鉴定出一群新的骨髓来源的CD8α⁺β⁻树突状表皮细胞。随后，这群独特的细胞数量被CD8α⁺β⁺树突状表皮细胞的非胸腺依赖性扩增所超越。

Identification of a novel population of CD8 alpha+ beta- bone marrow-derived dendritic epidermal cells. This unique population is subsequently outnumbered by thymus-independent expansion of the CD8 alpha+ beta+ dendritic epidermal cells.

作者信息

Hayakawa J, Shiohara T, Moriya N, Arahari K, Nagashima M, Yagita H, Ishikawa H

机构信息

Department of Dermatology, Kyorin University School of Medicine, Tokyo, Japan.

出版信息

J Immunol. 1993 Dec 1;151(11):5984-92.

PMID:8245443

Abstract

Maturation of some T cell populations has been suggested to occur in epithelial tissues. The CD8 molecule, which is expressed as heterodimers made of alpha/beta-chains on virtually all peripheral T cells, is preferentially expressed as homodimers made only of alpha-chains on a subset of CD8+ mouse gut intraepithelial lymphocytes, which arise from bone marrow (BM) precursors in a thymus-independent mechanism. This unique population of CD8 alpha+ beta- T cells, however, has not been identified in other lymphoid tissues in normal adult mice. Because our previous study demonstrated that reconstitution of thymectomized irradiated mice with T cell-depleted BM cells resulted in the appearance of CD8+, TCR-alpha beta+ dendritic epidermal cells (DEC) and suggested that a proportion of the BM-derived DEC may mature within the epidermis, we asked whether the unique phenotype of CD8 alpha+ beta- could be detected among the CD8+ BM-derived DEC. In this report for the first time we identified this unique population of CD8 alpha+ beta- cells among the DEC. Although this population comprised the predominant fraction of the BM-derived DEC in the early post-transfer period (2 to 3 mo), gradual shift from the CD8 alpha+ beta+ phenotypes occurred during the late post-transfer period (4 to 6 mo) independently of the presence of the thymus. Kinetic studies on the BM-derived DEC revealed that this phenotypic shift could be caused by the subsequent expansion of the CD8 alpha+ beta+ DEC. In contrast, the CD8 alpha+ beta- population was the major subset of the BM-derived intraepithelial lymphocytes throughout the entire observation period and the phenotypic shift with age was never observed. These results indicate that CD8 alpha+ beta- cells are preferentially detected on T cells that home to the epithelial tissues and that in the epidermis, but not in the gut epithelia, the subsequent expansion of the CD8 alpha+ beta+ DEC would dilute the high number of the CD8 alpha+ beta- cells.

摘要

一些T细胞群体的成熟被认为发生在上皮组织中。CD8分子在几乎所有外周T细胞上以由α/β链组成的异二聚体形式表达，而在一小部分CD8⁺小鼠肠道上皮内淋巴细胞上则优先以仅由α链组成的同二聚体形式表达，这些淋巴细胞通过非胸腺依赖机制起源于骨髓（BM）前体。然而，在正常成年小鼠的其他淋巴组织中尚未鉴定出这种独特的CD8α⁺β⁻T细胞群体。由于我们之前的研究表明，用T细胞耗尽的BM细胞重建胸腺切除并经辐射的小鼠会导致CD8⁺、TCR-αβ⁺树突状表皮细胞（DEC）的出现，并提示一部分BM来源的DEC可能在表皮内成熟，因此我们询问在CD8⁺BM来源的DEC中是否能检测到CD8α⁺β⁻的独特表型。在本报告中，我们首次在DEC中鉴定出了这种独特的CD8α⁺β⁻细胞群体。尽管在转移后早期（2至3个月），该群体构成了BM来源的DEC的主要部分，但在转移后晚期（4至6个月），CD8α⁺β⁺表型逐渐发生转变，且与胸腺的存在无关。对BM来源的DEC的动力学研究表明，这种表型转变可能是由随后CD8α⁺β⁺DEC的扩增引起的。相比之下，CD8α⁺β⁻群体在整个观察期内都是BM来源的上皮内淋巴细胞的主要亚群，且从未观察到随年龄的表型转变。这些结果表明，CD8α⁺β⁻细胞优先在归巢到上皮组织的T细胞上被检测到，并且在表皮中，但不在肠道上皮中，随后CD8α⁺β⁺DEC的扩增会稀释大量的CD8α⁺β⁻细胞。