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Tebben K, Yirampo S, Coulibaly D, Koné AK, Laurens MB, Stucke EM, Dembélé A, Tolo Y, Traoré K, Niangaly A, Berry AA, Kouriba B, Plowe CV, Doumbo OK, Lyke KE, Takala-Harrison S, Thera MA, Travassos MA, Serre D. Immune gene expression changes more during a malaria transmission season than between consecutive seasons. Microbiol Spectr 2024:e0096024. [PMID: 39162546 DOI: 10.1128/spectrum.00960-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 07/08/2024] [Indexed: 08/21/2024] Open
Abstract
Plasmodium parasites, the causative organism of malaria, caused over 600,000 deaths in 2022. In Mali, Plasmodium falciparum causes the majority of malaria cases and deaths and is transmitted seasonally. Anti-malarial immunity develops slowly over repeated exposures to P. falciparum and some aspects of this immunity (e.g., antibody titers) wane during the non-transmission, dry season. Here, we sequenced RNA from 33 pediatric blood samples collected during P. falciparum infections at the beginning or end of a transmission season, and characterized the host and parasite gene expression profiles for paired, consecutive infections. We found that human gene expression changes more over the course of one transmission season than between seasons, with signatures of partial development of an adaptive immune response during one transmission season and stability in gene expression during the dry season. Additionally, we found that P. falciparum gene expression did not vary with timing during the season and remained stable both across and between seasons, despite varying human immune pressures. Our results provide insights into the dynamics of anti-malarial immune response development over short time frames that could be exploited by future vaccine and prevention efforts. IMPORTANCE Our work seeks to understand how the immune response to Plasmodium falciparum malaria changes between infections that occur during low and high malaria transmission seasons, and highlights that immune gene expression changes more during the high transmission season. This provides important insight into the dynamics of the anti-malarial immune response that are important to characterize over these short time frames to better understand how to exploit this immune response with future vaccine efforts.
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Affiliation(s)
- Kieran Tebben
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Salif Yirampo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K Koné
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Matthew B Laurens
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Emily M Stucke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ahmadou Dembélé
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Youssouf Tolo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Karim Traoré
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Andrea A Berry
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Bourèma Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Christopher V Plowe
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Kirsten E Lyke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Shannon Takala-Harrison
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mahamadou A Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mark A Travassos
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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2
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Seidu Z, Lamptey H, Lopez-Perez M, Whittle NO, Oppong SK, Kyei-Baafour E, Pobee ANA, Adjei GO, Hviid L, Ofori MF. Plasmodium falciparum infection and naturally acquired immunity to malaria antigens among Ghanaian children in northern Ghana. Parasite Epidemiol Control 2023; 22:e00317. [PMID: 37501921 PMCID: PMC10369471 DOI: 10.1016/j.parepi.2023.e00317] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 03/28/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Background The surge in malaria cases and deaths in recent years, particularly in Africa, despite the widespread implementation of malaria-control measures could be due to inefficiencies in malaria control and prevention measures in malaria-endemic communities. In this context, this study provides the malaria situation report among children in three Municipalities in Northern Ghana, where Seasonal Malaria Chemotherapy (SMC) is implemented by Ghana Health Service (GHS). Methods A cross-sectional household survey was carried out to assess the malaria knowledge, attitudes, and practices (KAP) and malaria prevalence in 394 households in 13 rural communities in the Kumbugu, Nanton and Tolon Municipalities, Northern Region, Ghana. This was followed by screening for P. falciparum infection with anti-HRP2 RDT and PCR among children 1-17 years in the households. Plasma levels of IgG specific for crude P. falciparum antigen (3D7) and four recombinant malaria antigens (CSP, GLURP, MSP3, and Pfs230) were assessed by ELISA. The malaria and parasitaemia data were converted into frequency and subgroup proportions and disaggregated by study sites and demographic information of the participants. The ELISA data was converted to arbitrary units (AU) and similarly compared across study sites and demographic information. Results The P. falciparum infection rate and frequency of malaria were high in the study areas with significant age-dependent and inter-community differences, which were reflected by differences in plasma levels of P. falciparum-specific IgG. Over 60% of households reported the use of bed nets and indoor insecticide sprays/coils, and 14% mentioned bush clearing around homes (14%) as malaria preventive measures. Community health centres were the preferred place for households (88%) to seek malaria treatment but over-the-counter drug stores were the major source (66%) of their antimalarials. Overall, malaria preventive and treatment practices were sub-optimal. Conclusions P. falciparum infection and malaria are still high in the studied communities, indicating that preventive and control measures against the disease in the region remain inadequate. Efforts to ensure high SMC compliance and to improve preventative and treatment practices thus seem cost-beneficial "low-hanging fruits" in the fight against malaria in the Northern Region of Ghana.
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Affiliation(s)
- Zakaria Seidu
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- West Africa Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, University for Development Studies, Nyankpala, Ghana
| | - Helena Lamptey
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Mary Lopez-Perez
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Nora Owusuwaa Whittle
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Stephen Kwesi Oppong
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Eric Kyei-Baafour
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Abigail Naa Adjorkor Pobee
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - George Obeng Adjei
- Centre for Tropical Clinical Pharmacology and Therapeutics, School of Medicine and Dentistry, College of Health Sciences, University of Ghana, Korle-Bu, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Michael F. Ofori
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
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3
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Malaria Vaccines. Infect Dis (Lond) 2023. [DOI: 10.1007/978-1-0716-2463-0_536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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4
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Egwu CO, Aloke C, Chukwu J, Agwu A, Alum E, Tsamesidis I, Aja PM, Offor CE, Obasi NA. A world free of malaria: It is time for Africa to actively champion and take leadership of elimination and eradication strategies. Afr Health Sci 2022; 22:627-640. [PMID: 37092107 PMCID: PMC10117514 DOI: 10.4314/ahs.v22i4.68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
The global burden of malaria seems unabated. Africa carries the greatest burden accounting for over 95% of the annual cases of malaria. For the vision of a world free of malaria by Global Technical Strategy to be achieved, Africa must take up the stakeholder's role. It is therefore imperative that Africa rises up to the challenge of malaria and champion the fight against it. The fight against malaria may just be a futile or mere academic venture if Africans are not directly and fully involved. This work reviews the roles playable by Africans in order to curb the malaria in Africa and the world at large.
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Affiliation(s)
- Chinedu Ogbonnia Egwu
- Medical Biochemistry Department, College of Medicine, Alex-Ekwueme Federal University Ndufu-Alike Ikwo, P.M.B. 1010 Ebonyi State, Nigeria
| | - Chinyere Aloke
- Medical Biochemistry Department, College of Medicine, Alex-Ekwueme Federal University Ndufu-Alike Ikwo, P.M.B. 1010 Ebonyi State, Nigeria
- Protein Structure-Function and Research Unit, School of Molecular and Cell Biology, Faculty of Science, University of the Witwatersrand, Braamfontein, Johannesburg 2050, South Africa
| | - Jennifer Chukwu
- World Health Organization, United Nations House Plot 617/618 Central Area District PMB 2861 Abuja, Nigeria
| | - Anthony Agwu
- Biochemistry Department, Ebonyi State University Abakaliki, P.M.B. 053 Ebonyi State Nigeria
| | - Esther Alum
- Biochemistry Department, Ebonyi State University Abakaliki, P.M.B. 053 Ebonyi State Nigeria
| | - Ioannis Tsamesidis
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki 54124 Greece
| | - Patrick M Aja
- Biochemistry Department, Ebonyi State University Abakaliki, P.M.B. 053 Ebonyi State Nigeria
| | - Christian E Offor
- Biochemistry Department, Ebonyi State University Abakaliki, P.M.B. 053 Ebonyi State Nigeria
| | - Nwogo Ajuka Obasi
- Medical Biochemistry Department, College of Medicine, Alex-Ekwueme Federal University Ndufu-Alike Ikwo, P.M.B. 1010 Ebonyi State, Nigeria
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5
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Sobota RS, Goron AR, Berry AA, Bailey JA, Coulibaly D, Adams M, Kone AK, Kouriba B, Doumbo OK, Sztein MB, Felgner PL, Plowe CV, Lyke KE, Thera MA, Travassos MA. Serologic and Cytokine Profiles of Children with Concurrent Cerebral Malaria and Severe Malarial Anemia Are Distinct from Other Subtypes of Severe Malaria. Am J Trop Med Hyg 2022; 107:315-319. [PMID: 35895583 PMCID: PMC9393435 DOI: 10.4269/ajtmh.22-0135] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/25/2022] [Indexed: 11/07/2022] Open
Abstract
We used a protein microarray featuring Plasmodium falciparum field variants of a merozoite surface antigen to examine malaria exposure in Malian children with different severe malaria syndromes. Unlike children with cerebral malaria alone or severe malarial anemia alone, those with concurrent cerebral malaria and severe malarial anemia had serologic responses demonstrating a broader prior parasite exposure pattern than matched controls with uncomplicated disease. Comparison of levels of malaria-related cytokines revealed that children with the concurrent phenotype had elevated levels of interleukin (IL)-6, IL-8, and IL-10. Our results suggest that the pathophysiology of this severe subtype is unique and merits further investigation.
