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Tumwine-Downey I, Deroost K, Levy P, McLaughlin S, Hosking C, Langhorne J. Antibody-dependent immune responses elicited by blood stage-malaria infection contribute to protective immunity to the pre-erythrocytic stages. CURRENT RESEARCH IN IMMUNOLOGY 2022; 4:100054. [PMID: 36593995 PMCID: PMC9803926 DOI: 10.1016/j.crimmu.2022.100054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/21/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Advances in transcriptomics and proteomics have revealed that different life-cycle stages of the malaria parasite, Plasmodium, share antigens, thus allowing for the possibility of eliciting immunity to a parasite life-cycle stage that has not been experienced before. Using the Plasmodium chabaudi (AS strain) model of malaria in mice, we investigated how isolated exposure to blood-stage infection, bypassing a liver-stage infection, yields significant protection to sporozoite challenge resulting in lower liver parasite burdens. Antibodies are the main immune driver of this protection. Antibodies induced by blood-stage infection recognise proteins on the surface of sporozoites and can impair sporozoite gliding motility in vitro, suggesting a possible function in vivo. Furthermore, mice lacking B cells and/or secreted antibodies are not protected against a sporozoite challenge in mice that had a previous blood-stage infection. Conversely, effector CD4+ and CD8+ T cells do not seem to play a role in protection from sporozoite challenge of mice previously exposed only to the blood stages of P. chabaudi. The protective response against pre-erythrocytic stages can be induced by infections initiated by serially passaged blood-stage parasites as well as recently mosquito transmitted parasites and is effective against a different strain of P. chabaudi (CB strain), but not against another rodent malaria species, P. yoelii. The possibility to induce protective cross-stage antibodies advocates the need to consider both stage-specific and cross-stage immune responses to malaria, as natural infection elicits exposure to all life-cycle stages. Future investigation into these cross-stage antibodies allows the opportunity for candidate antigens to contribute to malaria vaccine development.
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Affiliation(s)
| | | | | | | | | | - Jean Langhorne
- Corresponding author. Malaria Immunology Laboratory, Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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2
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Metwally DM, Alajmi RA, El-Khadragy MF, Al-Quraishy S. Silver Nanoparticles Biosynthesized With Salvia officinalis Leaf Exert Protective Effect on Hepatic Tissue Injury Induced by Plasmodium chabaudi. Front Vet Sci 2021; 7:620665. [PMID: 33614756 PMCID: PMC7889953 DOI: 10.3389/fvets.2020.620665] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 12/29/2020] [Indexed: 01/24/2023] Open
Abstract
Malaria is an important health problem in subtropical and tropical areas around the world. Infection with protozoan parasites of the Plasmodium genus, which grow inside host erythrocytes, causes malaria and may lead to morbidity and mortality. Liver tissue plays an important role in the pathogenesis of malaria and is closely involved in parasitic pre-erythrocytic development. Numerous published studies have demonstrated that the liver is not only the source of Plasmodium parasites prior to erythrocytic growth but is also a primary immune effector toward the blood stage of the malaria life cycle. Despite efforts to improve antimalarial drugs and vaccines, Plasmodium species that cause severe malaria are being detected increasingly frequently in endemic regions. In this study, Salvia officinalis (S. officinalis) leaf extract was employed to synthesize silver nanoparticles (Ag-NPs). This method is eco-friendly and represents a single-step technique for the biosynthetic process; therefore, it has attracted considerable attention. Accordingly, we biosynthesized Ag-NPs with extract of the S. officinalis leaf and examined the antimalarial activity of these nanoparticles in a murine model of Plasmodium chabaudi malaria (P. chabaudi malaria). Forty mice were chosen and classified into four types: infected group, healthy control, pretreated mice infected after treatment with 50 mg/kg of S. officinalis leaf extract-biosynthesized Ag-NPs for two weeks, and post-treated mice infected before treatment with 50 mg/kg of S. officinalis leaf extract-biosynthesized Ag-NPs (administered daily for 7 d). In this study, both pre-treatment and post-treatment with Ag-NPs produced a substantial reduction in parasitemia relative to the infected group. We investigated the antiplasmodial and hepatoprotective effects of S. officinalis leaf extract-biosynthesized Ag-NPs on P. chabaudi-induced inflammation and hepatic oxidative stress markers.
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Affiliation(s)
- Dina M Metwally
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.,Department of Parasitology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt
| | - Reem A Alajmi
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Manal F El-Khadragy
- Department of Biology, Faculty of Science, Princess Nourah Bint Abdelrahman University, Riyadh, Saudi Arabia.,Department of Zoology and Entomology, Faculty of Science, Helwan University, Cairo, Egypt
| | - Saleh Al-Quraishy
- Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
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3
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Enders MH, Bayarsaikhan G, Ghilas S, Chua YC, May R, de Menezes MN, Ge Z, Tan PS, Cozijnsen A, Mollard V, Yui K, McFadden GI, Lahoud MH, Caminschi I, Purcell AW, Schittenhelm RB, Beattie L, Heath WR, Fernandez-Ruiz D. Plasmodium berghei Hsp90 contains a natural immunogenic I-Ab-restricted antigen common to rodent and human Plasmodium species. CURRENT RESEARCH IN IMMUNOLOGY 2021; 2:79-92. [PMID: 35492393 PMCID: PMC9040146 DOI: 10.1016/j.crimmu.2021.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 01/13/2023] Open
Abstract
Thorough understanding of the role of CD4 T cells in immunity can be greatly assisted by the study of responses to defined specificities. This requires knowledge of Plasmodium-derived immunogenic epitopes, of which only a few have been identified, especially for the mouse C57BL/6 background. We recently developed a TCR transgenic mouse line, termed PbT-II, that produces CD4+ T cells specific for an MHC class II (I-Ab)-restricted Plasmodium epitope and is responsive to both sporozoites and blood-stage P. berghei. Here, we identify a peptide within the P. berghei heat shock protein 90 as the cognate epitope recognised by PbT-II cells. We show that C57BL/6 mice infected with P. berghei blood-stage induce an endogenous CD4 T cell response specific for this epitope, indicating cells of similar specificity to PbT-II cells are present in the naïve repertoire. Adoptive transfer of in vitro activated TH1-, or particularly TH2-polarised PbT-II cells improved control of P. berghei parasitemia in C57BL/6 mice and drastically reduced the onset of experimental cerebral malaria. Our results identify a versatile, potentially protective MHC-II restricted epitope useful for exploration of CD4 T cell-mediated immunity and vaccination strategies against malaria. Identification of a novel MHC-II-restricted epitope in P. berghei Hsp90 that is the cognate antigen of PbT-II CD4+ T cells. This epitope is conserved among mouse malaria parasites and in Plasmodium falciparum, which causes human malaria. Exposure to liver or blood stage P. berghei infection expands a population of endogenous Hsp90-specific CD4+ T cells. Dendritic cell-targeted vaccination generates memory PbT-II cells and endogenous Hsp90-specific CD4+ T cells. TH1- and TH2-polarised PbT-II cells reduce P. berghei parasitaemia and mitigate development of experimental cerebral malaria.
