The study of a differential induced FOXP3 expression by transforming growth factor-β1 between CD4+and CD8+ T lymphocytes

Objective To study the different induced expressions of FOXP3 by transforming growth factor-β1 (TGF-β1) between CD4+ and CD8+ T lymphocytes.Methods After the cultures of CD4+ cells and or CD8 + cells under an anti-TCR stimulation condition with an addition of TGF [β1 or not for 4 days respectively,the induced FOXP3 expressions were detected through the flow cytometric intracellular staining.Meanwhile we also examined the proliferative activity of TGF β1 induced FOXP3 expressing lymphocytes through a CFSE labeling experiment and the effect of TGF-β1 on cell apoptosis by annexin V staining.Results TGF-β1 selectively induced the CD4+ T lymphocytes to express FOXP3 (PBMC:29.66±3.624 vs 7.430±0.643; NIL:31.74±2.612 vs 8.637±1.146); The induced cells also had a proliferative activity (94.39 ± 1.179) and could secrete IFN-γ efficiently after activation (39.58±1.611); TGF-β1 could reduce the apoptosis rate of CD8+T lymphocytes(25.39±2.158 vs 9.320±0.3219).Conclusions Consistent with the discovery that ＞95％ of the FOXP3+lymphocytes in TIL (tumor infiltrating lymphocytes) of HCC (human hepatocelluar carcinoma) patients were concentrated in CD4+ T lymphocytes (97.15±0.3807,n=10),TGF-β1 induced the CD4 +T lymphocytes to express FOXP3 in preference to CD8+T lymphocytes; But with different to natural Tregs,the induced cells still could proliferate and secrete IFN-γactively after an effective stimulation;CD8+ T lymphocytes were more easily suffering cell apoptosis after activation than CD4+ T lymphocytes,and TGF-β1 could rescue the more cell apoptosis. Key words: Transforming growth factor-β1 ; Transcription factor, FOXP3; Hepatic cellcarcinoma; Treg; Apoptosis