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Affiliation(s)
- Rafal S. Sobota
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
- Ken and Ruth Davee Department of Neurology, Northwestern University, Chicago, Illinois
| | - Abby R. Goron
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea A. Berry
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jason A. Bailey
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Matthew Adams
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Abdoulaye K. Kone
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Ogobara K. Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Marcelo B. Sztein
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Philip L. Felgner
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California
| | - Christopher V. Plowe
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kirsten E. Lyke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mahamadou A. Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Mark A. Travassos
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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6
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Hoffmann-Veltung H, Anabire NG, Ofori MF, Janhmatz P, Ahlborg N, Hviid L, Quintana MDP. Analysis of allelic cross-reactivity of monoclonal IgG antibodies by a multiplexed reverse FluoroSpot assay. eLife 2022; 11:79245. [PMID: 35838346 PMCID: PMC9286747 DOI: 10.7554/elife.79245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/24/2022] [Indexed: 11/13/2022] Open
Abstract
The issue of antibody cross-reactivity is of central importance in immunology, and not least in protective immunity to Plasmodium falciparum malaria, where key antigens show substantial allelic variation (polymorphism). However, serological analysis often does not allow the distinction between true cross-reactivity (one antibody recognizing multiple antigen variants) and apparent cross-reactivity (presence of multiple variant-specific antibodies), as it requires analysis at the single B-cell/monoclonal antibody level. ELISpot is an assay that enables that, and a recently developed multiplexed variant of ELISpot (FluoroSpot) facilitates simultaneous assessment of B-cell/antibody reactivity to several different antigens. In this study, we present a further enhancement of this assay that makes direct analysis of monoclonal antibody-level cross-reactivity with allelic variants feasible. Using VAR2CSA-type PfEMP1-a notoriously polymorphic antigen involved in the pathogenesis of placental malaria-as a model, we demonstrate the robustness of the assay and its applicability to analysis of true cross-reactivity of monoclonal VAR2CSA-specific antibodies in naturally exposed individuals. The assay is adaptable to the analysis of other polymorphic antigens, rendering it a powerful tool in studies of immunity to malaria and many other diseases.
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Affiliation(s)
- Henriette Hoffmann-Veltung
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nsoh Godwin Anabire
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana.,Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Michael Fokuo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | | | - Niklas Ahlborg
- Mabtech AB, Nacka Strand, Sweden.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm, Sweden
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Maria Del Pilar Quintana
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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7
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Olsen RW, Suurbaar J, Jensen AR. Production of anti-PfEMP1 Polyclonal Antisera in Rats and Mice. Methods Mol Biol 2022; 2470:381-389. [PMID: 35881360 DOI: 10.1007/978-1-0716-2189-9_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Plasmodium falciparum-infected erythrocytes (IEs) bind various host receptors via members of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family expressed on the surface of the IEs. Antibody reagents are needed to investigate interactions between specific PfEMP1 proteins and receptors expressed by human endothelial cells. This protocol describes the production of rat and mouse polyclonal anti-PfEMP1 antibodies. Polyclonal antibodies are relatively easy to produce and have advantages compared to monoclonal antibodies (see Chapters 28 - 30 ) for some applications. An ELISA-based method to test the polyclonal antibodies before their use in more advanced procedures is also presented.
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Affiliation(s)
- Rebecca W Olsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Jennifer Suurbaar
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- West Africa Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Anja Ramstedt Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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8
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Olsen RW, Suurbaar J, Jensen AR. Affinity Purification of PfEMP1-Specific Antibodies from Human Blood. Methods Mol Biol 2022; 2470:369-379. [PMID: 35881359 DOI: 10.1007/978-1-0716-2189-9_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Acquired immunity against Plasmodium falciparum infections relies heavily on IgG antibodies specific for PfEMP1 proteins expressed on the surface of infected erythrocytes. Purified human antibodies can be used, for example, to study the interactions between specific PfEMP1 proteins and receptors expressed by human endothelial cells, and to identify which IgG antibodies play a functional role in natural acquired immunity.This chapter describe how to affinity purify PfEMP1-specific human antibodies on an affinity column coupled with PfEMP1 protein. We include ELISA-based methods for identification of human plasma samples reactive against PfEMP1, and for testing of affinity purified IgG antibodies prior to their use in more advanced procedures.
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Affiliation(s)
- Rebecca W Olsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Jennifer Suurbaar
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- West Africa Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Anja Ramstedt Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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9
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Lopez-Perez M, Viwami F, Seidu Z, Jensen ATR, Doritchamou J, Ndam NT, Hviid L. PfEMP1-Specific Immunoglobulin G Reactivity Among Beninese Pregnant Women With Sickle Cell Trait. Open Forum Infect Dis 2021; 8:ofab527. [PMID: 34909438 PMCID: PMC8664683 DOI: 10.1093/ofid/ofab527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/14/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Sickle cell trait (HbAS) protects against severe Plasmodium falciparum malaria but not against placental malaria (PM). In this study, P falciparum erythrocyte membrane protein (PfEMP1)-specific antibodies were measured in HbAA and HbAS Beninese pregnant women as a proxy of exposure to specific PfEMP1 variants. METHODS Plasma samples collected at delivery from 338 HbAA and 63 HbAS women were used to measure immunoglobulin (Ig)G levels to 6 recombinant PfEMP1 proteins and 3 corresponding native proteins expressed on the infected erythrocyte (IE) surface. Immunoglobulin G-mediated inhibition of VAR2CSA+ IEs adhesion to chondroitin sulfate A (CSA) was also tested. RESULTS Levels of PfEMP1-specific IgG were similar in the 2 groups, except for native IT4VAR09 on IEs, where IgG levels were significantly higher in HbAS women. Adjusted odds ratios for women with positive IgG to HB3VAR06 and PFD1235w suggest a lower risk of infection with these virulent variants among HbAS individuals. The percentage of IEs binding to CSA did not differ between HbAA and HbAS women, but it correlated positively with levels of anti-VAR2CSA and parity. Women with PM had lower levels of anti-VAR2CSA-specific IgG and lower IgG-mediated inhibition of IE adhesion to CSA. CONCLUSIONS The findings support similar malaria exposure in HbAA and HbAS women and a lack of HbAS-dependent protection against placental infection among pregnant women.
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Affiliation(s)
- Mary Lopez-Perez
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Firmine Viwami
- UMR 261 MERIT, Université de Paris, Institut de Recherche pour le Développement, Paris, France
- Institut de Recherche Clinique du Benin, Abomey Calavi, Benin
| | - Zakaria Seidu
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- West Africa Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Anja T R Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Nicaise Tuikue Ndam
- UMR 261 MERIT, Université de Paris, Institut de Recherche pour le Développement, Paris, France
- Institut de Recherche Clinique du Benin, Abomey Calavi, Benin
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
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10
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The Role of Coinfections in the EBV-Host Broken Equilibrium. Viruses 2021; 13:v13071399. [PMID: 34372605 PMCID: PMC8310153 DOI: 10.3390/v13071399] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/29/2021] [Accepted: 07/12/2021] [Indexed: 12/17/2022] Open
Abstract
The Epstein–Barr virus (EBV) is a well-adapted human virus, and its infection is exclusive to our species, generally beginning in the childhood and then persisting throughout the life of most of the affected adults. Although this infection generally remains asymptomatic, EBV can trigger life-threatening conditions under unclear circumstances. The EBV lifecycle is characterized by interactions with other viruses or bacteria, which increases the probability of awakening its pathobiont capacity. For instance, EBV infects B cells with the potential to alter the germinal center reaction (GCR)—an adaptive immune structure wherein mutagenic-driven processes take place. HIV- and Plasmodium falciparum-induced B cell hyperactivation also feeds the GCR. These agents, along with the B cell tropic KSHV, converge in the ontogeny of germinal center (GC) or post-GC lymphomas. EBV oral transmission facilitates interactions with local bacteria and HPV, thereby increasing the risk of periodontal diseases and head and neck carcinomas. It is less clear as to how EBV is localized in the stomach, but together with Helicobacter pylori, they are known to be responsible for gastric cancer. Perhaps this mechanism is reminiscent of the local inflammation that attracts different herpesviruses and enhances graft damage and chances of rejection in transplanted patients. In this review, we discussed the existing evidence suggestive of EBV possessing the potential to synergize or cooperate with these agents to trigger or worsen the disease.
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11
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Ventimiglia NT, Stucke EM, Coulibaly D, Berry AA, Lyke KE, Laurens MB, Bailey JA, Adams M, Niangaly A, Kone AK, Takala-Harrison S, Kouriba B, Doumbo OK, Felgner PL, Plowe CV, Thera MA, Travassos MA. Malian adults maintain serologic responses to virulent PfEMP1s amid seasonal patterns of fluctuation. Sci Rep 2021; 11:14401. [PMID: 34257318 PMCID: PMC8277812 DOI: 10.1038/s41598-021-92974-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 06/08/2021] [Indexed: 12/03/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein-1s (PfEMP1s), diverse malaria proteins expressed on the infected erythrocyte surface, play an important role in pathogenesis, mediating adhesion to host vascular endothelium. Antibodies to particular non-CD36-binding PfEMP1s are associated with protection against severe disease. We hypothesized that given lifelong P. falciparum exposure, Malian adults would have broad PfEMP1 serorecognition and high seroreactivity levels during follow-up, particularly to non-CD36-binding PfEMP1s such as those that attach to endothelial protein C receptor (EPCR) and intercellular adhesion molecule-1 (ICAM-1). Using a protein microarray, we determined serologic responses to 166 reference PfEMP1 fragments during a dry and subsequent malaria transmission season in Malian adults. Malian adult sera had PfEMP1 serologic responses throughout the year, with decreased reactivity to a small subset of PfEMP1 fragments during the dry season and increases in reactivity to a different subset of PfEMP1 fragments during the subsequent peak malaria transmission season, especially for intracellular PfEMP1 domains. For some individuals, PfEMP1 serologic responses increased after the dry season, suggesting antigenic switching during asymptomatic infection. Adults were more likely to experience variable serorecognition of CD36-binding PfEMP1s than non-CD36-binding PfEMP1s that bind EPCR or ICAM-1, which remained serorecognized throughout the year. Sustained seroreactivity to non-CD36-binding PfEMP1s throughout adulthood amid seasonal fluctuation patterns may reflect underlying protective severe malaria immunity and merits further investigation.
