Department of Rheumatology and Immunology, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China.
Department of Ultrasound, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China.
Iran J Allergy Asthma Immunol. 2024 Oct 6;23(5):539-549. doi: 10.18502/ijaai.v23i5.16749.
Rheumatoid arthritis (RA) is frequent, an imbalance between helper cells (Th) and regulatory T cells (Treg) is the fundamental immunological cause of RA. This study investigates how recombinant human programmed cell death 1 (PD-L1) protein affects circulating T follicular helper (cTfh), circulating T follicular regulatory (cTfr), and their equilibrium. Magnetic bead sorting was used to select CD4+CXCR5+T cells from RA patients' and healthy individuals' peripheral blood mononuclear cells for in vitro growth. Recombinant human PD-L1 protein stimulated CD4+CXCR5+T cells. Cell counting kit 8 (CCK-8), flow cytometry surface labeling, ELISA, and RT-PCR were used to measure CD4+CXCR5+T cell proliferation inhibition, cTfh and cTfr frequencies, IL-21 expression, and PI3K, AKT, Bcl-6, and Blimp-1 mRNA levels. The recombinant human PD-L1 protein dose-dependently inhibited the proliferation of CD4+CXCR5+T cells in active RA peripheral blood. However, it has a weaker inhibitory effect on healthy peripheral blood CD4+CXCR5+T cells. PD-L1 protein decreased cTfh in active RA peripheral blood CD4+CXCR5+T overall cultured cells but did not affect cTfr; The cTfr/cTfh ratio increased but did not affect the frequency of cTfh and cTfr in healthy persons' cultured CD4+CXCR5+T cells. PD-L1 protein reduced IL-21 in CD4+CXCR5+T cell culture supernatant from active RA peripheral blood. Recombinant human PD-L1 protein lowered PI3K, AKT, and Bcl-6 mRNA in active RA peripheral blood CD4+CXCR5+T cell culture, including significant differences. But Blinmp-1 mRNA variations were neither substantial nor statistically different. PD-1/PD-L1 limits cTfh proliferation, differentiation, and activation via the PI3K/AKT signaling pathway regulates its immunological balance with cTfr, and corrects the cTfr/cTfh imbalance by controlling their interaction.
类风湿关节炎（RA）较为常见，辅助性 T 细胞（Th）和调节性 T 细胞（Treg）失衡是 RA 的基本免疫学原因。本研究旨在探讨重组人程序性细胞死亡蛋白 1（PD-L1）如何影响循环滤泡辅助性 T 细胞（cTfh）、循环滤泡调节性 T 细胞（cTfr）及其平衡。采用磁珠分选法从 RA 患者和健康个体外周血单个核细胞中分离 CD4+CXCR5+T 细胞进行体外扩增。用重组人 PD-L1 蛋白刺激 CD4+CXCR5+T 细胞，用细胞计数试剂盒 8（CCK-8）、流式细胞术表面标记、ELISA 和 RT-PCR 检测 CD4+CXCR5+T 细胞增殖抑制率、cTfh 和 cTfr 频率、IL-21 表达及 PI3K、AKT、Bcl-6 和 Blimp-1mRNA 水平。结果显示，重组人 PD-L1 蛋白呈剂量依赖性抑制 RA 患者外周血 CD4+CXCR5+T 细胞增殖，但对健康个体外周血 CD4+CXCR5+T 细胞的抑制作用较弱。PD-L1 蛋白降低 RA 患者外周血 CD4+CXCR5+T 细胞整体培养细胞中的 cTfh，但不影响 cTfr；cTfr/cTfh 比值升高，但不影响健康个体培养的 CD4+CXCR5+T 细胞中 cTfh 和 cTfr 的频率。PD-L1 蛋白降低 RA 患者外周血 CD4+CXCR5+T 细胞培养上清液中 IL-21 的水平。重组人 PD-L1 蛋白降低 RA 患者外周血 CD4+CXCR5+T 细胞中 PI3K、AKT 和 Bcl-6mRNA，但 Blimp-1mRNA 变化不显著或无统计学差异。结论：PD-1/PD-L1 通过 PI3K/AKT 信号通路抑制 cTfh 增殖、分化和活化，调节其与 cTfr 的免疫平衡，通过控制相互作用纠正 cTfr/cTfh 失衡。
