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Hassert M, Arumugam S, Harty JT. Memory CD8+ T cell-mediated protection against liver-stage malaria. Immunol Rev 2023; 316:84-103. [PMID: 37014087 PMCID: PMC10524177 DOI: 10.1111/imr.13202] [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: 01/15/2023] [Revised: 03/09/2023] [Accepted: 03/21/2023] [Indexed: 04/05/2023]
Abstract
Nearly half of the world's population is at risk of malaria, a disease caused by the protozoan parasite Plasmodium, which is estimated to cause more than 240,000,000 infections and kill more than 600,000 people annually. The emergence of Plasmodia resistant to chemoprophylactic treatment highlights the urgency to develop more effective vaccines. In this regard, whole sporozoite vaccination approaches in murine models and human challenge studies have provided substantial insight into the immune correlates of protection from malaria. From these studies, CD8+ T cells have come to the forefront, being identified as critical for vaccine-mediated liver-stage immunity that can prevent the establishment of the symptomatic blood stages and subsequent transmission of infection. However, the unique biological characteristics required for CD8+ T cell protection from liver-stage malaria dictate that more work must be done to design effective vaccines. In this review, we will highlight a subset of studies that reveal basic aspects of memory CD8+ T cell-mediated protection from liver-stage malaria infection.
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Affiliation(s)
- Mariah Hassert
- Department of Pathology, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
| | - Sahaana Arumugam
- Department of Pathology, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
- Medical Scientist Training Program, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
- Interdisciplinary Graduate Program in Immunology, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
| | - John T. Harty
- Department of Pathology, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
- Interdisciplinary Graduate Program in Immunology, University of Iowa- Carver College of Medicine, Iowa City, IA, USA
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Immunoprofiling Identifies Functional B and T Cell Subsets Induced by an Attenuated Whole Parasite Malaria Vaccine as Correlates of Sterile Immunity. Vaccines (Basel) 2022; 10:vaccines10010124. [PMID: 35062785 PMCID: PMC8780163 DOI: 10.3390/vaccines10010124] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/06/2022] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Immune correlates of protection remain elusive for most vaccines. An identified immune correlate would accelerate the down-selection of vaccine formulations by reducing the need for human pathogen challenge studies that are currently required to determine vaccine efficacy. Immunization via mosquito-delivered, radiation-attenuated P. falciparum sporozoites (IMRAS) is a well-established model for efficacious malaria vaccines, inducing greater than 90% sterile immunity. The current immunoprofiling study utilized samples from a clinical trial in which vaccine dosing was adjusted to achieve only 50% protection, thus enabling a comparison between protective and non-protective immune signatures. In-depth immunoprofiling was conducted by assessing a wide range of antigen-specific serological and cellular parameters and applying our newly developed computational tools, including machine learning. The computational component of the study pinpointed previously un-identified cellular T cell subsets (namely, TNFα-secreting CD8+CXCR3−CCR6− T cells, IFNγ-secreting CD8+CCR6+ T cells and TNFα/FNγ-secreting CD4+CXCR3−CCR6− T cells) and B cell subsets (i.e., CD19+CD24hiCD38hiCD69+ transitional B cells) as important factors predictive of protection (92% accuracy). Our study emphasizes the need for in-depth immunoprofiling and subsequent data integration with computational tools to identify immune correlates of protection. The described process of computational data analysis is applicable to other disease and vaccine models.
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Patra S, Singh M, Wasnik K, Pareek D, Gupta PS, Mukherjee S, Paik P. Polymeric Nanoparticle Based Diagnosis and Nanomedicine for Treatment and Development of Vaccines for Cerebral Malaria: A Review on Recent Advancement. ACS APPLIED BIO MATERIALS 2021; 4:7342-7365. [PMID: 35006689 DOI: 10.1021/acsabm.1c00635] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebral malaria occurs due to Plasmodium falciparum infection, which causes 228 million infections and 450,000 deaths worldwide every year. African people are mostly affected with nearly 91% cases, of which 86% are pregnant women and infants. India and Brazil are the other two countries severely suffering from malaria endemicity. Commonly used drugs have severe side effects, and unfortunately no suitable vaccine is available in the market today. In this line, this review is focused on polymeric nanomaterials and nanocapsules that can be used for the development of effective diagnostic strategies, nanomedicines, and vaccines in the management of cerebral malaria. Further, this review will help scientists and medical professionals by updating the status on the development stages of polymeric nanoparticle based diagnostics, nanomedicines, and vaccines and strategies to eradicate cerebral malaria. In addition to this, the predominant focus of this review is antimalarial agents based on polymer nanomedicines that are currently in the preclinical and clinical trial stages, and potential developments are suggested as well. This review further will have an important social and commercial impact worldwide for the development of polymeric nanomedicines and strategies for the treatment of cerebral malaria.
