Termination of natural tolerance to alpha-foetoprotein in rats: study of cell-mediated immunity in the macrophage migration inhibition test.

Immunization of rats with mouse alpha-foetoprotein has been earlier shown to induce the antibody response to self AFP or rats. In this work a single injection of AFPm resulted in termination of natural tolerance of effector T-cells to AFPr, as shown by the macrophage migration inhibition test using peritoneal exudate cells from immunized animals. A significant reaction was elicited by both AFPm and AFPr in the course of primary, secondary and third immunization with AFPm. Pronounced MMI reaction to AFPm and AFPr has developed when AFPr was used as a booster antigen after primary injection with AFPm. Both the kinetics and magnitude of cell-mediated response to heterologous and self AFP injected either in CFA or without it were studied by the MMI test. T-cells of immune PEC were demonstrated by T-B separation to be responsible for MMI elicited by AFPm and AFPr.