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Cao Y, Hayashi CTH, Araujo MDS, Tripathi AK, Andrade AO, Medeiros JF, Vinetz J, Kumar N. Evaluation of combination vaccines targeting transmission of Plasmodium falciparum and P. vivax. Vaccine 2024; 42:126140. [PMID: 39033079 PMCID: PMC11338703 DOI: 10.1016/j.vaccine.2024.07.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 07/02/2024] [Accepted: 07/12/2024] [Indexed: 07/23/2024]
Abstract
Transmission-blocking vaccines interrupting malaria transmission within mosquitoes represent an ideal public health tool to eliminate malaria at the population level. Plasmodium falciparum and P. vivax account for more than 90% of the global malaria burden, co-endemic in many regions of the world. P25 and P48/45 are two leading candidates for both species and have shown promising transmission-blocking activity in preclinical and clinical studies. However, neither of these target antigens as individual vaccines has induced complete transmission inhibition in mosquitoes. In this study, we assessed immunogenicity of combination vaccines based on P25 and P48/45 using a DNA vaccine platform to broaden vaccine specificity against P. falciparum and P. vivax. Individual DNA vaccines encoding Pvs25, Pfs25, Pvs48/45 and Pfs48/45, as well as various combinations including (Pvs25 + Pvs48/45), (Pfs25 + Pfs48/45), (Pvs25 + Pfs25), and (Pvs48/45 + Pfs48/45), were evaluated in mice using in vivo electroporation. Potent antibody responses were induced in mice immunized with individual and combination DNA vaccines, and specific antibody responses were not compromised when combinations of DNA vaccines were evaluated against individual DNA vaccines. The anti-Pvs25 IgG from individual and combination groups revealed concentration-dependent transmission-reducing activity (TRA) in direct membrane feeding assays (DMFA) using blood from P. vivax-infected donors in Brazil and independently in ex vivo MFA using Pvs25-transgenic P. berghei. Similarly, anti-Pfs25 and anti-Pfs48/45 IgGs from mice immunized with Pfs25 and Pfs48/45 DNA vaccines individually and in various combinations revealed antibody dose-dependent TRA in standard membrane feeding assays (SMFA) using culture-derived P. falciparum gametocytes. However, antibodies induced by immunization with Pvs48/45 DNA vaccines were ineffective in DMFA and require further vaccine construct optimization, considering the possibility of induction of both transmission-blocking and transmission-enhancing antibodies revealed by competition ELISA. These studies provide a rationale for combining multiple antigens to simultaneously target transmission of malaria caused by P. falciparum and P. vivax.
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MESH Headings
- Malaria Vaccines/immunology
- Malaria Vaccines/administration & dosage
- Animals
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Falciparum/immunology
- Plasmodium falciparum/immunology
- Plasmodium falciparum/genetics
- Plasmodium vivax/immunology
- Plasmodium vivax/genetics
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Malaria, Vivax/immunology
- Mice
- Vaccines, DNA/immunology
- Vaccines, DNA/administration & dosage
- Antibodies, Protozoan/immunology
- Antibodies, Protozoan/blood
- Female
- Vaccines, Combined/immunology
- Vaccines, Combined/administration & dosage
- Antigens, Protozoan/immunology
- Antigens, Protozoan/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/genetics
- Mice, Inbred BALB C
- Humans
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Affiliation(s)
- Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington D.C., USA
| | - Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington D.C., USA
| | - Maisa da Silva Araujo
- Plataforma de Produção e Infecção de Vetores da Malária, Laboratório de Entomologia - FIOCRUZ RO, Rua da Beira 7671, CEP 76812-245 Porto Velho RO, Brazil; Programa de Pós-Graduação em Saúde Pública, Faculdade de Saúde Pública, Universidade Federal de São Paulo, São Paulo 01246-904, SP, Brazil
| | - Abhai K Tripathi
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Alice Oliveira Andrade
- Plataforma de Produção e Infecção de Vetores da Malária, Laboratório de Entomologia - FIOCRUZ RO, Rua da Beira 7671, CEP 76812-245 Porto Velho RO, Brazil; Programa de Pós-Graduação em Saúde Pública, Faculdade de Saúde Pública, Universidade Federal de São Paulo, São Paulo 01246-904, SP, Brazil
| | - Jansen Fernandes Medeiros
- Plataforma de Produção e Infecção de Vetores da Malária, Laboratório de Entomologia - FIOCRUZ RO, Rua da Beira 7671, CEP 76812-245 Porto Velho RO, Brazil; Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, Fiocruz Rondônia 76812-245, Brazil
| | - Joseph Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA; Department of Cellular and Molecular Sciences, Faculty of Sciences, and Alexander von Humboldt Institute of Tropical Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington D.C., USA.
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Lyons FMT, Gabriela M, Tham WH, Dietrich MH. Plasmodium 6-Cysteine Proteins: Functional Diversity, Transmission-Blocking Antibodies and Structural Scaffolds. Front Cell Infect Microbiol 2022; 12:945924. [PMID: 35899047 PMCID: PMC9309271 DOI: 10.3389/fcimb.2022.945924] [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: 05/17/2022] [Accepted: 06/22/2022] [Indexed: 11/30/2022] Open
Abstract
The 6-cysteine protein family is one of the most abundant surface antigens that are expressed throughout the Plasmodium falciparum life cycle. Many members of the 6-cysteine family have critical roles in parasite development across the life cycle in parasite transmission, evasion of the host immune response and host cell invasion. The common feature of the family is the 6-cysteine domain, also referred to as s48/45 domain, which is conserved across Aconoidasida. This review summarizes the current approaches for recombinant expression for 6-cysteine proteins, monoclonal antibodies against 6-cysteine proteins that block transmission and the growing collection of crystal structures that provide insights into the functional domains of this protein family.
