The epidermis of mouse skin is usually populated by dendritic epidermal T cells (γδDETC) expressing an invariant Vγ5Vδ1⁺ TCR. In Tcrd^−/− mice, skin-resident γδDETC are replaced by αβDETC carrying polyclonal αβ TCRs. Although they exhibit a dendritic morphology, αβDETC were reported to be less functional than genuine γδDETC, likely because their TCR is unable to interact with the original TCR ligands of γδDETC. However, the TCR repertoire of those replacement DETC in Tcrd^−/− mice might provide clues for understanding the development and selection of canonical γδDETC. Here, we compare the phenotype and TCR repertoires of wild-type and Tcrd^−/− mouse skin T cells. Our data reveal that αβDETC are CD4/CD8 double negative and express an MHC-independent TCR repertoire. Furthermore, we identify a second MHC-independent population of CD103^hi CD4/ CD8 double-negative αβ T cells in the dermis of Tcrd^−/− mice.

中文翻译：

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αβ T 细胞替代 Tcrd-/- 小鼠的真皮和表皮 γδ T 细胞表达 MHC 非依赖性 TCR 库

小鼠皮肤的表皮通常由表达不变 Vγ5Vδ1 ⁺ TCR的树突状表皮 T 细胞 (γδDETC) 填充。在Tcrd ^-/-小鼠中，皮肤驻留的 γδDETC 被携带多克隆 αβ TCR 的 αβDETC 取代。尽管它们表现出树枝状形态，但据报道，αβDETC 的功能不如真正的 γδDETC，这可能是因为它们的 TCR 无法与 γδDETC 的原始 TCR 配体相互作用。然而，Tcrd ^-/-小鼠中那些替代 DETC 的 TCR 库可能为理解规范 γδDETC 的发展和选择提供线索。在这里，我们比较了野生型和Tcrd的表型和 TCR 库^-/-小鼠皮肤 T 细胞。我们的数据显示 αβDETC 是 CD4/CD8 双阴性并表达独立于 MHC 的 TCR 库。此外，我们确定CD103的第二MHC-独立人口^喜在真皮CD4 / CD8双负αβT细胞TCRD ^{/ - -}小鼠。