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Frimpong A, Kusi KA, Tornyigah B, Ofori MF, Ndifon W. Characterization of T cell activation and regulation in children with asymptomatic Plasmodium falciparum infection. Malar J 2018; 17:263. [PMID: 30005684 PMCID: PMC6045887 DOI: 10.1186/s12936-018-2410-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/07/2018] [Indexed: 02/08/2023] Open
Abstract
Background Asymptomatic Plasmodium infections are characterized by the absence of clinical disease and the ability to restrict parasite replication. Increasing levels of regulatory T cells (Tregs) in Plasmodium falciparum infections have been associated with the risk of developing clinical disease, suggesting that individuals with asymptomatic infections may have reduced Treg frequency. However, the relationship between Tregs, cellular activation and parasite control in asymptomatic malaria remains unclear. Methods In a cross-sectional study, the levels of Tregs and other T cell activation phenotypes were compared using flow cytometry in symptomatic, asymptomatic and uninfected children before and after stimulation with infected red blood cell lysates (iRBCs). In addition, the association between these T cell phenotypes and parasitaemia were investigated. Results In children with asymptomatic infections, levels of Tregs and activated T cells were comparable to those in healthy controls but significantly lower than those in symptomatic children. After iRBC stimulation, levels of Tregs remained lower for asymptomatic versus symptomatic children. In contrast, levels of activated T cells were higher for asymptomatic children. Strikingly, the pre-stimulation levels of two T cell activation phenotypes (CD8+CD69+ and CD8+CD25+CD69+) and the post-stimulation levels of two regulatory phenotypes (CD4+CD25+Foxp3+ and CD8+CD25+Foxp3+) were significantly positively correlated with and explained 68% of the individual variation in parasitaemia. A machine-learning model based on levels of these four phenotypes accurately distinguished between asymptomatic and symptomatic children (sensitivity = 86%, specificity = 94%), suggesting that these phenotypes govern the observed variation in disease status. Conclusion Compared to symptomatic P. falciparum infections, in children asymptomatic infections are characterized by lower levels of Tregs and activated T cells, which are associated with lower parasitaemia. The results indicate that T cell regulatory and activation phenotypes govern both parasitaemia and disease status in paediatric malaria in the studied sub-Saharan African population. Electronic supplementary material The online version of this article (10.1186/s12936-018-2410-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Augustina Frimpong
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, P. O. Box LG 54, Accra, Ghana. .,Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Accra, Ghana. .,African Institute for Mathematical Sciences, P.O. Box DL 676, Cape-Coast, Ghana.
| | - Kwadwo Asamoah Kusi
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, P. O. Box LG 54, Accra, Ghana.,Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Accra, Ghana
| | - Bernard Tornyigah
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Accra, Ghana
| | - Michael Fokuo Ofori
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Legon, P. O. Box LG 54, Accra, Ghana.,Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, P.O. Box LG 581, Accra, Ghana
| | - Wilfred Ndifon
- African Institute for Mathematical Sciences, P.O. Box DL 676, Cape-Coast, Ghana. .,African Institute for Mathematical Sciences, University of Stellenbosch, 7 Melrose Rd, Muizenberg, Cape Town, 7945, South Africa.
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Endothelial-Leukocyte Interaction in Severe Malaria: Beyond the Brain. Mediators Inflamm 2015; 2015:168937. [PMID: 26491221 PMCID: PMC4605361 DOI: 10.1155/2015/168937] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/25/2015] [Accepted: 09/01/2015] [Indexed: 01/23/2023] Open
Abstract
Malaria is the most important parasitic disease worldwide, accounting for 1 million deaths each year. Severe malaria is a systemic illness characterized by dysfunction of brain tissue and of one or more peripheral organs as lungs and kidney. The most severe and most studied form of malaria is associated with cerebral complications due to capillary congestion and the adhesion of infected erythrocytes, platelets, and leukocytes to brain vasculature. Thus, leukocyte rolling and adhesion in the brain vascular bed during severe malaria is singular and distinct from other models of inflammation. The leukocyte/endothelium interaction and neutrophil accumulation are also observed in the lungs. However, lung interactions differ from brain interactions, likely due to differences in the blood-brain barrier and blood-air barrier tight junction composition of the brain and lung endothelium. Here, we review the importance of endothelial dysfunction and the mechanism of leukocyte/endothelium interaction during severe malaria. Furthermore, we hypothesize a possible use of adjunctive therapies to antimalarial drugs that target the interaction between the leukocytes and the endothelium.
