Department of Microbiology, Immunology, and Cancer Biology, Carter Immunology Center, University of Virginia School of Medicine , Charlottesville, VA , USA.
Front Immunol. 2013 Aug 19;4:241. doi: 10.3389/fimmu.2013.00241. eCollection 2013.
T cell activation induces homing receptors that bind ligands on peripheral tissue vasculature, programing movement to sites of infection and injury. There are three major types of CD8 effector T cells based on homing receptor expression, which arise in distinct lymphoid organs. Recent publications indicate that naïve, effector, and memory T cell migration is more complex than once thought; while many effectors enter peripheral tissues, some re-enter lymph nodes (LN), and contain central memory precursors. LN re-entry can depend on CD62L or peripheral tissue homing receptors. Memory T cells in LN tend to express the same homing receptors as their forebears, but often are CD62Lneg. Homing receptors also control CD8 T cell tumor entry. Tumor vasculature has low levels of many peripheral tissue homing receptor ligands, but portions of it resemble high endothelial venules (HEV), enabling naïve T cell entry, activation, and subsequent effector activity. This vasculature is associated with positive prognoses in humans, suggesting it may sustain ongoing anti-tumor responses. These findings reveal new roles for homing receptors expressed by naïve, effector, and memory CD8 T cells in controlling entry into lymphoid and non-lymphoid tissues.
T 细胞活化诱导归巢受体与外周组织脉管系统上的配体结合，编程迁移至感染和损伤部位。根据归巢受体表达的不同，CD8 效应 T 细胞有三种主要类型，它们在不同的淋巴器官中产生。最近的出版物表明，初始、效应和记忆 T 细胞的迁移比以前认为的要复杂得多；虽然许多效应物进入外周组织，但有些会重新进入淋巴结 (LN)，并包含中央记忆前体。LN 的再进入可能依赖于 CD62L 或外周组织归巢受体。LN 中的记忆 T 细胞往往表达与其前体相同的归巢受体，但通常 CD62L 阴性。归巢受体还控制 CD8 T 细胞进入肿瘤。肿瘤脉管系统中许多外周组织归巢受体配体的水平较低，但其中一部分类似于高内皮静脉 (HEV)，使初始 T 细胞能够进入、激活和随后发挥效应功能。这种脉管系统与人类的良好预后相关，表明它可能维持持续的抗肿瘤反应。这些发现揭示了归巢受体在控制初始、效应和记忆 CD8 T 细胞进入淋巴和非淋巴组织中的新作用。