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Affiliation(s)
| | - Emily M Stucke
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Drissa Coulibaly
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Andrea A Berry
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E Lyke
- University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Jason A Bailey
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew Adams
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Amadou Niangaly
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Abdoulaye K Kone
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | | | - Bourema Kouriba
- University of Sciences, Techniques and Technologies, Bamako, Mali
| | - Ogobara K Doumbo
- University of Sciences, Techniques and Technologies, Bamako, Mali
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12
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Stability and Hopf Bifurcation Analysis of a Vector-Borne Disease Model with Two Delays and Reinfection. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2021. [DOI: 10.1155/2021/6648959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this paper, a vector-borne disease model with two delays and reinfection is established and considered. First of all, the existence of the equilibrium of the system, under different cases of two delays, is discussed through analyzing the corresponding characteristic equation of the linear system. Some conditions that the system undergoes Hopf bifurcation at the endemic equilibrium are obtained. Furthermore, by employing the normal form method and the center manifold theorem for delay differential equations, some explicit formulas used to describe the properties of bifurcating periodic solutions are derived. Finally, the numerical examples and simulations are presented to verify our theoretical conclusions. Meanwhile, the influences of the degree of partial protection for recovered people acquired by a primary infection on the endemic equilibrium and the critical values of the two delays are analyzed.
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13
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Adequacy of Severe Malaria Markers and Prognostic Scores in an Intensive Care Unit in Luanda, Angola: A Clinical Study. J Clin Med 2020; 9:jcm9123862. [PMID: 33261096 PMCID: PMC7760046 DOI: 10.3390/jcm9123862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/24/2020] [Accepted: 11/20/2020] [Indexed: 11/17/2022] Open
Abstract
Severe Plasmodium falciparum malaria remains the primary cause of mortality in several African countries, including Angola, where severe malaria patient admission into intensive care units (ICU) is mandatory. The present observational and prospective study enrolled 101 consecutive severe malaria patients admitted at the ICU of Américo Boavida University Hospital (Luanda, Angola). Malaria was confirmed by microscopy and RDT, and WHO criteria were used to define severe malaria. The Sequential Organ Failure Assessment (SOFA) score was used to monitor organ dysfunctions. Surviving and nonsurviving patients were compared using bivariate statistical methods. Two-step cluster analysis was used to find discriminant organ dysfunctions that may correlate better with the observed mortality (16.8%), which was much lower than the one generated by the SOFA score. The study population was young, and 87% of the patients were local native residents. There was no statistically significant correlation between the parasitemia and the outcome. Hematological and cerebral dysfunctions were prevalent but were not discriminant when cluster analyses were performed to detect homogeneous subgroups of patients. In conclusion, the SOFA score was readily applicable and efficient in monitoring daily organ dysfunction but was not effective enough in predicting the outcome of severe malaria patients.
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14
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Hviid L. Precipitated Malaria: It Never Rains but It Pours. Trends Parasitol 2020; 36:721-723. [PMID: 32507384 DOI: 10.1016/j.pt.2020.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 10/24/2022]
Abstract
Occasionally, Plasmodium falciparum malaria is apparently precipitated by traumatic events (e.g., a landmine accident) or by noninfectious events (e.g., pregnancy). The authors reporting such cases often seem as baffled as many of their readers probably are. However, the case reports may contain important clues regarding malaria pathogenesis and immunity.
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Affiliation(s)
- Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
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15
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Wanduku D. The stationary distribution and stochastic persistence for a class of disease models: Case study of malaria. INT J BIOMATH 2020. [DOI: 10.1142/s1793524520500242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper presents a nonlinear family of stochastic SEIRS models for diseases such as malaria in a highly random environment with noises from the disease transmission and natural death rates, and also from the random delays of the incubation and immunity periods. Improved analytical methods and local martingale characterizations are applied to find conditions for the disease to persist near an endemic steady state, and also for the disease to remain permanently in the system over time. Moreover, the ergodic stationary distribution for the stochastic process describing the disease dynamics is defined, and the statistical characteristics of the distribution are given numerically. The results of this study show that the disease will persist and become permanent in the system, regardless of (1) whether the noises are from the disease transmission rate and/or from the natural death rates or (2) whether the delays in the system are constant or random for individuals in the system. Furthermore, it is shown that “weak” noise is associated with the existence of an endemic stationary distribution for the disease, while “strong” noise is associated with extinction of the population over time. Numerical simulation examples for Plasmodium vivax malaria are given.
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Affiliation(s)
- Divine Wanduku
- Department of Mathematical Sciences, Georgia Southern University, 65 Georgia Avenue, Room 3042, Statesboro, GA 30460, USA
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16
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Quintana MDP, Smith-Togobo C, Moormann A, Hviid L. Endemic Burkitt lymphoma - an aggressive childhood cancer linked to Plasmodium falciparum exposure, but not to exposure to other malaria parasites. APMIS 2020; 128:129-135. [PMID: 32133709 DOI: 10.1111/apm.13018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/02/2019] [Indexed: 12/12/2022]
Abstract
Burkitt lymphoma (BL) is an aggressive non-Hodgkin lymphoma. The prevalence of BL is ten-fold higher in areas with stable transmission of Plasmodium falciparum malaria, where it is the most common childhood cancer, and is referred to as endemic BL (eBL). In addition to its association with exposure to P. falciparum infection, eBL is strongly associated with Epstein-Barr virus (EBV) infection (>90%). This is in contrast to BL as it occurs outside P. falciparum-endemic areas (sporadic BL), where only a minority of the tumours are EBV-positive. Although the striking geographical overlap in the distribution of eBL and P. falciparum was noted shortly after the first detailed description of eBL in 1958, the molecular details of the interaction between malaria and eBL remain unresolved. It is furthermore unexplained why exposure to P. falciparum appears to be essentially a prerequisite to the development of eBL, whereas other types of malaria parasites that infect humans have no impact. In this brief review, we summarize how malaria exposure may precipitate the malignant transformation of a B-cell clone that leads to eBL, and propose an explanation for why P. falciparum uniquely has this capacity.
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Affiliation(s)
- Maria Del Pilar Quintana
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cecilia Smith-Togobo
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biochemistry, Cell and Molecular Biology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Ann Moormann
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
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17
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Jensen AR, Adams Y, Hviid L. Cerebral Plasmodium falciparum malaria: The role of PfEMP1 in its pathogenesis and immunity, and PfEMP1-based vaccines to prevent it. Immunol Rev 2020; 293:230-252. [PMID: 31562653 PMCID: PMC6972667 DOI: 10.1111/imr.12807] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022]
Abstract
Malaria, a mosquito-borne infectious disease caused by parasites of the genus Plasmodium continues to be a major health problem worldwide. The unicellular Plasmodium-parasites have the unique capacity to infect and replicate within host erythrocytes. By expressing variant surface antigens Plasmodium falciparum has evolved to avoid protective immune responses; as a result in endemic areas anti-malaria immunity develops gradually over many years of multiple and repeated infections. We are studying the role of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) expressed by asexual stages of P. falciparum responsible for the pathogenicity of severe malaria. The immunopathology of falciparum malaria has been linked to cyto-adhesion of infected erythrocytes to specific host receptors. A greater appreciation of the PfEMP1 molecules important for the development of protective immunity and immunopathology is a prerequisite for the rational discovery and development of a safe and protective anti-disease malaria vaccine. Here we review the role of ICAM-1 and EPCR receptor adhering falciparum-parasites in the development of severe malaria; we discuss our current research to understand the factors involved in the pathogenesis of cerebral malaria and the feasibility of developing a vaccine targeted specifically to prevent this disease.
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Affiliation(s)
- Anja Ramstedt Jensen
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Infectious DiseasesRigshospitaletCopenhagenDenmark
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18
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Cai LM, Li Z, Liu J. Modeling and analyzing dynamics of malaria transmission with host immunity. INT J BIOMATH 2019. [DOI: 10.1142/s1793524519500748] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this paper, we investigate a compartmental model for malaria transmission, where the host individuals are distributed according to their immune status. The acquired immunity of malaria is usually booted upon each exposure and gradually declines between the consecutive bouts of the disease. It is assumed that the recovered host individuals may be reinfected due to the immunity waning over time. The existence and stability of equilibria in the system, and the effect of the immunity status on dynamics of the system, are investigated, respectively. The phenomena of multiple endemic equilibria in our model are also observed. Our obtained results show that malaria may keep recurring under the first lower prevalence, however, when malaria is spreading in a population, it may remain at a different endemic level under suitable control strategies.
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Affiliation(s)
- Li-Ming Cai
- School of Mathematics and Statistics, Xinyang Normal University, Xinyang 464000, P. R. China
| | - Zhaoqing Li
- School of Mathematics and Statistics, Xinyang Normal University, Xinyang 464000, P. R. China
| | - Jinliang Liu
- School of Mathematics and Statistics, Xinyang Normal University, Xinyang 464000, P. R. China
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19
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Earland D, Buchwald AG, Sixpence A, Chimenya M, Damson M, Seydel KB, Mathanga DP, Taylor TE, Laufer MK. Impact of Multiplicity of Plasmodium falciparum Infection on Clinical Disease in Malawi. Am J Trop Med Hyg 2019; 101:412-415. [PMID: 31219007 PMCID: PMC6685583 DOI: 10.4269/ajtmh.19-0093] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/22/2019] [Indexed: 11/07/2022] Open
Abstract
Multiplicity of infection (MOI), the number of unique Plasmodium falciparum parasite genotypes found in one infected individual, may contribute to the development of clinical malaria disease. However, the independent contribution of MOI and parasite density to clinical disease has not been well characterized. We conducted a two-year longitudinal cohort study of adults and children in a high-transmission setting in Malawi to test the hypothesis that increased MOI was independently associated with clinical disease, after accounting for parasite density. Of 1,062 episodes of infection, 477 (44.9%) were associated with symptoms. After controlling for repeated measures within an individual, key demographic factors, and parasite density, there was no association between MOI and clinical disease (OR = 1.02, 95% CI: 0.70-1.51). Although the limited ability to discern MOI in low-density asymptomatic infections may have impacted our results, we conclude that MOI is not an independent risk factor for clinical disease.