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4
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Gbedande K, Carpio VH, Stephens R. Using two phases of the CD4 T cell response to blood-stage murine malaria to understand regulation of systemic immunity and placental pathology in Plasmodium falciparum infection. Immunol Rev 2020; 293:88-114. [PMID: 31903675 PMCID: PMC7540220 DOI: 10.1111/imr.12835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/08/2019] [Accepted: 12/09/2019] [Indexed: 02/06/2023]
Abstract
Plasmodium falciparum infection and malaria remain a risk for millions of children and pregnant women. Here, we seek to integrate knowledge of mouse and human T helper cell (Th) responses to blood-stage Plasmodium infection to understand their contribution to protection and pathology. Although there is no complete Th subset differentiation, the adaptive response occurs in two phases in non-lethal rodent Plasmodium infection, coordinated by Th cells. In short, cellular immune responses limit the peak of parasitemia during the first phase; in the second phase, humoral immunity from T cell-dependent germinal centers is critical for complete clearance of rapidly changing parasite. A strong IFN-γ response kills parasite, but an excess of TNF compared with regulatory cytokines (IL-10, TGF-β) can cause immunopathology. This common pathway for pathology is associated with anemia, cerebral malaria, and placental malaria. These two phases can be used to both understand how the host responds to rapidly growing parasite and how it attempts to control immunopathology and variation. This dual nature of T cell immunity to Plasmodium is discussed, with particular reference to the protective nature of the continuous generation of effector T cells, and the unique contribution of effector memory T cells.
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Affiliation(s)
- Komi Gbedande
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Victor H Carpio
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Robin Stephens
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
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5
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Pérez-Mazliah D, Gardner PJ, Schweighoffer E, McLaughlin S, Hosking C, Tumwine I, Davis RS, Potocnik AJ, Tybulewicz VL, Langhorne J. Plasmodium-specific atypical memory B cells are short-lived activated B cells. eLife 2018; 7:39800. [PMID: 30387712 PMCID: PMC6242553 DOI: 10.7554/elife.39800] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 10/31/2018] [Indexed: 12/15/2022] Open
Abstract
A subset of atypical memory B cells accumulates in malaria and several infections, autoimmune disorders and aging in both humans and mice. It has been suggested these cells are exhausted long-lived memory B cells, and their accumulation may contribute to poor acquisition of long-lasting immunity to certain chronic infections, such as malaria and HIV. Here, we generated an immunoglobulin heavy chain knock-in mouse with a BCR that recognizes MSP1 of the rodent malaria parasite, Plasmodium chabaudi. In combination with a mosquito-initiated P. chabaudi infection, we show that Plasmodium-specific atypical memory B cells are short-lived and disappear upon natural resolution of chronic infection. These cells show features of activation, proliferation, DNA replication, and plasmablasts. Our data demonstrate that Plasmodium-specific atypical memory B cells are not a subset of long-lived memory B cells, but rather short-lived activated cells, and part of a physiologic ongoing B-cell response.
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Affiliation(s)
| | - Peter J Gardner
- MRC National Institute for Medical Research, London, United Kingdom
| | | | | | | | | | - Randall S Davis
- Department of Medicine, University of Alabama at Birmingham, Birmingham, United States.,Department of Microbiology, University of Alabama at Birmingham, Birmingham, United States.,Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, United States
| | - Alexandre J Potocnik
- School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
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6
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Pérez-Mazliah D, Nguyen MP, Hosking C, McLaughlin S, Lewis MD, Tumwine I, Levy P, Langhorne J. Follicular Helper T Cells are Essential for the Elimination of Plasmodium Infection. EBioMedicine 2017; 24:216-230. [PMID: 28888925 PMCID: PMC5652023 DOI: 10.1016/j.ebiom.2017.08.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 08/31/2017] [Accepted: 08/31/2017] [Indexed: 01/11/2023] Open
Abstract
CD4+ follicular helper T (Tfh) cells have been shown to be critical for the activation of germinal center (GC) B-cell responses. Similar to other infections, Plasmodium infection activates both GC as well as non-GC B cell responses. Here, we sought to explore whether Tfh cells and GC B cells are required to eliminate a Plasmodium infection. A CD4 T cell-targeted deletion of the gene that encodes Bcl6, the master transcription factor for the Tfh program, resulted in complete disruption of the Tfh response to Plasmodium chabaudi in C57BL/6 mice and consequent disruption of GC responses and IgG responses and the inability to eliminate the otherwise self-resolving chronic P. chabaudi infection. On the other hand, and contrary to previous observations in immunization and viral infection models, Signaling Lymphocyte Activation Molecule (SLAM)-Associated Protein (SAP)-deficient mice were able to activate Tfh cells, GC B cells, and IgG responses to the parasite. This study demonstrates the critical role for Tfh cells in controlling this systemic infection, and highlights differences in the signals required to activate GC B cell responses to this complex parasite compared with those of protein immunizations and viral infections. Therefore, these data are highly pertinent for designing malaria vaccines able to activate broadly protective B-cell responses. Chronic Plasmodium infection cannot be eliminated in the absence of Tfh cell responses. SAP-deficient mice are able to activate GC Tfh and GC B-cell responses to Plasmodium infection. There is a hierarchical requirement for the control of chronic Plasmodium infection following IL-21R > Tfh cells > SAP.
Successful vaccines work through activation of protective B-cell responses. Malaria, caused by Plasmodium infection transmitted by mosquito bites, remains a global threat. Despite substantial efforts, a vaccine able to bring about high levels of protection from Plasmodium infection remains elusive. Here, using an experimental malaria model including natural mosquito transmission, we demonstrate that proper activation of follicular helper CD4+ T cells is essential for the control and eradication of chronic Plasmodium infection through protective B-cell responses. Thus, it is strongly advisable for novel vaccine efforts to monitor the robust activation of this important immune compartment.
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7
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Pérez-Mazliah D, Ng DHL, Freitas do Rosário AP, McLaughlin S, Mastelic-Gavillet B, Sodenkamp J, Kushinga G, Langhorne J. Disruption of IL-21 signaling affects T cell-B cell interactions and abrogates protective humoral immunity to malaria. PLoS Pathog 2015; 11:e1004715. [PMID: 25763578 PMCID: PMC4370355 DOI: 10.1371/journal.ppat.1004715] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/29/2015] [Indexed: 12/22/2022] Open
Abstract
Interleukin-21 signaling is important for germinal center B-cell responses, isotype switching and generation of memory B cells. However, a role for IL-21 in antibody-mediated protection against pathogens has not been demonstrated. Here we show that IL-21 is produced by T follicular helper cells and co-expressed with IFN-γ during an erythrocytic-stage malaria infection of Plasmodium chabaudi in mice. Mice deficient either in IL-21 or the IL-21 receptor fail to resolve the chronic phase of P. chabaudi infection and P. yoelii infection resulting in sustained high parasitemias, and are not immune to re-infection. This is associated with abrogated P. chabaudi-specific IgG responses, including memory B cells. Mixed bone marrow chimeric mice, with T cells carrying a targeted disruption of the Il21 gene, or B cells with a targeted disruption of the Il21r gene, demonstrate that IL-21 from T cells signaling through the IL-21 receptor on B cells is necessary to control chronic P. chabaudi infection. Our data uncover a mechanism by which CD4+ T cells and B cells control parasitemia during chronic erythrocytic-stage malaria through a single gene, Il21, and demonstrate the importance of this cytokine in the control of pathogens by humoral immune responses. These data are highly pertinent for designing malaria vaccines requiring long-lasting protective B-cell responses. The importance of antibody and B-cell responses for control of the erythrocytic-stage of the malaria parasite, Plasmodium, was first described when immune serum, passively transferred into Plasmodium falciparum-infected children, reduced parasitemia. This was later confirmed in experimental models in which mice deficient in B cells were unable to eliminate erythrocytic-stage infections. The signals required to activate these protective long-lasting B cell responses towards Plasmodium have not been investigated. IL-21 has been shown to be important for development of B-cell responses after immunization; however, a direct requirement for IL-21 in the control of infection via B-cell dependent mechanisms has never been demonstrated. In this paper, we have used mouse models of erythrocytic P. chabaudi and P. yoelii 17X(NL) infections in combination with IL-21/IL-21R deficiency to show that IL-21 from CD4+ T cells is required to eliminate Plasmodium infection by activating protective, long-lasting B-cell responses. Disruption of IL-21 signaling in B cells prevents the elimination of the parasite resulting in sustained high parasitemias, with no development of memory B-cells, lack of antigen-specific plasma cells and antibodies, and thus no protective immunity against a second challenge infection. Our data demonstrate the absolute requirement of IL-21 for B-cell control of this systemic infection. This has important implications for the design of vaccines against Plasmodium.
