CD137/CD137L信号通路在体外T细胞增殖反应和体内SGVHD诱导中的作用

Blockade of CD137/CD137L signaling pathway with anti-CD137L mAb inhibits the T cell proliferation in vitro and induces the murine syngeneic graft versus host disease in vivo

目的:探讨抗CD137L单克隆抗体在体外、体内阻断CD137/CD137L信号通路对T细胞体外增殖的影响以及对小鼠同基因型移植物抗宿主病(syngeneic graft versus host disease,SGVHD)的作用。方法:体外混合淋巴细胞反应中加入不同浓度的抗CD137L单克隆抗体,观察抗体对T细胞增殖的影响。同基因骨髓细胞移植给致死剂量X射线照射的受体小鼠后,腹腔注射环孢素A(cyclosporine A,CsA)诱导SGVHD,并于诱导治疗的第10天起给治疗组小鼠腹腔注射抗CD137L单克隆抗体进行干预治疗。观察各组小鼠的临床症状(体重下降,腹泻),组织病理学和细胞因子改变。结果:体外用抗CD137L单抗阻断CD137/CD137L通路后,可抑制淋巴细胞的增殖和IL-2的产生。体内注射抗CD137L单抗,小鼠SGVHD的发生率为25%,显著低于诱导组小鼠SGVHD 67%的发生率,两者差异具有统计学意义(P<0.01)。SGVHD小鼠肝脏和结肠组织病理学呈严重炎症细胞浸润,组织中细胞因子IL-12I、FN-γ、TNF-αmRNA水平升高。而抗体治疗组小鼠组织病理学呈轻度炎症细胞浸润,组织中细胞因子IL-12I、FN-γ、TNF-αmRNA水平较低或检测不到,而IL-4mRNA水平升高。结论:单独用抗CD137L单克隆抗体阻断CD137/CD137L信号通路在体外可明显抑制混合淋巴细胞反应,在体内可明显抑制小鼠SGVHD的发生。

Objective：To primarily explore the effects of blockade of CD137/CD137L signaling pathway with anti-CD137L monoclonal antibody on T cell proliferation in vitro and routine syngeneic graft versus host disease （SGVHD） induction in vivo. Methods： Different doses of anti-CD137L monoclonal antibody were added into mixed lymphocyte reaction system, and the T cell proliferations were measured with 3H TdR incorporation method. Recipient mice were lethally irradiated with X-ray, transplanted with syngeneic bone marrow cells via tail vein and peritoneally injected CsA,while the mice in treatment group were peritoneally administered anti-CD137L monoclonal antibody from the 10^th day following transplantation. All mice were monitored the clinical symptoms （such as weight loss and diarrhea）,pathological changes and cytokine profiles. Results： Anti-CD137L moneclonal antibody could inhibit the T cell proliferation and decrease the level of IL-2 in vitro in a dose-dependent manner. The mice with anti-CD137L mAb treatment had lower SGVHD incidence and compared with results from the mice without anti-CD137L mAb （25% vs 67%, P 〈 0.01）. The results from pathological observation and RT-PCR detection demonstrated that anti-CD137L antibody could inhibit the inflammatory cells infiltration and decrease the IL-12, IFN-γ, TNF-αmRNA expression in liver and colon. Conclusion： Blockade of CD137/CD137L signaling pathway with anti-CD137L moneclonal antibody alone can significantly inhibit the T cell proliferation in vitro and the murine SGVHD development in vivo.