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Affiliation(s)
- Dominique Earland
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Alick Sixpence
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Mabvuto Chimenya
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Milius Damson
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Karl B. Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Don P. Mathanga
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie E. Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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20
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Stability and Hopf Bifurcation of a Vector-Borne Disease Model with Saturated Infection Rate and Reinfection. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2019; 2019:1352698. [PMID: 31341509 PMCID: PMC6590565 DOI: 10.1155/2019/1352698] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/04/2019] [Accepted: 05/13/2019] [Indexed: 11/17/2022]
Abstract
This paper established a delayed vector-borne disease model with saturated infection rate and cure rate. First of all, according to the basic reproductive number R 0, we determined the disease-free equilibrium E 0 and the endemic equilibrium E 1. Through the analysis of the characteristic equation, we consider the stability of two equilibriums. Furthermore, the effect on the stability of the endemic equilibrium E 1 by delay was studied, the existence of Hopf bifurcations of this system in E 1 was analyzed, and the length of delay to preserve stability was estimated. The direction and stability of the Hopf bifurcation were also been determined. Finally, we performed some numerical simulation to illustrate our main results.
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21
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Hviid L, Smith-Togobo C, Willcox BE. Human Vδ1 + T Cells in the Immune Response to Plasmodium falciparum Infection. Front Immunol 2019; 10:259. [PMID: 30837999 PMCID: PMC6382743 DOI: 10.3389/fimmu.2019.00259] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/29/2019] [Indexed: 02/03/2023] Open
Abstract
Naturally acquired protective immunity to Plasmodium falciparum malaria is mainly antibody-mediated. However, other cells of the innate and adaptive immune system also play important roles. These include so-called unconventional T cells, which express a γδ T-cell receptor (TCR) rather than the αβ TCR expressed by the majority of T cells—the conventional T cells. The γδ T-cell compartment can be divided into distinct subsets. One expresses a TCR involving Vγ9 and Vδ2, while another major subset uses instead a TCR composed of Vδ1 paired with one of several types of γ chains. The former of these subsets uses a largely semi-invariant TCR repertoire and responds in an innate-like fashion to pyrophosphate antigens generated by various stressed host cells and infectious pathogens, including P. falciparum. In this short review, we focus instead on the Vδ1 subset, which appears to have a more adaptive immunobiology, but which has been much less studied in general and in malaria in particular. We discuss the evidence that Vδ1+ cells do indeed play a role in malaria and speculate on the function and specificity of this cell type, which is increasingly attracting the attention of immunologists.
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Affiliation(s)
- Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Cecilia Smith-Togobo
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, Ghana
| | - Benjamin E Willcox
- Cancer Immunology and Immunotherapy Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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22
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Abrard S, Cousin B, Fleury C, Fouquet O, Beydon L. Cardiopulmonary Bypass and Malaria Relapse. J Cardiothorac Vasc Anesth 2018; 32:2282-2285. [DOI: 10.1053/j.jvca.2017.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Indexed: 11/11/2022]
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23
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Wanduku D. Threshold conditions for a family of epidemic dynamic models for malaria with distributed delays in a non-random environment. INT J BIOMATH 2018. [DOI: 10.1142/s1793524518500857] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A family of deterministic SEIRS epidemic dynamic models for malaria is presented. The family type is determined by a general functional response for the nonlinear incidence rate of the disease. Furthermore, the malaria models exhibit three random delays — the incubation periods of the plasmodium inside the female mosquito and human hosts, and also the period of effective acquired natural immunity against the disease. Insights about the effects of the delays and the nonlinear incidence rate of the disease on (1) eradication and (2) persistence of malaria in the human population are obtained via analyzing and interpreting the global asymptotic stability results of the disease-free and endemic equilibrium of the system. The basic reproduction numbers and other threshold values for malaria are calculated, and superior threshold conditions for the stability of the equilibria are found. Numerical simulation results are presented.
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Affiliation(s)
- Divine Wanduku
- Department of Mathematical Sciences, Georgia Southern University, 65 Georgia Ave, Room 3042, Statesboro, Georgia 30460, USA
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IgG Responses to the Plasmodium falciparum Antigen VAR2CSA in Colombia Are Restricted to Pregnancy and Are Not Induced by Exposure to Plasmodium vivax. Infect Immun 2018; 86:IAI.00136-18. [PMID: 29784859 PMCID: PMC6056870 DOI: 10.1128/iai.00136-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/11/2018] [Indexed: 12/20/2022] Open
Abstract
Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). The VAR2CSA subtype of PfEMP1 mediates IE binding in the placenta. Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). The VAR2CSA subtype of PfEMP1 mediates IE binding in the placenta. VAR2CSA-specific IgG is normally acquired only after exposure to placental parasites. However, it was recently reported that men and children from Colombia often have high levels of functional VAR2CSA-specific IgG. This potentially undermines the current understanding of malaria immunity in pregnant women, and we thus conducted a study to assess further the levels of VAR2CSA-specific IgG in pregnant and nonpregnant Colombians. Plasma IgG against two full-length recombinant PfEMP1 proteins (one of the VAR2CSA type and one not) produced in baculovirus-transfected insect cells was detected frequently among Colombian men, children, and pregnant women with acute or previous malaria exposure. In contrast, IgG reactivity to a homologous full-length VAR2CSA-type protein expressed in Chinese hamster ovary (CHO) cells was low and infrequent among the Colombian plasma samples, as was reactivity to both corresponding native PfEMP1 proteins. Moreover, human and rabbit antibodies specific for Plasmodium vivax Duffy-binding protein (PvDBP), a protein with some homology to PfEMP1, did not react with VAR2CSA-type recombinant or native proteins, although the mouse monoclonal and PvDBP-specific antibody 3D10 was weakly reactive with recombinant proteins expressed in baculovirus-transfected insect cells. Our data indicate that the previously reported Colombian IgG reactivity to recombinant VAR2CSA is not malaria specific and that the acquisition of VAR2CSA-specific IgG is restricted to pregnancy, in Colombia and elsewhere.
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25
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Kinetics of antibody responses to PfRH5-complex antigens in Ghanaian children with Plasmodium falciparum malaria. PLoS One 2018; 13:e0198371. [PMID: 29883485 PMCID: PMC5993283 DOI: 10.1371/journal.pone.0198371] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/17/2018] [Indexed: 11/21/2022] Open
Abstract
Plasmodium falciparum PfRH5 protein binds Ripr, CyRPA and Pf113 to form a complex that is essential for merozoite invasion of erythrocytes. The inter-genomic conservation of the PfRH5 complex proteins makes them attractive blood stage vaccine candidates. However, little is known about how antibodies to PfRH5, CyRPA and Pf113 are acquired and maintained in naturally exposed populations, and the role of PfRH5 complex proteins in naturally acquired immunity. To provide such data, we studied 206 Ghanaian children between the ages of 1–12 years, who were symptomatic, asymptomatic or aparasitemic and healthy. Plasma levels of antigen-specific IgG and IgG subclasses were measured by ELISA at several time points during acute disease and convalescence. On the day of admission with acute P. falciparum malaria, the prevalence of antibodies to PfRH5-complex proteins was low compared to other merozoite antigens (EBA175, GLURP-R0 and GLURP-R2). At convalescence, the levels of RH5-complex-specific IgG were reduced, with the decay of PfRH5-specific IgG being slower than the decay of IgG specific for CyRPA and Pf113. No correlation between IgG levels and protection against P. falciparum malaria was observed for any of the PfRH5 complex proteins. From this we conclude that specific IgG was induced against proteins from the PfRH5-complex during acute P. falciparum malaria, but the prevalence was low and the IgG levels decayed rapidly after treatment. These data indicate that the levels of IgG specific for PfRH5-complex proteins in natural infections in Ghanaian children were markers of recent exposure only.
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Plasmodium falciparum Recrudescence Two Years after Treatment of an Uncomplicated Infection without Return to an Area Where Malaria Is Endemic. Antimicrob Agents Chemother 2018; 62:AAC.01892-17. [PMID: 29229635 DOI: 10.1128/aac.01892-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 12/03/2017] [Indexed: 11/20/2022] Open
Abstract
We report evidence, confirmed by the lack of travel activity outside of France and genetic diversity analysis using polymorphic microsatellite markers, that Plasmodium falciparum malaria infection effectively treated with an artemisinin-based combination can remain dormant and relapse during pregnancy at least 2 years after treatment.
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28
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Manirakiza A, Serdouma E, Ngbalé RN, Moussa S, Gondjé S, Degana RM, Bata GGB, Moyen JM, Delmont J, Grésenguet G, Sepou A. A brief review on features of falciparum malaria during pregnancy. J Public Health Afr 2017; 8:668. [PMID: 29456824 PMCID: PMC5812306 DOI: 10.4081/jphia.2017.668] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 08/16/2017] [Accepted: 08/17/2017] [Indexed: 11/22/2022] Open
Abstract
Malaria in pregnancy is a serious public health problem in tropical areas. Frequently, the placenta is infected by accumulation of Plasmodium falciparum-infected erythrocytes in the intervillous space. Falciparum malaria acts during pregnancy by a range of mechanisms, and chronic or repeated infection and co-infections have insidious effects. The susceptibility of pregnant women to malaria is due to both immunological and humoral changes. Until a malaria vaccine becomes available, the deleterious effects of malaria in pregnancy can be avoided by protection against infection and prompt treatment with safe, effective antimalarial agents; however, concurrent infections such as with HIV and helminths during pregnancy are jeopardizing malaria control in sub-Saharan Africa.
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Affiliation(s)
| | | | | | - Sandrine Moussa
- Pasteur Institute of Bangui, Bangui, Central African Republic
| | - Samuel Gondjé
- Ministry of Public Health, Population and AIDS Control, Bangui, Central African Republic
| | - Rock Mbetid Degana
- Ministry of Public Health, Population and AIDS Control, Bangui, Central African Republic
| | | | - Jean Methode Moyen
- Ministry of Public Health, Population and AIDS Control, Bangui, Central African Republic
| | - Jean Delmont
- Center for Training and Research in Tropical Medicine and Health, Faculty of Medicine North, Marseille, France
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Moris P, Jongert E, van der Most RG. Characterization of T-cell immune responses in clinical trials of the candidate RTS,S malaria vaccine. Hum Vaccin Immunother 2017; 14:17-27. [PMID: 28934066 PMCID: PMC5791571 DOI: 10.1080/21645515.2017.1381809] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The candidate malaria vaccine RTS,S has demonstrated 45.7% efficacy over 18 months against all clinical disease in a phase-III field study of African children. RTS,S targets the circumsporozoite protein (CSP), which is expressed on the Plasmodium sporozoite during the pre-erythrocyte stage of its life-cycle; the stage between mosquito bite and liver infection. Early in the development of RTS,S, it was recognized that CSP-specific cell-mediated immunity (CMI) was required to complement CSP-specific antibody-mediated immunity. In reviewing RTS,S clinical studies, associations between protection and various types of CMI (CSP-specific CD4+ T cells and INF-γ ELISPOTs) have been identified, but not consistently. It is plausible that certain CD4+ T cells support antibody responses or co-operate with other immune-cell types to potentially elicit protection. However, the identities of vaccine correlates of protection, implicating either CSP-specific antibodies or T cells remain elusive, suggesting that RTS,S clinical trials may benefit from additional immunogenicity analyses that can be informed by the results of controlled human malaria infection studies.
