B7家族新成员HHLA2在人类恶性肿瘤中的研究现状

The research status of a new member of B7 family HHLA2 in human malignant tumors

HHLA2 （human endogenous retrovirus-H long terminal repeat-associating 2 ）是第二信号分子B7家族的一个新成员，与不同的受体结合提供T细胞活化的共抑制或共刺激信号。研究表明，HHLA2很少表达于人类正常组织，却高表达于多种人类恶性肿瘤组织，提示HHLA2可能参与免疫逃逸，对恶性肿瘤的发生、发展、转移及预后有一定影响，可能是恶性肿瘤免疫治疗的一个新靶点。因而，深入研究HHLA2在多种恶性肿瘤中的表达情况有重要意义。

HHLA2, which is a new member of B7 family of the second signal molecules, provides coin- hibitory or eostimulatory signals of the activation of T cell while binding to different receptors. Studies have shown that HHLA2 was rarely expressed in normal human tissues, but it was highly expressed in a variety of ma- lignant tumors, suggesting that HHLA2 may be involved in the immune escape and the development of malignant tumors. Thus, HHLA2 might be a potential target for tumors immunotherapy. Further research on the expression of HHLA2 in malignant tumors is of great significance.