Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qijun Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
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20
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Alegana VA, Khazenzi C, Akech SO, Snow RW. Estimating hospital catchments from in-patient admission records: a spatial statistical approach applied to malaria. Sci Rep 2020; 10:1324. [PMID: 31992809 PMCID: PMC6987150 DOI: 10.1038/s41598-020-58284-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/07/2020] [Indexed: 01/20/2023] Open
Abstract
Admission records are seldom used in sub-Saharan Africa to delineate hospital catchments for the spatial description of hospitalised disease events. We set out to investigate spatial hospital accessibility for severe malarial anaemia (SMA) and cerebral malaria (CM). Malaria admissions for children between 1 month and 14 years old were identified from prospective clinical surveillance data recorded routinely at four referral hospitals covering two complete years between December 2015 to November 2016 and November 2017 to October 2018. These were linked to census enumeration areas (EAs) with an age-structured population. A novel mathematical-statistical framework that included EAs with zero observations was used to predict hospital catchment for malaria admissions adjusting for spatial distance. From 5766 malaria admissions, 5486 (95.14%) were linked to specific EA address, of which 272 (5%) were classified as cerebral malaria while 1001 (10%) were severe malaria anaemia. Further, results suggest a marked geographic catchment of malaria admission around the four sentinel hospitals although the extent varied. The relative rate-ratio of hospitalisation was highest at <1-hour travel time for SMA and CM although this was lower outside the predicted hospital catchments. Delineation of catchments is important for planning emergency care delivery and in the use of hospital data to define epidemiological disease burdens. Further hospital and community-based studies on treatment-seeking pathways to hospitals for severe disease would improve our understanding of catchments.
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Affiliation(s)
- Victor A Alegana
- Kenya Medical Research Institute - Wellcome Trust Research Programme, P.O. Box, 43640-00100, Nairobi, Kenya.
- Geography and Environmental Science, University of Southampton, SO17 1BJ, Southampton, UK.
- Faculty of Science and Technology, Lancaster University, LA1 4YR, Lancaster, UK.
| | - Cynthia Khazenzi
- Kenya Medical Research Institute - Wellcome Trust Research Programme, P.O. Box, 43640-00100, Nairobi, Kenya
| | - Samuel O Akech
- Kenya Medical Research Institute - Wellcome Trust Research Programme, P.O. Box, 43640-00100, Nairobi, Kenya
| | - Robert W Snow
- Kenya Medical Research Institute - Wellcome Trust Research Programme, P.O. Box, 43640-00100, Nairobi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, OX3 7LJ, Oxford, UK
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21
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Winer B, Edgel KA, Zou X, Sellau J, Hadiwidjojo S, Garver LS, McDonough CE, Kelleher NL, Thomas PM, Villasante E, Ploss A, Gerbasi VR. Identification of Plasmodium falciparum proteoforms from liver stage models. Malar J 2020; 19:10. [PMID: 31910830 PMCID: PMC6947969 DOI: 10.1186/s12936-019-3093-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 12/26/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immunization with attenuated malaria sporozoites protects humans from experimental malaria challenge by mosquito bite. Protection in humans is strongly correlated with the production of T cells targeting a heterogeneous population of pre-erythrocyte antigen proteoforms, including liver stage antigens. Currently, few T cell epitopes derived from Plasmodium falciparum, the major aetiologic agent of malaria in humans are known. METHODS In this study both in vitro and in vivo malaria liver stage models were used to sequence host and pathogen proteoforms. Proteoforms from these diverse models were subjected to mild acid elution (of soluble forms), multi-dimensional fractionation, tandem mass spectrometry, and top-down bioinformatics analysis to identify proteoforms in their intact state. RESULTS These results identify a group of host and malaria liver stage proteoforms that meet a 5% false discovery rate threshold. CONCLUSIONS This work provides proof-of-concept for the validity of this mass spectrometry/bioinformatic approach for future studies seeking to reveal malaria liver stage antigens towards vaccine development.
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Affiliation(s)
- Benjamin Winer
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ, 08544, USA
| | - Kimberly A Edgel
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Xiaoyan Zou
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA.,The Henry M Jackson Foundation, 6720A Rockledge Dr., Rockville, MD, 20817, USA
| | - Julie Sellau
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ, 08544, USA.,Department of Molecular Biology and Immunology, Molecular Infection Immunology, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359, Hamburg, Germany
| | - Sri Hadiwidjojo
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA.,The Henry M Jackson Foundation, 6720A Rockledge Dr., Rockville, MD, 20817, USA
| | - Lindsey S Garver
- Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20190, USA
| | | | - Neil L Kelleher
- Northwestern University National Resource for Translational Proteomics, Evanston, IL, 60208, USA
| | - Paul M Thomas
- Northwestern University National Resource for Translational Proteomics, Evanston, IL, 60208, USA
| | - Eileen Villasante
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ, 08544, USA.
| | - Vincent R Gerbasi
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA. .,Northwestern University National Resource for Translational Proteomics, Evanston, IL, 60208, USA.
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22
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Hu Y, Wang L, Mbenda HGN, Soe MT, Yu C, Feng H, Kyaw MP, Cui L, Zhu X, Cao Y. Genetic diversity, natural selection and haplotype grouping of Plasmodium vivax Duffy-binding protein genes from eastern and western Myanmar borders. Parasit Vectors 2019; 12:546. [PMID: 31747970 PMCID: PMC6864963 DOI: 10.1186/s13071-019-3803-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/12/2019] [Indexed: 12/17/2022] Open
Abstract
Background Merozoite proteins of the malaria parasites involved in the invasion of red blood cells are selected by host immunity and their diversity is greatly influenced by changes in malaria epidemiology. In the Greater Mekong Subregion (GMS), malaria transmission is concentrated along the international borders and there have been major changes in malaria epidemiology with Plasmodium vivax becoming the dominant species in many regions. Here, we aimed to evaluate the genetic diversity of P. vivax Duffy-binding protein gene domain II (pvdbp-II) in isolates from the eastern and western borders of Myanmar, and compared it with that from global P. vivax populations. Methods pvdbp-II sequences were obtained from 85 and 82 clinical P. vivax isolates from the eastern and western Myanmar borders, respectively. In addition, 504 pvdbp-II sequences from nine P. vivax populations of the world were retrieved from GenBank and used for comparative analysis of genetic diversity, recombination and population structure of the parasite population. Results The nucleotide diversity of the pvdbp-II sequences from the Myanmar border parasite isolates was not uniform, with the highest diversity located between nucleotides 1078 and 1332. Western Myanmar isolates had a unique R391C mutation. Evidence of positive natural selection was detected in pvdbp-II gene in P. vivax isolates from the eastern Myanmar area. P. vivax parasite populations in the GMS, including those from the eastern, western, and central Myanmar as well as Thailand showed low-level genetic differentiation (FST, 0.000–0.099). Population genetic structure analysis of the pvdbp-II sequences showed a division of the GMS populations into four genetic clusters. A total of 60 PvDBP-II haplotypes were identified in 210 sequences from the GMS populations. Among the epitopes in PvDBP-II, high genetic diversity was found in epitopes 45 (379-SIFGT(D/G)(E/K)(K/N)AQQ(R/H)(R/C)KQ-393, π = 0.029) and Ia (416-G(N/K)F(I/M)WICK(L/I)-424], Ib [482-KSYD(Q/E)WITR-490, π = 0.028) in P. vivax populations from the eastern and western borders of Myanmar. Conclusions The pvdbp-II gene is genetically diverse in the eastern and western Myanmar border P. vivax populations. Positive natural selection and recombination occurred in pvdbp-II gene. Low-level genetic differentiation was identified, suggesting extensive gene flow of the P. vivax populations in the GMS. These results can help understand the evolution of the P. vivax populations in the course of regional malaria elimination and guide the design of PvDBP-II-based vaccine.![]()
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Affiliation(s)
- Yubing Hu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Lin Wang
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Huguette Gaelle Ngassa Mbenda
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Chunyun Yu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Hui Feng
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | | | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
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23
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Prospects for Malaria Vaccines: Pre-Erythrocytic Stages, Blood Stages, and Transmission-Blocking Stages. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9751471. [PMID: 31687404 PMCID: PMC6794966 DOI: 10.1155/2019/9751471] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 08/06/2019] [Accepted: 09/09/2019] [Indexed: 12/18/2022]
Abstract
Malaria is a disease of public health importance in many parts of the world. Currently, there is no effective way to eradicate malaria, so developing safe, efficient, and cost-effective vaccines against this disease remains an important goal. Current research on malaria vaccines is focused on developing vaccines against pre-erythrocytic stage parasites and blood-stage parasites or on developing a transmission-blocking vaccine. Here, we briefly describe the progress made towards a vaccine against Plasmodium falciparum, the most pathogenic of the malaria parasite species to infect humans.