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Affiliation(s)
- Damián Pérez-Mazliah
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | - Dorothy Hui Lin Ng
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | | | - Sarah McLaughlin
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | - Béatris Mastelic-Gavillet
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | - Jan Sodenkamp
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | - Garikai Kushinga
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research (NIMR), London, United Kingdom
- * E-mail:
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8
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Ng DHL, Skehel JJ, Kassiotis G, Langhorne J. Recovery of an antiviral antibody response following attrition caused by unrelated infection. PLoS Pathog 2014; 10:e1003843. [PMID: 24391499 PMCID: PMC3879355 DOI: 10.1371/journal.ppat.1003843] [Citation(s) in RCA: 15] [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: 03/15/2013] [Accepted: 11/05/2013] [Indexed: 01/28/2023] Open
Abstract
The homeostatic mechanisms that regulate the maintenance of immunological memory to the multiple pathogen encounters over time are unknown. We found that a single malaria episode caused significant dysregulation of pre-established Influenza A virus-specific long-lived plasma cells (LLPCs) resulting in the loss of Influenza A virus-specific Abs and increased susceptibility to Influenza A virus re-infection. This loss of LLPCs involved an FcγRIIB-dependent mechanism, leading to their apoptosis. However, given enough time following malaria, the LLPC pool and humoral immunity to Influenza A virus were eventually restored. Supporting a role for continuous conversion of Influenza A virus-specific B into LLPCs in the restoration of Influenza A virus immunity, B cell depletion experiments also demonstrated a similar requirement for the long-term maintenance of serum Influenza A virus-specific Abs in an intact LLPC compartment. These findings show that, in addition to their established role in the anamnestic response to reinfection, the B cell pool continues to be a major contributor to the maintenance of long-term humoral immunity following primary Influenza A virus infection, and to the recovery from attrition following heterologous infection. These data have implications for understanding the longevity of protective efficacy of vaccinations in countries where continuous infections are endemic. Antibody responses to infectious pathogens are critical in host survival, recovery and protection from reinfection; they also correlate with the success of vaccination. It is currently thought that antibody serum titers are maintained at protective levels over long periods of time by specialized long-lived antibody-secreting plasma cells residing in the bone marrow. Indeed, antibodies against the original virus can still be found in survivors of the 1918 Spanish Flu, more than 90 years ago. However, it is also becoming clear that subsequent infection with heterologous pathogens may cause attrition of previously established immunological memory, in order to accommodate new lymphocyte specificities in the finite space of the host. This phenomenon is seemingly at odds with long-term maintenance of immunological memory. We also show that a single episode of malaria, caused by infection by Plasmodium chabaudi, leads to the loss of preexisting plasma cells, serum antibodies and protective immunity against Influenza A virus. However, Influenza A virus-specific immunity does eventually recover in these animals with the replenishment of plasma cells by B cells over the course of several weeks. Thus, the reported mechanism reconciles attrition of immunological memory by heterologous infection and long-term stability, and places B cells, instead of their descendant plasma cells, at the center of humoral memory.
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Affiliation(s)
- Dorothy H. L. Ng
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - John J. Skehel
- Division of Virology, MRC National Institute for Medical Research, London, United Kingdom
| | - George Kassiotis
- Division of Immunoregulation, MRC National Institute for Medical Research, London, United Kingdom
- * E-mail: (GK); (JL)
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
- * E-mail: (GK); (JL)
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9
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Cheong FW, Fong MY, Lau YL, Mahmud R. Immunogenicity of bacterial-expressed recombinant Plasmodium knowlesi merozoite surface protein-142 (MSP-142). Malar J 2013; 12:454. [PMID: 24354660 PMCID: PMC3878241 DOI: 10.1186/1475-2875-12-454] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 12/17/2013] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium knowlesi is the fifth Plasmodium species that can infect humans. The Plasmodium merozoite surface protein-142 (MSP-142) is a potential candidate for malaria vaccine. However, limited studies have focused on P. knowlesi MSP-142. Methods A ~42 kDa recombinant P. knowlesi MSP-142 (pkMSP-142) was expressed using an Escherichia coli system. The purified pkMSP-142 was evaluated with malaria and non-malaria human patient sera (n = 189) using Western blots and ELISA. The immunogenicity of pkMSP-142 was evaluated in mouse model. Results The purified pkMSP-142 had a sensitivity of 91.0% for detection of human malaria in both assays. Specificity was 97.5 and 92.6% in Western blots and ELISA, respectively. Levels of cytokine interferon-gamma, interleukin-2, interleukin-4, and interleukin-10 significantly increased in pkMSP-142-immunized mice as compared to the negative control mice. pkMSP-142-raised antibody had high endpoint titres, and the IgG isotype distribution was IgG1 > IgG2b > IgG3 > IgG2a. Conclusions pkMSP-142 was highly immunogenic and able to detect human malaria. Hence, pkMSP-142 would be a useful candidate for malaria vaccine development and seroprevalence studies.
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Affiliation(s)
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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10
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Fairlie-Clarke KJ, Allen JE, Read AF, Graham AL. Quantifying variation in the potential for antibody-mediated apparent competition among nine genotypes of the rodent malaria parasite Plasmodium chabaudi. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2013; 20:270-5. [PMID: 24056014 PMCID: PMC3898986 DOI: 10.1016/j.meegid.2013.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 01/01/2023]
Abstract
Within-host competition among parasite genotypes affects epidemiology as well as the evolution of virulence. In the rodent malaria Plasmodium chabaudi, competition among genotypes, as well as clone-specific and clone-transcending immunity are well documented. However, variation among genotypes in the induction of antibodies is not well understood, despite the important role of antibodies in the clearance of malaria infection. Here, we quantify the potential for antibodies induced by one clone to bind another (i.e., to cause antibody-mediated apparent competition) for nine genetically distinct P. chabaudi clones. We hypothesised that clones would vary in the strength of antibody induction, and that the propensity for clone-transcending immunity between a pair of clones would increase with increasing genetic relatedness at key antigenic loci. Using serum collected from mice 35 days post-infection, we measured titres of antibody to an unrelated antigen, Keyhole Limpet Haemocyanin (KLH), and two malaria antigens: recombinant Apical Membrane Antigen-1 (AMA-1) and Merozoite Surface Protein-119 (MSP-119). Amino acid sequence homology within each antigenic locus was used as a measure of relatedness. We found significant parasite genetic variation for the strength of antibody induction. We also found that relatedness at MSP-119 but not AMA-1 predicted clone-transcending binding. Our results help explain the outcome of chronic-phase mixed infections and generate testable predictions about the pairwise competitive ability of P. chabaudi clones.
