PD-L2在血液系统肿瘤免疫治疗中的研究进展

随着程序性死亡受体1(programmed death receptor-1，PD-1)/程序性死亡受体配体1(programmed death-ligand 1，PD-L1)抑制剂在多种实体肿瘤临床治疗中取得广泛进展，血液系统肿瘤亦拉开了免疫疗法帷幕。然而，免疫检查点阻断疗法仍存在应答率低、药物耐药和副作用严重等挑战，需要进一步寻找新的免疫治疗靶点。B7家族中的程序性死亡受体配体2(programmed death-ligand 2，PD-L2)亦可以和PD-1结合，进而抑制免疫细胞功能。此外，PD-L2可以调控肿瘤免疫逃逸，在血液系统肿瘤中的治疗潜力仍有待研究。故本文对PD-L2的生物学特征、在血液系统肿瘤中的表达及在免疫治疗中的研究进展进行简要综述，为血液系统肿瘤通过PD-1/PD-L2通路治疗提供理论依据。

Research progress on PD-L2 in immunotherapy of hematological tumors

With the extensive progress of programmed death receptor-1(PD-1)/programmed death-ligand 1(PD-L1) inhibitors in the clinical therapy of a variety of solid tumors,hematological tumors immunotherapy has opened a new chapter.However,there are still challenges in the immune checkpoint blocking therapy,such as low response rate,drug resistance,and serious side effects.Therefore,it is necessary to further explore new immunotherapeutic targets.Programmed death-ligand 2 (PD-L2) in B7 immunoglobulin family can bind to PD-1 and inhibit the function of immune cells.Beyond that,it remains to clarify which is the mechanism of PD-L2 in immune regulation and its therapeutic potential in hematological tumors.Accordingly,this review will concentrate on the biological characteristics of PD-L2,its expression,and immunotherapy in hematological tumors,to hope that PD-1/PD-L2 pathways will play a role in immunotherapy in the future.