T-cell subsets induced in Listeria monocytogenes-immune mice. Ly phenotypes of T cells interacting with macrophages in vitro.

Interactions of peritoneal exudate T lymphocytes from listeria-immune mice with macrophages from normal mice in the presence of heat-killed listeriae result in the induction of interleukins. The data show that Ly 1+, 23- T cells specific for listeria antigens are essential for interleukin induction and make it likely that, in addition, Ly 1+, 23+ T cells are required for optimal responses.