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Affiliation(s)
- Karen J Fairlie-Clarke
- Institutes of Evolution, Immunology and Infection Research, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh, UK.
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11
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Cheong FW, Lau YL, Fong MY, Mahmud R. Evaluation of recombinant Plasmodium knowlesi merozoite surface protein-1(33) for detection of human malaria. Am J Trop Med Hyg 2013; 88:835-40. [PMID: 23509118 DOI: 10.4269/ajtmh.12-0250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Plasmodium knowlesi is now known as the fifth Plasmodium species that can cause human malaria. The Plasmodium merozoite surface protein (MSP) has been reported to be potential target for vaccination and diagnosis of malaria. MSP-1(33) has been shown to be immunogenic and its T cell epitopes could mediate cellular immune protection. However, limited studies have focused on P. knowlesi MSP-133. In this study, an approximately 28-kDa recombinant P. knowlesi MSP-1(33) (pkMSP-1(33)) was expressed by using an Escherichia coli system. The purified pkMSP-1(33) reacted with serum samples of patients infected with P. knowlesi (31 of 31, 100%) and non-P. knowlesi malaria (27 of 28, 96.43%) by Western blotting. The pkMSP-1(33) also reacted with P. knowlesi (25 of 31, 80.65%) and non-P. knowlesi malaria sera (20 of 28, 71.43%) in an enzyme-linked immunosorbent assay (ELISA). Most of the non-malarial infection (49 of 52 in by Western blotting and 46 of 52 in the ELISA) and healthy donor serum samples (65 of 65 by Western blotting and ELISA) did not react with recombinant pkMSP-1(33).
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Affiliation(s)
- Fei Wen Cheong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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12
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Bisseye C, Yindom LM, Simporé J, Morgan WD, Holder AA, Ismaili J. An engineered Plasmodium falciparum C-terminal 19-kilodalton merozoite surface protein 1 vaccine candidate induces high levels of interferon-gamma production associated with cellular immune responses to specific peptide sequences in Gambian adults naturally exposed to malaria. Clin Exp Immunol 2012; 166:366-73. [PMID: 22059995 DOI: 10.1111/j.1365-2249.2011.04467.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The 19-kDa C-terminal region of merozoite surface protein 1 (MSP1(19)), a major blood stage malaria vaccine candidate, is the target of cellular and humoral immune responses in humans naturally infected with Plasmodium falciparum. We have previously described engineered variants of this protein, designed to be better vaccine candidates, but the human immune response to these proteins has not been characterized fully. Here we have investigated the antigenicity of one such variant compared to wild-type MSP1(19)-derived protein and peptides. Gambian adults produced both high T helper type 1 (Th1) [interferon (IFN)-γ] and Th0/Th2 [interleukin (IL)-13 and sCD30] responses to the wild-type MSP1(19) and the modified protein as wells as to peptides derived from both forms. Response to the modified MSP1(19) (with three amino acid substitutions: Glu27Tyr, Leu31Arg and Glu43Leu) relative to the wild-type, included higher IFN-γ production. Interestingly, some peptides evoked different patterns of cytokine responses. Modified peptides induced higher IL-13 production than the wild-type, while the conserved peptides P16 and P19 induced the highest IFN-γ and IL-13 and/or sCD30 release, respectively. We identified P16 as the immunodominant peptide that was recognized by cells from 63% of the study population, and not restricted to any particular human leucocyte antigen D-related (HLA-DR) type. These findings provide new and very useful information for future vaccine development and formulation as well as potential Th1/Th2 immunmodulation using either wild-type or modified protein in combination with their peptides.
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Affiliation(s)
- C Bisseye
- Medical Research Council Laboratories, Banjul, The Gambia
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Pollitt LC, Mideo N, Drew DR, Schneider P, Colegrave N, Reece SE. Competition and the Evolution of Reproductive Restraint in Malaria Parasites. Am Nat 2011; 177:358-67. [DOI: 10.1086/658175] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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14
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Effector memory Th1 CD4 T cells are maintained in a mouse model of chronic malaria. PLoS Pathog 2010; 6:e1001208. [PMID: 21124875 PMCID: PMC2991260 DOI: 10.1371/journal.ppat.1001208] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 10/25/2010] [Indexed: 11/19/2022] Open
Abstract
Protection against malaria often decays in the absence of infection, suggesting that protective immunological memory depends on stimulation. Here we have used CD4+ T cells from a transgenic mouse carrying a T cell receptor specific for a malaria protein, Merozoite Surface Protein-1, to investigate memory in a Plasmodium chabaudi infection. CD4+ memory T cells (CD44hiIL-7Rα+) developed during the chronic infection, and were readily distinguishable from effector (CD62LloIL-7Rα−) cells in acute infection. On the basis of cell surface phenotype, we classified memory CD4+ T cells into three subsets: central memory, and early and late effector memory cells, and found that early effector memory cells (CD62LloCD27+) dominated the chronic infection. We demonstrate a linear pathway of differentiation from central memory to early and then late effector memory cells. In adoptive transfer, CD44hi memory cells from chronically infected mice were more effective at delaying and reducing parasitemia and pathology than memory cells from drug-treated mice without chronic infection, and contained a greater proportion of effector cells producing IFN-γ and TNFα, which may have contributed to the enhanced protection. These findings may explain the observation that in humans with chronic malaria, activated effector memory cells are best maintained in conditions of repeated exposure. Protective immunity against malaria develops only after several infections and can be lost on leaving an area in which malaria is transmitted. This suggests that the chronic infection may maintain the protective immune response. In this paper we have used a mouse model of a blood-stage malaria infection to examine the memory response of CD4+ T cells during chronic infection. These T cells are required for protective immunity, and also play a part in the inflammatory response that gives rise to malaria disease. Understanding what constitutes a protective CD4+ T cell may help us design more protective vaccines. We show that these memory CD4+ T cells persist in an activated state, produce the inflammatory cytokines TNFα and IFN-γ, and are more protective than “resting” memory CD4+ T cells obtained from mice in which the infection has been eliminated. This may explain why people are better protected against malaria disease when they are infected frequently.
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Ndungu FM, Cadman ET, Coulcher J, Nduati E, Couper E, MacDonald DW, Ng D, Langhorne J. Functional memory B cells and long-lived plasma cells are generated after a single Plasmodium chabaudi infection in mice. PLoS Pathog 2009; 5:e1000690. [PMID: 20011127 PMCID: PMC2784955 DOI: 10.1371/journal.ppat.1000690] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 11/11/2009] [Indexed: 11/18/2022] Open
Abstract
Antibodies have long been shown to play a critical role in naturally acquired immunity to malaria, but it has been suggested that Plasmodium-specific antibodies in humans may not be long lived. The cellular mechanisms underlying B cell and antibody responses are difficult to study in human infections; therefore, we have investigated the kinetics, duration and characteristics of the Plasmodium-specific memory B cell response in an infection of P. chabaudi in mice. Memory B cells and plasma cells specific for the C-terminal region of Merozoite Surface Protein 1 were detectable for more than eight months following primary infection. Furthermore, a classical memory response comprised predominantly of the T-cell dependent isotypes IgG2c, IgG2b and IgG1 was elicited upon rechallenge with the homologous parasite, confirming the generation of functional memory B cells. Using cyclophosphamide treatment to discriminate between long-lived and short-lived plasma cells, we demonstrated long-lived cells secreting Plasmodium-specific IgG in both bone marrow and in spleens of infected mice. The presence of these long-lived cells was independent of the presence of chronic infection, as removal of parasites with anti-malarial drugs had no impact on their numbers. Thus, in this model of malaria, both functional Plasmodium-specific memory B cells and long-lived plasma cells can be generated, suggesting that defects in generating these cell populations may not be the reason for generating short-lived antibody responses. Malaria causes considerable human suffering resulting from associated high mortality, morbidity and reduced economic productivity in endemic areas. Current control methods are thwarted by a multiplicity of problems including rapidly developing resistance for anti-malarial drugs and insecticide-treated nets, and huge costs and hence poor coverage with bed nets in poor countries. Understanding the basis of the inefficiency of immunity to malaria in childhood will greatly aid the search for effective vaccines, which together with drugs and vector control, will be essential in the drive to eliminate malaria. Because of the strong evidence associating anti-malarial antibodies with anti-parasitic and anti-disease effects, vaccines inducing protective long-lasting antibody responses are attractive. However, it has been suggested that antibody responses to some Plasmodium antigens may be not long-lived. It would be important to determine whether long-lived plasma cells and memory B cells are generated after a malaria infection; however, these studies are difficult to perform in humans. Therefore we investigated the kinetics, duration and characteristics of the two cell types responsible for long-term antibody production in a mouse model of malaria. We show here that malaria-specific memory B cells and plasma cells are still detectable more than eight months after infection, and that both long-lived malaria-specific antibody-secreting cells and functional malaria-specific memory B cells can be made after a single infection.