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Affiliation(s)
- Sukanya Patra
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Monika Singh
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Kirti Wasnik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Divya Pareek
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Prem Shankar Gupta
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
| | - Sudip Mukherjee
- Department of Bioengineering, Rice University, Houston, Texas 77030, United States
| | - Pradip Paik
- School of Biomedical Engineering, Indian Institute of Technology-BHU, Varanasi 221005, India
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Proteogenomic analysis of the total and surface-exposed proteomes of Plasmodium vivax salivary gland sporozoites. PLoS Negl Trop Dis 2017; 11:e0005791. [PMID: 28759593 PMCID: PMC5552340 DOI: 10.1371/journal.pntd.0005791] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 08/10/2017] [Accepted: 07/10/2017] [Indexed: 12/29/2022] Open
Abstract
Plasmodium falciparum and Plasmodium vivax cause the majority of human malaria cases. Research efforts predominantly focus on P. falciparum because of the clinical severity of infection and associated mortality rates. However, P. vivax malaria affects more people in a wider global range. Furthermore, unlike P. falciparum, P. vivax can persist in the liver as dormant hypnozoites that can be activated weeks to years after primary infection, causing relapse of symptomatic blood stages. This feature makes P. vivax unique and difficult to eliminate with the standard tools of vector control and treatment of symptomatic blood stage infection with antimalarial drugs. Infection by Plasmodium is initiated by the mosquito-transmitted sporozoite stage, a highly motile invasive cell that targets hepatocytes in the liver. The most advanced malaria vaccine for P. falciparum (RTS,S, a subunit vaccine containing of a portion of the major sporozoite surface protein) conferred limited protection in Phase III trials, falling short of WHO-established vaccine efficacy goals. However, blocking the sporozoite stage of infection in P. vivax, before the establishment of the chronic liver infection, might be an effective malaria vaccine strategy to reduce the occurrence of relapsing blood stages. It is also thought that a multivalent vaccine comprising multiple sporozoite surface antigens will provide better protection, but a comprehensive analysis of proteins in P. vivax sporozoites is not available. To inform sporozoite-based vaccine development, we employed mass spectrometry-based proteomics to identify nearly 2,000 proteins present in P. vivax salivary gland sporozoites. Analysis of protein post-translational modifications revealed extensive phosphorylation of glideosome proteins as well as regulators of transcription and translation. Additionally, the sporozoite surface proteins CSP and TRAP, which were recently discovered to be glycosylated in P. falciparum salivary gland sporozoites, were also observed to be similarly modified in P. vivax sporozoites. Quantitative comparison of the P. vivax and P. falciparum salivary gland sporozoite proteomes revealed a high degree of similarity in protein expression levels, including among invasion-related proteins. Nevertheless, orthologs with significantly different expression levels between the two species could be identified, as well as highly abundant, species-specific proteins with no known orthologs. Finally, we employed chemical labeling of live sporozoites to isolate and identify 36 proteins that are putatively surface-exposed on P. vivax salivary gland sporozoites. In addition to identifying conserved sporozoite surface proteins identified by similar analyses of other Plasmodium species, our analysis identified several as-yet uncharacterized proteins, including a putative 6-Cys protein with no known ortholog in P. falciparum. Malaria is one of the most important infectious diseases in the world with hundreds of millions of new cases every year. Malaria is caused by parasites of the genus Plasmodium which have a complex life cycle, alternating between mosquito and mammalian hosts. Human infections are initiated with a sporozoite inoculum deposited into the skin by parasite-infected mosquitoes as they probe for blood. Sporozoites must locate blood vessels and enter the circulation to reach the liver where they invade and grow in hepatocytes. In the case of Plasmodium vivax, one of the two Plasmodium species responsible for the majority of the disease burden in the world, the parasite has the ability to persist for months in the liver after the initial infection and its activation causes the recurring appearance of the parasite in the blood. Though all clinical symptoms are attributable to the blood stages, it is only by attacking the transmission stages before the formation of hypnozoites (the persisting parasites in the liver) that an impact on the burden of vivax malaria can be achieved. We used state-of-the-art mass spectrometry-based proteomics tools to identify the total protein make-up of P. vivax sporozoites. By analyzing which proteins are exposed to the parasite surface and determining the degree of protein’s post-translational modifications, our investigation will aid the understanding of the novel biology of sporozoites and importantly, advise the development of potential vaccine candidates targeting this parasite stage.