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Affiliation(s)
- Frankie M. T. Lyons
- The Walter and Eliza Hall Institute of Medical Research, Infectious Diseases and Immune Defence Division, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Mikha Gabriela
- The Walter and Eliza Hall Institute of Medical Research, Infectious Diseases and Immune Defence Division, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Wai-Hong Tham
- The Walter and Eliza Hall Institute of Medical Research, Infectious Diseases and Immune Defence Division, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
| | - Melanie H. Dietrich
- The Walter and Eliza Hall Institute of Medical Research, Infectious Diseases and Immune Defence Division, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia
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Xu C, Qiao M, Huo X, Liao Z, Su J. An Oral Microencapsulated Vaccine Loaded by Sodium Alginate Effectively Enhances Protection Against GCRV Infection in Grass Carp (Ctenopharyngodon idella). Front Immunol 2022; 13:848958. [PMID: 35401526 PMCID: PMC8987307 DOI: 10.3389/fimmu.2022.848958] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
Grass carp reovirus (GCRV) is highly infectious and lethal to grass carp, causing huge economic losses to the aquaculture industry annually. Currently, vaccination is the most effective method against viral infections. Among the various vaccination methods, the oral vaccination is an ideal way in aquaculture. However, low protective efficiency is the major problem for oral vaccination owing to some reasons, such as antigen degradation and low immunogenicity. In our study, we screened the antigenic epitopes of GCRV-II and prepared an oral microencapsulated vaccine using sodium alginate (SA) as a carrier and flagellin B (FlaB) as an adjuvant, and evaluated its protective effects against GCRV-II infection in grass carp. The full length and three potential antigenic epitope regions of GCRV-II VP56 gene were expressed in Escherichia coli and purified by glutathione affinity column respectively. The optimal antigen (VP56-3) was screened by enzyme-linked immunosorbent assay (ELISA). Adjuvant FlaB was also expressed in E. coli and purified by Ni2+ affinity column. Subsequently, we prepared the oral vaccines using sodium alginate as a carrier. The vaccine (SA-VP56-3/FlaB) forms microsphere (1.24 ± 0.22 μm), examined by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering assay. SA-VP56-3/FlaB vaccine has excellent stability, slow-release, and low toxicity by dynamic light scattering assay, release dynamic assay, in vivo fluorescence imaging system, hemolytic activity and cytotoxicity. Then we vaccinated grass carp orally with SA-VP56-3/FlaB and measured immune-related parameters (serum neutralizing antibody titer, serum enzyme activity (TSOD, LZM, C3), immune-related genes ((IgM, IFN1, MHC-II, CD8 in head kidney and spleen), IgZ in hindgut)). The results showed that SA-VP56-3/FlaB significantly induced strong immune responses, compared to other groups. The highest survival rate achieved in SA-VP56-3/FlaB microencapsulated vaccine (56%) in 2 weeks post GCRV challenge, while 10% for the control group. Meanwhile, the tissue virus load in survival grass carp is lowest in SA-VP56-3/FlaB group. These results indicated that SA-VP56-3/FlaB could be a candidate oral vaccine against GCRV-II infection in aquaculture.
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Affiliation(s)
- Chuang Xu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, China
| | - Meihua Qiao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China
| | - Xingchen Huo
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China
| | - Zhiwei Liao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China
| | - Jianguo Su
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Hubei Hongshan Laboratory, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, China
- *Correspondence: Jianguo Su,
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Elucidating functional epitopes within the N-terminal region of malaria transmission blocking vaccine antigen Pfs230. NPJ Vaccines 2022; 7:4. [PMID: 35027567 PMCID: PMC8758780 DOI: 10.1038/s41541-021-00423-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/30/2021] [Indexed: 11/24/2022] Open
Abstract
Pfs230 is a leading malaria transmission blocking vaccine (TBV) candidate. Comprising 3135 amino acids (aa), the large size of Pfs230 necessitates the use of sub-fragments as vaccine immunogens. Therefore, determination of which regions induce functional antibody responses is essential. We previously reported that of 27 sub-fragments spanning the entire molecule, only five induced functional antibodies. A “functional” antibody is defined herein as one that inhibits Plasmodium falciparum parasite development in mosquitoes in a standard membrane-feeding assay (SMFA). These five sub-fragments were found within the aa 443–1274 range, and all contained aa 543–730. Here, we further pinpoint the location of epitopes within Pfs230 that are recognized by functional antibodies using antibody depletion and enrichment techniques. Functional epitopes were not found within the aa 918–1274 region. Within aa 443–917, further analysis showed the existence of functional epitopes not only within the aa 543–730 region but also outside of it. Affinity-purified antibodies using a synthetic peptide matching aa 543–588 showed activity in the SMFA. Immunization with a synthetic peptide comprising this segment, formulated either as a carrier-protein conjugate vaccine or with a liposomal vaccine adjuvant system, induced antibodies in mice that were functional in the SMFA. These findings provide key insights for Pfs230-based vaccine design and establish the feasibility for the use of synthetic peptide antigens for a malaria TBV.
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Gao Y, Huo X, Wang Z, Yuan G, Liu X, Ai T, Su J. Oral Administration of Bacillus subtilis Subunit Vaccine Significantly Enhances the Immune Protection of Grass Carp against GCRV-II Infection. Viruses 2021; 14:v14010030. [PMID: 35062234 PMCID: PMC8779733 DOI: 10.3390/v14010030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/16/2021] [Accepted: 12/16/2021] [Indexed: 12/16/2022] Open
Abstract
Grass carp reovirus (GCRV) is a severe virus that causes great losses to grass carp culture every year, and GCRV-II is the current popular and fatal strain. VP56, fibrin on the outer surface of GCRV-II, mediates cell attachment. In this study, we firstly divided the VP56 gene into four fragments to screen the optimal antigen by enzyme-linked immunosorbent assay and neutralizing antibody methods. The second fragment VP56-2 demonstrates the optimal efficiency and was employed as an antigen in the following experiments. Bacillus subtilis were used as a carrier, and VP56-2 was expressed on the surface of the spores. Then, we performed the oral immunization for grass carp and the challenge with GCRV-II. The survival rate was remarkably raised, and mRNA expressions of IgM were significantly up-regulated in spleen and head kidney tissues in the B. s-CotC-VP56-2 group. Three crucial immune indexes (complement C3, lysozyme and total superoxide dismutase) in the sera were also significantly enhanced. mRNA expressions of four important genes (TNF-α, IL-1β, IFN1 and MHC-II) were significantly strengthened. Tissue lesions were obviously attenuated by histopathological slide examination in trunk kidney and spleen tissues. Tissue viral burdens were significantly reduced post-viral challenge. These results indicated that the oral recombinant B. subtilis VP56-2 subunit vaccine is effective for controlling GCRV infection and provides a feasible strategy for the control of fish virus diseases.
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Affiliation(s)
- Yang Gao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
| | - Xingchen Huo
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
| | - Zhensheng Wang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
| | - Gailing Yuan
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
| | - Xiaoling Liu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
| | - Taoshan Ai
- Wuhan Chopper Fishery Bio-Tech Co., Ltd., Wuhan Academy of Agricultural Science, Wuhan 430207, China;
| | - Jianguo Su
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; (Y.G.); (X.H.); (Z.W.); (G.Y.); (X.L.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
- Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan 430070, China
- Correspondence: ; Tel./Fax: +86-27-87282227
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Scaria PV, Anderson C, Muratova O, Alani N, Trinh HV, Nadakal ST, Zaidi I, Lambert L, Beck Z, Barnafo EK, Rausch KM, Rowe C, Chen B, Matyas GR, Rao M, Alving CR, Narum DL, Duffy PE. Malaria transmission-blocking conjugate vaccine in ALFQ adjuvant induces durable functional immune responses in rhesus macaques. NPJ Vaccines 2021; 6:148. [PMID: 34887448 PMCID: PMC8660773 DOI: 10.1038/s41541-021-00407-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/03/2021] [Indexed: 12/14/2022] Open
Abstract
Malaria transmission-blocking vaccines candidates based on Pfs25 and Pfs230 have advanced to clinical studies. Exoprotein A (EPA) conjugate of Pfs25 in Alhydrogel® developed functional immunity in humans, with limited durability. Pfs230 conjugated to EPA (Pfs230D1-EPA) with liposomal adjuvant AS01 is currently in clinical trials in Mali. Studies with these conjugates revealed that non-human primates are better than mice to recapitulate the human immunogenicity and functional activity. Here, we evaluated the effect of ALFQ, a liposomal adjuvant consisting of TLR4 agonist and QS21, on the immunogenicity of Pfs25-EPA and Pfs230D1-EPA in Rhesus macaques. Both conjugates generated strong antibody responses and functional activity after two vaccinations though activity declined rapidly. A third vaccination of Pfs230D1-EPA induced functional activity lasting at least 9 months. Antibody avidity increased with each vaccination and correlated strongly with functional activity. IgG subclass analysis showed induction of Th1 and Th2 subclass antibody levels that correlated with activity.