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Salwati E, Minigo G, Woodberry T, Piera KA, de Silva HD, Kenangalem E, Tjitra E, Coppel RL, Price RN, Anstey NM, Plebanski M. Differential cellular recognition of antigens during acute Plasmodium falciparum and Plasmodium vivax malaria. J Infect Dis 2011; 203:1192-1199. [PMID: 21451007 DOI: 10.1093/infdis/jiq166] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Plasmodium falciparum and Plasmodium vivax are co-endemic in the Asia-Pacific region. Their capacity to induce and sustain diverse T-cell responses underpins protective immunity. We compared T-cell responses to the largely conserved merozoite surface protein-5 (PfMSP5) during acute and convalescent falciparum and vivax malaria. METHODS Lymphoproliferation and IFN--γ secretion to PfMSP5 and purified protein derivate were quantified in adults with falciparum (n=34), and vivax malaria (n=12) or asymptomatic residents (n=10) of Papua, Indonesia. Responses were reassessed 7-28 days following treatment. RESULTS The frequency of IFN-γ responders to PfMSP5 was similar in acute falciparum (63%) or vivax (67%) malaria. However, significantly more IFN-γ-secreting cells were detectable during vivax compared with falciparum infection. Purified protein derivative responses showed a similarly enhanced pattern. While rapidly lost in vivax patients, PfMSP5-specific responses in falciparum malaria remained to day 28. By contrast, frequency and magnitude of lymphoproliferation to PfMSP5 were similar for falciparum and vivax infections. CONCLUSION Cellular PfMSP5-specific responses are most frequent during either acute falciparum or vivax malaria, indicating functional T-cell responses to conserved antigens. Both effector and central memory T-cell functions are increased. Greater IFN-γ responses in acute P. vivax, suggest enhancement of pre-existing effector T-cells during acute vivax infection.
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Affiliation(s)
- Ervi Salwati
- National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia
| | - Gabriela Minigo
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Department of Immunology, Monash University, Victoria, Australia
| | - Tonia Woodberry
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | - Kim A Piera
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
| | | | - Enny Kenangalem
- Menzies-NIHRD Collaborative Research Program and District Health Authority, Timika, Papua, Indonesia
| | - Emiliana Tjitra
- National Institute of Health Research and Development (NIHRD), Ministry of Health, Jakarta, Indonesia
| | - Ross L Coppel
- Department of Microbiology, Monash University, Victoria, Australia
| | - Ric N Price
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Centre for Vaccinology and Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Oxford.,Division of Medicine, Royal Darwin Hospital, Darwin, Australia
| | - Nicholas M Anstey
- Global Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Australia.,Division of Medicine, Royal Darwin Hospital, Darwin, Australia
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Jeurink PV, Vissers YM, Rappard B, Savelkoul HF. T cell responses in fresh and cryopreserved peripheral blood mononuclear cells: Kinetics of cell viability, cellular subsets, proliferation, and cytokine production. Cryobiology 2008; 57:91-103. [DOI: 10.1016/j.cryobiol.2008.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Revised: 06/04/2008] [Accepted: 06/05/2008] [Indexed: 01/12/2023]
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Kemp K, Akanmori BD, Kurtzhals JAL, Adabayeri V, Goka BQ, Hviid L. Acute P. falciparum malaria induces a loss of CD28- T IFN-gamma producing cells. Parasite Immunol 2002; 24:545-8. [PMID: 12694605 DOI: 10.1046/j.1365-3024.2002.00599.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
P. falciparum malaria is associated with increased activation among peripheral lymphocytes. In the present study, we investigated markers of susceptibility to apoptosis and expression of IFN-gamma and IL-4 by CD28-and CD28+T cells in West African children with acute P. falciparum malaria. The study showed increased susceptibility to apoptosis and cytokine production among T lymphocytes during acute malaria but also that T cells, in particular IFN-gamma producing CD28-T cells, were substantially reduced. These results are in line with previous studies suggesting that certain T cell subsets are sequestered away from the peripheral blood during P. falciparum malaria.
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Affiliation(s)
- Kåre Kemp
- Centre for Medical Parasitology at Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet) and Institute for Medical Microbiology and Immunology, University of Copenhagen, Copenhagen, Denmark.
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