Extrafollicular CD4 T cell-derived IL-10 functions rapidly and transiently to support anti-Plasmodium humoral immunity.

Immunity against malaria depends on germinal center (GC)-derived antibody responses that are orchestrated by T follicular helper (TFH) cells. Emerging data show that the regulatory cytokine IL-10 plays an essential role in promoting GC B cell responses during both experimental malaria and virus infe...

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Bibliographic Details
Main Authors: Fionna A Surette, Jenna J Guthmiller, Lei Li, Alexandria J Sturtz, Rahul Vijay, Rosemary L Pope, Brandon L McClellan, Angela D Pack, Ryan A Zander, Peng Shao, Linda Yu-Ling Lan, Daniel Fernandez-Ruiz, William R Heath, Patrick C Wilson, Noah S Butler
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2021-02-01
Series:PLoS Pathogens
Online Access:https://doi.org/10.1371/journal.ppat.1009288
Description
Summary:Immunity against malaria depends on germinal center (GC)-derived antibody responses that are orchestrated by T follicular helper (TFH) cells. Emerging data show that the regulatory cytokine IL-10 plays an essential role in promoting GC B cell responses during both experimental malaria and virus infections. Here we investigated the cellular source and temporal role of IL-10, and whether IL-10 additionally signals to CD4 T-cells to support anti-Plasmodium humoral immunity. Distinct from reports of virus infection, we found that IL-10 was expressed by conventional, Foxp3-negative effector CD4 T cells and functioned in a B cell-intrinsic manner only during the first 96 hours of Plasmodium infection to support humoral immunity. The critical functions of IL-10 manifested only before the orchestration of GC responses and were primarily localized outside of B cell follicles. Mechanistically, our studies showed that the rapid and transient provision of IL-10 promoted B cell expression of anti-apoptotic factors, MHC class II, CD83, and cell-cell adhesion proteins that are essential for B cell survival and interaction with CD4 T cells. Together, our data reveal temporal features and mechanisms by which IL-10 critically supports humoral immunity during blood-stage Plasmodium infection, information that may be useful for developing new strategies designed to lessen the burden of malaria.
ISSN:1553-7366
1553-7374