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24
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Strašek N, Lavrenčič L, Oštrek A, Slapšak D, Grošelj U, Klemenčič M, Brodnik Žugelj H, Wagger J, Novinec M, Svete J. Tetrahydro-1H,5H-pyrazolo[1,2-a]pyrazole-1-carboxylates as inhibitors of Plasmodium falciparum dihydroorotate dehydrogenase. Bioorg Chem 2019; 89:102982. [PMID: 31132601 DOI: 10.1016/j.bioorg.2019.102982] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/29/2019] [Accepted: 05/08/2019] [Indexed: 11/25/2022]
Abstract
The reactions between 5-substituted pyrazolidine-3-ones, aldehydes, and methyl methacrylate provided tetrahydropyrazolo[1,2-a]pyrazole-1-carboxylates as mixtures of syn- and anti-diastereomers. Testing for inhibition of dihydroorotate dehydrogenase of Plasmodium falciparum (PfDHODH) revealed high activity of some anti-isomers of the methyl esters, while the corresponding carboxylic acids and carboxamides were not active. The most active representative, methyl (1S*,3S*,5R*)-1,5-dimethyl-7-oxo-3-phenyltetrahydro-1H,5H-pyrazolo[1,2-a]pyrazole-1-carboxylate (IC50 = 2.9 ± 0.3 μM), also exhibited very high selectivity of the parasite enzyme vs. the human enzyme, PfDHODH/HsDHODH > 350. According to the molecular docking score, this high activity is explainable by synergic interactions of the methyl, phenyl and the CO2Me substituent with the hydrophobic pockets in the active site of the enzyme. The carboxylic acid and carboxamides derived from this compound did not inhibit PfDHODH.
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Affiliation(s)
- Nika Strašek
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Lara Lavrenčič
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Andraž Oštrek
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Dejan Slapšak
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Uroš Grošelj
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Marina Klemenčič
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Helena Brodnik Žugelj
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Jernej Wagger
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia
| | - Marko Novinec
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia.
| | - Jurij Svete
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000 Ljubljana, Slovenia.
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25
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Noon JB, Schwarz EM, Ostroff GR, Aroian RV. A highly expressed intestinal cysteine protease of Ancylostoma ceylanicum protects vaccinated hamsters from hookworm infection. PLoS Negl Trop Dis 2019; 13:e0007345. [PMID: 31009474 PMCID: PMC6497320 DOI: 10.1371/journal.pntd.0007345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/02/2019] [Accepted: 03/28/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Human hookworms (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) are intestinal blood-feeding parasites that infect ~500 million people worldwide and are among the leading causes of iron-deficiency anemia in the developing world. Drugs are useful against hookworm infections, but hookworms rapidly reinfect people, and the parasites can develop drug resistance. Therefore, having a hookworm vaccine would be of tremendous benefit. METHODOLOGY/PRINCIPAL FINDINGS We investigated the vaccine efficacy in outbred Syrian hamsters of three A. ceylanicum hookworm antigen candidates from two classes of proteins previously identified as promising vaccine candidates. These include two intestinally-enriched, putatively secreted cathepsin B cysteine proteases (AceyCP1, AceyCPL) and one small Kunitz-type protease inhibitor (AceySKPI3). Recombinant proteins were produced in Pichia pastoris, and adsorbed to Alhydrogel. Recombinant AceyCPL (rAceyCPL)/Alhydrogel and rAceySKPI3/Alhydrogel induced high serum immunoglobulin G (IgG) titers in 8/8 vaccinates, but were not protective. rAceyCP1/Alhydrogel induced intermediate serum IgG titers in ~60% of vaccinates in two different trials. rAceyCP1 serum IgG responders had highly significantly decreased hookworm burdens, fecal egg counts and clinical pathology compared to Alhydrogel controls and nonresponders. Protection was highly correlated with rAceyCP1 serum IgG titer. Antisera from rAceyCP1 serum IgG responders, but not nonresponders or rAceyCPL/Alhydrogel vaccinates, significantly reduced adult A. ceylanicum motility in vitro. Furthermore, rAceyCP1 serum IgG responders had canonical Th2-specific recall responses (IL4, IL5, IL13) in splenocytes stimulated ex vivo. CONCLUSIONS/SIGNIFICANCE These findings indicate that rAceyCP1 is a promising vaccine candidate and validates a genomic/transcriptomic approach to human hookworm vaccine discovery.
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Affiliation(s)
- Jason B. Noon
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Erich M. Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Gary R. Ostroff
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Raffi V. Aroian
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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26
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Kurup SP, Anthony SM, Hancox LS, Vijay R, Pewe LL, Moioffer SJ, Sompallae R, Janse CJ, Khan SM, Harty JT. Monocyte-Derived CD11c + Cells Acquire Plasmodium from Hepatocytes to Prime CD8 T Cell Immunity to Liver-Stage Malaria. Cell Host Microbe 2019; 25:565-577.e6. [PMID: 30905437 DOI: 10.1016/j.chom.2019.02.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/04/2018] [Accepted: 02/07/2019] [Indexed: 01/16/2023]
Abstract
Plasmodium sporozoites inoculated by mosquitoes migrate to the liver and infect hepatocytes prior to release of merozoites that initiate symptomatic blood-stage malaria. Plasmodium parasites are thought to be restricted to hepatocytes throughout this obligate liver stage of development, and how liver-stage-expressed antigens prime productive CD8 T cell responses remains unknown. We found that a subset of liver-infiltrating monocyte-derived CD11c+ cells co-expressing F4/80, CD103, CD207, and CSF1R acquired parasites during the liver stage of malaria, but only after initial hepatocyte infection. These CD11c+ cells found in the infected liver and liver-draining lymph nodes exhibited transcriptionally and phenotypically enhanced antigen-presentation functions and primed protective CD8 T cell responses against Plasmodium liver-stage-restricted antigens. Our findings highlight a previously unrecognized aspect of Plasmodium biology and uncover the fundamental mechanism by which CD8 T cell responses are primed against liver-stage malaria antigens.
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Affiliation(s)
- Samarchith P Kurup
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Scott M Anthony
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Lisa S Hancox
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Rahul Vijay
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Lecia L Pewe
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Steven J Moioffer
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA
| | - Ramakrishna Sompallae
- Department of Pathology, University of Iowa, Iowa City, IA 52242, USA; Iowa Institute of Human Genetics, University of Iowa, Iowa City, IA 52242, USA
| | - Chris J Janse
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center (LUMC), 2333ZA Leiden, the Netherlands
| | - Shahid M Khan
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center (LUMC), 2333ZA Leiden, the Netherlands
| | - John T Harty
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA 52242, USA; Department of Pathology, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City, IA 52242, USA.
