Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T cell activation.

中文翻译：

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通过与磷脂酰丝氨酸结合调节 Tim-3 功能

Tim-3 是一种跨膜蛋白，在慢性刺激的 CD4+ 辅助 T 细胞和 CD8+ 细胞毒性 T 细胞亚群上高度表达，在急性激活和感染期间具有更短暂的表达。Tim-3 也由多种类型的骨髓细胞组成型表达。与其他 TIM 家族成员一样，Tim-3 可以与凋亡细胞展示的磷脂酰丝氨酸结合，并且这种相互作用已被证明可介导树突细胞对此类细胞的摄取和抗原向 CD8+ T 细胞的交叉呈递。相比之下，Tim-3 对 PS 的识别可能如何调节 Tim-3+ T 细胞的功能尚不清楚。在他们最近的论文中，Lemmon 及其同事首次证明 Tim-3 对 PS 的识别导致 T 细胞活化增强。