Production of cytokines by immature erythroid cells derived from human embryonic liver.

It is well known that regulatory interactions between hematopoietic and lymphoid cells are mediated by different mediators. The cells of erythroid lineage are not an exception and have a regulatory effect on hemato- and immunopoiesis that can be mediated through the production of cytokines i.e. by soluble factors - a universal mechanism for cell regulation in hematopoietic and immune systems. It has been previously shown that erythroid progenitor cells from mice express mRNA of cytokines such as IL-1 alpha and beta, IL-4, IL-6, IFN-gamma, GM-CSF and TGF-beta. In this report we present the results of the production of the main immunoregulatory cytokines by erythroid cells derived from human embryonic liver. It was revealed that the cell population enriched with erythroid progenitors, isolated from human fetal liver, can produce IL-1 beta, IL-2, IL-4, IL-6. The levels of production of cytokines by immature erythroid progenitor cells is compared to the levels of corresponding cytokines produced by mitogen-stimulated peripheral blood mononuclear cells. The production of these cytokines changed quantitatively under the effect of erythropoietin, and are correlated with the expression of differentiation markers of erythroid cells such as AG-EB and Glycophorin A. The role of cytokine production by erythroid cells in hemato- and immunopoiesis and the mechanisms of self-regulation of proliferation and differentiation of erythroid progenitor cells is discussed.