Changes in phagocytic activity and morphology of reticuloendothelial organs in mice induced by antilymphocyte serum.

Abstract

SummaryRabbit anti‐mouse antilymphocyte sera and antilymphocyte globulin preparations went studied for their effects on (1) phagocytic activity of peritoneal and fixed macrophages and (2) morphology of reticuloendothelial organs. Antilymphocyte sera did nut adversely affect the ability of peritoneal macrophages to carry out phagocytosis in vivo or in vitro. One and 2 does of antilymphocyte sera given to mice depressed the rate of carbon clearance from the circulation; multiple doses of antilymphocyte sera stimulated the rate of carbon clearance and induced marked hepatosplenomegaly. The increased liver mass in serum‐treated mice was due mainly to hypertrophy although some antilymphocyte sera‐treated mice also exhibited an increase in the relative numbers of Kupffer cells. Splenic enlargement followed administration of unabsorbed antilymphocyte sera as well as antilymphocyte sera that had been absorbed with mouse erythrocytes and bone marrow cells. Histologically, these enlarged spleens showed marked lymphoid depletion and intense extramedullary haematopoiesis. The changes in phagocytic activity and morphology of reticuloendothelial organs observed in adult mice used in the present investigation closely parallel those which have been reported to occur in neonatally thymectomized mice. The results obtained thus tend to support the concept that antilymphocyte sera can confer a state of “immunothymectomy” when administered to adult animals, and, furthermore, are in accord with its principal mode of action.