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27
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Salgado-Mejias P, Alves FL, Françoso KS, Riske KA, Silva ER, Miranda A, Soares IS. Structure of Rhoptry Neck Protein 2 is essential for the interaction in vitro with Apical Membrane Antigen 1 in Plasmodium vivax. Malar J 2019; 18:25. [PMID: 30683104 PMCID: PMC6347818 DOI: 10.1186/s12936-019-2649-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/13/2019] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND In several Apicomplexa, the formation of moving junctions (MJs) at the interface between the external membranes of the invading parasite and the host cell is essential for the process of parasite invasion. In Plasmodium falciparum and Toxoplasma gondii, the MJ is composed of the Apical Membrane Antigen 1 (AMA1) and Rhoptry Neck Proteins (RONs) complex; specifically, AMA1 interacts with RON2 during host cell invasion. METHODS Recombinant proteins based on Plasmodium vivax RON2 (A2033-P2100) and its synthetic peptide fragments, one cyclic and one linear, based on PvRON2 (D2035-T2074) were generated and used to evaluate the interaction with P. vivax AMA1 (PvAMA1) by the far western blot, surface plasmon resonance (SPR), and isothermal titration microcalorimetry (ITC) methods. The structural studies of peptides were performed by circular dichroism, and the structural analysis of the complex of PvAMA1 with peptides based on PvRON2 (D2035-T2074) was conducted with small-angle X-ray scattering (SAXS). RESULTS Surface plasmon resonance (KD = 23.91 ± 2.078 μmol/L) and ITC (K = 3 × 105 mol/L) studies conclusively showed an interaction between the cyclic peptide based on PvRON2 and PvAMA1-His6. In contrast, the linear peptide and recombinant PvRON2 (GST fusion protein) did not show an interaction with PvAMA1. However, the interaction among recombinant proteins PvRON2.2 and PvAMA1-His6 was possible to show by far western blot. CONCLUSIONS The results show that the PvRON2 structure, particularly the S-S bond between C2051 and C2063, is determinant for the existence of the interaction between PvAMA1 and PvRON2.
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Affiliation(s)
- Perla Salgado-Mejias
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil.,Department of Chemical Sciences and Natural Resources, Faculty of Engineering and Science, University of La Frontera, Temuco, Chile
| | - Flavio L Alves
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Kátia S Françoso
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Karin A Riske
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Emerson R Silva
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Antonio Miranda
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Irene S Soares
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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28
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Tan J, Piccoli L, Lanzavecchia A. The Antibody Response to Plasmodium falciparum: Cues for Vaccine Design and the Discovery of Receptor-Based Antibodies. Annu Rev Immunol 2018; 37:225-246. [PMID: 30566366 DOI: 10.1146/annurev-immunol-042617-053301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plasmodium falciparum remains a serious public health problem and a continuous challenge for the immune system due to the complexity and diversity of the pathogen. Recent advances from several laboratories in the characterization of the antibody response to the parasite have led to the identification of critical targets for protection and revealed a new mechanism of diversification based on the insertion of host receptors into immunoglobulin genes, leading to the production of receptor-based antibodies. These advances have opened new possibilities for vaccine design and passive antibody therapies to provide sterilizing immunity and control blood-stage parasites.
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Affiliation(s)
- Joshua Tan
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom.,Current affiliation: National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852, USA
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland;
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,VIR Biotechnology, San Francisco, California 94158, USA
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29
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Faleiro R, Karunarathne DS, Horne-Debets JM, Wykes M. The Contribution of Co-signaling Pathways to Anti-malarial T Cell Immunity. Front Immunol 2018; 9:2926. [PMID: 30631323 PMCID: PMC6315188 DOI: 10.3389/fimmu.2018.02926] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/29/2018] [Indexed: 12/30/2022] Open
Abstract
Plasmodium spp., the causative agent of malaria, caused 212 million infections in 2016 with 445,000 deaths, mostly in children. Adults acquire enough immunity to prevent clinical symptoms but never develop sterile immunity. The only vaccine for malaria, RTS,S, shows promising protection of a limited duration against clinical malaria in infants but no significant protection against severe disease. There is now abundant evidence that T cell functions are inhibited during malaria, which may explain why vaccine are not efficacious. Studies have now clearly shown that T cell immunity against malaria is subdued by multiple the immune regulatory receptors, in particular, by programmed cell-death-1 (PD-1). Given there is an urgent need for an efficacious malarial treatment, compounded with growing drug resistance, a better understanding of malarial immunity is essential. This review will examine molecular signals that affect T cell-mediated immunity against malaria.
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Affiliation(s)
- Rebecca Faleiro
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | | | | | - Michelle Wykes
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
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30
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Dutta S, Tewari A, Balaji C, Verma R, Moitra A, Yadav M, Agrawal P, Sahal D, Jarori GK. Strain-transcending neutralization of malaria parasite by antibodies against Plasmodium falciparum enolase. Malar J 2018; 17:304. [PMID: 30126436 PMCID: PMC6102825 DOI: 10.1186/s12936-018-2455-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/13/2018] [Indexed: 11/17/2022] Open
Abstract
Background Plasmodium enolase is a target for the growth neutralizing antibodies. Interestingly, the three invasive stages i.e. sporozoites, merozoites, and ookinetes express this protein on their cell surface. Polyclonal anti-Plasmodium falciparum enolase (Pfeno) antibodies disrupt traversal of ookinete through mosquito mid-gut wall as well as have inhibitory effect on parasite growth at erythrocytic stage. In a recent study, it was observed that immunization with a unique epitope of parasite enolase (EWGWS) could confer partial protection against mouse malaria. Further validation is needed for the protective potential of this unique epitope in otherwise highly conserved enolase. Methods In order to investigate the efficacy of growth inhibitory potential of the epitope of P falciparum enolase, a monoclonal antibody specific to EWGWS is generated. In vitro parasite growth inhibition assays and passive immunization of Plasmodium yoelii (or Plasmodium berghei) infected mice were used to assess the parasite growth neutralizing activity of the antibody. Results Screening a panel of monoclonal antibodies raised against recombinant Pfeno that were specific to EWGWS resulted in isolation of H12E1. This antibody recognized only EWGWS epitope containing enolases. H12E1 strongly inhibited parasite growth in culture. This inhibition was strain transcending. Passive infusion of this antibody in P. yoelii or P. berghei infected mice showed significant reduction in parasitemia as compared to controls (p < 0.001). Surface Plasmon Resonance measurements indicated high affinity binding of H12E1 to P. falciparum enolase (KD ~ 7.6 × 10−9M). Conclusions A monoclonal antibody directed against EWGWS epitope of Pfeno was shown to inhibit the growth of blood stage malarial parasites. This inhibition was species/strain transcending and is likely to arise due to blockade of enolase on the surface of merozoites, functionally implicating Pfeno in invasion related events. Presence of enolase on the cell surface of merozoites and ookinetes could potentially result in inhibition of host cell invasions at erythrocytic and transmission stages in the parasite life cycle. It is suggested that antibodies against EWGWS epitope have the potential to confer dual stage, species and strain transcending protection against malaria. Electronic supplementary material The online version of this article (10.1186/s12936-018-2455-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sneha Dutta
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India.,Department of Genetics and Complex Diseases, Harvard T. H. Chan School of Public Health, Graduate School of Arts and Sciences, Harvard University, Boston, USA
| | - Aneesha Tewari
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India.,Department of Biology, Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology (MIT), Boston, USA
| | - Chinthapalli Balaji
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India
| | - Reena Verma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India
| | - Anasuya Moitra
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India
| | - Mamta Yadav
- International Center for Genetic Engineering and Biotechnology, Aruna Asif Ali Marg, New Delhi, India
| | - Prakhar Agrawal
- International Center for Genetic Engineering and Biotechnology, Aruna Asif Ali Marg, New Delhi, India
| | - Dinkar Sahal
- International Center for Genetic Engineering and Biotechnology, Aruna Asif Ali Marg, New Delhi, India
| | - Gotam K Jarori
- Department of Biological Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, India.
