Open AccessT Cell Production of IFNγ in Response to TLR7/IL-12 Stimulates Optimal B Cell Responses to Viruses
Author(s) -
Kira Rubtsova,
Anatoly V. Rubtsov,
Kalani Halemano,
Sam X. Li,
John W. Kappler,
Mario L. Santiago,
Philippa Marrack
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0166322
Subject(s) - tlr7 , biology , cd8 , t cell , immunoglobulin class switching , interferon , microbiology and biotechnology , immunology , isotype , b cell , antibody , immune system , toll like receptor , innate immune system , monoclonal antibody
Knowledge of the processes that underlie IgG subclass switching could inform strategies designed to counteract infections and autoimmunity. Here we show that TLR7 ligands induce subsets of memory CD4 and CD8 T cells to secrete interferon γ (IFNγ) in the absence of antigen receptor stimulation. In turn, TLR ligation and IFNγ cause B cells to express the transcription factor, T-bet, and to switch immunoglobulin production to IgG2a/c. Absence of TLR7 in T cells leads to the impaired T-bet expression in B cells and subsequent inefficient IgG2a isotype switching both in vitro and during the infection with Friend virus in vivo. Our results reveal a surprising mechanism of antiviral IgG subclass switching through T-cell intrinsic TLR7/IL-12 signaling.