Paus R, Eichmüller S, Hofmann U, Czarnetzki B M, Robinson P
Department of Dermatology, University Hospital R. Virchow, Freie Universität Berlin, Germany.
Br J Dermatol. 1994 Aug;131(2):177-83. doi: 10.1111/j.1365-2133.1994.tb08488.x.
Not all keratinocytes in human and rat hair follicles express MHC class I antigens (MHC I). In the present study, we report the first immunohistological profile of classical and non-classical MHC I expression in the skin of adolescent C57 BL-6 mice during the induced hair cycle. MHC I immunoreactivity (H-2b, H-2Db) is absent in the matrix and inner root sheath of growing (= anagen) hair follicles, and the dermal papillae are H-2b negative during catagen and telogen. This lack of normal MHC I expression may serve to sequester potentially damaging autoantigens from immune recognition. In addition, we present the first evidence of non-classical MHC class I antigen expression in normal mammalian skin: during the entire hair cycle, the distal hair follicle shows strong Qa-2 immunoreactivity, which appears to be restricted to an epithelial follicle compartment densely populated by gamma-delta T cells with which Qa-2 molecules may interact as part of a primitive antibacterial defense system of the follicle. The murine hair cycle is an attractive model for dissecting the functional roles of H-2b and Qa-2 molecules in hair biology and in related tissue-interaction systems.
人类和大鼠毛囊中的并非所有角质形成细胞都表达MHC I类抗原（MHC I）。在本研究中，我们报告了诱导毛发生长周期期间青春期C57 BL-6小鼠皮肤中经典和非经典MHC I表达的首个免疫组织学特征。在生长期（即生长期）毛囊的基质和内根鞘中不存在MHC I免疫反应性（H-2b、H-2Db），在退行期和休止期，真皮乳头H-2b呈阴性。这种正常MHC I表达的缺失可能有助于将潜在有害的自身抗原与免疫识别隔离开来。此外，我们首次展示了正常哺乳动物皮肤中非经典MHC I类抗原表达的证据：在整个毛发生长周期中，毛囊远端显示出强烈的Qa-2免疫反应性，这似乎局限于一个上皮毛囊区室，该区域密集分布着γ-δT细胞，Qa-2分子可能作为毛囊原始抗菌防御系统的一部分与其相互作用。小鼠毛发生长周期是剖析H-2b和Qa-2分子在毛发生物学及相关组织相互作用系统中的功能作用的一个有吸引力的模型。