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Doolan DL, Apte SH, Proietti C. Genome-based vaccine design: the promise for malaria and other infectious diseases. Int J Parasitol 2014; 44:901-13. [PMID: 25196370 DOI: 10.1016/j.ijpara.2014.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 01/08/2023]
Abstract
Vaccines are one of the most effective interventions to improve public health, however, the generation of highly effective vaccines for many diseases has remained difficult. Three chronic diseases that characterise these difficulties include malaria, tuberculosis and HIV, and they alone account for half of the global infectious disease burden. The whole organism vaccine approach pioneered by Jenner in 1796 and refined by Pasteur in 1857 with the "isolate, inactivate and inject" paradigm has proved highly successful for many viral and bacterial pathogens causing acute disease but has failed with respect to malaria, tuberculosis and HIV as well as many other diseases. A significant advance of the past decade has been the elucidation of the genomes, proteomes and transcriptomes of many pathogens. This information provides the foundation for new 21st Century approaches to identify target antigens for the development of vaccines, drugs and diagnostic tests. Innovative genome-based vaccine strategies have shown potential for a number of challenging pathogens, including malaria. We advocate that genome-based rational vaccine design will overcome the problem of poorly immunogenic, poorly protective vaccines that has plagued vaccine developers for many years.
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Affiliation(s)
- Denise L Doolan
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia.
| | - Simon H Apte
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
| | - Carla Proietti
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4029, Australia
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White MT, Griffin JT, Ghani AC. The design and statistical power of treatment re-infection studies of the association between pre-erythrocytic immunity and infection with Plasmodium falciparum. Malar J 2013; 12:278. [PMID: 23927576 PMCID: PMC3751675 DOI: 10.1186/1475-2875-12-278] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 07/01/2013] [Indexed: 11/30/2022] Open
Abstract
Background Understanding the role of pre-erythrocytic immune responses to Plasmodium falciparum parasites is crucial for understanding the epidemiology of malaria. However, published studies have reported inconsistent results on the association between markers of pre-erythrocytic immunity and protection from malaria. Methods The design and statistical methods of studies of pre-erythrocytic immunity were reviewed, and factors affecting the likelihood of detecting statistically significant associations were assessed. Treatment re-infection studies were simulated to estimate the effects of study size, transmission intensity, and sampling frequency on the statistical power to detect an association between markers of pre-erythrocytic immunity and protection from infection. Results Nine of nineteen studies reviewed reported statistically significant associations between markers of pre-erythrocytic immunity and protection from infection. Studies with large numbers of participants in high-transmission settings, followed longitudinally with active detection of infection and with immune responses analysed as continuous variables, were most likely to detect statistically significant associations. Simulation of treatment re-infection studies highlights that many studies are underpowered to detect statistically significant associations, providing an explanation for the finding that only some studies report significant associations between pre-erythrocytic immune responses and protection from infection. Conclusions The findings of the review and model simulations are consistent with the hypothesis that pre-erythrocytic immune responses prevent P. falciparum infections, but that many studies are underpowered to consistently detect this effect.
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Affiliation(s)
- Michael T White
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, UK.
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Khan SM, Janse CJ, Kappe SHI, Mikolajczak SA. Genetic engineering of attenuated malaria parasites for vaccination. Curr Opin Biotechnol 2012; 23:908-16. [PMID: 22560204 DOI: 10.1016/j.copbio.2012.04.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 04/06/2012] [Accepted: 04/12/2012] [Indexed: 01/28/2023]
Abstract
Vaccination with live-attenuated Plasmodium sporozoites that arrest in the liver can completely protect against a malaria infection both in animal models and in humans; this has provided the conceptual basis for the most promising, but also challenging, approach to develop an efficacious malaria vaccine. Advances in genetic manipulation of Plasmodium in conjunction with improved genomic and biological information has enabled new approaches to design genetically attenuated parasites (GAPs). In this review we discuss the principles in discovery and development of GAPs in preclinical models that are important in selecting GAP parasites for first-in-human clinical studies. Finally, we highlight the challenges in manufacture, formulation and delivery of a live-attenuated whole parasite malaria vaccine, as well as the further refinements that may be implemented in the next generation GAP vaccines.
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Affiliation(s)
- Shahid M Khan
- Leiden Malaria Research Group, Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands.
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Abstract
There is no licenced vaccine against any human parasitic disease and Plasmodium falciparum malaria, a major cause of infectious mortality, presents a great challenge to vaccine developers. This has led to the assessment of a wide variety of approaches to malaria vaccine design and development, assisted by the availability of a safe challenge model for small-scale efficacy testing of vaccine candidates. Malaria vaccine development has been at the forefront of assessing many new vaccine technologies including novel adjuvants, vectored prime-boost regimes and the concept of community vaccination to block malaria transmission. Most current vaccine candidates target a single stage of the parasite's life cycle and vaccines against the early pre-erythrocytic stages have shown most success. A protein in adjuvant vaccine, working through antibodies against sporozoites, and viral vector vaccines targeting the intracellular liver-stage parasite with cellular immunity show partial efficacy in humans, and the anti-sporozoite vaccine is currently in phase III trials. However, a more effective malaria vaccine suitable for widespread cost-effective deployment is likely to require a multi-component vaccine targeting more than one life cycle stage. The most attractive near-term approach to develop such a product is to combine existing partially effective pre-erythrocytic vaccine candidates.