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Affiliation(s)
- Puthupparampil V. Scaria
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Charles Anderson
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Olga Muratova
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Nada Alani
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Hung V. Trinh
- grid.507680.c0000 0001 2230 3166U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA ,grid.201075.10000 0004 0614 9826Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD 20817 USA
| | - Steven T. Nadakal
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Irfan Zaidi
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Lynn Lambert
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Zoltan Beck
- grid.507680.c0000 0001 2230 3166U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA ,grid.201075.10000 0004 0614 9826Henry M. Jackson Foundation for the Advancement of Military Medicine, 6720A Rockledge Drive, Bethesda, MD 20817 USA ,grid.410513.20000 0000 8800 7493Present Address: Pfizer, Vaccine Research and Development, Pearl River, NY USA
| | - Emma K. Barnafo
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Kelly M. Rausch
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Chris Rowe
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Beth Chen
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Gary R. Matyas
- grid.507680.c0000 0001 2230 3166U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
| | - Mangala Rao
- grid.507680.c0000 0001 2230 3166U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
| | - Carl R. Alving
- grid.507680.c0000 0001 2230 3166U.S. Military HIV Research Program, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910 USA
| | - David L. Narum
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
| | - Patrick E. Duffy
- grid.419681.30000 0001 2164 9667Laboratory of Malaria Immunology and Vaccinology, NIAID/NIH, 29 Lincoln Drive, Building 29B, Bethesda, MD 20892-2903 USA
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Keleta Y, Ramelow J, Cui L, Li J. Molecular interactions between parasite and mosquito during midgut invasion as targets to block malaria transmission. NPJ Vaccines 2021; 6:140. [PMID: 34845210 PMCID: PMC8630063 DOI: 10.1038/s41541-021-00401-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/01/2021] [Indexed: 11/21/2022] Open
Abstract
Despite considerable effort, malaria remains a major public health burden. Malaria is caused by five Plasmodium species and is transmitted to humans via the female Anopheles mosquito. The development of malaria vaccines against the liver and blood stages has been challenging. Therefore, malaria elimination strategies advocate integrated measures, including transmission-blocking approaches. Designing an effective transmission-blocking strategy relies on a sophisticated understanding of the molecular mechanisms governing the interactions between the mosquito midgut molecules and the malaria parasite. Here we review recent advances in the biology of malaria transmission, focusing on molecular interactions between Plasmodium and Anopheles mosquito midgut proteins. We provide an overview of parasite and mosquito proteins that are either targets for drugs currently in clinical trials or candidates of promising transmission-blocking vaccines.
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Affiliation(s)
- Yacob Keleta
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Julian Ramelow
- Herbert Wertheim College of Medicine, Florida International University, Miami, FL, 33199, USA
| | - Liwang Cui
- College of Public Health, University of South Florida, Tampa, FL, 33612, USA
| | - Jun Li
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA.
- Biomolecular Science Institute, Florida International University, Miami, FL, 33199, USA.
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Pirahmadi S, Afzali S, Zargar M, Zakeri S, Mehrizi AA. How can we develop an effective subunit vaccine to achieve successful malaria eradication? Microb Pathog 2021; 160:105203. [PMID: 34547408 DOI: 10.1016/j.micpath.2021.105203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/05/2021] [Accepted: 09/17/2021] [Indexed: 12/16/2022]
Abstract
Malaria, a mosquito-borne infection, is the most widespread parasitic disease. Despite numerous efforts to eradicate malaria, this disease is still a health concern worldwide. Owing to insecticide-resistant vectors and drug-resistant parasites, available controlling measures are insufficient to achieve a malaria-free world. Thus, there is an urgent need for new intervention tools such as efficient malaria vaccines. Subunit vaccines are the most promising malaria vaccines under development. However, one of the major drawbacks of subunit vaccines is the lack of efficient and durable immune responses including antigen-specific antibody, CD4+, and CD8+ T-cell responses, long-lived plasma cells, memory cells, and functional antibodies for parasite neutralization or inhibition of parasite invasion. These types of responses could be induced by whole organism vaccines, but eliciting these responses with subunit vaccines has been proven to be more challenging. Consequently, subunit vaccines require several policies to overcome these challenges. In this review, we address common approaches that can improve the efficacy of subunit vaccines against malaria.
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Affiliation(s)
- Sakineh Pirahmadi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Shima Afzali
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Mostafa Zargar
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran
| | - Sedigheh Zakeri
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
| | - Akram Abouie Mehrizi
- Malaria and Vector Research Group (MVRG), Biotechnology Research Center (BRC), Pasteur Institute of Iran, Tehran, Iran.
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Mabrouk MT, Huang WC, Deng B, Li-Purcell N, Seffouh A, Ortega J, Ekin Atilla-Gokcumen G, Long CA, Miura K, Lovell JF. Lyophilized, antigen-bound liposomes with reduced MPLA and enhanced thermostability. Int J Pharm 2020; 589:119843. [PMID: 32890653 DOI: 10.1016/j.ijpharm.2020.119843] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/24/2020] [Accepted: 08/30/2020] [Indexed: 12/16/2022]
Abstract
Thermostability and decreased component costs are desirable features for adjuvanted, recombinant vaccines. We previously showed that a model malaria transmission-blocking vaccine candidate antigen, Pfs25, can be rendered more immunogenic when mixed with liposomes containing cobalt porphyrin-phospholipid (CoPoP) and a synthetic monophosphoryl lipid A (MPLA) variant. CoPoP can induce stable particle formation of recombinant antigens based on interaction with their polyhistidine tag. In the present work, different synthetic MPLA variants and concentrations were assessed in CoPoP liposomes. Long-term biophysical stability and immunogenicity were not adversely impacted by a 60% reduction in MPLA content. When admixed with Pfs25, the adjuvant formulations effectively induced functional antibodies in immunized mice and rabbits. Lyophilized, antigen-bound liposomes were formed using sucrose and trehalose cryoprotectants, which improved vaccine reconstitution for a variety of model antigens. Compared to liquid storage, the lyophilized Pfs25 and CoPoP liposomes exhibited thermostability with respect to size, biochemical integrity, binding capacity, protein folding and immunogenicity. Following 6 weeks of storage at 60 °C, the most extended storage period assessed, the lyophilized formulation induced functional antibodies in mice with immunization.
