The dynamics study of proliferation of CD4⁺CD25⁺ Treg cells induced by transforming growth factor-β1 in neonatal cord blood

Objective: To explore proliferative activity of CD4⁺CD25⁺ Treg cells induced by transforming growth factor-β1(TGF-β1) in neonatal cord blood.Methods: Cord blood mononuclear cells were labeled with carboxyfluorescein diacetate,succinimidyl ester(CFSE),and then stimulated with TGF-β1,CD3mAb and cultured in 10% NBS-1640 medium in presence of IL-2.The dynamics of proliferation of CD4⁺CD25⁺ and CD8⁺ T cells on day 4,day 6,day 8 after culture was determined by flow cytometry.Results: Proliferative kinetics analysis showed proliferation index(PI) on day 6 and day 8 of culture with TGF-β1 in CD4⁺CD25⁺ Treg cells(11.52 and 23.04) were significantly higher than those in control cells(6.68 and 10.46) and those cultured with TGF-β1 in CD8⁺ T cells(4.23 and 5.43).On day 8 of culture with TGF-β1,proportion of the generations from 8th to 10th in CD4⁺CD25⁺ Treg(52.74%) was strikingly higher than those in control cells(36.26%) and those in CD8⁺ T cells cultured with TGF-β1(13.54%),while the proportion of the generations from 8th to 10th in control CD8⁺ T cells was 29.44%.Conclusions: Proliferative activity of CD4⁺CD25⁺ Treg cells induced by TGF-β1 in neonatal cord blood was obviously stronger than that of CD8⁺ T cells.