In vitro inhibition of macrophage spreading by antigens and lymphokines: correlation with the footpad test and kinetics of inhibition.

As inhibition of spreading of mouse peritoneal macrophages is the basis for an in vitro test of cellular immunity, this test was used to investigate the correlation between in vitro and in vivo results and the kinetics of inhibition of spreading. BALB/c and NIH strain mice were immunized with human or bovine serum albumin or bovine gamma globulin. They displayed a positive footpad test when challenged with the specific antigen (21 days later). Peritoneal cells (PC) of mice with a strong footpad reaction were used for the spreading inhibition test. Intensity of spreading inhibition correlated well (r = -0.93) with that of the footpad reaction. Spreading inhibition had a cyclic pattern. A similar pattern was observed after incubation of PC with preformed lymphokines. The cyclic pattern was probably caused by a repeated action of lymphokines on spread macrophages, resulting in reversible and re-inducible inhibition.