Summary
A study was designed to determine the effects of heated and unheated human, calf, rabbit, guinea pig and mouse serum on rates of phagocytosis and digestion of P-32 labeled Histoplasma capsulatum by peritoneal macrophages obtained from control and immunized mice. The results obtained were as follows:
Ingestion rates by macrophages from normal and immune mice were not significantly different in the presence of heated or unheated heterologous and homologous sera.
Macrophages from immunized mice digested H. capsulatum more rapidly than those from normal mice in the presence of heated and unheated human, rabbit, guinea pig and mouse serum and unheated calf serum, but not in the presence of heated calf serum.
Heat labile factors in unheated sera induced transitory increases in rates of cytopepsis of H. capsulatum ingested by both normal and “immune” phagocytes.
Cytopeptic rates of both cell populations were highest in the presence of heated and unheated mouse or guinea pig serum, whereas the rates in the presence of heated human, rabbit, or calf serum were not significantly different. Unheated rabbit and calf sera induced intermediate rates of digestion by the phagocytes.
Footnotes
Investigation supported in part by research grants from the National Institute of Allergy and Infectious Diseases, Public Health Service and the National Tuberculosis Association; American Trudeau Society. The material in this paper is from a thesis submitted by William Wu to the Department of Microbiology, University of Utah, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, August, 1962.