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Carlos BC, Fotoran WL, Menezes MJ, Cabral FJ, Bastos MF, Costa FT, Sousa-Neto JA, Ribolla PE, Wunderlich G, Ferreira MU. Expressed var gene repertoire and variant surface antigen diversity in a shrinking Plasmodium falciparum population. Exp Parasitol 2016; 170:90-99. [DOI: 10.1016/j.exppara.2016.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/01/2016] [Accepted: 09/20/2016] [Indexed: 10/21/2022]
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Holding T, Recker M. Maintenance of phenotypic diversity within a set of virulence encoding genes of the malaria parasite Plasmodium falciparum. J R Soc Interface 2016; 12:20150848. [PMID: 26674193 PMCID: PMC4707858 DOI: 10.1098/rsif.2015.0848] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Infection by the human malaria parasite Plasmodium falciparum results in a broad spectrum of clinical outcomes, ranging from severe and potentially life-threatening malaria to asymptomatic carriage. In a process of naturally acquired immunity, individuals living in malaria-endemic regions build up a level of clinical protection, which attenuates infection severity in an exposure-dependent manner. Underlying this shift in the immunoepidemiology as well as the observed range in malaria pathogenesis is the var multigene family and the phenotypic diversity embedded within. The var gene-encoded surface proteins Plasmodium falciparum erythrocyte membrane protein 1 mediate variant-specific binding of infected red blood cells to a diverse set of host receptors that has been linked to specific disease manifestations, including cerebral and pregnancy-associated malaria. Here, we show that cross-reactive immune responses, which minimize the within-host benefit of each additionally expressed gene during infection, can cause selection for maximum phenotypic diversity at the genome level. We further show that differential functional constraints on protein diversification stably maintain uneven ratios between phenotypic groups, in line with empirical observation. Our results thus suggest that the maintenance of phenotypic diversity within P. falciparum is driven by an evolutionary trade-off that optimizes between within-host parasite fitness and between-host selection pressure.
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Affiliation(s)
- Thomas Holding
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn TR10 9EZ, UK
| | - Mario Recker
- Centre for Mathematics and the Environment, University of Exeter, Penryn Campus, Penryn TR10 9EZ, UK
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Arnot DE, Jensen ATR. Antigenic Variation and the Genetics and Epigenetics of the PfEMP1 Erythrocyte Surface Antigens in Plasmodium falciparum Malaria. ADVANCES IN APPLIED MICROBIOLOGY 2016; 74:77-96. [PMID: 21459194 DOI: 10.1016/b978-0-12-387022-3.00007-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
How immunity to malaria develops remains one of the great unresolved issues in bio-medicine and resolution of its various paradoxes is likely to be the key to developing effective malaria vaccines. The basic epidemiological observations are; under conditions of intense natural transmission, humans do become immune to P. falciparum malaria, but this is a slow process requiring multiple disease episodes which many, particularly young children, do not survive. Adult survivors are immune to the symptoms of malaria, and unless pregnant, can control the growth of most or all new inoculations. Sterile immunity is not achieved and chronic parasitization of apparently healthy adults is the norm. In this article, we analyse the best understood malaria "antigenic variation" system, that based on Plasmodium falciparum's PfEMP1-type cytoadhesion antigens, and critically review recent literature on the function and control of this multi-gene family of parasite variable surface antigens.
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Affiliation(s)
- David E Arnot
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, CSS Oester Farimagsgade 5, Copenhagen K, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), CSS Oester Farimagsgade 5, Copenhagen K, Denmark; Institute of Immunology and Infection Research, School of Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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Abstract
INTRODUCTION Placental malaria (PM) is a major public health problem that constitutes a significant health concern for the mother, and especially for the developing fetus and offspring. Current means of prevention have limitations, including a restricted window of intervention that excludes the first trimester of pregnancy, and the fact that very few drugs can be used for this purpose. The identification of the VAR2CSA antigen, specific to PM parasites, offers an excellent opportunity to develop a vaccine against this disease. Proof of concept of a first-generation vaccine is nearing completion, and two clinical trials are underway. AREAS COVERED This review focuses on PM, which is mainly caused by Plasmodium falciparum. The review highlights recent advances and the key milestones that led to the identification of the optimal vaccine target within the large VAR2CSA protein. The paper also points out how future improvements can strengthen this process to achieve an effective vaccine in the field. EXPERT OPINION The approach taken to develop a P. falciparum erythrocyte membrane protein 1-based vaccine to protect pregnant women is very promising in view of the current difficulties of achieving a sterilizing vaccine against malaria parasite. This approach could help us to control the deleterious effect of malaria infections that characterize severe clinical forms.
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Hviid L, Jensen ATR. PfEMP1 - A Parasite Protein Family of Key Importance in Plasmodium falciparum Malaria Immunity and Pathogenesis. ADVANCES IN PARASITOLOGY 2015; 88:51-84. [PMID: 25911365 DOI: 10.1016/bs.apar.2015.02.004] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Plasmodium falciparum causes the most severe form of malaria and is responsible for essentially all malaria-related deaths. The accumulation in various tissues of erythrocytes infected by mature P. falciparum parasites can lead to circulatory disturbances and inflammation, and is thought to be a central element in the pathogenesis of the disease. It is mediated by the interaction of parasite ligands on the erythrocyte surface and a range of host receptor molecules in many organs and tissues. Among several proteins and protein families implicated in this process, the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family of high-molecular weight and highly variable antigens appears to be the most prominent. In this chapter, we aim to provide a systematic overview of the current knowledge about these proteins, their structure, their function, how they are presented on the erythrocyte surface, and how the var genes encoding them are regulated. The role of PfEMP1 in the pathogenesis of malaria, PfEMP1-specific immune responses, and the prospect of PfEMP1-specific vaccination against malaria are also covered briefly.
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Affiliation(s)
- Lars Hviid
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Anja T R Jensen
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
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35
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Bailey JA, Pablo J, Niangaly A, Travassos MA, Ouattara A, Coulibaly D, Laurens MB, Takala-Harrison SL, Lyke KE, Skinner J, Berry AA, Jasinskas A, Nakajima-Sasaki R, Kouriba B, Thera MA, Felgner PL, Doumbo OK, Plowe CV. Seroreactivity to a large panel of field-derived Plasmodium falciparum apical membrane antigen 1 and merozoite surface protein 1 variants reflects seasonal and lifetime acquired responses to malaria. Am J Trop Med Hyg 2015; 92:9-12. [PMID: 25294612 PMCID: PMC4347399 DOI: 10.4269/ajtmh.14-0140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 07/26/2014] [Indexed: 11/07/2022] Open
Abstract
Parasite antigen diversity poses an obstacle to developing an effective malaria vaccine. A protein microarray containing Plasmodium falciparum apical membrane antigen 1 (AMA1, n = 57) and merozoite surface protein 1 19-kD (MSP119, n = 10) variants prevalent at a malaria vaccine testing site in Bandiagara, Mali, was used to assess changes in seroreactivity caused by seasonal and lifetime exposure to malaria. Malian adults had significantly higher magnitude and breadth of seroreactivity to variants of both antigens than did Malian children. Seroreactivity increased over the course of the malaria season in children and adults, but the difference was more dramatic in children. These results help to validate diversity-covering protein microarrays as a promising tool for measuring the breadth of antibody responses to highly variant proteins, and demonstrate the potential of this new tool to help guide the development of malaria vaccines with strain-transcending efficacy.
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Affiliation(s)
- Jason A Bailey
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Jozelyn Pablo
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Amadou Niangaly
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Mark A Travassos
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Amed Ouattara
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Drissa Coulibaly
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Matthew B Laurens
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Shannon L Takala-Harrison
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Kirsten E Lyke
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Jeff Skinner
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Andrea A Berry
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Algis Jasinskas
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Rie Nakajima-Sasaki
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Bourema Kouriba
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Mahamadou A Thera
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Philip L Felgner
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Ogobara K Doumbo
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
| | - Christopher V Plowe
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland; Division of Infectious Diseases, Department of Medicine, University of California, Irvine, California; Laboratory of Immunogenetics, National Institutes of Health, Bethesda, Maryland; Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, University of Sciences, Techniques and Technology, Bamako, Mali
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Campo JJ, Aponte JJ, Skinner J, Nakajima R, Molina DM, Liang L, Sacarlal J, Alonso PL, Crompton PD, Felgner PL, Dobaño C. RTS,S vaccination is associated with serologic evidence of decreased exposure to Plasmodium falciparum liver- and blood-stage parasites. Mol Cell Proteomics 2014; 14:519-31. [PMID: 25547414 DOI: 10.1074/mcp.m114.044677] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The leading malaria vaccine candidate, RTS,S, targets the sporozoite and liver stages of the Plasmodium falciparum life cycle, yet it provides partial protection against disease associated with the subsequent blood stage of infection. Antibodies against the vaccine target, the circumsporozoite protein, have not shown sufficient correlation with risk of clinical malaria to serve as a surrogate for protection. The mechanism by which a vaccine that targets the asymptomatic sporozoite and liver stages protects against disease caused by blood-stage parasites remains unclear. We hypothesized that vaccination with RTS,S protects from blood-stage disease by reducing the number of parasites emerging from the liver, leading to prolonged exposure to subclinical levels of blood-stage parasites that go undetected and untreated, which in turn boosts pre-existing antibody-mediated blood-stage immunity. To test this hypothesis, we compared antibody responses to 824 P. falciparum antigens by protein array in Mozambican children 6 months after receiving a full course of RTS,S (n = 291) versus comparator vaccine (n = 297) in a Phase IIb trial. Moreover, we used a nested case-control design to compare antibody responses of children who did or did not experience febrile malaria. Unexpectedly, we found that the breadth and magnitude of the antibody response to both liver and asexual blood-stage antigens was significantly lower in RTS,S vaccinees, with the exception of only four antigens, including the RTS,S circumsporozoite antigen. Contrary to our initial hypothesis, these findings suggest that RTS,S confers protection against clinical malaria by blocking sporozoite invasion of hepatocytes, thereby reducing exposure to the blood-stage parasites that cause disease. We also found that antibody profiles 6 months after vaccination did not distinguish protected and susceptible children during the subsequent 12-month follow-up period but were strongly associated with exposure. Together, these data provide insight into the mechanism by which RTS,S protects from malaria.
