Matsushima Ryohei, Wakamatsu Ei, Machiyama Hiroaki, Nishi Wataru, Yoshida Yosuke, Nishikawa Tetsushi, Toyota Hiroko, Furuhata Masae, Nishijima Hitoshi, Takeuchi Arata, Suzuki Makoto, Yokosuka Tadashi
Department of Thoracic Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan.
Department of Immunology, Tokyo Medical University, Tokyo 160-8402, Japan.
iScience. 2024 Dec 21;28(1):111669. doi: 10.1016/j.isci.2024.111669. eCollection 2025 Jan 17.
A co-signaling receptor, 2B4, has dual effects in immune cells, but its actual functions in T cells remain elusive. Here, using super-resolution imaging technology with an immunological synapse model, we showed that 2B4 forms "2B4 microclusters" immediately after 2B4-CD48 binding. A lipid phosphatase, SHIP-1, subsequently combined with 2B4 to form coinhibitory signalosomes, leading to the suppression of cytokine production. An activating adapter, SLAM-associated protein (SAP), attenuated the clustering of SHIP-1 and recruited a kinase, Fyn, enhancing the Vav1 signaling pathway as costimulatory signalosomes. Furthermore, we found that a chimeric antigen receptor with a 2B4 tail (2B4-CAR) retained the original signal transduction mechanism of 2B4. With endogenous levels of SAP expression, 2B4-CAR-T cells exposed sufficient antitumor efficacy without excess cytokine production. Our results may help explain the biphasic feature of 2B4 in T cell responses from the viewpoint of the signalosome and provide a new candidate for CAR development.
共信号受体2B4在免疫细胞中具有双重作用，但其在T细胞中的实际功能仍不清楚。在这里，我们使用超分辨率成像技术结合免疫突触模型，发现2B4与CD48结合后立即形成“2B4微簇”。脂质磷酸酶SHIP-1随后与2B4结合形成共抑制信号小体，导致细胞因子产生受到抑制。激活适配器——信号淋巴细胞激活分子相关蛋白（SAP），减弱SHIP-1的聚集并招募激酶Fyn，作为共刺激信号小体增强Vav1信号通路。此外，我们发现带有2B4尾巴的嵌合抗原受体（2B4-CAR）保留了2B4原有的信号转导机制。在内源性SAP表达水平下，2B4-CAR-T细胞展现出足够的抗肿瘤功效且不会产生过量细胞因子。我们的研究结果可能有助于从信号小体的角度解释2B4在T细胞反应中的双相特征，并为嵌合抗原受体的开发提供新的候选对象。