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Bermúdez M, Moreno-Pérez DA, Arévalo-Pinzón G, Curtidor H, Patarroyo MA. Plasmodium vivax in vitro continuous culture: the spoke in the wheel. Malar J 2018; 17:301. [PMID: 30126427 PMCID: PMC6102941 DOI: 10.1186/s12936-018-2456-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/13/2018] [Indexed: 01/01/2023] Open
Abstract
Understanding the life cycle of Plasmodium vivax is fundamental for developing strategies aimed at controlling and eliminating this parasitic species. Although advances in omic sciences and high-throughput techniques in recent years have enabled the identification and characterization of proteins which might be participating in P. vivax invasion of target cells, exclusive parasite tropism for invading reticulocytes has become the main obstacle in maintaining a continuous culture for this species. Such advance that would help in defining each parasite protein’s function in the complex process of P. vivax invasion, in addition to evaluating new therapeutic agents, is still a dream. Advances related to maintenance, culture medium supplements and the use of different sources of reticulocytes and parasites (strains and isolates) have been made regarding the development of an in vitro culture for P. vivax; however, only some cultures having few replication cycles have been obtained to date, meaning that this parasite’s maintenance goes beyond the technical components involved. Although it is still not yet clear which molecular mechanisms P. vivax prefers for invading young CD71+ reticulocytes [early maturation stages (I–II–III)], changes related to membrane proteins remodelling of such cells could form part of the explanation. The most relevant aspects regarding P. vivax in vitro culture and host cell characteristics have been analysed in this review to explain possible reasons why the species’ continuous in vitro culture is so difficult to standardize. Some alternatives for P. vivax in vitro culture have also been described.
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Affiliation(s)
- Maritza Bermúdez
- Receptor-ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia
| | - Darwin Andrés Moreno-Pérez
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia.,Livestock Sciences Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Calle 222 No. 55-37, Bogotá, DC, Colombia
| | - Gabriela Arévalo-Pinzón
- Receptor-ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia
| | - Hernando Curtidor
- Receptor-ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia.,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 No. 63C-69, Bogotá, DC, Colombia
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 No. 26-20, Bogotá, Colombia. .,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Carrera 24 No. 63C-69, Bogotá, DC, Colombia.
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32
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Shankar EM, Vignesh R, Dash AP. Recent advances on T-cell exhaustion in malaria infection. Med Microbiol Immunol 2018; 207:167-174. [PMID: 29936565 DOI: 10.1007/s00430-018-0547-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
Abstract
T-cell exhaustion reportedly leads to dysfunctional immune responses of antigen-specific T cells. Investigations have revealed that T cells expand into functionally defective phenotypes with poor recall/memory abilities to parasitic antigens. The exploitation of co-inhibitory pathways represent a highly viable area of translational research that has very well been utilized against certain cancerous conditions. Malaria, at times, evolve into a sustained chronic state where T cells express several co-inhibitory molecules (negative immune checkpoints) facilitating parasite escape and sub-optimal protective responses. Experimental evidence suggests that blockade of co-inhibitory molecules on T cells in malaria could result in the sustenance of protective responses together with dramatic parasite clearance. The role of several co-inhibitory molecules in malaria infection largely remain unclear, and here we discussed the potential applicability of co-inhibitory molecules in the management of malaria with a view to harness protective host responses against chronic disease and associated consequences.
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Affiliation(s)
- Esaki M Shankar
- Division of Infection Biology and Medical Microbiology, Department of Life Sciences (DLS), School of Basic and Applied Sciences, Central University of Tamil Nadu (CUTN), Thiruvarur, Tamilnadu, 610 005, India.
| | - R Vignesh
- Laboratory-Based Department, Universiti Kuala Lumpur Royal College of Medicine Perak (UniKL-RCMP), Ipoh, Malaysia
| | - A P Dash
- Central University of Tamil Nadu (CUTN), Thiruvarur, Tamilnadu, 610 005, India
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Bhurani V, Mohankrishnan A, Morrot A, Dalai SK. Developing effective vaccines: Cues from natural infection. Int Rev Immunol 2018; 37:249-265. [PMID: 29927676 DOI: 10.1080/08830185.2018.1471479] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ultimate goal of any vaccine is to generate a heterogeneous and stable pool of memory lymphocytes. Vaccine are designed with the hope to generate antigen specific long-lived T cell responses, as it may be the case in natural infection; however, inducing such response by sub-unit vaccine has been a challenge. Although significant progress has been made, there is lot of scope for designing novel vaccine strategies by taking cues from the natural infection. This review focuses upon the roadblocks and the possible ways to overcome them leading to developing effective vaccines. Here we propose that mimicking the natural course of infection as well as the inclusion of non-target antigens in vaccine formulations might generate heterogeneous pool of memory T cells to ensure long-lived protection.
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Affiliation(s)
- Vishakha Bhurani
- a Institute of Science , Nirma University , Ahmedabad , Gujarat , India
| | | | - Alexandre Morrot
- b Faculdade de Medicina , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,c Instituto Oswaldo Cruz , Fiocruz , Rio de Janeiro , Brazil
| | - Sarat Kumar Dalai
- a Institute of Science , Nirma University , Ahmedabad , Gujarat , India
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Sherrard-Smith E, Sala KA, Betancourt M, Upton LM, Angrisano F, Morin MJ, Ghani AC, Churcher TS, Blagborough AM. Synergy in anti-malarial pre-erythrocytic and transmission-blocking antibodies is achieved by reducing parasite density. eLife 2018; 7:35213. [PMID: 29914622 PMCID: PMC6008048 DOI: 10.7554/elife.35213] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/18/2018] [Indexed: 01/05/2023] Open
Abstract
Anti-malarial pre-erythrocytic vaccines (PEV) target transmission by inhibiting human infection but are currently partially protective. It has been posited, but never demonstrated, that co-administering transmission-blocking vaccines (TBV) would enhance malaria control. We hypothesized a mechanism that TBV could reduce parasite density in the mosquito salivary glands, thereby enhancing PEV efficacy. This was tested using a multigenerational population assay, passaging Plasmodium berghei to Anopheles stephensi mosquitoes. A combined efficacy of 90.8% (86.7-94.2%) was observed in the PEV +TBV antibody group, higher than the estimated efficacy of 83.3% (95% CrI 79.1-87.0%) if the two antibodies acted independently. Higher PEV efficacy at lower mosquito parasite loads was observed, comprising the first direct evidence that co-administering anti-sporozoite and anti-transmission interventions act synergistically, enhancing PEV efficacy across a range of TBV doses and transmission intensities. Combining partially effective vaccines of differing anti-parasitic classes is a pragmatic, powerful way to accelerate malaria elimination efforts.
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Affiliation(s)
- Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Leanna M Upton
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Fiona Angrisano
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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Nlinwe ON, Kusi KA, Adu B, Sedegah M. T-cell responses against Malaria: Effect of parasite antigen diversity and relevance for vaccine development. Vaccine 2018; 36:2237-2242. [PMID: 29573877 DOI: 10.1016/j.vaccine.2018.03.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 01/21/2018] [Accepted: 03/07/2018] [Indexed: 11/24/2022]
Abstract
The on-going agenda for global malaria elimination will require the development of additional disease control and prevention measures since currently available tools are showing signs of inadequacy. Malaria vaccines are seen as one such important addition to the control arsenal since vaccines have proven to be highly effective public health tools against important human diseases. Both cell-mediated and antibody responses are generally believed to be important for malaria parasite control, although the exact targets of T and B cell responses against malaria have not been clearly defined. However, our current understanding of the immune response to malaria suggests that T cell responses against multiple antigenic targets may potentially be key for the development of a highly efficacious malaria vaccine. This review takes a comprehensive look at the available literature on T cell-mediated immunity against all human stages of the malaria parasite and the effect of antigen diversity on these responses. The implications of these interrelationships for the development of an effective vaccine for malaria are also highlighted.