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Affiliation(s)
- Moustafa T Mabrouk
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Wei-Chiao Huang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Nasi Li-Purcell
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Amal Seffouh
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec H3A 0C7, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec H3A 0C7, Canada
| | | | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Jonathan F Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA.
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10
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Huang WC, Deng B, Mabrouk MT, Seffouh A, Ortega J, Long C, Miura K, Wu Y, Lovell JF. Particle-based, Pfs230 and Pfs25 immunization is effective, but not improved by duplexing at fixed total antigen dose. Malar J 2020; 19:309. [PMID: 32859199 PMCID: PMC7453371 DOI: 10.1186/s12936-020-03368-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022] Open
Abstract
Background The Plasmodium falciparum sexual-stage surface proteins Pfs25 and Pfs230 are antigen candidates for a malaria transmission-blocking vaccine (TBV), and have been widely investigated as such. It is not clear whether simultaneously presenting these two antigens in a particulate vaccine would enhance the transmission reducing activity (TRA) of induced antibodies. To assess this, immunization was carried out with liposomes containing synthetic lipid adjuvant monophosphoryl lipid A (MPLA), and cobalt-porphyrin-phospholipid (CoPoP), which rapidly converts recombinant, his-tagged antigens into particles. Methods His-tagged, recombinant Pfs25 and Pfs230C1 were mixed with CoPoP liposomes to form a bivalent vaccine. Antigens were fluorescently labelled to infer duplex particleization serum-stability and binding kinetics using fluorescence resonance energy transfer. Mice and rabbits were immunized with individual or duplexed particleized Pfs25 and Pfs230C1, at fixed total antigen doses. The resulting antibody responses were assessed for magnitude and TRA. Results Pfs230C1 and Pfs25 rapidly bound CoPoP liposomes to form a serum-stable, bivalent particle vaccine. In mice, immunization with 5 ng of total antigen (individual antigen or duplexed) elicited functional antibodies against Pfs25 and Pfs230. Compared to immunization with the individual antigen, Pfs25 antibody production was moderately lower for the bivalent CoPoP vaccine, whereas Pfs230C1 antibody production was not impacted. All antibodies demonstrated at least 92% inhibition in oocyst density at 750 μg/mL purified mouse IgG in the standard membrane feeding assay (SMFA). At lower IgG concentrations, the bivalent vaccine did not improve TRA; antibodies induced by particleized Pfs25 alone showed stronger function in these conditions. In rabbits, immunization with a 20 µg total antigen dose with the duplexed antigens yielded similar antibody production against Pfs25 and Pfs230 compared to immunization with a 20 µg dose of individual antigens. However, no enhanced TRA was observed with duplexing. Conclusions Pfs25, Pfs230 or the duplexed combination can readily be prepared as particulate vaccines by mixing CoPoP liposomes with soluble, recombinant antigens. This approach induces potent transmission-reducing antibodies following immunization in mice and rabbits. Immunization with bivalent, particleized, Pfs230 and Pfs25 did not yield antibodies with superior TRA compared to immunization with particleized Pfs25 as a single antigen. Altogether, duplexing antigens is straightforward and effective using CoPoP liposomes, but is likely to be more useful for targeting distinct parasite life stages.
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Affiliation(s)
- Wei-Chiao Huang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Moustafa T Mabrouk
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Amal Seffouh
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec, H3A 0C7, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec, H3A 0C7, Canada
| | - Carole Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Yimin Wu
- PATH's Malaria Vaccine Initiative (MVI), Washington, DC, 20001, USA
| | - Jonathan F Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA.
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11
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Antibody response of a particle-inducing, liposome vaccine adjuvant admixed with a Pfs230 fragment. NPJ Vaccines 2020; 5:23. [PMID: 32218995 PMCID: PMC7080793 DOI: 10.1038/s41541-020-0173-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/24/2020] [Indexed: 02/07/2023] Open
Abstract
Pfs230 is a malaria transmission-blocking antigen candidate, expressed on the surface of Plasmodium falciparum gametocytes. A recombinant, his-tagged Pfs230 fragment (Pfs230C1; amino acids 443–731) formed serum-stable particles upon incubation with liposomes containing cobalt-porphyrin-phospholipid (CoPoP). In mice, immunization with Pfs230C1, admixed with the adjuvants Alum, Montanide ISA720 or CoPoP liposomes (also containing synthetic monophosphoryl lipid A; PHAD), resulted in elicitation of IgG antibodies, but only those induced with CoPoP/PHAD or ISA720 strongly reduced parasite transmission. Immunization with micrograms of Pfs230C1 adjuvanted with identical liposomes lacking cobalt (that did not induce particle formation) or Alum was less effective than immunization with nanograms of Pfs230C1 with CoPoP/PHAD. CoPoP/PHAD and ISA720 adjuvants induced antibodies with similar Pfs230C1 avidity but higher IgG2-to-IgG1 ratios than Alum, which likely contributed to enhanced functional activity. Unlike prior work with another transmission-blocking antigen (Pfs25), Pfs230C1 was found to be effectively taken up by antigen-presenting cells without particle formation. The anti-Pfs230C1 IgG response was durable in mice for 250 days following immunization with CoPoP/PHAD, as were antibody avidity and elevated IgG2-to-IgG1 ratios. Immunization of rabbits with 20 µg Pfs230C1 admixed with CoPoP/PHAD elicited antibodies that inhibited parasite transmission. Taken together, these results show that liposomes containing CoPoP and PHAD are an effective vaccine adjuvant platform for recombinant malaria transmission blocking antigens.
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Lee SM, Hickey JM, Miura K, Joshi SB, Volkin DB, King CR, Plieskatt JL. A C-terminal Pfs48/45 malaria transmission-blocking vaccine candidate produced in the baculovirus expression system. Sci Rep 2020; 10:395. [PMID: 31942034 PMCID: PMC6962329 DOI: 10.1038/s41598-019-57384-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/30/2019] [Indexed: 11/09/2022] Open
Abstract
The Plasmodium falciparum gametocyte surface protein, Pfs48/45, is a potential target for malaria transmission-blocking vaccines. However, due to its size and complexity, expression of the full-length protein has been difficult, leading to focus on the C-terminal six cysteine domain (6C) with the use of fusion proteins to facilitate expression and folding. In this study, we utilized the baculovirus system to evaluate the expression of three Pfs48/45 proteins including the full-length protein, the 6C domain fragment and the 6C domain mutant to prevent glycosylation. Expression of the recombinant Pfs48/45 proteins was conducted in super Sf9 cells combined with the use of tunicamycin to prevent N-glycosylation. The proteins were then evaluated as immunogens in mice to demonstrate the induction of functionally active polyclonal antibody responses as measured in the standard membrane feeding assay (SMFA). Only the 6C protein was found to exhibit significant transmission-reducing activity. Further characterization of the biologically active 6C protein demonstrated it was homogeneous in terms of size, charge, conformation, absence of glycosylation, and containing proper disulfide bond pairings. This study presents an alternative expression system, without the need of a fusion protein partner, for the Pfs48/45 6C protein fragment including further evaluation as a potential transmission-blocking vaccine candidate.
