Matic Maja
Department of Biochemistry, SUNY at Stony Brook, Stony Brook, NY 11794, USA.
Hum Immunol. 2005 Sep;66(9):962-8. doi: 10.1016/j.humimm.2005.07.007. Epub 2005 Aug 25.
By means of flow cytometry, we demonstrate that a subpopulation of cells in the basal layer of the human epidermis has undetectable levels of major histocompatibility complex (MHC) class I molecule. The percentage of MHC class I-negative cells in the basal layer ranged 0.5%-2%. MHC class I-negative cells were characterized by small size (low forward scatter) and low granularity (low side scatter). Upon culturing of MHC class I-negative cells, increase of MHC class I expression was observed. This expression was lower than the expression of MHC class I molecule both in cultured MHC class I-positive cells and in ex vivo keratinocytes. Furthermore, stimulation of MHC class I-negative keratinocytes with interferon gamma (IFN-gamma) did not bring about further increase in MHC class I expression. MHC class I-negative cells were identified as keratinocytes as they expressed keratin 14 and formed keratinocyte colonies in vitro.
通过流式细胞术，我们证明人类表皮基底层中的一个细胞亚群主要组织相容性复合体（MHC）I类分子水平检测不到。基底层中MHC I类阴性细胞的百分比在0.5%-2%之间。MHC I类阴性细胞的特征是体积小（前向散射低）和颗粒度低（侧向散射低）。培养MHC I类阴性细胞后，观察到MHC I类表达增加。这种表达低于培养的MHC I类阳性细胞和离体角质形成细胞中MHC I类分子的表达。此外，用干扰素γ（IFN-γ）刺激MHC I类阴性角质形成细胞不会导致MHC I类表达进一步增加。MHC I类阴性细胞被鉴定为角质形成细胞，因为它们表达角蛋白14并在体外形成角质形成细胞集落。
