CXCL12介导中枢记忆细胞而非初始T细胞在外周淋巴结中的不依赖CCR7的归巢。
CXCL12 mediates CCR7-independent homing of central memory cells, but not naive T cells, in peripheral lymph nodes.
作者信息
Scimone M Lucila, Felbinger Thomas W, Mazo Irina B, Stein Jens V, Von Andrian Ulrich H, Weninger Wolfgang
机构信息
The CBR Institute for Biomedical Research, 200 Longwood Ave., Boston, MA 02115, USA.
出版信息
J Exp Med. 2004 Apr 19;199(8):1113-20. doi: 10.1084/jem.20031645.
Central memory CD8(+) T cells (T(CM)) confer superior protective immunity against infections compared with other T cell subsets. T(CM) recirculate mainly through secondary lymphoid organs, including peripheral lymph nodes (PLNs). Here, we report that T(CM), unlike naive T cells, can home to PLNs in both a CCR7-dependent and -independent manner. Homing experiments in paucity of lymph node T cells (plt/plt) mice, which do not express CCR7 ligands in secondary lymphoid organs, revealed that T(CM) migrate to PLNs at approximately 20% of wild-type (WT) levels, whereas homing of naive T cells was reduced by 95%. Accordingly, a large fraction of endogenous CD8(+) T cells in plt/plt PLNs displayed a T(CM) phenotype. Intravital microscopy of plt/plt subiliac lymph nodes showed that T(CM) rolled and firmly adhered (sticking) in high endothelial venules (HEVs), whereas naive T cells were incapable of sticking. Sticking of T(CM) in plt/plt HEVs was pertussis toxin sensitive and was blocked by anti-CXCL12 (SDF-1alpha). Anti-CXCL12 also reduced homing of T(CM) to PLNs in WT animals by 20%, indicating a nonredundant role for this chemokine in the presence of physiologic CCR7 agonists. Together, these data distinguish naive T cells from T(CM), whereby only the latter display greater migratory flexibility by virtue of their increased responsiveness to both CCR7 ligands and CXCL12 during homing to PLN.
与其他T细胞亚群相比,中枢记忆性CD8(+) T细胞(T(CM))能提供更强的抗感染保护性免疫。T(CM)主要通过二级淋巴器官进行再循环,包括外周淋巴结(PLN)。在此,我们报告,与初始T细胞不同,T(CM)能够以依赖CCR7和不依赖CCR7的方式归巢至PLN。在二级淋巴器官中不表达CCR7配体的淋巴结T细胞缺乏(plt/plt)小鼠中进行的归巢实验显示,T(CM)迁移至PLN的水平约为野生型(WT)水平的20%,而初始T细胞的归巢减少了95%。因此,plt/plt PLN中很大一部分内源性CD8(+) T细胞表现出T(CM)表型。对plt/plt髂下淋巴结进行的活体显微镜观察显示,T(CM)在高内皮微静脉(HEV)中滚动并牢固黏附(黏附),而初始T细胞则无法黏附。T(CM)在plt/plt HEV中的黏附对百日咳毒素敏感,并被抗CXCL12(SDF-1α)阻断。抗CXCL12还使WT动物中T(CM)向PLN的归巢减少了20%,表明在存在生理性CCR7激动剂的情况下,这种趋化因子具有不可替代的作用。总之,这些数据区分了初始T细胞和T(CM),即只有后者在归巢至PLN的过程中,由于对CCR7配体和CXCL12的反应性增加而表现出更大的迁移灵活性。