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Affiliation(s)
- Omarine Nfor Nlinwe
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana.
| | - Kwadwo Asamoah Kusi
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana.
| | - Bright Adu
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Legon, Accra, Ghana.
| | - Martha Sedegah
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 209 l0-7500, USA.
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Effect of tamoxifen on the sphingolipid biosynthetic pathway in the different intraerythrocytic stages of the apicomplexa Plasmodium falciparum. Biochem Biophys Res Commun 2018; 497:1082-1088. [PMID: 29496449 DOI: 10.1016/j.bbrc.2018.02.183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 11/21/2022]
Abstract
Parasites of the genus Plasmodium responsible for Malaria are obligate intracellular pathogens residing in mammalian red blood cells, hepatocytes, or mosquito midgut epithelial cells. Regarding that detailed knowledge on the sphingolipid biosynthetic pathway of the apicomplexan protozoan parasites is scarce, different stages of Plasmodium falciparum were treated with tamoxifen in order to evaluate the effects of this drug on the glycosphingolipid biosynthesis. Thin layer chromatography, High performance reverse phase chromatography and UV-MALDI-TOF mass spectrometry were the tools used for the analysis. In the ring forms, the increase of NBD-phosphatidyl inositol biosynthesis was notorious but differences at NBD-GlcCer levels were undetectable. In trophozoite forms, an abrupt decrease of NBD-acylated GlcDHCer and NBD-GlcDHCer in addition to an increase of NBD-PC biosynthesis was observed. On the contrary, in schizonts, tamoxifen seems not to be producing substantial changes in lipid biosynthesis. Our findings indicate that in this parasite, tamoxifen is exerting an inhibitory action on Glucosylceramidesynthase and sphingomyelin synthase levels. Moreover, regarding that Plasmodium does not biosynthesize inositolphosphoceramides, the accumulation of phosphatidylinositol should indicate an inhibitory action on glycosylinositol phospholipid synthesis.
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Modeling the effect of boost timing in murine irradiated sporozoite prime-boost vaccines. PLoS One 2018; 13:e0190940. [PMID: 29329308 PMCID: PMC5766151 DOI: 10.1371/journal.pone.0190940] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 12/22/2017] [Indexed: 11/29/2022] Open
Abstract
Vaccination with radiation-attenuated sporozoites has been shown to induce CD8+ T cell-mediated protection against pre-erythrocytic stages of malaria. Empirical evidence suggests that successive inoculations often improve the efficacy of this type of vaccines. An initial dose (prime) triggers a specific cellular response, and subsequent inoculations (boost) amplify this response to create a robust CD8+ T cell memory. In this work we propose a model to analyze the effect of T cell dynamics on the performance of prime-boost vaccines. This model suggests that boost doses and timings should be selected according to the T cell response elicited by priming. Specifically, boosting during late stages of clonal contraction would maximize T cell memory production for vaccines using lower doses of irradiated sporozoites. In contrast, single-dose inoculations would be indicated for higher vaccine doses. Experimental data have been obtained that support theoretical predictions of the model.
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Botwe AK, Asante KP, Adjei G, Assafuah S, Dosoo D, Owusu-Agyei S. Dynamics in multiplicity of Plasmodium falciparum infection among children with asymptomatic malaria in central Ghana. BMC Genet 2017; 18:67. [PMID: 28716086 PMCID: PMC5514501 DOI: 10.1186/s12863-017-0536-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Accepted: 07/11/2017] [Indexed: 12/18/2022] Open
Abstract
Background The determinants of malaria parasite virulence is not entirely known, but the outcome of malaria infection (asymptomatic or symptomatic) has been associated with carriage of distinct parasite genotypes. Alleles considered important for erythrocyte invasion and selected as candidate targets for malaria vaccine development are increasingly being shown to have distinct characteristics in infection outcomes. Any unique/distinct patterns or alleles linked to infection outcome should be reproducible for a given malaria-cohort regardless of location, time or intervention. This study compared merozoite surface protein 2 (MSP2) genotypes from children with asymptomatic malaria at same geographical location, from two time periods. Results As the prevalence and incidence of malaria (measured for other studies) significantly reduced between 2004 (time point one) and 2009 (time point two), MSP2 multiplicity of infections (MOI) also reduced significantly from 2.3 at time point (TP) one to 1.9 at TP two. IC/3D7 genotypes out-numbered FC27 genotypes at both time points. At TP2 however, FC27 allele diversity was more than the IC/3D7 allele diversity. A decrease in the IC/3D7:FC27 genotype proportions from 2:1 at TP1 to 1:1 at TP2, seemed to be driven mainly by a decrease in carriage of IC/3D7 alleles. MOI was higher in the dry season than in the subsequent wet season, but the decrease was not significant at TP2. Conclusion MSP2 MOI was higher in the dry season than in the subsequent wet season, while the carriage of IC/3D7 alleles decreased over this time period. It may be that decreases in transmission are related specifically to the IC/3D7 allelic family. The influence of transmission on MSP2 allele diversity needs to be clearly deciphered in studies which should include the use of sensitive methods for the detection of polymorphic parasite markers for both symptomatic and asymptomatic malaria. Such studies will enable better understanding of associations between allelic variants, MOI, transmission, malaria infection and disease.
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Affiliation(s)
- Akua Kyerewaa Botwe
- Ghana Health Service. Health Research Unit, Kintampo Health Research Centre. MOH/GHS, P.O.Box 200, College of Health Street, Kintampo, Brong Ahafo, Ghana. .,Department of Medicine, Solna, Karolinska Institutet, Stockholm, 17176, Sverige, Sweden.
| | - Kwaku Poku Asante
- Ghana Health Service. Health Research Unit, Kintampo Health Research Centre. MOH/GHS, P.O.Box 200, College of Health Street, Kintampo, Brong Ahafo, Ghana
| | - George Adjei
- Ghana Health Service. Health Research Unit, Kintampo Health Research Centre. MOH/GHS, P.O.Box 200, College of Health Street, Kintampo, Brong Ahafo, Ghana
| | - Samuel Assafuah
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - David Dosoo
- Ghana Health Service. Health Research Unit, Kintampo Health Research Centre. MOH/GHS, P.O.Box 200, College of Health Street, Kintampo, Brong Ahafo, Ghana
| | - Seth Owusu-Agyei
- Ghana Health Service. Health Research Unit, Kintampo Health Research Centre. MOH/GHS, P.O.Box 200, College of Health Street, Kintampo, Brong Ahafo, Ghana
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Identification of Protective B-Cell Epitopes within the Novel Malaria Vaccine Candidate Plasmodium falciparum Schizont Egress Antigen 1. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00068-17. [PMID: 28468980 DOI: 10.1128/cvi.00068-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/16/2017] [Indexed: 02/03/2023]
Abstract
Naturally acquired antibodies to Plasmodium falciparum schizont egress antigen 1 (PfSEA-1A) are associated with protection against severe malaria in children. Vaccination of mice with SEA-1A from Plasmodium berghei (PbSEA-1A) decreases parasitemia and prolongs survival following P. berghei ANKA challenge. To enhance the immunogenicity of PfSEA-1A, we identified five linear B-cell epitopes using peptide microarrays probed with antisera from nonhuman primates vaccinated with recombinant PfSEA-1A (rPfSEA-1A). We evaluated the relationship between epitope-specific antibody levels and protection from parasitemia in a longitudinal treatment-reinfection cohort in western Kenya. Antibodies to three epitopes were associated with 16 to 17% decreased parasitemia over an 18-week high transmission season. We are currently designing immunogens to enhance antibody responses to these three epitopes.
