The role of macrophages in the amplified in vitro response to sheep red blood cells by spleen cells from Corynebacterium parvum treated mice

Abstract

Antibody production against sheep red blood cells (SRBC) was studied in Marbrook cultures of spleen cells from C. parvum (CP) treated and normal CBA-T6T6 mice. CP given 7 days prior to spleen cell harvest exerted an adjuvant effect on the direct plaque-forming cell (PFC) response, which was most marked with sub- and supraoptimal doses of SRBC. Under the same conditions no IgG production against SRBC could be detected in the CP treated cultures. When spleen cells were harvested 2 days or 2–4 wk after CP injection IgM production against SRBC was diminished as compared to controls. CP treatment resulted in the emergence and persistence of adherent peritoneal cells (PC) which were more efficient than untreated adherent PC in promoting a direct PFC response to SRBC by normal macrophage depleted spleen cells. The results suggest that the CP adjuvant action is mediated via stimulated macrophages on whose surface antigen presentation to antibody-forming cells is intensified.