In vivo cytokine production in murine listeriosis. Evidence for immunoregulation by gamma delta+ T cells.

Differential cytokine production by gamma delta+ T cells influences Th1 and Th2 responses. Here, we describe the in vivo kinetics of peritoneal and splenic gamma delta+, CD4+, and CD8+ T cell cytokine responses during primary and secondary Listeria infections. The data show differences in the kinetics of IFN-gamma-producing alpha beta+ splenocytes consistent with immunologic memory. Most noteworthy, however, was the elevated production of IL-10 by splenic gamma delta+ T cells in the red pulp and marginal zones that coincided with maximal IFN-gamma production and with a decrease in inflammation and tissue damage. This result implies a role for gamma delta+ T cells in the control of Th1 responses.