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Affiliation(s)
- Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA.
| | - John M Hickey
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, 20852, USA
| | - Sangeeta B Joshi
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - David B Volkin
- Department of Pharmaceutical Chemistry, Vaccine Analytics and Formulation Center, University of Kansas, Lawrence, KS, 66047, USA
| | - C Richter King
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - Jordan L Plieskatt
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
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13
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de Jong RM, Tebeje SK, Meerstein‐Kessel L, Tadesse FG, Jore MM, Stone W, Bousema T. Immunity against sexual stage Plasmodium falciparum and Plasmodium vivax parasites. Immunol Rev 2020; 293:190-215. [PMID: 31840844 PMCID: PMC6973022 DOI: 10.1111/imr.12828] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 12/25/2022]
Abstract
The efficient spread of malaria from infected humans to mosquitoes is a major challenge for malaria elimination initiatives. Gametocytes are the only Plasmodium life stage infectious to mosquitoes. Here, we summarize evidence for naturally acquired anti-gametocyte immunity and the current state of transmission blocking vaccines (TBV). Although gametocytes are intra-erythrocytic when present in infected humans, developing Plasmodium falciparum gametocytes may express proteins on the surface of red blood cells that elicit immune responses in naturally exposed individuals. This immune response may reduce the burden of circulating gametocytes. For both P. falciparum and Plasmodium vivax, there is a solid evidence that antibodies against antigens present on the gametocyte surface, when co-ingested with gametocytes, can influence transmission to mosquitoes. Transmission reducing immunity, reducing the burden of infection in mosquitoes, is a well-acknowledged but poorly quantified phenomenon that forms the basis for the development of TBV. Transmission enhancing immunity, increasing the likelihood or intensity of transmission to mosquitoes, is more speculative in nature but is convincingly demonstrated for P. vivax. With the increased interest in malaria elimination, TBV and monoclonal antibodies have moved to the center stage of malaria vaccine development. Methodologies to prioritize and evaluate products are urgently needed.
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MESH Headings
- Antibodies, Blocking/immunology
- Antibodies, Protozoan/immunology
- Host-Parasite Interactions/immunology
- Humans
- Immunity
- Immunomodulation
- Life Cycle Stages
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Plasmodium vivax/growth & development
- Plasmodium vivax/immunology
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Affiliation(s)
- Roos M. de Jong
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Lisette Meerstein‐Kessel
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Centre for Molecular and Biomolecular InformaticsRadboud Institute for Molecular Life SciencesNijmegenThe Netherlands
| | - Fitsum G. Tadesse
- Armauer Hansen Research InstituteAddis AbabaEthiopia
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Matthijs M. Jore
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Will Stone
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
| | - Teun Bousema
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
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14
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Tripathi NK, Shrivastava A. Recent Developments in Bioprocessing of Recombinant Proteins: Expression Hosts and Process Development. Front Bioeng Biotechnol 2019; 7:420. [PMID: 31921823 PMCID: PMC6932962 DOI: 10.3389/fbioe.2019.00420] [Citation(s) in RCA: 249] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 11/29/2019] [Indexed: 12/22/2022] Open
Abstract
Infectious diseases, along with cancers, are among the main causes of death among humans worldwide. The production of therapeutic proteins for treating diseases at large scale for millions of individuals is one of the essential needs of mankind. Recent progress in the area of recombinant DNA technologies has paved the way to producing recombinant proteins that can be used as therapeutics, vaccines, and diagnostic reagents. Recombinant proteins for these applications are mainly produced using prokaryotic and eukaryotic expression host systems such as mammalian cells, bacteria, yeast, insect cells, and transgenic plants at laboratory scale as well as in large-scale settings. The development of efficient bioprocessing strategies is crucial for industrial production of recombinant proteins of therapeutic and prophylactic importance. Recently, advances have been made in the various areas of bioprocessing and are being utilized to develop effective processes for producing recombinant proteins. These include the use of high-throughput devices for effective bioprocess optimization and of disposable systems, continuous upstream processing, continuous chromatography, integrated continuous bioprocessing, Quality by Design, and process analytical technologies to achieve quality product with higher yield. This review summarizes recent developments in the bioprocessing of recombinant proteins, including in various expression systems, bioprocess development, and the upstream and downstream processing of recombinant proteins.
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Affiliation(s)
- Nagesh K. Tripathi
- Bioprocess Scale Up Facility, Defence Research and Development Establishment, Gwalior, India
| | - Ambuj Shrivastava
- Division of Virology, Defence Research and Development Establishment, Gwalior, India
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15
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The Pfs230 N-terminal fragment, Pfs230D1+: expression and characterization of a potential malaria transmission-blocking vaccine candidate. Malar J 2019; 18:356. [PMID: 31703583 PMCID: PMC6839146 DOI: 10.1186/s12936-019-2989-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/24/2019] [Indexed: 12/31/2022] Open
Abstract
Background Control and elimination of malaria can be accelerated by transmission-blocking interventions such as vaccines. A surface antigen of Plasmodium falciparum gametocytes, Pfs230, is a leading vaccine target antigen, and has recently progressed to experimental clinical trials. To support vaccine product development, an N-terminal Pfs230 antigen was designed to increase yield, as well as to improve antigen quality, integrity, and homogeneity. Methods A scalable baculovirus expression system was used to express the Pfs230D1+ construct (aa 552–731), which was subsequently purified and analysed. Pfs230D1+ was designed to avoid glycosylation and protease digestion, thereby potentially increasing homogeneity and stability. The resulting Pfs230D1+ protein was compared to a previous iteration of the Pfs230 N-terminal domain, Pfs230C1 (aa 443–731), through physiochemical characterization and in vivo analysis. The induction of functional antibody responses was confirmed via the standard membrane feeding assay (SMFA). Results Pfs230D1+ was produced and purified to an overall yield of 23 mg/L culture supernatant, a twofold yield increase over Pfs230C1. The Pfs230D1+ protein migrated as a single band via SDS-PAGE and was detected by anti-Pfs230C1 monoclonal antibodies. Evaluation by SDS-PAGE, chromatography (size-exclusion and reversed phase) and capillary isoelectric focusing demonstrated the molecule had improved homogeneity in terms of size, conformation, and charge. Intact mass spectrometry confirmed its molecular weight and that it was free of glycosylation, a key difference to the prior Pfs230C1 protein. The correct formation of the two intramolecular disulfide bonds was initially inferred by binding of a conformation specific monoclonal antibody and directly confirmed by LC/MS and peptide mapping. When injected into mice the Pfs230D1+ protein elicited antibodies that demonstrated transmission-reducing activity, via SMFA, comparable to Pfs230C1. Conclusion By elimination of an O-glycosylation site, a potential N-glycosylation site, and two proteolytic cleavage sites, an improved N-terminal Pfs230 fragment was produced, termed D1+, which is non-glycosylated, homogeneous, and biologically active. An intact protein at higher yield than that previously observed for the Pfs230C1 fragment was achieved. The results indicate that Pfs230D1+ protein produced in the baculovirus expression system is an attractive antigen for transmission-blocking vaccine development.
