1. Vδ2+ T cell response to malaria correlates with protection from infection but is attenuated with repeated exposure
- Author
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Esther Sikyomu, Kenneth Musinguzi, Agaba Katureebe, Bryan Greenhouse, Lila A. Farrington, Tara I. McIntyre, Kate Naluwu, Michelle J. Boyle, Margaret E. Feeney, Fredrick Lutwama, Prasanna Jagannathan, Felistas Nankya, John Rek, Rachel Budker, Katherine Bowen, Grant Dorsey, Moses R. Kamya, and Mayimuna Nalubega
- Subjects
0301 basic medicine ,medicine.medical_treatment ,T-Lymphocytes ,lcsh:Medicine ,Parasitemia ,0302 clinical medicine ,Receptors ,2.1 Biological and endogenous factors ,Aetiology ,lcsh:Science ,Child ,Pediatric ,Multidisciplinary ,Transmission (medicine) ,Age Factors ,Receptors, Antigen, T-Cell, gamma-delta ,3. Good health ,Cytokine ,medicine.anatomical_structure ,Infectious Diseases ,Antigen ,Child, Preschool ,Cytokines ,medicine.symptom ,Infection ,T cell ,Plasmodium falciparum ,Asymptomatic ,Article ,Vaccine Related ,03 medical and health sciences ,Rare Diseases ,In vivo ,Immunity ,Clinical Research ,parasitic diseases ,medicine ,Humans ,Lymphocyte Count ,Preschool ,gamma-delta ,business.industry ,Prevention ,Inflammatory and immune system ,lcsh:R ,medicine.disease ,T-Cell ,Malaria ,Vector-Borne Diseases ,030104 developmental biology ,Good Health and Well Being ,Immunology ,lcsh:Q ,business ,Biomarkers ,030215 immunology - Abstract
Vδ2+ γδ T cells are semi-innate T cells that expand markedly following P. falciparum (Pf) infection in naïve adults, but are lost and become dysfunctional among children repeatedly exposed to malaria. The role of these cells in mediating clinical immunity (i.e. protection against symptoms) to malaria remains unclear. We measured Vδ2+ T cell absolute counts at acute and convalescent malaria timepoints (n = 43), and Vδ2+ counts, cellular phenotype, and cytokine production following in vitro stimulation at asymptomatic visits (n = 377), among children aged 6 months to 10 years living in Uganda. Increasing age was associated with diminished in vivo expansion following malaria, and lower Vδ2 absolute counts overall, among children living in a high transmission setting. Microscopic parasitemia and expression of the immunoregulatory markers Tim-3 and CD57 were associated with diminished Vδ2+ T cell pro-inflammatory cytokine production. Higher Vδ2 pro-inflammatory cytokine production was associated with protection from subsequent Pf infection, but also with an increased odds of symptoms once infected. Vδ2+ T cells may play a role in preventing malaria infection in children living in endemic settings; progressive loss and dysfunction of these cells may represent a disease tolerance mechanism that contributes to the development of clinical immunity to malaria.
- Published
- 2017