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Jacob D, Ruffie C, Combredet C, Formaglio P, Amino R, Ménard R, Tangy F, Sala M. Yeast lysates carrying the nucleoprotein from measles virus vaccine as a novel subunit vaccine platform to deliver Plasmodium circumsporozoite antigen. Malar J 2017; 16:259. [PMID: 28662722 PMCID: PMC5492716 DOI: 10.1186/s12936-017-1908-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/26/2017] [Indexed: 11/17/2022] Open
Abstract
Background Yeast cells represent an established bioreactor to produce recombinant proteins for subunit vaccine development. In addition, delivery of vaccine antigens directly within heat-inactivated yeast cells is attractive due to the adjuvancy provided by the yeast cell. In this study, Pichia pastoris yeast lysates carrying the nucleoprotein (N) from the measles vaccine virus were evaluated as a novel subunit vaccine platform to deliver the circumsporozoite surface antigen (CS) of Plasmodium. When expressed in Pichia pastoris yeast, the N protein auto-assembles into highly multimeric ribonucleoparticles (RNPs). The CS antigen from Plasmodium berghei (PbCS) was expressed in Pichia pastoris yeast in fusion with N, generating recombinant PbCS-carrying RNPs in the cytoplasm of yeast cells. Results When evaluated in mice after 3–5 weekly subcutaneous injections, yeast lysates containing N-PbCS RNPs elicited strong anti-PbCS humoral responses, which were PbCS-dose dependent and reached a plateau by the pre-challenge time point. Protective efficacy of yeast lysates was dose-dependent, although anti-PbCS antibody titers were not predictive of protection. Multimerization of PbCS on RNPs was essential for providing benefit against infection, as immunization with monomeric PbCS delivered in yeast lysates was not protective. Three weekly injections with N-PbCS yeast lysates in combination with alum adjuvant produced sterile protection in two out of six mice, and significantly reduced parasitaemia in the other individuals from the same group. This parasitaemia decrease was of the same extent as in mice immunized with non-adjuvanted N-PbCS yeast lysates, providing evidence that the yeast lysate formulation did not require accessory adjuvants for eliciting efficient parasitaemia reduction. Conclusions This study demonstrates that yeast lysates are an attractive auto-adjuvant and efficient platform for delivering multimeric PbCS on measles N-based RNPs. By combining yeast lysates that carry RNPs with a large panel of Plasmodium antigens, this technology could be applied to developing a multivalent vaccine against malaria. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1908-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daria Jacob
- Institut Pasteur, Viral Genomics and Vaccination Unit, CNRS, UMR-3965, 28, Rue Du Dr Roux, 75015, Paris, France.
| | - Claude Ruffie
- Institut Pasteur, Viral Genomics and Vaccination Unit, CNRS, UMR-3965, 28, Rue Du Dr Roux, 75015, Paris, France
| | - Chantal Combredet
- Institut Pasteur, Viral Genomics and Vaccination Unit, CNRS, UMR-3965, 28, Rue Du Dr Roux, 75015, Paris, France
| | - Pauline Formaglio
- Institut Pasteur, Malaria Biology and Genetics Unit, 75015, Paris, France.,Institute of Molecular and Clinical Immunology, Otto-von-Guericke University, Magdeburg, Germany
| | - Rogerio Amino
- Institut Pasteur, Malaria Biology and Genetics Unit, 75015, Paris, France
| | - Robert Ménard
- Institut Pasteur, Malaria Biology and Genetics Unit, 75015, Paris, France
| | - Frédéric Tangy
- Institut Pasteur, Viral Genomics and Vaccination Unit, CNRS, UMR-3965, 28, Rue Du Dr Roux, 75015, Paris, France
| | - Monica Sala
- Institut Pasteur, Viral Genomics and Vaccination Unit, CNRS, UMR-3965, 28, Rue Du Dr Roux, 75015, Paris, France
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Ntege EH, Takashima E, Morita M, Nagaoka H, Ishino T, Tsuboi T. Blood-stage malaria vaccines: post-genome strategies for the identification of novel vaccine candidates. Expert Rev Vaccines 2017; 16:769-779. [PMID: 28604122 DOI: 10.1080/14760584.2017.1341317] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION An efficacious malaria vaccine is necessary to advance the current control measures towards malaria elimination. To-date, only RTS,S/AS01, a leading pre-erythrocytic stage vaccine completed phase 3 trials, but with an efficacy of 28-36% in children, and 18-26% in infants, that waned over time. Blood-stage malaria vaccines protect against disease, and are considered effective targets for the logical design of next generation vaccines to improve the RTS,S field efficacy. Therefore, novel blood-stage vaccine candidate discovery efforts are critical, albeit with several challenges including, high polymorphisms in vaccine antigens, poor understanding of targets of naturally protective immunity, and difficulties in the expression of high AT-rich plasmodial proteins. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects of malaria vaccine research and development. We focused on post-genome vaccine candidate discovery, malaria vaccine development, sequence diversity, pre-clinical and clinical trials. Expert commentary: Post-genome high-throughput technologies using wheat germ cell-free protein synthesis technology and immuno-profiling with sera from malaria patients with clearly defined outcomes are highlighted to overcome current challenges of malaria vaccine candidate discovery.
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Affiliation(s)
- Edward H Ntege
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Eizo Takashima
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Masayuki Morita
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Hikaru Nagaoka
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
| | - Tomoko Ishino
- b Division of Molecular Parasitology , Proteo-Science Center, Ehime University , Toon , Ehime , Japan
| | - Takafumi Tsuboi
- a Division of Malaria Research , Proteo-Science Center, Ehime University , Matsuyama , Ehime , Japan
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Virus-Like Particle (VLP) Plus Microcrystalline Tyrosine (MCT) Adjuvants Enhance Vaccine Efficacy Improving T and B Cell Immunogenicity and Protection against Plasmodium berghei/vivax. Vaccines (Basel) 2017; 5:vaccines5020010. [PMID: 28468322 PMCID: PMC5492007 DOI: 10.3390/vaccines5020010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/18/2017] [Accepted: 04/21/2017] [Indexed: 02/01/2023] Open
Abstract
Vaccination is the most effective prophylactic tool against infectious diseases. Despite continued efforts to control malaria, the disease still generally represents a significant unmet medical need. Microcrystalline tyrosine (MCT) is a well described depot used in licensed allergy immunotherapy products and in clinical development. However, its proof of concept in prophylactic vaccines has only recently been explored. MCT has never been used in combination with virus-like particles (VLPs), which are considered to be one of the most potent inducers of cellular and humoral immune responses in mice and humans. In the current study we assessed the potential of MCT to serve as an adjuvant in the development of a vaccine against malaria either alone or combined with VLP using Plasmodium vivax thrombospondin-related adhesive protein (TRAP) as a target antigen. We chemically coupled PvTRAP to VLPs derived from the cucumber mosaic virus fused to a universal T-cell epitope of the tetanus toxin (CMVtt), formulated with MCT and compared the induced immune responses to PvTRAP formulated in PBS or Alum. The protective capacity of the various formulations was assessed using Plasmodium berghei expressing PvTRAP. All vaccine formulations using adjuvants and/or VLP increased humoral immunogenicity for PvTRAP compared to the antigen alone. The most proficient responder was the group of mice immunized with the vaccine formulated with PvTRAP-VLP + MCT. The VLP-based vaccine formulated in MCT also induced the strongest T cell response and conferred best protection against challenge with recombinant Plasmodium berghei. Thus, the combination of VLP with MCT may take advantage of the properties of each component and appears to be an alternative biodegradable depot adjuvant for development of novel prophylactic vaccines.
