Depression of Phagocytic Activity of the Reticuloendothelial System by Antilymphocytic Serum 1

Abstract

Summary

Antilymphocytic serum induced a profound decrease in phagocytic activity of the RES as reflected by the impairment in the intravascular clearance of gelatinized “RE test lipid emulsion.” The phagocytic alterations were due to a selective impairment in hepatic phagocytosis, as localization of the labeled test emulsion by lung and spleen was unaltered. The depression of hepatic phagocytosis was not related to an alteration in plasma opsonic activity. A direct injurious effect of ALS on Kupffer cells was demonstrated not only by the ALS-induced impairment in Kupffer cell phagocytic activity, as assayed by in vitro techniques, but also by the cytotoxicity of ALS on macrophages. The immunosuppressive activity of ALS, as well as certain other detrimental consequences of ALS administration may be related, in part, to ALS-induced alteration of the macrophage host-defense system.