Effect of taurine on the proliferation and differentiation of human peripheral blood T lym⁃phocytes in vitro

Objective:To study the effect and mechanism of taurine(Tau)on the activation, proliferation, and dif-ferentiation of human peripheral blood T lymphocytes in vitro.Methods:Peripheral blood lymphocytes were aseptically isolated from healthy volunteers to establish the model of activation and proliferation of T cells stimu-lated by phytohaemagglutinin (PHA) in vitro.The control group, PHA stimulation group (PHA 5 μg/mL group), and Tau treatment group (PHA+Tau 80 mmol/L group, PHA+Tau 160 mmol/L group) were set up.Cell counting kit-8(CCK-8)assay detected the T lymphocyte proliferation rate.The cell morphology was observed with Wright-Giemsa staining and the conversion rate was calculated.T lymphocyte proliferation marker Ki67, Th1 transcrip-tion factor T-bet and cytokines interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), Th2 transcription factors GATA-3 and interleukin-4/6(IL-4/6)and the expres-sions of apoptosis-related factors Fas and FasL gene were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR).Reactive ox-ygen species (ROS) kits were used to detect the level of intracellular ROS.Results:Compared with the control group, T lymphocyte conversion rate, proliferation rate, proliferation marker Ki67, Th1-related factors T-bet, IFNγ, TNF-α, apoptosis-related factor Fas gene expression and intracellular ROS level of PHA 5 μg/mL group in-creased (P< 0.05), while apoptosis-related factor FasL gene, Th2-related factors GATA-3 and IL-6 gene expres-sion levels decreased(P< 0.05).Compared with the PHA 5 μg/mL group, T lymphocyte conversion rate, prolifer-ation rate, Ki67 gene expression and intracellular ROS level in PHA+Tau 80 mmol/L group and PHA+Tau 160 mmol/L group decreased (P< 0.05).The gene expression levels of Th2-related factors IL-4 and IL-6 increased(P< 0.05).There were no significant differences in the gene expression levels of Th1-related factors IFN-γ and FasL (P> 0.05).There were no significant differences in the gene expression levels of Th1-related factors T-bet and TNF-α, and Th2-related factors GATA-3 and Fas in PHA+Tau 80 mmol/L group(P> 0.05).The gene expres-sion levels of Th1-related factors T-bet and TNF-α, and Th2-related factors GATA-3 and Fas increased in PHA+Tau 160 mmol/L group (P< 0.05).Conclusion:Tau may inhibit the proliferation and conversion of T lympho-cytes by down-regulating the expression of Ki67 and enhancing the Fas-AICD pathway.Moreover, Tau may play a role in regulating the activation, proliferation and differentiation of T lymphocytes by reducing intracellular ROS level, increasing Th1/Th2 activation levels and regulating the balance of Th1/Th2 towards Th1 differentia-tion.