In vivo priming of mice with antigen and lipid A bestows proliferative ability on peritoneal exudate T cells in response to antigen or anti-αβ TCR antibody in the absence of macrophages in vitro

Abstract

Requirement of macrophages for the in vivo proliferative response of the peritoneal exudate T cells of mice that had been primed in vivo with antigen and lipid A was investigated. Two weeks in advance, C3H/HeN mice (lak) were primed with horse red blood cells (HRBC) and synthetic lipid A. The highly purified T cells [T(HRBC+lipid A)] proliferated in response to HRBC or anti-αβ T cell receptor (TCR) antibody. However, T cells [T(HRBC)] that had been prepared from the mice primed with SRBC did not respond to HRBC and anti-αβ TCR antibody. When T(HRBC) were co-cultured in the presence of HRBC or anti-αβ TCR antibody with an adherent cell population (macrophages) prepared from PEC, the T(HRBC) proliferated. Previous treatment of T(HRBC+lipid A) with anti-CD45 (180 kDa) antibody plus C abolished the response, while the same pretreatment of T(HRBC) did not abolish the response in the presence of macrophages. The previous treatment of these cells with CD45 (220 kDa) antibody plus C eliminated their proliferative response. These results suggest that T(HRBC+lipid A) are different from T(HRBC) on macrophage-dependency, and T(HRBC+lipid A) expressing CD45 (180 kDa) on the membrane are the proliferative cells when their αβ T cell receptors (TCR) are stimulated with the antigen or anti-TCR antibody.