The regulatory role of interleukin 2-responsive T lymphocytes on early and mature erythroid progenitor proliferation.
To analyze the role of T lymphocytes in human erythropoiesis, we evaluated the effect of recombinant interleukin 2 (IL 2) on marrow CFU-E and BFU-E colony formation in vitro. IL 2 resulted in an increase in CFU-E and BFU-E colony numbers in a dose-dependent manner. This increase could be prevented by anti-Tac, a monoclonal antibody to the IL 2 receptor. Moreover, anti-Tac on its own resulted in an overall decrease in colony numbers. Depletion of marrow adherent cells did not alter the effect of either IL 2 or anti-Tac on colony growth. Following the removal of marrow T lymphocytes, CFU-E and BFU-E colony formation proceeded normally; however, the effects of IL 2 and anti-Tac were markedly diminished. Readdition of T lymphocytes to the cultures restored the IL 2 effect. Although T lymphocytes were not themselves essential for in vitro erythropoiesis, our studies suggest that IL 2 and IL 2-responsive T cells can regulate both early and mature stages of erythroid differentiation.
D000818:Animals; D000911:Antibodies, Monoclonal; D002455:Cell Division; D003114:Colony-Forming Units Assay; D004920:Erythropoiesis; D006801:Humans; D007376:Interleukin-2 / Q000502:physiology*; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013234:Stem Cells / Q000166:cytology*; D013601:T-Lymphocytes / Q000502:physiology*
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D011994:Recombinant Proteins