Fate and Immunogenicity of Antigens Endocytosed by Macrophages

Abstract

Soluble and particulate antigens taken up by macrophages are immunogenic. The immunogenicity of macrophage-associated antigens has been tested in several experimental system. In one such system live macrophages — after exposure to the antigen — are transferred into mice; the immune response of the mice to the antigen associated with live macrophages is then studied (1-T). The immunogenicity of soluble proteins bound to macrophages has been attributed mostly to molecules of non pinocytosed antigen retained on the plasma membrane of macrophages (6,8). On the other hand, the pathway by which particulate or heavily aggregated antigens are presented to lymphocytes for immunological recognition has not been elucidated. These large antigens are totally endocytosed following their binding to the membrane of the macrophages and presumably may be submitted to the action of enzymes from intracellular vesicles.

This is publication No. from the Department of Experimental Pathology, Scripps Clinic and Research Foundation, La Jolla, California. This research was supported by U.S. Public Health Service Grant AI 07007.

Supported by an American Cancer Society fellowship.