Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA.
Immunol Rev. 2023 May;315(1):108-125. doi: 10.1111/imr.13185. Epub 2023 Jan 18.
Historically, the immune system was believed to develop along a linear axis of maturity from fetal life to adulthood. Now, it is clear that distinct layers of immune cells are generated from unique waves of hematopoietic progenitors during different windows of development. This model, known as the layered immune model, has provided a useful framework for understanding why distinct lineages of B cells and γδ T cells arise in succession and display unique functions in adulthood. However, the layered immune model has not been applied to CD8 T cells, which are still often viewed as a uniform population of cells belonging to the same lineage, with functional differences between cells arising from environmental factors encountered during infection. Recent studies have challenged this idea, demonstrating that not all CD8 T cells are created equally and that the functions of individual CD8 T cells in adults are linked to when they were created in the host. In this review, we discuss the accumulating evidence suggesting there are distinct ontogenetic subpopulations of CD8 T cells and propose that the layered immune model be extended to the CD8 T cell compartment.
从历史上看，人们认为免疫系统沿着从胎儿期到成年期的成熟线性轴发展。现在，很明显，在不同的发育窗口中，独特的造血祖细胞波会产生不同层次的免疫细胞。这种模型被称为分层免疫模型，为理解为什么 B 细胞和 γδ T 细胞的不同谱系会相继出现并在成年期表现出独特的功能提供了一个有用的框架。然而，分层免疫模型尚未应用于 CD8 T 细胞，人们通常仍将其视为同一谱系的单一细胞群，细胞之间的功能差异源于感染过程中遇到的环境因素。最近的研究挑战了这一观点，表明并非所有 CD8 T 细胞都是平等产生的，并且成年个体中单个 CD8 T 细胞的功能与其在宿主体内产生的时间有关。在这篇综述中，我们讨论了越来越多的证据表明存在不同的 CD8 T 细胞个体发生亚群，并提出将分层免疫模型扩展到 CD8 T 细胞区室。