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Affiliation(s)
- Adrian V S Hill
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX37DQ, UK.
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Mwacharo J, Dunachie SJ, Kai O, Hill AVS, Bejon P, Fletcher HA. Quantitative PCR evaluation of cellular immune responses in Kenyan children vaccinated with a candidate malaria vaccine. PLoS One 2009; 4:e8434. [PMID: 20037644 PMCID: PMC2792766 DOI: 10.1371/journal.pone.0008434] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 11/23/2009] [Indexed: 11/29/2022] Open
Abstract
Background The T-cell mediated immune response plays a central role in the control of malaria after natural infection or vaccination. There is increasing evidence that T-cell responses are heterogeneous and that both the quality of the immune response and the balance between pro-inflammatory and regulatory T-cells determines the outcome of an infection. As Malaria parasites have been shown to induce immunosuppressive responses to the parasite and non-related antigens this study examined T-cell mediated pro-inflammatory and regulatory immune responses induced by malaria vaccination in children in an endemic area to determine if these responses were associated with vaccine immunogenicity. Methods Using real–time RT- PCR we profiled the expression of a panel of key markers of immunogenecity at different time points after vaccination with two viral vector vaccines expressing the malaria TRAP antigen (FP9-TRAP and MVA-TRAP) or following rabies vaccination as a control. Principal Findings The vaccine induced modest levels of IFN-γ mRNA one week after vaccination. There was also an increase in FoxP3 mRNA expression in both TRAP stimulated and media stimulated cells in the FFM ME-TRAP vaccine group; however, this may have been driven by natural exposure to parasite rather than by vaccination. Conclusion Quantitative PCR is a useful method for evaluating vaccine induced cell mediated immune responses in frozen PBMC from children in a malaria endemic country. Future studies should seek to use vaccine vectors that increase the magnitude and quality of the IFN-γ immune response in naturally exposed populations and should monitor the induction of a regulatory T cell response.
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Affiliation(s)
- Jedidah Mwacharo
- Centre for Geographical Medical Research, Kenya Medical Research Institute, Kilifi, Kenya.
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Moormann AM, Sumba PO, Tisch DJ, Embury P, King CH, Kazura JW, John CC. Stability of interferon-gamma and interleukin-10 responses to Plasmodium falciparum liver stage antigen 1 and thrombospondin-related adhesive protein immunodominant epitopes in a highland population from Western Kenya. Am J Trop Med Hyg 2009; 81:489-495. [PMID: 19706920 PMCID: PMC3634720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Long-term planning to prevent malaria epidemics requires in-depth understanding of immunity to Plasmodium falciparum in areas of unstable transmission. Cytokine responses to immunodominant epitope peptides from liver stage antigen 1 (LSA-1) and thrombospondin-related adhesive protein (TRAP) were evaluated over a nine-month interval in adults and children in Kenya from a malaria epidemic-prone highland area after several years of low transmission. The proportion and magnitude of interferon-gamma ELISPOT responses and the proportion of interleukin-10 responders to LSA-1 and TRAP peptides tended to be higher in adults than children. Frequencies of interferon-gamma responders to these peptides were similar at the two time points, but responses were not consistently generated by the same persons. These results suggest that T cell memory to pre-erythrocytic stage malaria antigens is maintained but may be unavailable for consistent detection in peripheral blood, and that these antigens induce both pro-inflammatory and anti-inflammatory cytokine responses in this population.
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Affiliation(s)
- Ann M Moormann
- Center for Global Health and Diseases, and Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, Ohio, 44106-7286, USA.
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Dubovsky F, Malkin E. Malaria vaccines. Vaccines (Basel) 2008. [DOI: 10.1016/b978-1-4160-3611-1.50056-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Wykes M, Good MF. A case for whole-parasite malaria vaccines. Int J Parasitol 2007; 37:705-12. [PMID: 17408673 DOI: 10.1016/j.ijpara.2007.02.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 02/13/2007] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
Malaria causes morbidity in 300-500 million people each year and claims 2-3 millions lives annually, mostly children in sub-Saharan Africa. In 1983, the cloning of malaria antigens offered great promise for developing a viable subunit vaccine. However, an efficacious human vaccine is still not available. Immunological studies on how the host's immune system interacts with the parasite and studies on the pathogenic aspect of Plasmodium have found that several factors can impede protection by current vaccines. These findings suggest a novel approach needs to be considered.