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Pearce SC, McWhinnie RL, Nano FE. Synthetic temperature-inducible lethal gene circuits in Escherichia coli. MICROBIOLOGY-SGM 2017; 163:462-471. [PMID: 28430101 DOI: 10.1099/mic.0.000446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Temperature sensitivity is often used as a way to attenuate micro-organisms to convert them into live vaccines. In this work, we explore the use of temperature-sensitive (TS) genetic circuits that express lethal genes as a widely applicable approach to TS attenuation. We tested different combinations of TS repressors and cognate promoters controlling the expression of genes encoding restriction endonucleases inserted at four different non-essential sites in the Escherichia coli chromosome. We found that the presence of the restriction endonuclease genes did not affect the viability of the host strains at the permissive temperature, but that expression of the genes at elevated temperatures killed the strains to varying extents. The chromosomal insertion site of the lethal cassettes affected their functionality, and insertion at one site, ycgH, rendered them ineffective at inducing death at high temperature. Induction of a TS circuit in a growing culture led to a reduced cell mass and a reduction of the number of cells that could exclude a dye that indicated viability. Incubation of cells carrying a TS lethal gene circuit initially grown at low temperature and then suspended in phosphate buffered saline at high temperature led to about 100-fold loss of cell viability per day, compared to a minimal loss of viability for the parental strain. Strains carrying either one or two TS lethal circuits could generate mutants that survived at high temperature. These mutants included complete deletions of the lethal gene circuits.
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Affiliation(s)
- Stephanie C Pearce
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Ralph L McWhinnie
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Francis E Nano
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
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A Plasmodium vivax Plasmid DNA- and Adenovirus-Vectored Malaria Vaccine Encoding Blood-Stage Antigens AMA1 and MSP1 42 in a Prime/Boost Heterologous Immunization Regimen Partially Protects Aotus Monkeys against Blood-Stage Challenge. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00539-16. [PMID: 28179404 DOI: 10.1128/cvi.00539-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/06/2017] [Indexed: 01/30/2023]
Abstract
Malaria is caused by parasites of the genus Plasmodium, which are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of Plasmodium falciparum, it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside Africa, stressing the importance of developing a vaccine against P. vivax malaria. In this study, we assessed the immunogenicity and protective efficacy of two P. vivax antigens, apical membrane antigen 1 (AMA1) and the 42-kDa C-terminal fragment of merozoite surface protein 1 (MSP142) in a plasmid recombinant DNA prime/adenoviral (Ad) vector boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with plasmid DNA alone, Ad alone, prime/boost regimens with each antigen, prime/boost regimens with both antigens, and empty vector controls and then subjected to blood-stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, on the basis of their ability to induce the longest prepatent period and the longest time to the peak level of parasitemia, the lowest peak and mean levels of parasitemia, the smallest area under the parasitemia curve, and the highest self-cure rate. Overall, prechallenge MSP142 antibody titers strongly correlated with a decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, the P. vivax plasmid DNA/Ad serotype 5 vaccine encoding blood-stage parasite antigens AMA1 and MSP142 in a heterologous prime/boost immunization regimen provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and this regimen for further development.
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Mahmoudi S, Keshavarz H. Efficacy of phase 3 trial of RTS, S/AS01 malaria vaccine: The need for an alternative development plan. Hum Vaccin Immunother 2017; 13:2098-2101. [PMID: 28272979 DOI: 10.1080/21645515.2017.1295906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Although vaccines would be the ideal tool for control, prevention, elimination, and eradication of many infectious diseases, developing of parasites vaccines such as malaria vaccine is very complex. The most advanced malaria vaccine candidate RTS,S, a pre-erythrocytic vaccine, has been recommended for licensure by EMEA. The results of this phase III trial suggest that this candidate malaria vaccine has relatively little efficacy, and the vaccine apparently will not meet the goal of malaria eradication by itself. Since there are many vaccine candidates in the pipeline 1 that are being evaluated in vaccine trials, further study on using of alternative parasite targets and vaccination strategies are highly recommended.
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Affiliation(s)
- Shima Mahmoudi
- a Pediatric Infectious Disease Research Center , Tehran University of Medical Science , Tehran , Iran.,b Center for Research of Endemic Parasites of Iran (CREPI) , Tehran University of Medical Sciences , Tehran , Iran
| | - Hossein Keshavarz
- b Center for Research of Endemic Parasites of Iran (CREPI) , Tehran University of Medical Sciences , Tehran , Iran.,c Department of Medical Parasitology and Mycology , School of Public Heath, Tehran, University of Medical Science , Tehran , Iran
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The Power of Malaria Vaccine Trials Using Controlled Human Malaria Infection. PLoS Comput Biol 2017; 13:e1005255. [PMID: 28081133 PMCID: PMC5230743 DOI: 10.1371/journal.pcbi.1005255] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 11/21/2016] [Indexed: 11/25/2022] Open
Abstract
Controlled human malaria infection (CHMI) in healthy human volunteers is an important and powerful tool in clinical malaria vaccine development. However, power calculations are essential to obtain meaningful estimates of protective efficacy, while minimizing the risk of adverse events. To optimize power calculations for CHMI-based malaria vaccine trials, we developed a novel non-linear statistical model for parasite kinetics as measured by qPCR, using data from mosquito-based CHMI experiments in 57 individuals. We robustly account for important sources of variation between and within individuals using a Bayesian framework. Study power is most dependent on the number of individuals in each treatment arm; inter-individual variation in vaccine efficacy and the number of blood samples taken per day matter relatively little. Due to high inter-individual variation in the number of first-generation parasites, hepatic vaccine trials required significantly more study subjects than erythrocytic vaccine trials. We provide power calculations for hypothetical malaria vaccine trials of various designs and conclude that so far, power calculations have been overly optimistic. We further illustrate how upcoming techniques like needle-injected CHMI may reduce required sample sizes. Controlled human malaria infection (CHMI) in healthy human volunteers is an important and powerful tool in clinical malaria vaccine development. However, to obtain meaningful estimates of protective efficacy, it is important to include an appropriate minimum number of participants, while minimizing the risks and burden for volunteers. Existing power calculations have limited value due to important influential assumptions. To optimize power calculations for malaria vaccine trials, we developed a non-linear, Bayesian statistical model for parasite kinetics as measured by quantitative real-time polymerase chain reaction, using existing data from mosquito-based CHMI experiments. Using our model, we provide improved, robust power calculations for various hypothetical malaria vaccine trials, taking account of important sources of variation between and within individuals. We conclude that so far, power calculations for malaria vaccine trials have been overly optimistic. We further illustrate how upcoming techniques like needle-injected CHMI may reduce required sample sizes.
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Mahmoudi S, Keshavarz H. Efficacy of Phase 3 Trial of RTS, S/AS01 Malaria Vaccine in infants: a systematic review and meta-analysis. Hum Vaccin Immunother 2017:0. [PMID: 28059665 DOI: 10.1080/21645515.2016.1271686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Although vaccines would be the ideal tool for control, prevention, elimination, and eradication of many infectious diseases, developing of parasites vaccines such as malaria vaccine is very complex. The most advanced malaria vaccine candidate is RTS,S, a pre-erythrocytic vaccine for which pivotal phase III trial design is underway. Few recent malaria vaccine review articles have attempted to outline of all clinical trials that have occurred globally and no meta-analysis was performed on efficacy of Phase 3 Trial of RTS, S/AS01 Malaria vaccine up to now in infants. Therefore, a systematic review and meta-analysis was carried out to review new and existing data on efficacy of Phase 3 Trial of RTS, S/AS01 Malaria Vaccine in infants. The electronic databases searched were Pubmed (1965-present) and Web of Science (1970-present) (Search date: May, 2016). After full-text review of the papers evaluating clinical/severe malaria in several well-designed phase III field efficacy trials, 5 were determined to meet the eligibility criteria for inclusion in the systematic review. Four out of the 5 publications dealing with efficacy of Phase 3 Trial of RTS, S/AS01 malaria vaccine were included in the qualitative analysis. Pooled estimate of vaccine efficacy in clinical and severe malaria in children aged 5-17 mo was 29% (95% CL: 19%-46%) and 39% (95% CI 20%-74%), while this estimate vaccine in clinical and severe malaria in children aged 6-12 mo was 19% (95% CI 14%-24%) and 21 (95% CI 19%-37%), respectively. On the other hand, higher VE was seen in both per- protocol and intention-to-treat population in children aged 5-17 than the children aged 6-12 mo. The results of this meta-analysis suggest that this candidate malaria vaccine has relatively little efficacy, and the vaccine apparently will not meet the goal of malaria eradication by itself.