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Affiliation(s)
- Francis Maina Ndungu
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Emma Tamsin Cadman
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Joshua Coulcher
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Eunice Nduati
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
- KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Elisabeth Couper
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | | | - Dorothy Ng
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research, London, United Kingdom
- * E-mail:
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Okafor CMF, Anumudu CI, Omosun YO, Uthaipibull C, Ayede I, Awobode HO, Odaibo AB, Langhorne J, Holder AA, Nwuba RI, Troye-Blomberg M. Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection. Malar J 2009; 8:263. [PMID: 19930613 PMCID: PMC2785830 DOI: 10.1186/1475-2875-8-263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 11/23/2009] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the Plasmodium falciparum merozoite surface protein 1 (MSP1(19)), inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP1(19) had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP1(19) would affect critical T-cell responses to epitopes in this antigen. METHODS The cellular responses to wild-type MSP1(19) and a panel of modified MSP1(19) antigens were measured using an in-vitro assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to Plasmodium falciparum infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults. RESULTS Interestingly, stimulation indices (SI) for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP1(19). A protein with four amino acid substitutions (Glu27-->Tyr, Leu31-->Arg, Tyr34-->Ser and Glu43-->Leu) had the highest stimulation index (SI up to 360) and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins. CONCLUSION This study suggests that specific MSP1(19) variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.
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Affiliation(s)
- Christian MF Okafor
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
- College of Art and Sciences, Northwest University, 5520, 108th Ave. NE, Kirkland WA 98033, USA
| | - Chiaka I Anumudu
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
| | - Yusuf O Omosun
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
- Department of Biotechnology, Bells University of Technology, Sango-Otta, Nigeria
| | - Chairat Uthaipibull
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
- Protein-Ligand Engineering and Molecular Biology Laboratory, National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, Pathumthani, Thailand
| | - Idowu Ayede
- Oni Memorial Children's Hospital, Ring Road, Ibadan, Nigeria
| | - Henrietta O Awobode
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
| | - Alex B Odaibo
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Anthony A Holder
- Division of Parasitology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Roseangela I Nwuba
- Cellular Parasitology Programme, Department of Zoology University of Ibadan, Ibadan, Nigeria
| | - Marita Troye-Blomberg
- Department of Immunology, Wenner-Gren Institute, Arrhenius Laboratories, Stockholm University, Stockholm, Sweden
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Migrating monocytes recruited to the spleen play an important role in control of blood stage malaria. Blood 2009; 114:5522-31. [PMID: 19837977 DOI: 10.1182/blood-2009-04-217489] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Host responses controlling blood-stage malaria include both innate and acquired immune effector mechanisms. During Plasmodium chabaudi infection in mice, a population of CD11b(high)Ly6C(+) monocytes are generated in bone marrow, most of which depend on the chemokine receptor CCR2 for migration from bone marrow to the spleen. In the absence of this receptor mice harbor higher parasitemias. Most importantly, splenic CD11b(high)Ly6C(+) cells from P chabaudi-infected wild-type mice significantly reduce acute-stage parasitemia in CCR2(-/-) mice. The CD11b(high)Ly6C(+) cells in this malaria infection display effector functions such as production of inducible nitric oxide synthase and reactive oxygen intermediates, and phagocytose P chabaudi parasites in vitro, and in a proportion of the cells, in vivo in the spleen, suggesting possible mechanisms of parasite killing. In contrast to monocyte-derived dendritic cells, CD11b(high)Ly6C(+) cells isolated from malaria-infected mice express low levels of major histocompatibility complex II and have limited ability to present the P chabaudi antigen, merozoite surface protein-1, to specific T-cell receptor transgenic CD4 T cells and fail to activate these T cells. We propose that these monocytes, which are rapidly produced in the bone marrow as part of the early defense mechanism against invading pathogens, are important for controlling blood-stage malaria parasites.
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Huaman MC, Martin LB, Malkin E, Narum DL, Miller LH, Mahanty S, Long CA. Ex vivo cytokine and memory T cell responses to the 42-kDa fragment of Plasmodium falciparum merozoite surface protein-1 in vaccinated volunteers. THE JOURNAL OF IMMUNOLOGY 2008; 180:1451-61. [PMID: 18209040 DOI: 10.4049/jimmunol.180.3.1451] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A number of blood-stage malaria Ags are under development as vaccine candidates, but knowledge of the cellular responses to these vaccines in humans is limited. We evaluated the nature and specificity of cellular responses in healthy American volunteers vaccinated with a portion of the major merozoite surface protein-1 (MSP1) of Plasmodium falciparum, MSP1(42), formulated on Alhydrogel. Volunteers were vaccinated three times with 80 microg of either MSP1(42)-FVO/Alhydrogel or MSP1(42)-3D7/Alhydrogel. Cells collected 2 wk after the third vaccination produced Th1 cytokines, including IFN-gamma and IL-2 following Ag stimulation, and greater levels of the Th2 cytokines IL-5 and IL-13; the anti-inflammatory cytokine IL-10 and the molecule CD25 (IL-2Ralpha) were also detected. The volunteers were evaluated for the MSP1(42)-FVO or MSP1(42)-3D7 specificity of their T cell responses. Comparison of their responses to homologous and heterologous Ags showed ex vivo IFN-gamma and IL-5 levels that were significantly higher to homologous rather than to heterologous Ags. The epitopes involved in this stimulation were shown to be present in the dimorphic MSP1(33) portion of the larger MSP1(42)-3D7 polypeptide, and indirect experiment suggests the same for the MSP1(42)-FVO polypeptide. This contrasts with B cell responses, which were primarily directed to the conserved MSP1(19) portion. Furthermore, we explored the maturation of memory T cells and found that 46% of vaccinees showed specific memory T cells defined as CD4(+)CD45RO(+)CD40L(+) after long-term in vitro culture. The identification of human-specific CD4(+) memory T cells provides the foundation for future studies of these cells both after vaccination and in field studies.
