Macrophage activation by Listeria-specific T cell sub-populations (Abstract)

Abstract

Specific interaction of inflammatory T cells with intracellular bacteria (or bacterial antigens) and macrophages in vivo results in macrophage activation and granuloma formation, parallelled by delayed-type hypersensitivity reactions. Using the listeriosis model in mice, we have studied the Lyt phe-notype(s) of inflammatory T cells involved in macrophage activation both in vitro and in vivo. Specific inflammatory T cells from Listeria-infected mice were purified on nylon wool columns and selected for sub-populations by treatment with anti-Lyt antisera and complement. Inflammatory T cells involved in protection to Listeria organisms and in delayed-type hypersensitivity to Hsterial antigens were of the Lyt 123 phenotype. Participation of other Lyt T cell sub-sets in vivo could not be ruled out. In vitro interaction of Listeria-specific inflammatory T cells with listerial antigen and macrophages resulted in macrophage activation, as assessed by the production of myogenic protein. These in vitro data indicate that macrophage activation is accomplished by Lyt 1 T cells rather than Lyt 123 T cells. However, participation of Lyt 123 T cells appears likely.