SUMMARY CD8 T cells are crucial adaptive immune cells with cytotoxicity to fight against pathogens or abnormal self-cells via major histocompatibility complex class I-dependent priming pathways. The composition of the memory CD8 T cell pool is influenced by various factors. Physiological aging, chronic viral infection, and autoimmune diseases promote the accumulation of CD8 T cells with highly differentiated memory phenotypes. Accumulating studies have shown that some of these memory CD8 T cells also exhibit innate-like cytotoxicity and upregulate the expression of receptors associated with natural killer (NK) cells. Further analysis shows that these NK-like CD8 T cells have transcriptional profiles of both NK and CD8 T cells, suggesting the transformation of CD8 T cells into NK cells. However, the specific induction mechanism underlying NK-like transformation and the implications of this process for CD8 T cells are still unclear. This review aimed to deduce the possible differentiation model of NK-like CD8 T cells, summarize the functions of major NK cell receptors expressed on these cells and provide a new perspective for exploring the role of these CD8 T cells in health and disease.

中文翻译：

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NK 样 CD8 T 细胞：适应性记忆和先天免疫之间的一种潜在进化连续体

摘要 CD8 T 细胞是重要的适应性免疫细胞，具有细胞毒性，可通过主要组织相容性复合物 I 类依赖性启动途径对抗病原体或异常自身细胞。记忆CD8 T细胞库的组成受到多种因素的影响。生理衰老、慢性病毒感染和自身免疫性疾病促进具有高度分化记忆表型的CD8 T细胞的积累。越来越多的研究表明，其中一些记忆 CD8 T 细胞还表现出先天性细胞毒性，并上调与自然杀伤 (NK) 细胞相关的受体的表达。进一步分析表明，这些 NK 样 CD8 T 细胞具有 NK 和 CD8 T 细胞的转录谱，表明 CD8 T 细胞转化为 NK 细胞。然而，NK 样转化的具体诱导机制以及该过程对 CD8 T 细胞的影响仍不清楚。本综述旨在推断NK样CD8 T细胞可能的分化模型，总结这些细胞上表达的主要NK细胞受体的功能，为探索这些CD8 T细胞在健康和疾病中的作用提供新的视角。