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Affiliation(s)
- Maria Cecilia Huaman
- Malaria Vaccine Development Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
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Achtman AH, Stephens R, Cadman ET, Harrison V, Langhorne J. Malaria-specific antibody responses and parasite persistence after infection of mice with Plasmodium chabaudi chabaudi. Parasite Immunol 2007; 29:435-44. [PMID: 17727567 DOI: 10.1111/j.1365-3024.2007.00960.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
While it is known that antibodies are critical for clearance of malaria infections, it is not clear whether adequate antibody responses are maintained and what effect chronic infection has on this response. Here we show that mice with low-grade chronic primary infections of Plasmodium chabaudi or infections very recently eliminated have reduced second infections when compared with the second infection of parasite-free mice. We also show that parasite-specific antibody responses induced by infection of mice with Plasmodium chabaudi contain both short- and long-lived components as well as memory B cells responsible for a faster antibody response during re-infection. Furthermore, parasite-specific antibodies to the C-terminal fragment of merozoite surface protein-1 (MSP-1) undergo avidity maturation. However, antibodies with both low and high avidity persist throughout infection and after re-infection, suggesting repeated rounds of activation and maturation of memory B cells. Neither the avidity profile of the antibody response, nor its maintenance is affected by persisting live parasites. Therefore, differences in parasitemia in re-infection cannot be explained solely by higher levels of antibody or greater affinity maturation of malaria-specific antibodies. These data suggest that there may be an antibody-independent component to the early control of secondary infections in mice that are chronically infected.
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Affiliation(s)
- A H Achtman
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK
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20
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Cytokine responses of CD4+ T cells during a Plasmodium chabaudi chabaudi (ER) blood-stage infection in mice initiated by the natural route of infection. Malar J 2007; 6:77. [PMID: 17555592 PMCID: PMC1904224 DOI: 10.1186/1475-2875-6-77] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Accepted: 06/07/2007] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Investigation of host responses to blood stages of Plasmodium spp, and the immunopathology associated with this phase of the life cycle are often performed on mice infected directly with infected red blood cells. Thus, the effects of mosquito bites and the pre-erythrocytic stages of the parasite, which would be present in natural infection, are ignored In this paper, Plasmodium chabaudi chabaudi infections of mice injected directly with infected red blood cells were compared with those of mice infected by the bites of infected mosquitoes, in order to determine whether the courses of primary infection and splenic CD4 T cell responses are similar. METHODS C57Bl/6 mice were injected with red blood cells infected with P. chabaudi (ER) or infected via the bite of Anopheles stephensi mosquitoes. Parasitaemia were monitored by Giemsa-stained thin blood films. Total spleen cells, CD4+ T cells, and cytokine production (IFN-gamma, IL-2, IL-4, IL-10) were analysed by flow cytometry. In some experiments, mice were subjected to bites of uninfected mosquitoes prior to infectious bites in order to determine whether mosquito bites per se could affect a subsequent P. chabaudi infection. RESULTS P. chabaudi (ER) infections initiated by mosquito bite were characterized by lower parasitaemia of shorter duration than those observed after direct blood challenge. However, splenomegaly was comparable suggesting that parasitaemia alone does not account for the increase in spleen size. Total numbers of CD4 T cells and those producing IFN-gamma, IL-10 and IL-2 were reduced in comparison to direct blood challenge. By contrast, the reduction in IL-4 producing cells was less marked suggesting that there is a proportionally lower Th1-like response in mice infected via infectious mosquitoes. Strikingly, pre-exposure to bites of uninfected mosquitoes reduced the magnitude and duration of the subsequent mosquito-transmitted infection still further, but enhanced the response of CD4 T cells producing IFN-gamma and IL-4. CONCLUSION The data in this paper suggest that studying early host responses in blood stage malaria infections measured after direct blood challenge of mice may not completely reflect the natural situation, and more detailed investigations of blood-stage immunity after mosquito transmission in experimental models should be considered.
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Abstract
That humans in endemic areas become immune to malaria offers encouragement to the idea of developing protective vaccines. However natural immunity is relatively inefficient, being bought at the cost of substantial childhood mortality, and current vaccines are only partially protective. Understanding potential targets and mechanisms of protective immunity is important in the development and evaluation of future vaccines. Some of the problems in identifying such targets and mechanisms in humans naturally exposed to malaria may stem from conceptual and methodological issues related to defining who in a population is susceptible, problems in defining immune responsiveness at single time points and issues related to antigenic polymorphism, as well as the failure of many current approaches to examine functional aspects of the immune response. Protective immune responses may be directed to the pre erythrocytic parasite, to the free merozoite of the blood stage parasite or to new antigens induced on the infected red cell surface. Tackling the methodological issues of defining protection and immune response, together with studies that combine functional assays with new approaches such as allelic exchange and gene knock out offer opportunities for better defining key targets and mechanisms.
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Affiliation(s)
- K Marsh
- KEMRI Centre for Geographic Medicine Research Coast (CGMRC), PO Box 230, Kilifi, Kenya.
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22
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Achtman AH, Bull PC, Stephens R, Langhorne J. Longevity of the Immune Response and Memory to Blood-Stage Malaria Infection. Curr Top Microbiol Immunol 2005; 297:71-102. [PMID: 16265903 DOI: 10.1007/3-540-29967-x_3] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Immunity to malaria develops slowly with protection against the parasite lagging behind protection against disease symptoms. The data on the longevity of protective immune responses are sparse. However, studies of antibody responses associated with protection reveal that they consist of a short- and a long-lived component. Compared with the antibody levels observed in other infection and immunization systems, the levels of the short-lived antibody compartment drop below the detectable threshold with unusual rapidity. The prevalence of long-lived antibodies is comparable to that seen after bacterial and protozoan infections. There is even less available data concerning T cell longevity in malaria infection, but what there is seems to indicate that T cell memory is short in the absence of persistent antigen. In general, the degree and duration of parasite persistence represent a major factor determining how immune response longevity and protection correlate. The predilection for short-lived immune responses in malaria infection could be caused by a number of mechanisms resulting from the interplay of normal regulatory mechanisms of the immune system and immune evasion by the parasite. In conclusion, it appears that the parasite-host relationship has developed to favor some short-lived responses, which allow the host to survive while allowing the parasite to persist. Anti-malarial immune responses present a complex picture, and many aspects of regulation and longevity of the response require further research.
