Effects of CD4+ CD25+ regulatory T cells on immune function of patients with portal hypertensioninduced hypersplenism

Objective To study the significance of the increased CD4 + CD25 + regulatory T cells (Treg) in patients with portal hypertension-induced hypersplenism,and their effects on the immune function.Methods The proportions of CD4 + CD25 + CD127low/-Treg in peripheral venous blood,splenic vein and spleen tissue were examined by uisng flow cytometry in 46 patients with portal hypertension-induced hypersplenism,and compared with those in 14 normal control samples.The expression of forkhead box P3 (Foxp3) in spleen tissue was detected by using reverse transcriptase-polymerase chain reaction (RT-PCR).Enzyme linked immunosorbent assay (ELISA) was used to test the transforming growth factorβ (TGF-β),interleukin (IL)-2,IL-4 and IL-10 in peripheral venous blood.Their correlation was analyzed.Results The expression levels of CD4 + CD25 + CD1271ow/-Treg in spleen tissue and splenic vein of hypersplenism group were significantly higher than in control group.The Foxp3 expression in spleen tissue was significantly enhanced,CD4 + T,CD8 + T and IL-2 levels in peripheral venous blood were significantly reduced,and IL-10 and TGF-β contents were significantly increased in hypersplenism groups than in control group (P＜0.05).The contents of CD4+ CD25+ CD127low/-Treg and the levels of CD4+ T cells,CD8 + T cells and IL-2 showed a significantly negative correlation.Conclusion The expression of CD4 +CD25 + Treg in patients with portal hypertension-induced hypersplenism is significantly increased,which may be involved in immune regulation by inhibiting the activation of CD4 + T cells and CD8 + T cells and decreasing the IL-2 level,and promoting the secretion of cytokines IL-10 and TGF-β. Key words: Portal hypertension;  Hypersplenism ;  Immune function ;  Regulatory T cells