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16
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Liu F, Liu Q, Yu C, Zhao Y, Wu Y, Min H, Qiu Y, Jin Y, Miao J, Cui L, Cao Y. An MFS-Domain Protein Pb115 Plays a Critical Role in Gamete Fertilization of the Malaria Parasite Plasmodium berghei. Front Microbiol 2019; 10:2193. [PMID: 31616399 PMCID: PMC6764285 DOI: 10.3389/fmicb.2019.02193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Sexual reproduction is an essential process in the Plasmodium life cycle and a vulnerable step for blocking transmission from the human host to mosquitoes. In this study, we characterized the functions of a conserved cell membrane protein P115 in the rodent malaria parasite Plasmodium berghei ANKA. Pb115 was expressed in both asexual stages (schizonts) and sexual stages (gametocytes, gametes, and ookinetes), and was localized on the plasma membrane of gametes and ookinetes. In P. berghei, genetic deletion of Pb115 (Δpb115) did not affect asexual multiplication, nor did it affect gametocyte development or exflagellation of the male gametocytes. However, mosquitoes fed on Δpb115-infected mice showed 74% reduction in the prevalence of infection and 96.5% reduction in oocyst density compared to those fed on wild-type P. berghei-infected mice. The Δpb115 parasites showed significant defects in the interactions between the male and female gametes, and as a result, very few zygotes were formed in ookinete cultures. Cross fertilization with the male-defective Δpbs48/45 line and the female-defective Δpfs47 line further indicated that the fertilization defects of the Δpb115 lines were present in both male and female gametes. We evaluated the transmission-blocking potential of Pb115 by immunization of mice with a recombinant Pb115 fragment. In vivo mosquito feeding assay showed Pb115 immunization conferred modest, but significant transmission reducing activity with 44% reduction in infection prevalence and 39% reduction in oocyst density. Our results described functional characterization of a conserved membrane protein as a fertility factor in Plasmodium and demonstrated transmission-blocking potential of this antigen.
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Affiliation(s)
- Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Qingyang Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Chunyun Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Hui Min
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Yue Qiu
- The First Hospital of China Medical University, Shenyang, China
| | - Ying Jin
- Liaoning Research Institute of Family Planning, Shenyang, China
| | - Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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Outer membrane protein complex as a carrier for malaria transmission blocking antigen Pfs230. NPJ Vaccines 2019; 4:24. [PMID: 31312527 PMCID: PMC6614402 DOI: 10.1038/s41541-019-0121-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022] Open
Abstract
Malaria transmission blocking vaccines (TBV) target the mosquito stage of parasite development by passive immunization of mosquitoes feeding on a vaccinated human. Through uptake of vaccine-induced antibodies in a blood meal, mosquito infection is halted and hence transmission to another human host is blocked. Pfs230 is a gametocyte and gamete surface antigen currently under clinical evaluation as a TBV candidate. We have previously shown that chemical conjugation of poorly immunogenic TBV antigens to Exoprotein A (EPA) can enhance their immunogenicity. Here, we assessed Outer Membrane Protein Complex (OMPC), a membrane vesicle derived from Neisseria meningitidis, as a carrier for Pfs230. We prepared Pfs230-OMPC conjugates with varying levels of antigen load and examined immunogenicity in mice. Chemical conjugation of Pfs230 to OMPC enhanced immunogenicity and functional activity of the Pfs230 antigen, and OMPC conjugates achieved 2-fold to 20-fold higher antibody titers than Pfs230-EPA/AdjuPhos® at different doses. OMPC conjugates were highly immunogenic even at low doses, indicating a dose-sparing effect. EPA conjugates induced an IgG subclass profile biased towards a Th2 response, whereas OMPC conjugates induced a strong Th1-biased immune response with high levels of IgG2, which can benefit Pfs230 antibody functional activity, which depends on complement activation. OMPC is a promising carrier for Pfs230 vaccines. Malaria transmission blocking vaccines (TBV) target Plasmodium stages that transmit between human and mosquitos in order to interrupt the parasite’s life cycle and reduce spread. One TBV antigen currently under clinical development is Pf230, which is expressed on sexual Plasmodium stages. In this study, led by Patrick Duffy from the NIAID, researchers improve immunogenicity of Pf230. They chemically conjugate a part of Pf230 to membrane vesicles derived from bacteria, so-called outer membrane protein complexes (OMPC). Immunization of mice with Pf230-OMPC elicits a higher antibody response and a more balanced IgG subclass profile than control immunizations. Serum from Pf230-OMPC-vaccinated mice efficiently blocks infection of mosquitoes. These results with mice encourage further pre-clinical and clinical characterization of OMPC as a carrier for TBV antigens.
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Abstract
In the progression of the life cycle of Plasmodium falciparum, a small proportion of asexual parasites differentiate into male or female sexual forms called gametocytes. Just like their asexual counterparts, gametocytes are contained within the infected host's erythrocytes (RBCs). However, unlike their asexual partners, they do not exit the RBC until they are taken up in a blood meal by a mosquito. In the mosquito midgut, they are stimulated to emerge from the RBC, undergo fertilization, and ultimately produce tens of thousands of sporozoites that are infectious to humans. This transmission cycle can be blocked by antibodies targeting proteins exposed on the parasite surface in the mosquito midgut, a process that has led to the development of candidate transmission-blocking vaccines (TBV), including some that are in clinical trials. Here we review the leading TBV antigens and highlight the ongoing search for additional gametocyte/gamete surface antigens, as well as antigens on the surfaces of gametocyte-infected erythrocytes, which can potentially become a new group of TBV candidates.
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Lee SM, Plieskatt J, Krishnan S, Raina M, Harishchandra R, King CR. Expression and purification optimization of an N-terminal Pfs230 transmission-blocking vaccine candidate. Protein Expr Purif 2019; 160:56-65. [PMID: 30978392 PMCID: PMC6547048 DOI: 10.1016/j.pep.2019.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/26/2019] [Accepted: 04/06/2019] [Indexed: 11/28/2022]
Abstract
In an effort to control and eventually eliminate malaria, the development of transmission-blocking vaccines has long been sought. However, few antigens have been evaluated in clinical trials, often due to limitations in the expression and purification of the antigen in sufficient yield and quality. Pfs230, a surface antigen of gametocytes, has recently advanced to clinical evaluation as a conjugate vaccine using the Pseudomonas aeruginosa exoprotein A carrier protein. Here we continue to build upon prior work of developing a Pfs230 candidate in the baculovirus system, Pfs230C1 (aa 443–731), through systematic process development efforts to improve yield and purity. Various insect cells including High Five, Sf9 and Super Sf9 were first evaluated for quality and quantity of antigen, along with three insect cell media. In the selection of Sf9 cells, an intact Pfs230C1 was expressed and harvested at 48 h for downstream development. A downstream process, utilizing immobilized metal affinity column (IMAC), followed by ion exchange (IEX) membranes (Mustang S) and finally IEX chromatography (DEAE) yielded a pure Pfs230C1 protein. The complete process was repeated three times at the 20 L scale. To support the eventual chemistry manufacturing and controls (CMC) of Pfs230C1, analytical tools, including monoclonal antibodies, were developed to characterize the identity, integrity, and purity of Pfs230C1. These analytical tools, taken in combination with the optimized process, were implemented with Current Good Manufacturing Practices (cGMP) in mind with the ultimate objective of Phase I clinical trials. Super Sf9, Sf9 and High Five baculovirus cells were evaluated to express the Pfs230 construct. Following selection of Sf9 cells to minimize degradation, expression media was optimized. A purification approach was developed to produce a pure recombinant product free of host cell proteins. A variety of biochemical release assays were developed to support the release and stability of Pfs230. A scalable process suitable for cGMP manufacture was developed.