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Affiliation(s)
- A H Achtman
- Molecular Tumor Genetics and Immunogenetics, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
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Omosun YO, Anumudu CI, Adoro S, Odaibo AB, Sodeinde O, Holder AA, Nwagwu M, Nwuba RI. Variation in the relationship between anti-MSP-1(19) antibody response and age in children infected with Plasmodium falciparum during the dry and rainy seasons. Acta Trop 2005; 95:233-47. [PMID: 16055071 DOI: 10.1016/j.actatropica.2005.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Revised: 06/07/2005] [Accepted: 06/08/2005] [Indexed: 10/25/2022]
Abstract
Malaria remains a major parasitic disease in Africa, with 300-500 million new infections each year. There is therefore an urgent need for the development of new effective measures, including vaccines. Plasmodium falciparum merozoite surface protein-1(19) (MSP-1(19)) is a prime candidate for a blood-stage malaria vaccine. Blood samples were collected from children aged 10 days to 15 years in the months of January-March (N = 351) and October-November (N = 369) corresponding to the dry and rainy seasons, respectively. P. falciparum infection was determined by microscopy and enzyme linked immunosorbent assay (ELISA) was used to determine the total IgG and IgG subclasses. There was a significant increase in the mean anti-MSP-1(19) antibody titre in the dry season (p < 0.05), compared to the rainy season. A significantly positive correlation between the anti-MSP-1(19) antibody titre and parasite density (p < 0.01, r = 0.138) was observed. In the rainy season, unlike in the dry season, P. falciparum positive children had higher anti-MSP-1(19) antibody titres than P. falciparum negative children and this difference was significant (p < 0.05). When all individuals were grouped together, the anti-MSP-1(19) antibody titre increased with age in both seasons (r = 0.186 and 0.002), this increase was more apparent in the dry season. However, when the study population was divided into P. falciparum positive and negative groups, it was observed that in the rainy season, there was a negative correlation between anti-MSP-1(19) titre and age in P. falciparum positive individuals, while those who were P. falciparum negative had a positive correlation between anti-MSP-1(19) titre and age. Analysis of anti-MSP-1(19) IgG subclass showed that IgG1 and IgG3 mean titres were highest in both the dry and rainy seasons with an increase in the mean antibody titres for IgG1, IgG2 and IgG3 in the rainy season. In the dry season there was a positive correlation between IgG1, IgG2, and IgG3 titres with age, while IgG4 was negative, whereas in the rainy season there was a positive correlation between IgG2 and IgG4 (non-cytophilic antibodies) with age and a negative correlation for IgG1 and IgG3 (cytophilic antibodies) with age. Seasonal differences in the level of MSP-1(19) IgG subclass titres were observed for P. falciparum negative and positive individuals. Only samples, which were positive for IgG2 and IgG4, showed positive correlation between parasitemia and total IgG. The incidence of P. falciparum infection, which increases during the rainy season, might be an important determinant of anti-MSP-1(19) antibody levels in children living in Igbo-Ora and the results point to the fact that non-cytophilic antibodies to MSP-1(19) in children might be associated with an increase in total IgG and parasitemia.
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Affiliation(s)
- Y O Omosun
- Department of Zoology, University of Ibadan, Ibadan, Nigeria
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Stephens R, Albano FR, Quin S, Pascal BJ, Harrison V, Stockinger B, Kioussis D, Weltzien HU, Langhorne J. Malaria-specific transgenic CD4+ T cells protect immunodeficient mice from lethal infection and demonstrate requirement for a protective threshold of antibody production for parasite clearance. Blood 2005; 106:1676-84. [PMID: 15890689 DOI: 10.1182/blood-2004-10-4047] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Abstract
T cells are important in the immune response to malaria, both for their cytokines and their help for antibody production. To look at the relative importance of these roles, a T-cell receptor (TCR) transgenic mouse has been generated carrying a TCR specific for an epitope of the merozoite surface protein 1 (MSP-1) of the malaria parasite, Plasmodium chabaudi. In adoptive transfer experiments, malaria-specific CD4+ T cells expand and produce interferon γ (IFN-γ) early in infection, but the population contracts quickly despite prolonged persistence of the parasite. MSP-1-specific CD4+ cells can protect immunodeficient mice from lethal infection; however, the parasite is only completely cleared in the presence of B cells showing that T helper cells are critical. Levels of malaria-specific antibody and the speed of their production clearly correlate with the time of resolution of infection, indicating that a critical threshold of antibody production is required for parasite clearance. Furthermore, T cells specific for a shed portion of MSP-1 are able to provide help for antibody to the protective region, which remains bound to the infected erythrocyte, suggesting that MSP-1 has all of the components necessary for a good vaccine. (Blood. 2005;106:1676-1684)
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Affiliation(s)
- Robin Stephens
- National Institute of Medical Research, The Ridgeway, Mill Hill London, NW7 1AA, United Kingdom
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Langhorne J, Albano FR, Hensmann M, Sanni L, Cadman E, Voisine C, Sponaas AM. Dendritic cells, pro-inflammatory responses, and antigen presentation in a rodent malaria infection. Immunol Rev 2005; 201:35-47. [PMID: 15361231 DOI: 10.1111/j.0105-2896.2004.00182.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
An infection of mice with Plasmodium chabaudi is characterized by a rapid and marked inflammatory response with a rapid but regulated production of interleukin-12 (IL-12), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma). Recent studies have shown that dendritic cells (DCs) are activated in vivo in the spleen, are able to process and present malaria antigens during infection, and may provide a source of cytokines that contribute to polarization of the CD4 T-cell response. P. chabaudi-infected erythrocytes are phagocytosed by DCs, and peptides of malaria proteins are presented on major histocompatibility complex (MHC) class II. The complex disulfide-bonded structure of some malaria proteins can impede their processing in DCs, which may affect the magnitude of the CD4 T-cell response and influence T-helper 1 (Th1) or Th2 polarization. DCs exhibit a wide range of responses to parasite-infected erythrocytes depending on their source, their maturational state, and the Plasmodium species or strain. P. chabaudi-infected erythrocytes stimulate an increase in the expression of costimulatory molecules and MHC class II on mouse bone marrow-derived DCs, and they are able to induce the production of pro-inflammatory cytokines such as IL-12, TNF-alpha, and IL-6, thus enhancing the Th1 response of naïve T cells. IFN-gamma and TNF-alpha play a role in both protective immunity and the pathology of the infection, and the inflammatory disease may be regulated by IL-10 and transforming growth factor-beta. It will therefore be important to elucidate the host and parasite molecules that are involved in activation or suppression of the DCs and to understand the interplay between these opposing forces on the host response in vivo during a malaria infection.
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Affiliation(s)
- Jean Langhorne
- Division of Parasitology, National Institute for Medical Research, London, UK.
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26
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Scopel KKG, Fontes CJF, Ferreira MU, Braga EM. Plasmodium falciparum: IgG subclass antibody response to merozoite surface protein-1 among Amazonian gold miners, in relation to infection status and disease expression. Exp Parasitol 2005; 109:124-34. [PMID: 15687019 DOI: 10.1016/j.exppara.2004.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 11/18/2004] [Accepted: 12/02/2004] [Indexed: 10/25/2022]
Abstract
The merozoite surface protein-1 (MSP-1) of Plasmodium falciparum comprises two major targets of antibody-mediated immunity: the polymorphic block 2 and the 19-kDa C-terminal domain MSP-1(19). Here, we measured antibodies to three block 2 variants and MSP-1(19) among Amazonian gold miners and examined the repertoire of block 2 variants in local parasites. Main findings were as follows: (1) Only seven different block 2 variants were found in 18 DNA sequences analyzed. (2) No major difference was observed in IgG subclass distribution of antibodies from symptomatic P. falciparum-infected patients, asymptomatic parasite carriers, and non-infected subjects. (3) Antibodies to all block 2 antigens, but not to MSP-1(19), were biased towards IgG3 across different strata of cumulative malaria exposure. (4) Similar proportions of symptomatic and asymptomatic subjects failed to recognize the block 2 variant expressed by infecting parasites. These negative results underscore the limits of conventional antibody assays to evaluate clinical immunity to malaria.
