The T follicular helper (Tfh) cell subset of CD4 + Th cells promotes affinity maturation by B cells in germinal centers. The contribution of other Th cell subsets to B cell responses has not been fully explored in vivo. We addressed this issue by analyzing the T cell–dependent B cell response to the protein Ag PE in mice lacking specific Th cell subsets. As expected, PE-specific germinal center B cell production required Tfh cells. However, Tfh, Th1, or Th17 cell–deficient mice produced as many PE-specific, isotype-switched plasmablasts as wild-type mice. This response depended on Th cell expression of CD154 and Ag presentation by B cells. These results indicate that many Th cell subsets can promote plasmablast formation by providing CD40 signals to naive B cells.
Bibliographical noteFunding Information:
This work was supported by National Institutes of Health Grants R01 AI039614, R01 AI103760, and R37 AI027998 (to M.K.J.) and T32 AI007313 and F31 AI133716 (to J.A.K.) and by the Dennis W. Watson Fellowship from the University of Minnesota Microbiology and Immunology Department (to J.A.K.).
Copyright © 2019 by The American Association of Immunologists, Inc.