Cytotoxicity to allogeneic cells in the chicken I. Role of macrophages in the cytotoxic effect on 51Cr-labeled red blood cells by immune spleen cells

Abstract

Cytotoxic effector cells in SC and FP chicken spleens were induced by repeated intravenous immunizations with 2 × 10 7 allogeneic red blood cells (RBC). Spleen cells taken 3 days after the last of 3–8 injections caused significant 51Cr release over background from labeled RBC in 5–24 hours at 37° C. Maximal effect was obtained after 5 injections. The effector cells in intact chickens fractionated as adherent to nylon wool and to plastic surfaces and were resistant to rabbit anti-chicken thymus and C. Trypan blue in the incubation mixture greatly reduced the cytotoxic effect without raising the background significantly. The effector cell population in Aγ chickens consisted of a prominent adherent cell and a detectable non adherent T-cell component. The cytotoxic activity of nylon wool adherent cells was somewhat higher on 51Cr labeled syngeneic RBC than that of unfractionated immune spleen cells. However, adherent cells clearly had much higher activity against allogeneic RBC. It appeared therefore, that there was a macrophage-mediated specific cytotoxic effect in spleen cells from allo-immune chickens.