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Affiliation(s)
- Kézia K G Scopel
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte (MG), Brazil
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27
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Cigel F, Batchelder J, Burns JM, Yañez D, van der Heyde H, Manning DD, Weidanz WP. Immunity to blood-stage murine malarial parasites is MHC class II dependent. Immunol Lett 2004; 89:243-9. [PMID: 14556985 DOI: 10.1016/s0165-2478(03)00152-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
To determine whether MHC class II antigen presentation is essential for the induction of protective immunity against blood-stage malarial parasites, we used gene-targeted knockout (KO) mice to follow the time-course of nonlethal Plasmodium yoelii and Plasmodium chabaudi infections in two models of MHC class II deficiency. Infection of MHC class II KO (A(-/-)) mice with either parasite species resulted in an unremitting hyperparasitemia, whereas MHC-intact control mice resolved their parasitemia. In contrast, invariant chain KO (Ii(-/-)) mice, which present antigen via recycled but not nascent MHC class II molecules, eventually cured their infections when infected with P. yoelii. P. chabaudi parasitemia declined to subpatent levels in most Ii(-/-) mice but then recrudesced. Immunity to blood-stage malaria may be achieved by cell-mediated and antibody-mediated mechanisms of immunity, as such, the findings in A(-/-) mice indicate an essential role for MHC class II presentation of malarial antigens. Moreover, they suggest that protective immune responses to malarial antigens capable of eliminating blood-stage parasites are T cell dependent and can be induced with antigens processed in early and late endosomes.
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Affiliation(s)
- Francine Cigel
- Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, 1300 University Avenue, Madison, WI 53706, USA
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28
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Hensmann M, Li C, Moss C, Lindo V, Greer F, Watts C, Ogun SA, Holder AA, Langhorne J. Disulfide bonds in merozoite surface protein 1 of the malaria parasite impede efficient antigen processing and affect thein vivoantibody response. Eur J Immunol 2004; 34:639-648. [PMID: 14991593 DOI: 10.1002/eji.200324514] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The 19 kDa C-terminal fragment of the malaria parasite merozoite surface protein 1 (MSP1(19)) is a leading malaria vaccine candidate. In rodents, high antibody levels to this protein confer protective immunity, and can be generated by immunization with the antigen in adjuvants. In natural human infections, however, MSP1(19)-specific antibody responses can be short-lived and comparatively low, despite repeated exposure to infection. The tightly folded structure of MSP1(19) is stabilized by five or six disulfide bonds. These bonds impede antigen processing and, thereby, may affect the generation of CD4+ T cells providing help for B cells. Asparagine endopeptidase could digest unfolded, but not native MSP1(19) in vitro. Immunization with unfolded MSP1(19) resulted in a faster antibody response, and a combination of unfolded and native MSP1(19) increased antibody responses to the native form. Immunization with either form of the antigen activated similar numbers of CD4+ T cells, but, unlike the antibody response, CD4+ T cells immunized with one form of MSP119 were able to respond in vitro to the other form of the protein. Although the reduced form of MSP1(19) does not induce protective antibodies, our data suggest that inclusion of unfolded protein may improve the efficacy of MSP1(19) as a vaccine.
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Affiliation(s)
- Meike Hensmann
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
| | - Ching Li
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
| | - Catherine Moss
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
| | - Viv Lindo
- Department of Biochemistry, Wellcome Trust Biocentre, University of Dundee, Dundee, GB
| | | | - Colin Watts
- Department of Biochemistry, Wellcome Trust Biocentre, University of Dundee, Dundee, GB
| | - Solabomi A Ogun
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
| | - Anthony A Holder
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
| | - Jean Langhorne
- Division of Parasitology, National Institute for Medical Research, The Ridgeway, Mill Hill, London, GB
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Angov E, Aufiero BM, Turgeon AM, Van Handenhove M, Ockenhouse CF, Kester KE, Walsh DS, McBride JS, Dubois MC, Cohen J, Haynes JD, Eckels KH, Heppner DG, Ballou WR, Diggs CL, Lyon JA. Development and pre-clinical analysis of a Plasmodium falciparum Merozoite Surface Protein-1(42) malaria vaccine. Mol Biochem Parasitol 2003; 128:195-204. [PMID: 12742586 DOI: 10.1016/s0166-6851(03)00077-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Merozoite Surface Protein-1(42) (MSP-1(42)) is a leading vaccine candidate against erythrocytic malaria parasites. We cloned and expressed Plasmodium falciparum MSP-1(42) (3D7 clone) in Escherichia coli. The antigen was purified to greater than 95% homogeneity by using nickel-, Q- and carboxy-methyl (CM)-substituted resins. The final product, designated Falciparum Merozoite Protein-1 (FMP1), had endotoxin levels significantly lower than FDA standards. It was structurally correct based on binding conformation-dependent mAbs, and was stable. Functional antibodies from rabbits vaccinated with FMP1 in Freund's adjuvant inhibited parasite growth in vitro and also inhibited secondary processing of MSP-1(42). FMP1 formulated with GlaxoSmithKline Biologicals (GSK) adjuvant, AS02A or alum was safe and immunogenic in rhesus (Macaca mulatta) monkeys.
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Affiliation(s)
- Evelina Angov
- Department of Immunology, WRAIR, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA.
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30
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Garraud O, Perraut R, Diouf A, Nambei WS, Tall A, Spiegel A, Longacre S, Kaslow DC, Jouin H, Mattei D, Engler GM, Nutman TB, Riley EM, Mercereau-Puijalon O. Regulation of antigen-specific immunoglobulin G subclasses in response to conserved and polymorphic Plasmodium falciparum antigens in an in vitro model. Infect Immun 2002; 70:2820-7. [PMID: 12010968 PMCID: PMC127999 DOI: 10.1128/iai.70.6.2820-2827.2002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytophilic antibodies (Abs) play a critical role in protection against Plasmodium falciparum blood stages, yet little is known about the parameters regulating production of these Abs. We used an in vitro culture system to study the subclass distribution of antigen (Ag)-specific immunoglobulin G (IgG) produced by peripheral blood mononuclear cells (PBMCs) from individuals exposed to P. falciparum or unexposed individuals. PBMCs, cultivated with or without cytokines and exogenous CD40/CD40L signals, were stimulated with a crude parasite extract, recombinant vaccine candidates derived from conserved Ags (19-kDa C terminus of merozoite surface protein 1 [MSP1(19)], R23, and PfEB200), or recombinant Ags derived from the polymorphic Ags MSP1 block 2 and MSP2. No P. falciparum-specific Ab production was detected in PBMCs from unexposed individuals. PBMCs from donors exposed frequently to P. falciparum infections produced multiple IgG subclasses when they were stimulated with the parasite extract but usually only one IgG subclass when they were stimulated with a recombinant Ag. Optimal Ab production required addition of interleukin-2 (IL-2) and IL-10 for all antigenic preparations. The IgG subclass distribution was both donor and Ag dependent and was only minimally influenced by the exogenous cytokine environment. In vitro IgG production and subclass distribution correlated with plasma Abs to some Ags (MSP1(19), R23, and MSP2) but not others (PfEB200 and the three MSP1 block 2-derived Ags). Data presented here suggest that intrinsic properties of the protein Ag itself play a major role in determining the subclass of the Ab response, which has important implications for rational design of vaccine delivery.
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MESH Headings
- Adult
- Animals
- Antibodies, Protozoan/immunology
- Antigens, Protozoan/immunology
- Cells, Cultured
- Conserved Sequence
- Cytokines/immunology
- Endemic Diseases
- Female
- Humans
- Immunoglobulin G/immunology
- Immunoglobulin Isotypes/immunology
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/immunology
- Malaria, Falciparum/blood
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/immunology
- Male
- Merozoite Surface Protein 1/genetics
- Merozoite Surface Protein 1/immunology
- Models, Immunological
- Plasmodium falciparum/immunology
- Polymorphism, Genetic
- Protozoan Proteins/immunology
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/immunology
- Senegal/epidemiology
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Affiliation(s)
- Olivier Garraud
- Laboratoire d'Immunologie. Laboratoire d'Epidémiologie du Paludisme, Institut Pasteur de Dakar, Dakar, Senegal.
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