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Affiliation(s)
- Michelle Wykes
- The Queensland Institute of Medical Research, The Bancroft Centre, Brisbane, Qld, Australia.
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Bejon P, Keating S, Mwacharo J, Kai OK, Dunachie S, Walther M, Berthoud T, Lang T, Epstein J, Carucci D, Moris P, Cohen J, Gilbert SC, Peshu N, Marsh K, Hill AVS. Early gamma interferon and interleukin-2 responses to vaccination predict the late resting memory in malaria-naïve and malaria-exposed individuals. Infect Immun 2006; 74:6331-8. [PMID: 16966412 PMCID: PMC1695504 DOI: 10.1128/iai.00774-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two different cell populations respond to potent T-cell-inducing vaccinations. The induction and loss of effector cells can be seen using an ex vivo enzyme-linked immunospot (ELISPOT) assay, but the more durable resting memory response is demonstrable by a cultured ELISPOT assay. The relationship of the early effector response to durable resting memory is incompletely understood. Effector phenotype is usually identified by gamma interferon (IFN-gamma) production, but interleukin-2 (IL-2) has been specifically linked to the differentiation of memory cells. Here, IFN-gamma- and IL-2-secreting effector cells were identified by an ex vivo ELISPOT assay 1 week after vaccination and compared with the resting memory responses detected by a cultured ELISPOT assay 3 months later. The different kinetics and induction of IL-2 by different vaccines and natural exposure are described. Furthermore, both early IFN-gamma and IL-2 production independently predicted subsequent memory responses at 3 months in malaria-naïve volunteers, but only IFN-gamma predicted memory in malaria-exposed volunteers. However, dual ELISPOT assays were also performed on malaria-exposed volunteers to identify cells producing both cytokines simultaneously. This demonstrated that double-cytokine-producing cells were highly predictive of memory. This assay may be useful in predicting vaccinations most likely to generate stable, long-term memory responses.
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Affiliation(s)
- Philip Bejon
- Kenya Medical Research Institute, Centre for Geographical Medical Research (Coast), P.O. Box 230, Kilifi, Kenya.
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Herrera S, Gómez A, Vera O, Vergara J, Valderrama-Aguirre A, Maestre A, Méndez F, Wang R, Chitnis CE, Yazdani SS, Arévalo-Herrera M. Antibody response to Plasmodium vivax antigens in Fy-negative individuals from the Colombian Pacific coast. Am J Trop Med Hyg 2006; 73:44-9. [PMID: 16291766 DOI: 10.4269/ajtmh.2005.73.44] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The Duffy antigen (Fy) is necessary for Plasmodium vivax invasion of human erythrocytes. Some populations have a highly prevalent Fy-negative phenotype; such persons are naturally protected from P. vivax blood infection but are expected to completely support the P. vivax pre-erythrocytic cycle, representing a valuable model for studying the immune response during these parasitic stages. We typed 214 individuals, mostly Afro-Colombians, from a P. vivax-endemic area for Fy expression and determined the antibody response to P. vivax pre-erythrocytic (sporozoites and CS) and blood-stage antigens (blood forms, P. vivax merozoite surface protein 1, and P. vivax Duffy binding protein [PvDBP]). Antibody titers to P. vivax circumsporozoite protein, P11, and N-terminal peptides and the number of responders were similar in Fy-negative and Fy-positive individuals. The number of responders to sporozoites, blood forms, and PvDBP were different between these groups. Thus, Fy-negative individuals from malaria-endemic areas can be used to study the immune response to the P. vivax liver phase without interference of the erythrocytic cycle.
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Talaat AM, Stemke-Hale K. Expression library immunization: a road map for discovery of vaccines against infectious diseases. Infect Immun 2005; 73:7089-98. [PMID: 16239502 PMCID: PMC1273844 DOI: 10.1128/iai.73.11.7089-7098.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Adel M Talaat
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, 1656 Linden Drive, Madison, WI 53706-1581, USA.