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Affiliation(s)
- Joe J Campo
- ‡ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; §Manhiça Health Research Centre, Manhiça, Mozambique;
| | - John J Aponte
- ‡ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; §Manhiça Health Research Centre, Manhiça, Mozambique
| | - Jeff Skinner
- ¶Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD
| | - Rie Nakajima
- ‡‡Department of Medicine, University of California Irvine, Irvine, CA
| | | | - Li Liang
- ‡‡Department of Medicine, University of California Irvine, Irvine, CA
| | - Jahit Sacarlal
- §Manhiça Health Research Centre, Manhiça, Mozambique; **Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Pedro L Alonso
- ‡ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; §Manhiça Health Research Centre, Manhiça, Mozambique
| | - Peter D Crompton
- ¶Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD
| | - Philip L Felgner
- ‡‡Department of Medicine, University of California Irvine, Irvine, CA; ‖Antigen Discovery Inc., Irvine, CA
| | - Carlota Dobaño
- ‡ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain; §Manhiça Health Research Centre, Manhiça, Mozambique
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Fratus ASB, Cabral FJ, Fotoran WL, Medeiros MM, Carlos BC, Martha RD, da Silva LHP, Lopes SCP, Costa FTM, Wunderlich G. Antibody recognition of Plasmodium falciparum infected red blood cells by symptomatic and asymptomatic individuals in the Brazilian Amazon. Mem Inst Oswaldo Cruz 2014; 109:598-601. [PMID: 25099336 PMCID: PMC4156453 DOI: 10.1590/0074-0276140027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/12/2014] [Indexed: 12/31/2022] Open
Abstract
In the Amazon Region, there is a virtual absence of severe malaria and few fatal cases of naturally occurring Plasmodium falciparum infections; this presents an intriguing and underexplored area of research. In addition to the rapid access of infected persons to effective treatment, one cause of this phenomenon might be the recognition of cytoadherent variant proteins on the infected red blood cell (IRBC) surface, including the var gene encoded P. falciparum erythrocyte membrane protein 1. In order to establish a link between cytoadherence, IRBC surface antibody recognition and the presence or absence of malaria symptoms, we phenotype-selected four Amazonian P. falciparum isolates and the laboratory strain 3D7 for their cytoadherence to CD36 and ICAM1 expressed on CHO cells. We then mapped the dominantly expressed var transcripts and tested whether antibodies from symptomatic or asymptomatic infections showed a differential recognition of the IRBC surface. As controls, the 3D7 lineages expressing severe disease-associated phenotypes were used. We showed that there was no profound difference between the frequency and intensity of antibody recognition of the IRBC-exposed P. falciparum proteins in symptomatic vs. asymptomatic infections. The 3D7 lineages, which expressed severe malaria-associated phenotypes, were strongly recognised by most, but not all plasmas, meaning that the recognition of these phenotypes is frequent in asymptomatic carriers, but is not necessarily a prerequisite to staying free of symptoms.
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Affiliation(s)
| | - Fernanda Janku Cabral
- Departamento de Parasitologia, Instituto de Ciências Biomédicas,
Universidade de São Paulo, São Paulo, SP, Brasil
| | - Wesley Luzetti Fotoran
- Departamento de Parasitologia, Instituto de Ciências Biomédicas,
Universidade de São Paulo, São Paulo, SP, Brasil
| | - Márcia Melo Medeiros
- Departamento de Parasitologia, Instituto de Ciências Biomédicas,
Universidade de São Paulo, São Paulo, SP, Brasil
| | - Bianca Cechetto Carlos
- Departamento de Parasitologia, Instituto de Ciências Biomédicas,
Universidade de São Paulo, São Paulo, SP, Brasil
| | | | | | - Stefanie Costa Pinto Lopes
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia,
Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - Fabio Trindade Maranhão Costa
- Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia,
Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - Gerhard Wunderlich
- Departamento de Parasitologia, Instituto de Ciências Biomédicas,
Universidade de São Paulo, São Paulo, SP, Brasil
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38
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Yapi RB, Hürlimann E, Houngbedji CA, Ndri PB, Silué KD, Soro G, Kouamé FN, Vounatsou P, Fürst T, N’Goran EK, Utzinger J, Raso G. Infection and co-infection with helminths and Plasmodium among school children in Côte d'Ivoire: results from a National Cross-Sectional Survey. PLoS Negl Trop Dis 2014; 8:e2913. [PMID: 24901333 PMCID: PMC4046940 DOI: 10.1371/journal.pntd.0002913] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 04/16/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Helminth infection and malaria remain major causes of ill-health in the tropics and subtropics. There are several shared risk factors (e.g., poverty), and hence, helminth infection and malaria overlap geographically and temporally. However, the extent and consequences of helminth-Plasmodium co-infection at different spatial scales are poorly understood. METHODOLOGY This study was conducted in 92 schools across Côte d'Ivoire during the dry season, from November 2011 to February 2012. School children provided blood samples for detection of Plasmodium infection, stool samples for diagnosis of soil-transmitted helminth (STH) and Schistosoma mansoni infections, and urine samples for appraisal of Schistosoma haematobium infection. A questionnaire was administered to obtain demographic, socioeconomic, and behavioral data. Multinomial regression models were utilized to determine risk factors for STH-Plasmodium and Schistosoma-Plasmodium co-infection. PRINCIPAL FINDINGS Complete parasitological and questionnaire data were available for 5,104 children aged 5-16 years. 26.2% of the children were infected with any helminth species, whilst the prevalence of Plasmodium infection was 63.3%. STH-Plasmodium co-infection was detected in 13.5% and Schistosoma-Plasmodium in 5.6% of the children. Multinomial regression analysis revealed that boys, children aged 10 years and above, and activities involving close contact to water were significantly and positively associated with STH-Plasmodium co-infection. Boys, wells as source of drinking water, and water contact were significantly and positively associated with Schistosoma-Plasmodium co-infection. Access to latrines, deworming, higher socioeconomic status, and living in urban settings were negatively associated with STH-Plasmodium co-infection; whilst use of deworming drugs and access to modern latrines were negatively associated with Schistosoma-Plasmodium co-infection. CONCLUSIONS/SIGNIFICANCE More than 60% of the school children surveyed were infected with Plasmodium across Côte d'Ivoire, and about one out of six had a helminth-Plasmodium co-infection. Our findings provide a rationale to combine control interventions that simultaneously aim at helminthiases and malaria.
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Affiliation(s)
- Richard B. Yapi
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Eveline Hürlimann
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Clarisse A. Houngbedji
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
| | - Prisca B. Ndri
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Sciences de la Nature, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire
| | - Kigbafori D. Silué
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Gotianwa Soro
- Programme National de Santé Scolaire et Universitaire, Abidjan, Côte d’Ivoire
| | - Ferdinand N. Kouamé
- Programme National de Santé Scolaire et Universitaire, Abidjan, Côte d’Ivoire
| | - Penelope Vounatsou
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Thomas Fürst
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Centre for Health Policy, Imperial College London, London, United Kingdom
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Eliézer K. N’Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Jürg Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Giovanna Raso
- Département Environnement et Santé, Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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Ampomah P, Stevenson L, Ofori MF, Barfod L, Hviid L. Kinetics of B cell responses to Plasmodium falciparum erythrocyte membrane protein 1 in Ghanaian women naturally exposed to malaria parasites. THE JOURNAL OF IMMUNOLOGY 2014; 192:5236-44. [PMID: 24760153 DOI: 10.4049/jimmunol.1400325] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Naturally acquired protective immunity to Plasmodium falciparum malaria takes years to develop. It relies mainly on Abs, particularly IgG specific for Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) proteins on the infected erythrocyte surface. It is only partially understood why acquisition of clinical protection takes years to develop, but it probably involves a range of immune-evasive parasite features, not least of which are PfEMP1 polymorphism and clonal variation. Parasite-induced subversion of immunological memory and expansion of "atypical" memory B cells may also contribute. In this first, to our knowledge, longitudinal study of its kind, we measured B cell subset composition, as well as PfEMP1-specific Ab levels and memory B cell frequencies, in Ghanaian women followed from early pregnancy up to 1 y after delivery. Cell phenotypes and Ag-specific B cell function were assessed three times during and after pregnancy. Levels of IgG specific for pregnancy-restricted, VAR2CSA-type PfEMP1 increased markedly during pregnancy and declined after delivery, whereas IgG levels specific for two PfEMP1 proteins not restricted to pregnancy did not. Changes in VAR2CSA-specific memory B cell frequencies showed typical primary memory induction among primigravidae and recall expansion among multigravidae, followed by contraction postpartum in all. No systematic changes in the frequencies of memory B cells specific for the two other PfEMP1 proteins were identified. The B cell subset analysis confirmed earlier reports of high atypical memory B cell frequencies among residents of P. falciparum-endemic areas, and indicated an additional effect of pregnancy. Our study provides new knowledge regarding immunity to P. falciparum malaria and underpins efforts to develop PfEMP1-based vaccines against this disease.
