Phagocytic activity of human colostrum macrophages

ABSTRACT

1. We evaluated the ability of human colostrum adhering cells to phagocytize sheep red blood cells (E) incubated with rabbit anti-E IgG antibody (A) and zymosan particles incubated with fresh human serum or with the aqueous phase of colestrum. 2. The cells were found to have considerably intense phagocytuc ability, i.e., 96,8% phagocytized EA parcicles, 83.2% phagocytized zymosan particles opsonized with fresh human serum, and 73.3% phagocytized zymosan particles opsonized with the aqueous phase of colostrum. Thus, the aqueous phase of colostrum can opsonize zymosan particles, an activity attributed to the complement system. 3. Total hemolytic complement (V+CH50) and the C3 component in a pool of normal human serum were two-fold higher than in a pool of the aqueous phase of colostum. 4. These results indicate the existence of Fcgama and C3 receptors on the membrane of human colostum macrophages and suggest that these cells may be biologically active