| Abstract: | Modulation of phagocytic activity of resident hamster pulmonary alveolar macrophages was accomplished by incubation of the cells in lymphokines prepared by stimulation of hamster splenocytes with concanavalin A or alloantigens in mixed lymphocyte cultures. Alveolar macrophages preincubated in either of these lymphokine preparations possessed significantly greater ability to ingest IgG or IgM plus complement-coated sheep erythrocytes, via their Fc or complement receptors, respectively, than macrophages exposed to control preparations. Ingestion of yeast particles also was enhanced with macrophages incubated in supernatants from cultures of stimulated splenocytes. Supernatant fluids from either mitogen- or alloantigen-stimulated splenocytes possessed migration inhibitory activity with characteristics similar to MIF from other animals; the phagocytosis-enhancing activity shared some of these characteristics. |
