A role for interferon-gamma and transforming growth factor-beta in erythroid cell-mediated regulation of nitric oxide production in macrophages.

Interferon-gamma (IFN-gamma) and transforming growth factor-beta (TGF-beta) are known to be a potent inducer and inhibitor for macrophage (Mo) activation process, respectively. In the present study we established that the nucleated erythroid cells (NEC) separated from the spleens of adult (CBA x C57BL/6)F1 (CBF, H-2k/H-2d) mice following phenylhydrazine treatment are potentially capable of inducing nitric oxide (NO) production in thioglycollate broth-elicited peritoneal macrophages (Mo). The stimulating effect of both NEC and their culture supernatant on NO secretion by Mo was most apparent in the presence of bacterial lipopolysaccharide (LPS) and neutralizing antibodies (Abs) to TGF-beta and was largely reversed by the addition to the culture of neutralizing Abs to IFN-gamma. Collectively these results suggest that NEC, through production of IFN-gamma and TGF-beta, may exert a regulatory influence on development and functionality of cells pertaining to monocyte (Mc)/Mo lineage.