Attachment and ingestion of mycoplasmas by mouse macrophages. I. Kinetics of the interaction and effects on phagocyte glucose metabolism.

Rates of attachment and ingestion of Mycoplasma pulmonis by mouse peritoneal macrophages and the effect of the organism on phagocyte glucose metabolism were studied in vitro. Antimycoplasma antibody, but not complement, enhances attachment of mycoplasma to macrophages. Antibody-mediated attachment is not affected by the length of time the cell is maintained in culture or its adherence to a glass surface. Adherence of mycoplasma by nonimmunologic means to cell spread on glass is significantly greater than attachment to macrophages in suspension. Mycoplasmas attached to macrophage membrane do not increase glucose metabolism via the hexose monophosphate shunt. Because of this, the rate of glucose metabolism by macrophages is an accurate quantitative correlate of the recognition and ingestion stage of phagocytosis of mycoplasmas. Antibody induces a more rapid rate of particle ingestion than does altering the mycoplasma by proteolysis. Complement does not augment the rate of ingestion induced by antimycoplasma antibody. By analogy with enzyme and absorption kinetics, it appears likely that differences observed between phagocytosis induced by antibody and that induced by trypsin are due to different rates of recognition between particles rather than different ingestion mechanisms.