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Affiliation(s)
- Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA.
| | - Jordan Plieskatt
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
| | - Seetha Krishnan
- Syngene International Ltd, Plot No.2,3,4 &5 Phase IV, Bommasandra Jigani Link Road, Bommasandra Industrial Area, Bangalore, 560099, India
| | - Monika Raina
- Syngene International Ltd, Plot No.2,3,4 &5 Phase IV, Bommasandra Jigani Link Road, Bommasandra Industrial Area, Bangalore, 560099, India
| | - Rakeshkumar Harishchandra
- Syngene International Ltd, Plot No.2,3,4 &5 Phase IV, Bommasandra Jigani Link Road, Bommasandra Industrial Area, Bangalore, 560099, India
| | - C Richter King
- PATH's Malaria Vaccine Initiative (MVI), 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001-2621, USA
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20
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Miura K, Deng B, Wu Y, Zhou L, Pham TP, Diouf A, Wu CK, Lee SM, Plieskatt JL, Morin MJ, Long CA. ELISA units, IgG subclass ratio and avidity determined functional activity of mouse anti-Pfs230 antibodies judged by a standard membrane-feeding assay with Plasmodium falciparum. Vaccine 2019; 37:2073-2078. [PMID: 30850239 DOI: 10.1016/j.vaccine.2019.02.071] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/22/2019] [Accepted: 02/24/2019] [Indexed: 10/27/2022]
Abstract
The standard membrane-feeding assay (SMFA) is a functional assay that has been used to inform the development of transmission-blocking vaccines (TBV) against Plasmodium falciparum malaria. For Pfs230, a lead target antigen for TBV development, a few studies have tested either a single anti-Pfs230 polyclonal or monoclonal antibody (one antibody per study) at serial dilutions and showed a dose-dependent response. Further, there have been reports that the SMFA activity of anti-Pfs230 polyclonal and monoclonal antibodies were enhanced in the presence of complement. However, no analysis has been performed with multiple samples, and the impact of anti-Pfs230 antibody titers, IgG subclass profile and avidity were evaluated together in relation to transmission-reducing activity (TRA) by SMFA. In this report, a total of 39 unique anti-Pfs230 IgGs from five different mouse immunization studies were assessed for their ELISA units (EU), IgG2/IgG1 ratio and avidity by ELISA, and the functionality (% transmission-reducing activity, %TRA) by SMFA. The mice were immunized with Pfs230 alone, Pfs230 conjugated to CRM197, or a mixture of unconjugated Pfs230 and CRM197 proteins using Alhydrogel or Montanide ISA720 adjuvants. In all studies, the Pfs230 antigen was from the same source. There was a significant correlation between EU and %TRA (p < 0.0001 by a Spearman rank test) for the anti-Pfs230 IgGs. Notably, multiple linear regression analyses showed that both IgG2/IgG1 ratio and avidity significantly affected %TRA (p = 0.003 to p = 0.014, depending on the models) after adjusting for EU. The results suggest that in addition to antibody titers, IgG2/IgG1 ratio and avidity should each be evaluated to predict the biological activity of anti-Pfs230 antibodies for future vaccine development.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Yimin Wu
- PATH's Malaria Vaccine Initiative (MVI), Washington, DC 20001, USA
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Thao P Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Chia-Kuei Wu
- PATH's Malaria Vaccine Initiative (MVI), Washington, DC 20001, USA
| | - Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative (MVI), Washington, DC 20001, USA
| | | | | | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
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21
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Identification of domains within Pfs230 that elicit transmission blocking antibody responses. Vaccine 2019; 37:1799-1806. [PMID: 30824357 PMCID: PMC6708081 DOI: 10.1016/j.vaccine.2019.02.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/23/2019] [Accepted: 02/05/2019] [Indexed: 11/23/2022]
Abstract
A transmission-blocking vaccine (TBV) against Plasmodium falciparum is likely to be a valuable tool in a malaria eradication program. Pfs230 is one of the major TBV candidates, and multiple Pfs230-based vaccines induced antibodies, which prevented oocyst formation in mosquitoes as determined by a standard membrane-feeding assay (SMFA). Pfs230 is a >300 kDa protein consisting of 14 cysteine motif (CM) domains, and the size and cysteine-rich nature of the molecule have hampered its production as an intact protein. Except for one early study with maltose-binding protein fusion Pfs230 constructs expressed in Esherichia coli, all other studies have focused on only the first four CM domains in the Pfs230 molecule. To identify all possible TBV candidate domains, we systematically produced either single-CM-domain (a total of 14), 2-CM-domain (7), or 4-CM-domain (6) recombinant protein fragments using a eukaryotic wheat germ cell-free expression system (WGCFS). In addition, two more constructs which covered previously published regions, and an N-terminal prodomain construct spanning the natural cleavage site of Pfs230 were produced. Antisera against each fragment were generated in mice and we evaluated the reactivity to native Pfs230 protein by Western blots and immunofluorescence assay (IFA), and functionality by SMFA. All 30 WGCFS-produced Pfs230 constructs were immunogenic in mice. Approximately half of the mouse antibodies specifically recognized native Pfs230 by Western blots with variable band intensities. Among them, seven antibodies showed higher reactivities against native Pfs230 determined by IFA. Interestingly, antibodies against all protein fragments containing CM domain 1 displayed strong inhibitions in SMFA, while antibodies generated using constructs without CM domain 1 showed no inhibition. The results strongly support the concept that future Pfs230-based vaccine development should focus on the Pfs230 CM domain 1.