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Affiliation(s)
- Shima Mahmoudi
- a Pediatric Infectious Disease Research Center, Tehran University of Medical Science , Tehran , Iran
- b Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences , Tehran , Iran
| | - Hossein Keshavarz
- b Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences , Tehran , Iran
- c Department of Medical Parasitology and Mycology , School of Public Heath, Tehran University of Medical Science , Tehran , Iran
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Ravenhall M, Benavente ED, Mipando M, Jensen ATR, Sutherland CJ, Roper C, Sepúlveda N, Kwiatkowski DP, Montgomery J, Phiri KS, Terlouw A, Craig A, Campino S, Ocholla H, Clark TG. Characterizing the impact of sustained sulfadoxine/pyrimethamine use upon the Plasmodium falciparum population in Malawi. Malar J 2016; 15:575. [PMID: 27899115 PMCID: PMC5129638 DOI: 10.1186/s12936-016-1634-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/23/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malawi experienced prolonged use of sulfadoxine/pyrimethamine (SP) as the front-line anti-malarial drug, with early replacement of chloroquine and delayed introduction of artemisinin-based combination therapy. Extended use of SP, and its continued application in pregnancy is impacting the genomic variation of the Plasmodium falciparum population. METHODS Whole genome sequence data of P. falciparum isolates covering 2 years of transmission within Malawi, alongside global datasets, were used. More than 745,000 SNPs were identified, and differences in allele frequencies between countries assessed, as well as genetic regions under positive selection determined. RESULTS Positive selection signals were identified within dhps, dhfr and gch1, all components of the parasite folate pathway associated with SP resistance. Sitting predominantly on a dhfr triple mutation background, a novel copy number increase of ~twofold was identified in the gch1 promoter. This copy number was almost fixed (96.8% frequency) in Malawi samples, but found at less than 45% frequency in other African populations, and distinct from a whole gene duplication previously reported in Southeast Asian parasites. CONCLUSIONS SP resistance selection pressures have been retained in the Malawian population, with known resistance dhfr mutations at fixation, complemented by a novel gch1 promoter duplication. The effects of the duplication on the fitness costs of SP variants and resistance need to be elucidated.
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Affiliation(s)
- Matt Ravenhall
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Ernest Diez Benavente
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Mwapatsa Mipando
- Department of Physiology, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Anja T. R. Jensen
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | - Colin J. Sutherland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Cally Roper
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Nuno Sepúlveda
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Statistics and Applications of University of Lisbon, Lisbon, Portugal
| | | | - Jacqui Montgomery
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Kamija S. Phiri
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Anja Terlouw
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Alister Craig
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Harold Ocholla
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Taane G. Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
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Sanz S, López-Gutiérrez B, Bandini G, Damerow S, Absalon S, Dinglasan RR, Samuelson J, Izquierdo L. The disruption of GDP-fucose de novo biosynthesis suggests the presence of a novel fucose-containing glycoconjugate in Plasmodium asexual blood stages. Sci Rep 2016; 6:37230. [PMID: 27849032 PMCID: PMC5110956 DOI: 10.1038/srep37230] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/03/2016] [Indexed: 02/03/2023] Open
Abstract
Glycosylation is an important posttranslational protein modification in all eukaryotes. Besides glycosylphosphatidylinositol (GPI) anchors and N-glycosylation, O-fucosylation has been recently reported in key sporozoite proteins of the malaria parasite. Previous analyses showed the presence of GDP-fucose (GDP-Fuc), the precursor for all fucosylation reactions, in the blood stages of Plasmodium falciparum. The GDP-Fuc de novo pathway, which requires the action of GDP-mannose 4,6-dehydratase (GMD) and GDP-L-fucose synthase (FS), is conserved in the parasite genome, but the importance of fucose metabolism for the parasite is unknown. To functionally characterize the pathway we generated a PfGMD mutant and analyzed its phenotype. Although the labelling by the fucose-binding Ulex europaeus agglutinin I (UEA-I) was completely abrogated, GDP-Fuc was still detected in the mutant. This unexpected result suggests the presence of an alternative mechanism for maintaining GDP-Fuc in the parasite. Furthermore, PfGMD null mutant exhibited normal growth and invasion rates, revealing that the GDP-Fuc de novo metabolic pathway is not essential for the development in culture of the malaria parasite during the asexual blood stages. Nonetheless, the function of this metabolic route and the GDP-Fuc pool that is generated during this stage may be important for gametocytogenesis and sporogonic development in the mosquito.
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Affiliation(s)
- Sílvia Sanz
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Borja López-Gutiérrez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Giulia Bandini
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, 72 East Concord St, Boston, MA 02118, USA
| | - Sebastian Damerow
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Sabrina Absalon
- Division of Infectious Diseases, Boston Children's Hospital and Harvard Medical School, Boston MA 02115, USA
| | - Rhoel R Dinglasan
- The University of Florida Emerging Pathogens Institute, Department of Infectious Diseases &Pathology, Gainesville FL 32611, USA
| | - John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, 72 East Concord St, Boston, MA 02118, USA
| | - Luis Izquierdo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
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Mishra M, Mishra VK, Kashaw V, Iyer AK, Kashaw SK. Comprehensive review on various strategies for antimalarial drug discovery. Eur J Med Chem 2016; 125:1300-1320. [PMID: 27886547 DOI: 10.1016/j.ejmech.2016.11.025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 01/14/2023]
Abstract
The resistance of malaria parasites to existing drugs carries on growing and progressively limiting our ability to manage this severe disease and finally lead to a massive global health burden. Till now, malaria control has relied upon the traditional quinoline, antifolate and artemisinin compounds. Very few new antimalarials were developed in the past 50 years. Among recent approaches, identification of novel chemotherapeutic targets, exploration of natural products with medicinal significance, covalent bitherapy having a dual mode of action into a single hybrid molecule and malaria vaccine development are explored heavily. The proper execution of these approaches and proper investment from international agencies will accelerate the discovery of drugs that provide new hope for the control or eventual eradication of this global infectious disease. This review explores various strategies for assessment and development of new antimalarial drugs. Current status and scientific value of previous approaches are systematically reviewed and new approaches provide a pragmatic forecast for future developments are introduced as well.
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Affiliation(s)
- Mitali Mishra
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India
| | - Vikash K Mishra
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India
| | - Varsha Kashaw
- SVN Institute of Pharmaceutical Sciences, SVN University, Sagar, MP, India
| | - Arun K Iyer
- Use-inspired Biomaterials & Integrated Nano Delivery (U-BiND) Systems Laboratory, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, USA
| | - Sushil Kumar Kashaw
- Department of Pharmaceutical Sciences, Dr. Harisingh Gour University (A Central University), Sagar, MP, India; Use-inspired Biomaterials & Integrated Nano Delivery (U-BiND) Systems Laboratory, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, USA.
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