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16
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Pouniotis DS, Proudfoot O, Bogdanoska V, Scalzo K, Kovacevic S, Coppel RL, Plebanski M. Selectively impaired CD8+ but not CD4+ T cell cycle arrest during priming as a consequence of dendritic cell interaction with plasmodium-infected red cells. THE JOURNAL OF IMMUNOLOGY 2005; 175:3525-33. [PMID: 16148095 DOI: 10.4049/jimmunol.175.6.3525] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Individuals living in malaria-endemic areas show generally low T cell responses to malaria Ags. In this study, we show murine dendritic cell (DC) interaction with parasitized erythrocytes (pRBC) arrested their maturation, resulting in impaired ability to stimulate naive, but not recall T cell responses in vitro and in vivo. Moreover, within the naive T cell population, pRBC-treated DC were selectively deficient in priming CD8(+) but not CD4(+) T cells. Indeed, DC that had taken up pRBC were shown for the first time to efficiently prime CD4(+) T cell responses to a known protective merozoite Ag, MSP4/5. In contrast, impaired priming resulted in decreases in both proliferation and cytokine production by CD8(+) T cells. Deficient priming was observed to both a model and a Plasmodium berghei-specific CD8(+) T cell epitope. The mechanisms underlying the inability of parasite-treated DC to prime CD8(+) T cells were explored. pRBC treatment of DC from wild-type C57BL/6, but not from IL-10 knockout animals, suppressed DC-mediated T cell priming across a Transwell, suggesting active IL-10-dependent suppression. CD8(+) T cells were arrested at the G(0) stage of the cell cycle after two cell divisions post-Ag stimulation. The proliferation arrest was partially reversible by the addition of IL-2 or IL-7 to responder cultures. These results suggest that in malaria-endemic areas, priming of CD8(+) T cell responses may be more difficult to induce via vaccination than the priming of CD4(+) T cells. Moreover, pathogens may selectively target the CD8(+) T cell arm of protective immunity for immune evasion.
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Affiliation(s)
- Dodie S Pouniotis
- Vaccine and Infectious Diseases Unit, The Austin Research Institute, Heidelberg, Victoria, Australia
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Chauhan VS, Bhardwaj D. Current status of malaria vaccine development. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2003; 84:143-82. [PMID: 12934936 DOI: 10.1007/3-540-36488-9_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
There is an urgent need to develop an effective vaccine against malaria--a disease that has approximately 10% of the world population at risk of infection at any given time. The economic burden this disease puts on the medico-social set-up of countries in Sub-Saharan Africa and South East Asia is phenomenal. Increasing drug resistance and failure of vector control strategies have necessitated the search for a suitable vaccine that could be integrated into the extended program of immunization for countries in the endemic regions. Malaria vaccine development has seen a surge of activity in the last decade or so owing largely to the advances made in the fields of genetic engineering and biotechnology. This revolution has brought sweeping changes in the understanding of the biology of the parasite and has helped formulate newer more effective strategies to combat the disease. Latest developments in the field of malaria vaccine development will be discussed in this chapter.
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Affiliation(s)
- Virander Singh Chauhan
- Malaria Research Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi-110067, India.
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Rogers WO, Weiss WR, Kumar A, Aguiar JC, Tine JA, Gwadz R, Harre JG, Gowda K, Rathore D, Kumar S, Hoffman SL. Protection of rhesus macaques against lethal Plasmodium knowlesi malaria by a heterologous DNA priming and poxvirus boosting immunization regimen. Infect Immun 2002; 70:4329-35. [PMID: 12117942 PMCID: PMC128201 DOI: 10.1128/iai.70.8.4329-4335.2002] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We tested a cytokine-enhanced, multiantigen, DNA priming and poxvirus boosting vaccine regimen for prevention of malaria in the Plasmodium knowlesi-rhesus macaque model system. Animals were primed with a mixture of DNA plasmids encoding two preerythrocytic-stage proteins and two erythrocytic-stage proteins from P. knowlesi and combinations of the cytokines granulocyte-macrophage colony-stimulating factor, interleukin-4, and tumor necrosis factor alpha and were boosted with a mixture of four recombinant, attenuated vaccinia virus strains encoding the four P. knowlesi antigens. Two weeks after boosting, the geometric mean immunofluorescence titers in the immunized groups against sporozoites and infected erythrocytes ranged from 160 to 8,096 and from 1,810 to 5,120, respectively. The geometric mean anti-P. knowlesi circumsporozoite protein (PkCSP) titers ranged from 1,761 to 24,242. Peripheral blood mononuclear cells (PBMC) from the immunized monkeys produced gamma interferon (IFN-gamma) in response to incubation with pooled peptides from the PkCSP at frequencies of 10 to 571 spot-forming cells/10(6) PBMC. Following challenge with 100 infectious P. knowlesi sporozoites, 2 of 11 immunized monkeys were sterilely protected, and 7 of the 9 infected monkeys resolved their parasitemias spontaneously. In contrast, all four controls became infected and required treatment for overwhelming parasitemia. Early protection was strongly associated with IFN-gamma responses against a pool of peptides from the preerythrocytic-stage antigen, PkCSP. These findings demonstrate that a multistage, multiantigen, DNA priming and poxvirus boosting vaccine regimen can protect nonhuman primates from an otherwise lethal malaria sporozoite challenge.
