Liu Ting, Zheng Ming, Jia Li, Wang Mingyuan, Tang Longhai, Wen Zhenke, Zhang Miaojia, Yuan Fenghong
Department of Rheumatology, the Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, China.
Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Front Immunol. 2023 Mar 17;14:1157731. doi: 10.3389/fimmu.2023.1157731. eCollection 2023.
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease mainly mediated by IgG autoantibody. While follicular helper T (Tfh) cells are crucial for supporting IgG autoantibody generation in human SLE, underlying mechanisms for Tfh cell mal-differentiation remain unclear.
In total, 129 SLE patients and 37 healthy donors were recruited for this study. Circulating leptin was determined by ELISA from patients with SLE and healthy individuals. CD4 T cells isolated from SLE patients and healthy donors were activated with anti-CD3/CD28 beads under cytokine-unbiased conditions in the presence or absence of recombinant leptin protein, followed by detection for Tfh cell differentiation by quantifying intracellular transcription factor Bcl-6 and cytokine IL-21. AMPK activation was assessed by analyzing phosphor-AMPK using phosflow cytometry and immunoblots. Leptin receptor expression was determined using flow cytometry and its overexpression was achieved by transfection with an expression vector. Humanized SLE chimeras were induced by injecting patients' immune cells into immune-deficient NSG mice and used for translational studies.
Circulating leptin was elevated in patients with SLE, inversely associated with disease activity. In healthy individuals, leptin efficiently inhibited Tfh cell differentiation through inducing AMPK activation. Meanwhile, leptin receptor deficiency was a feature of CD4 T cells in SLE patients, impairing the inhibitory effect of leptin on the differentiation of Tfh cells. As a result, we observed the coexistence of high circulating leptin and increased Tfh cell frequencies in SLE patients. Accordingly, overexpression of leptin receptor in SLE CD4 T cells abrogated Tfh cell mal-differentiation and IgG anti-dsDNA generation in humanized lupus chimeras.
Leptin receptor deficiency blocks the inhibitory effect of leptin on SLE Tfh cell differentiation, serving as a promising therapeutic target for lupus management.
系统性红斑狼疮（SLE）是一种主要由IgG自身抗体介导的典型自身免疫性疾病。虽然滤泡辅助性T（Tfh）细胞对于人类SLE中IgG自身抗体的产生至关重要，但Tfh细胞分化异常的潜在机制仍不清楚。
本研究共招募了129例SLE患者和37名健康供体。通过ELISA测定SLE患者和健康个体的循环瘦素。在有无重组瘦素蛋白的情况下，在无细胞因子偏向的条件下用抗CD3/CD28磁珠激活从SLE患者和健康供体分离的CD4 T细胞，然后通过定量细胞内转录因子Bcl-6和细胞因子IL-21检测Tfh细胞分化。通过磷酸化流式细胞术和免疫印迹分析磷酸化AMPK来评估AMPK激活。使用流式细胞术测定瘦素受体表达，并通过用表达载体转染实现其过表达。通过将患者的免疫细胞注射到免疫缺陷的NSG小鼠中诱导人源化SLE嵌合体，并用于转化研究。
SLE患者的循环瘦素升高，与疾病活动呈负相关。在健康个体中，瘦素通过诱导AMPK激活有效抑制Tfh细胞分化。同时，瘦素受体缺陷是SLE患者CD4 T细胞的一个特征，损害了瘦素对Tfh细胞分化的抑制作用。因此，我们观察到SLE患者中循环瘦素水平高和Tfh细胞频率增加并存。相应地，SLE CD4 T细胞中瘦素受体的过表达消除了人源化狼疮嵌合体中Tfh细胞的异常分化和IgG抗双链DNA的产生。
瘦素受体缺陷阻断了瘦素对SLE Tfh细胞分化的抑制作用，是狼疮治疗的一个有前景的治疗靶点。
