Cellular immunity in vitro: migration inhibition and phagocytosis.

The activity of peritoneal exudate cells from candidin-sensitive and normal guinea pigs with and without antigen was studied in vitro with the aid of time-lapse, phase-contrast cinemicrography. Macrophages from normal animals migrate well on an agar medium and readily phagocytose Merthiolate-killed Candida albicans cells. A reduction in the migration of peritoneal macrophages from guinea pigs sensitized to C. albicans during the first 24 hr after exposure to antigen was accompanied by a decrease in phagocytosis of C. albicans cells. The macrophages were viable but comparatively immotile. Since the sensitized macrophages came from resistant donors, it is possible that the initial stage of cellular immunity to C. albicans is associated with a reduced activity of the phagocytic macrophages, apparently to limit spread of the pathogen from the infected area.