Stimulatory effect of forphenicinol on normal human bone marrow granulocyte-macrophage progenitor cells mediated by T-lymphocytes.

Forphenicinol, L-2-(4-formyl-3-hydroxymethylphenyl) glycine, is a newly discovered low molecular weight immunomodifier. Its effects on normal human bone marrow granulocyte-macrophage progenitor cells (CFU-C) were studied in vitro. Addition of forphenicinol to cell cultures resulted in a significant (p less than 0.05) increase in the number of, and preservation of the ability to form CFU-C colonies per fixed number of human non-adherent bone marrow cells. This effect was not observed in T-lymphocyte depleted fractions of human non-adherent bone marrow cells. Furthermore, colony stimulating factor was released when T-lymphocytes were incubated with forphenicinol. These data suggested that T-lymphocytes mediated the stimulatory effect of forphenicol on human bone marrow CFU-C.