背景:谷氨酰胺对T细胞的激活和功效至关重要,并可能在调节免疫环境中发挥作用。本研究旨在探讨谷氨酰胺在诱导调节性T细胞(iTregs)活化和增殖中的潜在作用。
方法:从外周血单个核细胞中分选CD4+CD45RA+T细胞并培养以分析iTreg分化。然后将谷氨酰胺添加到培养系统中,通过测定氧化磷酸化(OXPHOS)来评估谷氨酰胺对iTregs的影响,凋亡,和细胞因子分泌。此外,构建了人源化鼠移植物抗宿主病(GVHD)模型,以证实谷氨酰胺处理的iTregs在体内的疗效.
结果:体外培养后,谷氨酰胺显著提高Foxp3、CTLA-4、CD39、CD69、IL-10、TGF-β、和Ki67(CTLA-4,IL-10,TGF-β是iTregs的免疫抑制标志物)与对照iTregs相比(P<0.05)。此外,生长曲线表明,谷氨酰胺处理的iTregs的增殖能力优于对照iTregs(P<0.01)。与对照iTregs相比,补充谷氨酰胺可显著提高耗氧率和ATP产量(P<0.05),膜联蛋白V和Caspase3显著下调,BCL2上调(P<0.05)。然而,GPNA明显逆转谷氨酰胺的作用(P<0.05)。最后,一个xeno-GVHD小鼠模型成功建立,证实谷氨酰胺处理的iTregs增加小鼠的存活率,延迟减肥,减轻结肠损伤。
结论:补充谷氨酰胺可以提高iTregs的活性和免疫抑制作用,发生这种情况的可能机制与细胞增殖有关,凋亡,和OXPHOS。
BACKGROUND: Glutamine is crucial for the activation and efficacy of T cells, and may play a role in regulating the immune environment. This study aimed to investigate the potential role of glutamine in the activation and proliferation of induced regulatory T cells (iTregs).
METHODS: CD4+CD45RA+T cells were sorted from peripheral blood mononuclear cells and cultured to analyze
iTreg differentiation. Glutamine was then added to the culture system to evaluate the effects of glutamine on iTregs by determining oxidative phosphorylation (OXPHOS), apoptosis, and cytokine secretion. Additionally, a humanized murine graft-versus-host disease (GVHD) model was constructed to confirm the efficacy of glutamine-treated iTregs in vivo.
RESULTS: After being cultured in vitro, glutamine significantly enhanced the levels of Foxp3, CTLA-4, CD39, CD69, IL-10, TGF-β, and Ki67 (CTLA-4, IL-10, TGF-β are immunosuppressive markers of iTregs) compared with that of the control iTregs (P < 0.05). Furthermore, the growth curve showed that the proliferative ability of glutamine-treated iTregs was better than that of the control iTregs (P < 0.01). Compared with the control iTregs, glutamine supplementation significantly increased oxygen consumption rates and ATP production (P < 0.05), significantly downregulated Annexin V and Caspase 3, and upregulated BCL2 (P < 0.05). However, GPNA significantly reversed the effects of glutamine (P < 0.05). Finally, a xeno-GVHD mouse model was successfully established to confirm that glutamine-treated iTregs increased the mice survival rate, delayed weight loss, and alleviated colon injury.
CONCLUSIONS: Glutamine supplementation can improve the activity and immunosuppressive action of iTregs, and the possible mechanisms by which this occurs are related to cell proliferation, apoptosis, and OXPHOS.