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Affiliation(s)
- William O Rogers
- Malaria Program, Naval Medical Research Center, Silver Spring, Maryland 20910, USA.
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Kumar A, Weiss W, Tine JA, Hoffman SL, Rogers WO. ELISPOT assay for detection of peptide specific interferon-gamma secreting cells in rhesus macaques. J Immunol Methods 2001; 247:49-60. [PMID: 11150536 DOI: 10.1016/s0022-1759(00)00310-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A reliable procedure to measure antigen specific T cell responses in rhesus macaques is required to determine the efficacy of vaccines and immunotherapies. The currently available T cell assays are poorly quantifiable or technically difficult to perform. Classical 51Cr-release cytotoxic T cell (CTL) assays are cumbersome and difficult to quantitate reproducibly. Detection of specific T-cell using MHC-peptide tetrameric complexes is highly sensitive, but requires knowledge of MHC type and prior identification of T cell epitopes. We therefore developed a rhesus interferon-gamma (IFN-gamma) ELISPOT assay capable of detecting IFN-gamma secretion in response to stimulation with pooled 20-mer peptides. Peripheral blood mononuclear cells (PBMCs) from rhesus monkeys immunized with a DNA vaccine and recombinant canary pox encoding the Plasmodium knowlesi circumsporozoite protein (PkCSP) were incubated with pools of peptides from PkCSP. Positive responses to peptide pools and individual peptides ranging from 100 to 450 spot forming cells (SFC)/10(6) PBMC were detected in four of four immunized monkeys and in zero of two control monkeys. In two monkeys studied in detail, the IFN-gamma response was focussed on a single 20-mer peptide, QGDGANAGQPQAQGDGANAG, and was dependent on CD4(+), but not CD8(+), T cells. Background responses in control monkeys and preimmunization PBMCs ranged from 10 to 50 SFC/10(6) PBMC. The average within assay and between assay coefficients of variation (CV) for this peptide ELISPOT were 21.9 and 24.7%, respectively. This peptide IFN-gamma assay will be a useful tool for evaluation of T cell responses in rhesus macaques.
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Affiliation(s)
- A Kumar
- Malaria Program, Naval Medical Research Center, Silver Spring, MD 20910, USA
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Abstract
Malaria remains one of the world's worst health problems with 1.5 to 2.7 million deaths annually; these deaths are primarily among children under 5 years of age and pregnant women in sub-Saharan Africa. Of significance, more people are dying from malaria today than 30 years ago. This review considers the factors which have contributed to this gloomy picture, including those which relate to the vector, the female anopheline mosquito; to human activity such as creating new mosquito breeding sites, the impact of increased numbers of people, and how their migratory behavior can increase the incidence and spread of malaria; and the problems of drug resistance by the parasites to almost all currently available antimalarial drugs. In a selective manner, this review describes what is being done to ameliorate this situation both in terms of applying existing methods in a useful or even crucial role in control and prevention and in terms of new additions to the antimalarial armory that are being developed. Topics covered include biological control of mosquitoes, the use of insecticide-impregnated bed nets, transgenic mosquitoes manipulated for resistance to malaria parasites, old and new antimalarial drugs, drug resistance and how best to maintain the useful life of antimalarials, immunity to malaria and the search for antimalarial vaccines, and the malaria genome project and the potential benefits to accrue from it.
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Affiliation(s)
- R S Phillips
- Division of Infection and Immunity, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
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Zhang K, Fujioka H, Aikawa M, Kumar N. Plasmodium falciparum: detection of a novel asparagine-rich protein on the surface of sporozoite. Exp Parasitol 1999; 93:1-6. [PMID: 10464033 DOI: 10.1006/expr.1999.4435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We had previously cloned and characterized a gene for a novel asparagine-rich protein from P. falciparum (PfARP), a target of natural human immune response. The antibodies to PfARP were localized to the surface of parasitized red blood cells and reacted with intracellular components in all erythrocytic asexual and sexual stages of the parasite. We here describe reactivity of antibodies against this novel PfARP on the surface of mosquito stage sporozoite of P. falciparum by indirect immunofluorescence assay and immunoelectron microscopy, the latter revealing a highly periodic punctate pattern of distribution of PfARP on the surface of sporozoite. These results suggest a possibility that PfARP might represent yet another sporozoite surface protein.
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Affiliation(s)
- K Zhang
- Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, Maryland 21205, USA
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Abstract
Malaria, a disease responsible for immense human suffering, is caused by infection with Plasmodium spp. parasites, which have a very complex life cycle - antigenically unique stages infect different tissues of the body. This review details recent developments in our understanding of immunity both to pre-erythrocytic stage antigens and to erythrocytic stage antigens. The former is largely mediated via CD8(+) T cells and involves IFN-gamma, nitric oxide, IL-12 and natural killer cells; the latter varies (in different hosts and with different parasites) but is largely mediated by antibody, helper T cells, nitric oxide and gammadelta T cells. The recent progress towards clinical trials of vaccine candidates against both the pre-erythrocytic stage and erythrocytic stage is also summarized, in particular the use of heterologous prime/boost strategies for the former and the use of MSP1 as a candidate vaccine for the latter.
