Migration enhancement by tuftsin of human mononuclear cells and its effect on the migration inhibition factor test with tumor antigens.

Tuftsin, a physiological tetrapeptide which stimulates the phagocytic activity of polymorphonuclear neutrophils and macrophages, is found to enhance the migration of normal and sensitized human mononuclear cells. Furthermore, it abrogates the migration inhibition effect of human malignant melanoma antigen. This finding may represent a possible explanation for the unexpected migration enhancement often observed when the migration inhibition test is employed.