Antigen-specific production of colony-stimulating factors by Listeria monocytogenes-immune, L3T4-positive cells.

We investigated production of colony-stimulating factors by Listeria monocytogenes-immune spleen cells. Levels of total colony-stimulating factors in supernatants from antigen-stimulated immune cells were increased two- to fourfold over those in supernatants from nonimmune cells. Immune supernatants primarily induced formation of granulocyte colonies, whereas nonimmune supernatants induced formation of macrophage colonies. Immune supernatants had two- to 10-fold higher levels of macrophage colony-stimulating factor, as determined by radioimmunoassay, and higher levels of interleukin-3 and possibly granulocyte-macrophage colony-stimulating factor, as determined by factor-dependent cell line growth, than did nonimmune supernatants. Using enrichment and depletion techniques we showed that L3T4-positive T lymphocytes were responsible for most of the colony-stimulating factor production in the immune reaction.