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Affiliation(s)
- M F Good
- The Cooperative Research Centre for Vaccine Technology, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital 4029, Queensland, Australia.
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Plebanski M, Flanagan KL, Lee EA, Reece WH, Hart K, Gelder C, Gillespie G, Pinder M, Hill AV. Interleukin 10-mediated immunosuppression by a variant CD4 T cell epitope of Plasmodium falciparum. Immunity 1999; 10:651-60. [PMID: 10403640 DOI: 10.1016/s1074-7613(00)80064-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The immunodominant CD4 T cell epitope region, Th2R, of the circumsporozoite protein of Plasmodium falciparum is highly polymorphic. Such variation might be utilized by the parasite to escape from or interfere with CD4 T cell effector functions. Here, we show that costimulation with naturally occurring altered peptide ligands (APL) can induce a rapid change from IFNgamma production to the immunosuppressive mediator interleukin 10 (IL-10). This mechanism may contribute to the low levels of T cell responses observed to this pathogen in malaria-endemic areas.
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Affiliation(s)
- M Plebanski
- Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, John Radcliffe Hospital, United Kingdom.
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Hoffman SL, Rogers WO, Carucci DJ, Venter JC. From genomics to vaccines: malaria as a model system. Nat Med 1998; 4:1351-3. [PMID: 9846563 DOI: 10.1038/3934] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S L Hoffman
- Malaria Program, Naval Medical Research Center, Rockville, Maryland 20852, USA.
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Sedegah M, Jones TR, Kaur M, Hedstrom R, Hobart P, Tine JA, Hoffman SL. Boosting with recombinant vaccinia increases immunogenicity and protective efficacy of malaria DNA vaccine. Proc Natl Acad Sci U S A 1998; 95:7648-53. [PMID: 9636204 PMCID: PMC22711 DOI: 10.1073/pnas.95.13.7648] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
To enhance the efficacy of DNA malaria vaccines, we evaluated the effect on protection of immunizing with various combinations of DNA, recombinant vaccinia virus, and a synthetic peptide. Immunization of BALB/c mice with a plasmid expressing Plasmodium yoelii (Py) circumsporozoite protein (CSP) induces H-2Kd-restricted CD8+ cytotoxic T lymphocyte (CTL) responses and CD8+ T cell- and interferon (IFN)-gamma-dependent protection of mice against challenge with Py sporozoites. Immunization with a multiple antigenic peptide, including the only reported H-2Kd-restricted CD8+ T cell epitope on the PyCSP (PyCSP CTL multiple antigenic peptide) and immunization with recombinant vaccinia expressing the PyCSP induced CTL but only modest to minimal protection. Mice were immunized with PyCSP DNA, PyCSP CTL multiple antigenic peptide, or recombinant vaccinia expressing PyCSP, were boosted 9 wk later with the same immunogen or one of the others, and were challenged. Only mice immunized with DNA and boosted with vaccinia PyCSP (D-V) (11/16: 69%) or DNA (D-D) (7/16: 44%) had greater protection (P < 0. 0007) than controls. D-V mice had significantly higher individual levels of antibodies and class I-restricted CTL activity than did D-D mice; IFN-gamma production by ELIspot also was higher in D-V than in D-D mice. In a second experiment, three different groups of D-V mice each had higher levels of protection than did D-D mice, and IFN-gamma production was significantly greater in D-V than in D-D mice. The observation that priming with PyCSP DNA and boosting with vaccinia-PyCSP is more immunogenic and protective than immunizing with PyCSP DNA alone supports consideration of a similar sequential immunization approach in humans.
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MESH Headings
- Animals
- Antibodies, Protozoan/biosynthesis
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Female
- Fluorescent Antibody Technique, Indirect
- Interferon-gamma/metabolism
- Malaria/immunology
- Malaria/prevention & control
- Malaria Vaccines/immunology
- Malaria Vaccines/therapeutic use
- Mice
- Mice, Inbred BALB C
- Plasmodium yoelii/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- T-Lymphocytes, Cytotoxic/immunology
- Vaccines, DNA/immunology
- Vaccines, DNA/therapeutic use
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/therapeutic use
- Vaccinia virus/immunology
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Affiliation(s)
- M Sedegah
- Malaria Program, Naval Medical Research Institute, Bethesda, MD 20889-5607, USA
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