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Affiliation(s)
- Paulina Ampomah
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Liz Stevenson
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Michael F Ofori
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Lea Barfod
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Lars Hviid
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
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B-cell responses to pregnancy-restricted and -unrestricted Plasmodium falciparum erythrocyte membrane protein 1 antigens in Ghanaian women naturally exposed to malaria parasites. Infect Immun 2014; 82:1860-71. [PMID: 24566620 DOI: 10.1128/iai.01514-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Protective immunity to Plasmodium falciparum malaria acquired after natural exposure is largely antibody mediated. IgG-specific P. falciparum EMP1 (PfEMP1) proteins on the infected erythrocyte surface are particularly important. The transient antibody responses and the slowly acquired protective immunity probably reflect the clonal antigenic variation and allelic polymorphism of PfEMP1. However, it is likely that other immune-evasive mechanisms are also involved, such as interference with formation and maintenance of immunological memory. We measured PfEMP1-specific antibody levels by enzyme-linked immunosorbent assay (ELISA) and memory B-cell frequencies by enzyme-linked immunosorbent spot (ELISPOT) assay in a cohort of P. falciparum-exposed nonpregnant Ghanaian women. The antigens used were a VAR2CSA-type PfEMP1 (IT4VAR04) with expression restricted to parasites infecting the placenta, as well as two commonly recognized PfEMP1 proteins (HB3VAR06 and IT4VAR60) implicated in rosetting and not pregnancy restricted. This enabled, for the first time, a direct comparison in the same individuals of immune responses specific for a clinically important parasite antigen expressed only during well-defined periods (pregnancy) to responses specific for comparable antigens expressed independent of pregnancy. Our data indicate that PfEMP1-specific B-cell memory is adequately acquired even when antigen exposure is infrequent (e.g., VAR2CSA-type PfEMP1). Furthermore, immunological memory specific for VAR2CSA-type PfEMP1 can be maintained for many years without antigen reexposure and after circulating antigen-specific IgG has disappeared. The study provides evidence that natural exposure to P. falciparum leads to formation of durable B-cell immunity to clinically important PfEMP1 antigens. This has encouraging implications for current efforts to develop PfEMP1-based vaccines.
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Beaudet JM, Mansur L, Joo EJ, Kamhi E, Yang B, Clausen TM, Salanti A, Zhang F, Linhardt RJ. Characterization of human placental glycosaminoglycans and regional binding to VAR2CSA in malaria infected erythrocytes. Glycoconj J 2013; 31:109-16. [PMID: 24158546 DOI: 10.1007/s10719-013-9506-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 10/04/2013] [Accepted: 10/07/2013] [Indexed: 10/26/2022]
Abstract
Placental malaria is a serious problem in sub-Saharan Africa. Young women are particular susceptible to contracting this form of malaria during their first or second pregnancy despite previously acquired immunity from past infections. Placental malaria is caused by Plasmodium falciparum parasites expressing VAR2CSA on the erythrocyte surface. This protein adheres to a low-sulfated chondroitin sulfate-A found in placental tissue causing great harm to both mother and developing fetus. In rare cases, the localization of infected erythrocytes to the placenta can even result in the vertical transmission of malaria. In an effort to better understand this infection, chondroitin sulfate was isolated from the cotyledon part of the placenta, which should be accessible for parasite adhesion, as well as two non-accessible parts of the placenta to serve as controls. The placental chondroitin sulfate structures and their VAR2CSA binding were characterized. All portions of human placenta contained sufficient amounts of the appropriate low-sulfated chondroitin sulfate-A to display high-affinity binding to a recombinant truncated VAR2CSA construct, as determined using surface plasmon resonance. The cotyledon is the only placental tissue accessible to parasites in the bloodstream, suggesting it is the primary receptor for parasite infected red blood cells.
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Affiliation(s)
- Julie M Beaudet
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic, Troy, NY, 12180, USA
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Cairns ME, Asante KP, Owusu-Agyei S, Chandramohan D, Greenwood BM, Milligan PJ. Analysis of partial and complete protection in malaria cohort studies. Malar J 2013; 12:355. [PMID: 24093726 PMCID: PMC3850882 DOI: 10.1186/1475-2875-12-355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/02/2013] [Indexed: 11/15/2022] Open
Abstract
Background Malaria transmission is highly heterogeneous and analysis of incidence data must account for this for correct statistical inference. Less widely appreciated is the occurrence of a large number of zero counts (children without a malaria episode) in malaria cohort studies. Zero-inflated regression methods provide one means of addressing this issue, and also allow risk factors providing complete and partial protection to be disentangled. Methods Poisson, negative binomial (NB), zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) regression models were fitted to data from two cohort studies of malaria in children in Ghana. Multivariate models were used to understand risk factors for elevated incidence of malaria and for remaining malaria-free, and to estimate the fraction of the population not at risk of malaria. Results ZINB models, which account for both heterogeneity in individual risk and an unexposed sub-group within the population, provided the best fit to data in both cohorts. These approaches gave additional insight into the mechanism of factors influencing the incidence of malaria compared to simpler approaches, such as NB regression. For example, compared to urban areas, rural residence was found to both increase the incidence rate of malaria among exposed children, and increase the probability of being exposed. In Navrongo, 34% of urban residents were estimated to be at no risk, compared to 3% of rural residents. In Kintampo, 47% of urban residents and 13% of rural residents were estimated to be at no risk. Conclusion These results illustrate the utility of zero-inflated regression methods for analysis of malaria cohort data that include a large number of zero counts. Specifically, these results suggest that interventions that reach mainly urban residents will have limited overall impact, since some urban residents are essentially at no risk, even in areas of high endemicity, such as in Ghana.
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Affiliation(s)
- Matthew E Cairns
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, UK.
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Abstract
Trypanosomiasis remains one of the most serious constraints to economic development in sub-Saharan Africa and, as a consequence, related research has been subject to strong social and political as well as scientific influences. The epidemics of sleeping sickness that occurred at the turn of the 20th Century focussed research efforts on what became known as 'the colonial disease'. This focus is thought to have produced 'vertical' health services aimed at this one disease, while neglecting other important health issues. Given the scale of these epidemics, and the fact that the disease is fatal if left untreated, it is unsurprising that sleeping sickness dominated colonial medicine. Indeed, recent evidence indicates that, if anything, the colonial authorities greatly under-estimated the mortality attributable to sleeping sickness. Differences in approach to disease control between Francophone and Anglophone Africa, which in the past have been considered ideological, on examination prove to be logical, reflecting the underlying epidemiological divergence of East and West Africa. These epidemiological differences are ancient in origin, pre-dating the colonial period, and continue to the present day. Recent research has produced control solutions, for the African trypanosomiases of humans and livestock, that are effective, affordable and sustainable by small-holder farmers. Whether these simple solutions are allowed to fulfil their promise and become fully integrated into agricultural practice remains to be seen. After more than 100 years of effort, trypanosomiasis control remains a controversial topic, subject to the tides of fashion and politics.
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Affiliation(s)
- I Maudlin
- Centre for Tropical Veterinary Medicine, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, Roslin EH25 9RG, UK.
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Berger SS, Turner L, Wang CW, Petersen JEV, Kraft M, Lusingu JPA, Mmbando B, Marquard AM, Bengtsson DBAC, Hviid L, Nielsen MA, Theander TG, Lavstsen T. Plasmodium falciparum expressing domain cassette 5 type PfEMP1 (DC5-PfEMP1) bind PECAM1. PLoS One 2013; 8:e69117. [PMID: 23874884 PMCID: PMC3706608 DOI: 10.1371/journal.pone.0069117] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 06/07/2013] [Indexed: 11/18/2022] Open
Abstract
Members of the Plasmodium falciparum Erythrocyte Membrane protein 1 (PfEMP1) family expressed on the surface of malaria-infected erythrocytes mediate binding of the parasite to different receptors on the vascular lining. This process drives pathologies, and severe childhood malaria has been associated with the expression of particular subsets of PfEMP1 molecules. PfEMP1 are grouped into subtypes based on upstream sequences and the presence of semi-conserved PfEMP1 domain compositions named domain cassettes (DCs). Earlier studies have indicated that DC5-containing PfEMP1 (DC5-PfEMP1) are more likely to be expressed in children with severe malaria disease than in children with uncomplicated malaria, but these PfEMP1 subtypes only dominate in a relatively small proportion of the children with severe disease. In this study, we have characterised the genomic sequence characteristic for DC5, and show that two genetically different parasite lines expressing DC5-PfEMP1 bind PECAM1, and that anti-DC5-specific antibodies inhibit binding of DC5-PfEMP1-expressing parasites to transformed human bone marrow endothelial cells (TrHBMEC). We also show that antibodies against each of the four domains characteristic for DC5 react with native PfEMP1 expressed on the surface of infected erythrocytes, and that some of these antibodies are cross-reactive between the two DC5-containing PfEMP1 molecules tested. Finally, we confirm that anti-DC5 antibodies are acquired early in life by individuals living in malaria endemic areas, that individuals having high levels of these antibodies are less likely to develop febrile malaria episodes and that the antibody levels correlate positively with hemoglobin levels.