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22
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Huang WC, Deng B, Lin C, Carter KA, Geng J, Razi A, He X, Chitgupi U, Federizon J, Sun B, Long CA, Ortega J, Dutta S, King CR, Miura K, Lee SM, Lovell JF. A malaria vaccine adjuvant based on recombinant antigen binding to liposomes. NATURE NANOTECHNOLOGY 2018; 13:1174-1181. [PMID: 30297818 PMCID: PMC6286227 DOI: 10.1038/s41565-018-0271-3] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 09/03/2018] [Indexed: 05/04/2023]
Abstract
Pfs25 is a malaria transmission-blocking vaccine antigen candidate, but its apparently limited immunogenicity in humans has hindered clinical development. Here, we show that recombinant, polyhistidine-tagged (his-tagged) Pfs25 can be mixed at the time of immunization with pre-formed liposomes containing cobalt porphyrin-phospholipid, resulting in spontaneous nanoliposome antigen particleization (SNAP). Antigens are stably presented in uniformly orientated display via his-tag insertion in the cobalt porphyrin-phospholipid bilayer, without covalent modification or disruption of antigen conformation. SNAP immunization of mice and rabbits is well tolerated with minimal local reactogenicity, and results in orders-of-magnitude higher functional antibody generation compared with other 'mix-and-inject' adjuvants. Serum-stable antigen binding during transit to draining lymph nodes leads to enhanced antigen uptake by phagocytic antigen-presenting cells, with subsequent generation of long-lived, antigen-specific plasma cells. Seamless multiplexing with four additional his-tagged Plasmodium falciparum polypeptides induces strong and balanced antibody production, illustrating the simplicity of developing multistage particulate vaccines with SNAP immunization.
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Affiliation(s)
- Wei-Chiao Huang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Cuiyan Lin
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Kevin A Carter
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Jumin Geng
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Aida Razi
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec, Canada
| | - Xuedan He
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Upendra Chitgupi
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Jasmin Federizon
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Boyang Sun
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University Montreal, Quebec, Canada
| | - Sheetij Dutta
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative, Washington, DC, USA
| | - Jonathan F Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, USA.
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23
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Plasmodium genomics: an approach for learning about and ending human malaria. Parasitol Res 2018; 118:1-27. [PMID: 30402656 DOI: 10.1007/s00436-018-6127-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/19/2018] [Indexed: 12/31/2022]
Abstract
Malaria causes high levels of morbidity and mortality in human beings worldwide. According to the World Health Organization (WHO), about half a million people die of this disease each year. Malaria is caused by six species of parasites belonging to the Plasmodium genus: P. falciparum, P. knowlesi, P. vivax, P. malariae, P. ovale curtisi, and P. ovale wallikeri. Currently, malaria is being kept under control with varying levels of elimination success in different countries. The development of new molecular tools as well as the use of next-generation sequencing (NGS) technologies and novel bioinformatic approaches has improved our knowledge of malarial epidemiology, diagnosis, treatment, vaccine development, and surveillance strategies. In this work, the genetics and genomics of human malarias have been analyzed. Since the first P. falciparum genome was sequenced in 2002, various population-level genetic and genomic surveys, together with transcriptomic and proteomic studies, have shown the importance of molecular approaches in supporting malaria elimination.
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24
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Ishino T, Tsuboi T. Progress toward a transmission-blocking vaccine against malaria. THE LANCET. INFECTIOUS DISEASES 2018; 18:927-928. [PMID: 30061052 DOI: 10.1016/s1473-3099(18)30358-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 11/17/2022]
Affiliation(s)
- Tomoko Ishino
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
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25
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Abstract
Malaria is the major cause of mortality and morbidity in tropical countries. The causative agent, Plasmodium sp., has a complex life cycle and is armed with various mechanisms which ensure its continuous transmission. Gametocytes represent the sexual stage of the parasite and are indispensable for the transmission of the parasite from the human host to the mosquito. Despite its vital role in the parasite's success, it is the least understood stage in the parasite's life cycle. The presence of gametocytes in asymptomatic populations and induction of gametocytogenesis by most antimalarial drugs warrants further investigation into its biology. With a renewed focus on malaria elimination and advent of modern technology available to biologists today, the field of gametocyte biology has developed swiftly, providing crucial insights into the molecular mechanisms driving sexual commitment. This review will summarise key current findings in the field of gametocyte biology and address the associated challenges faced in malaria detection, control and elimination.
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26
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Kapoor N, Vanjak I, Rozzelle J, Berges A, Chan W, Yin G, Tran C, Sato AK, Steiner AR, Pham TP, Birkett AJ, Long CA, Fairman J, Miura K. Malaria Derived Glycosylphosphatidylinositol Anchor Enhances Anti-Pfs25 Functional Antibodies That Block Malaria Transmission. Biochemistry 2018; 57:516-519. [PMID: 29323879 PMCID: PMC5803671 DOI: 10.1021/acs.biochem.7b01099] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
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Malaria,
one of the most common vector borne human diseases, is a major world
health issue. In 2015 alone, more than 200 million people were infected
with malaria, out of which, 429 000 died. Even though artemisinin-based
combination therapies (ACT) are highly effective at treating malaria
infections, novel efforts toward development of vaccines to prevent
transmission are still needed. Pfs25, a postfertilization stage parasite
surface antigen, is a leading transmission-blocking vaccine (TBV)
candidate. It is postulated that Pfs25 anchors to the cell membrane
using a glycosylphosphatidylinositol (GPI) linker, which itself possesses
pro-inflammatory properties. In this study, Escherichia coli derived extract (XtractCF+TM) was used in cell free protein
synthesis [CFPS] to successfully express >200 mg/L of recombinant
Pfs25 with a C-terminal non-natural amino acid (nnAA), namely, p-azidomethyl phenylalanine (pAMF), which possesses a reactive
azide group. Thereafter, a unique conjugate vaccine (CV), namely,
Pfs25-GPI was generated with dibenzocyclooctyne (DBCO) derivatized
glycan core of malaria GPI using a simple but highly efficient copper
free click chemistry reaction. In mice immunized with Pfs25 or Pfs25-GPI,
the Pfs25-GPI group showed significantly higher titers compared to
the Pfs25 group. Moreover, only purified IgGs from Pfs25-GPI group
were able to significantly block transmission of parasites to mosquitoes,
as judged by a standard membrane feeding assay [SMFA]. To our knowledge,
this is the first report of the generation of a CV using Pfs25 and
malaria specific GPI where the GPI is shown to enhance the ability
of Pfs25 to elicit transmission blocking antibodies.
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Affiliation(s)
- Neeraj Kapoor
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - Ivana Vanjak
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - James Rozzelle
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - Aym Berges
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - Wei Chan
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - Gang Yin
- Sutro Biopharma , 310 Utah, South San Francisco, California 94080, United States
| | - Cuong Tran
- Sutro Biopharma , 310 Utah, South San Francisco, California 94080, United States
| | - Aaron K Sato
- Sutro Biopharma , 310 Utah, South San Francisco, California 94080, United States
| | - Alexander R Steiner
- Sutro Biopharma , 310 Utah, South San Francisco, California 94080, United States
| | - Thao P Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Rockville, Maryland 20852, United States
| | - Ashley J Birkett
- PATH's Malaria Vaccine Initiative (MVI) , Washington, D.C. 20001 United States
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Rockville, Maryland 20852, United States
| | - Jeff Fairman
- SutroVax, Inc. , 353 Hatch Drive, Foster City, California 94404, United States
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Rockville, Maryland 20852, United States
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