免疫抑制受体LILRB4在肿瘤和炎症性疾病中的研究进展

Advances in immunosuppressive receptor LILRB4 in tumors and inflammatory diseases

白细胞免疫球蛋白样受体LILRB4(ILT3或CD85k)是免疫抑制受体家族成员,主要表达于髓系来源免疫细胞的细胞膜,在免疫调节中通过激活自身抑制基序(ITIM)或抑制Fc受体激活基序(ITAM)发挥免疫抑制作用。在肿瘤中,LILRB4受体被激活后产生免疫抑制性的肿瘤微环境协助肿瘤的侵袭和转移。在炎症疾病中,LILRB4在单核细胞、巨噬细胞、肥大细胞等多种细胞上表达并减轻炎症反应。目前LILRB4已成为肿瘤以及多种炎症性疾病的治疗靶点,针对急性髓细胞性白血病(AML)的抗LILRB4单克隆抗体已进入临床试验。本综述从LILRB4的结构分布、信号转导、治疗靶点、新药开发等几方面进行探讨。

The leukocyte immunoglobulin-like receptor LILRB4(ILT3 or CD85k),a member of the immunosuppressive receptor family,is expressed predominantly on the cell membranes of immune cells of myeloid origin,and exerts an immunosuppressive effect in immune regulation by activating either the autoinhibitory motif(ITIM)or by inhibiting Fc receptor activation motif(ITAM).In tumors,activation of LILRB4 receptor generates an immunosuppressive tumor microenvironment that assists in tumor invasion and metastasis,and in inflammatory diseases,LILRB4 is expressed on a variety of cells,such as monocytes,macrophages,mast cells,etc.,and attenuates inflammatory responses.Currently,LILRB4 has become a therapeutic target for tumors and various inflammatory diseases,and anti-LILRB4 monoclonal antibodies against acute myeloid leukemia(AML)have entered clinical trials.This review discusses LILRB4 in terms of its structural distribution,signaling,therapeutic targets,and new drug development.