CD86，别名为B7.2，分子量为80Kd，表达于树突状细胞、单核细胞、记忆T淋巴细胞、生发中心B淋巴细胞、活化B淋巴细胞及活化T淋巴细胞。他属于免疫球蛋白超家族，其配体是CD28和CD152（CTLA4）。

CD86与诱导剂CD28和抑制剂CTLA4相互作用，是诱导T淋巴细胞增殖及产生IL-2的主要协同因子。

CD86在HD的R-S细胞、Ki-1淋巴细胞、EBV转化的B淋巴母细胞样细胞上均有表达。

CD86

The protein CD86 (Cluster of Differentiation 86) is a molecule expressed on antigen-presenting cells that provide costimulatory signals necessary for T cell activation and survival. It is the ligand for two proteins at the cell surface of T cells, CD28 antigen and CTLA-4 (cytotoxic T-lymphocyte-associated protein 4). CD86 is also known as B7.2. Its principal mode of action is by binding to CD28. Along with CD80, these molecules provide the necessary stimuli to prime T cells against antigens presented by antigen-presenting cells.

This gene encodes a type I membrane protein that is a member of the immunoglobulin superfamily. Binding of this protein with CD28 antigen is a costimulatory signal for activation of the T-cell. Binding of this protein with CTLA-4 negatively regulates T-cell activation and diminishes the immune response. Alternative splicing results in two transcript variants encoding different isoforms. Additional transcript variants have been described, but their full-length sequences have not been determined.