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Affiliation(s)
- Sanne S. Berger
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
- * E-mail: (SB); (TL)
| | - Louise Turner
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Christian W. Wang
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Jens E. V. Petersen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Maria Kraft
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - John P. A. Lusingu
- National Institute for Medical Research (NIMR), Tanga Medical Research Centre, Tanga, Tanzania
| | - Bruno Mmbando
- National Institute for Medical Research (NIMR), Tanga Medical Research Centre, Tanga, Tanzania
| | - Andrea M. Marquard
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Dominique B. A. C. Bengtsson
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Morten A. Nielsen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Thor G. Theander
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), University of Copenhagen, Copenhagen, Denmark
- * E-mail: (SB); (TL)
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45
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Plowe CV. Malaria Vaccines. Infect Dis (Lond) 2013. [DOI: 10.1007/978-1-4614-5719-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Baird JK. Tropical Health and Sustainability. Infect Dis (Lond) 2013. [DOI: 10.1007/978-1-4614-5719-0_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Bengtsson A, Joergensen L, Rask TS, Olsen RW, Andersen MA, Turner L, Theander TG, Hviid L, Higgins MK, Craig A, Brown A, Jensen ATR. A novel domain cassette identifies Plasmodium falciparum PfEMP1 proteins binding ICAM-1 and is a target of cross-reactive, adhesion-inhibitory antibodies. THE JOURNAL OF IMMUNOLOGY 2012; 190:240-9. [PMID: 23209327 DOI: 10.4049/jimmunol.1202578] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cerebral Plasmodium falciparum malaria is characterized by adhesion of infected erythrocytes (IEs) to the cerebral microvasculature. This has been linked to parasites expressing the structurally related group A subset of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family of IE adhesion ligands and to IEs with affinity for ICAM-1. However, recent evidence has cast doubt on both these associations, tempering hopes of the feasibility of developing a vaccine based on ICAM-1-binding PfEMP1. In this study, we report the identification of a domain cassette (DC) present in group A var genes from six genetically distinct P. falciparum parasites. The three domains in the cassette, which we call DC4, had a high level of sequence identity and cluster together phylogenetically. Erythrocytes infected by these parasites and selected in vitro for expression of DC4 adhered specifically to ICAM-1. The ICAM-1-binding capacity of DC4 was mapped to the C-terminal third of its Duffy-binding-like β3 domain. DC4 was the target of broadly cross-reactive and adhesion-inhibitory IgG Abs, and levels of DC4-specific and adhesion-inhibitory IgG increased with age among P. falciparum-exposed children. Our study challenges earlier conclusions that group A PfEMP1 proteins are not central to ICAM-1-specific IE adhesion and support the feasibility of developing a vaccine preventing cerebral malaria by inhibiting cerebral IE sequestration.
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Affiliation(s)
- Anja Bengtsson
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 1014, Denmark
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Jangpatarapongsa K, Xia H, Fang Q, Hu K, Yuan Y, Peng M, Gao Q, Sattabongkot J, Cui L, Li B, Udomsangpetch R. Immunity to malaria in Plasmodium vivax infection: a study in central China. PLoS One 2012; 7:e45971. [PMID: 23049909 PMCID: PMC3457974 DOI: 10.1371/journal.pone.0045971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 08/23/2012] [Indexed: 12/03/2022] Open
Abstract
Background P. vivax infection is characterised by relapsing fever, indicating reinfection by previously hidden parasites in the host. Relapsed infection can lead to the activation of the memory T cell pool, which may lead to protective immunity. This study aims to characterise immune responses in acute P. vivax-infected patients living in an area of central China characterised by only P. vivax infection. Methodology/Principal Findings We conducted a cross-sectional immune-phenotypic analysis of adults using the following inclusion criteria: acute P. vivax infection (N = 37), a history of P. vivax infection (N = 17), and no known history of P. vivax infection (N = 21). We also conducted a 2-week longitudinal analysis following acute P. vivax infection, in which PBMC proliferation was measured in response to P. vivax and P. falciparum blood stage lysates. Using flow cytometry, we showed elevated memory T cells in the blood during acute P. vivax infection. The levels of γδ T cells were two-fold higher than those measured in naive controls. This result suggested that in the two populations, memory and γδ T cells promptly responded to P. vivax parasites. Interestingly, P. falciparum antigens stimulated T cells obtained from P. vivax-infected patients during a day 14-convalescence, whereas lymphocytes from the naïve control group responded to a lower degree of convalescence. Conclusions/Significance Cell-mediated immunity during the convalescent period of the P. vivax-infected hosts was comprised of T cells that were specifically able to recognise P. falciparum antigens. Although the magnitude of the response was only half that measured after stimulation with P. vivax antigens, the matter of cross-antigenic stimulation is of great interest.
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Affiliation(s)
- Kulachart Jangpatarapongsa
- Center for Innovation Development and Technology Transfer, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Hui Xia
- Department of Parasitology, Bengbu Medical College, Anhui, China
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
| | - Qiang Fang
- Department of Parasitology, Bengbu Medical College, Anhui, China
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
| | - Kaiming Hu
- Department of Parasitology, Bengbu Medical College, Anhui, China
| | - Yuanying Yuan
- Department of Parasitology, Bengbu Medical College, Anhui, China
| | - Meiyu Peng
- Department of Immunology, Bengbu Medical College, Anhui, China
| | - Qi Gao
- Jiangsu Institute of Parasitic Disease, Wuxi, China
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Center, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, State College, Pennsylvania, United States of America
| | - Baiqing Li
- Anhui Key Laboratory of Infection and Immunity at Bengbu Medical College, Anhui, China
- Department of Immunology, Bengbu Medical College, Anhui, China
- * E-mail: (RU); (BL)
| | - Rachanee Udomsangpetch
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
- Center of Neglected Infectious Diseases, Mahidol University, Bangkok, Thailand
- * E-mail: (RU); (BL)
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Quadt KA, Barfod L, Andersen D, Bruun J, Gyan B, Hassenkam T, Ofori MF, Hviid L. The density of knobs on Plasmodium falciparum-infected erythrocytes depends on developmental age and varies among isolates. PLoS One 2012; 7:e45658. [PMID: 23029166 PMCID: PMC3447797 DOI: 10.1371/journal.pone.0045658] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 08/20/2012] [Indexed: 12/12/2022] Open
Abstract
Background The virulence of Plasmodium falciparum malaria is related to the parasite’s ability to evade host immunity through clonal antigenic variation and tissue-specific adhesion of infected erythrocytes (IEs). The P. falciparum erythrocyte membrane protein 1 (PfEMP1) family expressed on dome-shaped protrusions called knobs on the IE surface is central to both. Differences in receptor specificity and affinity of expressed PfEMP1 are important for IE adhesiveness, but it is not known whether differences in the number and size of the knobs on which the PfEMP1 proteins are expressed also play a role. Therefore, the aim of this study was to provide detailed information on isolate- and time-dependent differences in knob size and density. Methodology/Principal Findings We used atomic force microscopy to characterize knobs on the surface of P. falciparum-infected erythrocytes. Fourteen ex vivo isolates from Ghanaian children with malaria and 10 P. falciparum isolates selected in vitro for expression of a particular PfEMP1 protein (VAR2CSA) were examined. Knob density increased from ∼20 h to ∼35 h post-invasion, with significant variation among isolates. The knob density ex vivo, which was about five-fold higher than following long-term in vitro culture, started to decline within a few months of culture. Although knob diameter and height varied among isolates, we did not observe significant time-dependent variation in these dimensions. Conclusions/Significance The density of knobs on the P. falciparum-IE surface depends on time since invasion, but is also determined by the infecting isolate in a time-independent manner. This is the first study to quantitatively evaluate knob densities and dimensions on different P. falciparum isolates, to examine ex vivo isolates from humans, and to compare ex vivo and long-term in vitro-cultured isolates. Our findings contribute to the understanding of the interaction between P. falciparum parasites and the infected host.
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Affiliation(s)
- Katharina A. Quadt
- Centre for Medical Parasitology at i, Faculty of Health and Medical Sciences, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Lea Barfod
- Centre for Medical Parasitology at i, Faculty of Health and Medical Sciences, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Daniel Andersen
- Centre for Medical Parasitology at i, Faculty of Health and Medical Sciences, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Jonas Bruun
- Centre for Medical Parasitology at i, Faculty of Health and Medical Sciences, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Ben Gyan
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Tue Hassenkam
- Nano-Science Centre, Department of Chemistry, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Michael F. Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology at i, Faculty of Health and Medical Sciences, University of Copenhagen and at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- * E-mail:
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Partnering parasites: evidence of synergism between heavy Schistosoma haematobium and Plasmodium species infections in Kenyan children. PLoS Negl Trop Dis 2012; 6:e1723. [PMID: 22848765 PMCID: PMC3404100 DOI: 10.1371/journal.pntd.0001723] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Accepted: 05/23/2012] [Indexed: 11/19/2022] Open
Abstract
Background Residents of resource-poor tropical countries carry heavy burdens of concurrent parasitic infections, leading to high rates of morbidity and mortality. This study was undertaken to help identify the social and environmental determinants of multiple parasite infection in one such community. Methodology/Principal Findings Residents of Kingwede, Kenya aged 8 years and older were tested for presence and intensity of S. haematobium and Plasmodium spp. infections in a cross-sectional, household-based, community survey. Using General Estimating Equation (GEE) models, social and environmental determinants associated with patterns of co-infection were identified, with age being one of the most important factors. Children had 9.3 times the odds of co-infection compared to adults (95%CI = 5.3–16.3). Even after controlling for age, socio-economic position, and other correlates of co-infection, intense concomitant infections with the two parasites were found to cluster in a subset of individuals: the odds of heavy vs. light S. haematobium infection increased with increasing Plasmodium infection intensity suggesting the importance of unmeasured biological factors in determining intensity of co-infection. Conclusions/Significance Children in this community are more likely to be infected with multiple parasites than are adults and should therefore be targeted for prevention and control interventions. More importantly, heavy infections with multiple parasite species appear to cluster within a subset of individuals. Further studies focusing on these most vulnerable people are warranted. Parasitic diseases such as malaria and schistosomiasis account for a large proportion of global morbidity and mortality by contributing to malnutrition, developmental delays, loss of productivity, negative birth outcomes, disfigurement, physical handicap and social stigma. We studied these two infections in a community-wide, household-based study among residents of a coastal Kenyan village. With the use of newer PCR methods to detect sub-clinical malaria infections, and with the aid of statistical methods that could adjust for the household-level clustering of exposure factors, we found evidence that people of low socio-economic position are more likely to experience co-infection by these parasites. In addition, among children, we found that heavy infections clustered within a subset of individuals independent of their water contact, night activity, bednets use, and household distance to water, thus providing indirect evidence for biological interaction between these parasites in human hosts. If confirmed, these findings indicate that interventions focused on prevention and control of such co-infections could be concentrated on the most vulnerable groups of people in order to maximize benefits where resources are limited. Further studies of immunological and behavioral risk are warranted.
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