Serre G, Mils V, Haftek M, Vincent C, Croute F, Réano A, Ouhayoun J P, Bettinger S, Soleilhavoup J P
Laboratory of Cell Biology, Purpan School of Medicine, University of Toulouse III, France.
J Invest Dermatol. 1991 Dec;97(6):1061-72. doi: 10.1111/1523-1747.ep12492589.
Little is known about the process leading to desquamation in cornified epithelia. We describe late differentiation antigens (Ag) specific for human cornified squamous epithelia, defined by two murine monoclonal antibodies (MoAb), G36-19 and B17-21, produced after immunization with plantar stratum corneum (SC). Histologically, in epidermis both Ag are cytoplasmic in the lower stratum granulosum (SG), become pericellular in the upper SG, and progressively disappear in the lower SC. In contrast, they persist up to the desquamating corneocytes in the palmoplantar epidermis and hard palate epithelium, as well as in the three cornified epithelial components of the inner root sheath (IRS) of the hair follicle (HF). Cytologically, both Ag are expressed as surface spots only on rough corneocytes. They are largely preserved on cross-linked envelopes (CLE) of the fragile type. Ultrastructurally, both Ag appear in keratinosome-like cytoplasmic vesicles in the upper stratum spinosum (SS) and the SG keratinocytes, then are found in both the regular and reorganizing desmosomes of the SG keratinocytes, and lastly in the corneocyte-specific reorganized desmosomes we propose to name corneodesmosomes. On CLE, the Ag are located on fibrils gathered over the external side of the envelope. Immunochemically, the G36-19--defined epitope is sequential and shared by five non-cytokeratin protein antigens of molecular weight 33.5, 36.5, 40, 49, and 52 kD, the higher molecular weight polypeptides being possibly precursors of the 33.5-kD protein. In contrast, the B17-21 epitope, unaccessible by immunoblotting, is probably conformational. In long-term cultured keratinocytes, the Ag are only expressed when epidermal sheets are morphologically differentiated. The expression is enhanced in the absence of fetal calf serum (FCS) and of epidermal growth factor (EGF). G36-19 and B17-21 Ag participate in a corneodesmosome-CLE superstructure that is probably involved in corneocyte cohesiveness and partly responsible for the mechanical resistance of the SC. These Ag are relevant markers for studying desmosomal maturation during epidermal differentiation and desquamation.
关于角质化上皮中导致脱屑的过程，人们了解甚少。我们描述了人角质化鳞状上皮特有的晚期分化抗原（Ag），它们由两种鼠单克隆抗体（MoAb）G36 - 19和B17 - 21所定义，这两种抗体是在用足底角质层（SC）免疫后产生的。组织学上，在表皮中，这两种抗原在颗粒层下部（SG）为细胞质型，在颗粒层上部变为细胞周围型，并在角质层下部逐渐消失。相比之下，它们在掌跖表皮和硬腭上皮的脱屑角质形成细胞中持续存在，在毛囊（HF）内根鞘（IRS）的三个角质化上皮成分中也持续存在。细胞学上，这两种抗原仅在粗糙角质形成细胞上表现为表面斑点。它们在易碎型交联包膜（CLE）上大量保留。超微结构上，这两种抗原首先出现在棘层上部（SS）和颗粒层角质形成细胞中的角质体样细胞质小泡中，然后出现在颗粒层角质形成细胞的正常和重组桥粒中，最后出现在我们提议命名为角质桥粒的角质形成细胞特异性重组桥粒中。在CLE上，抗原位于包膜外侧聚集的纤维上。免疫化学方面，G36 - 19所定义的表位是连续的，并且由分子量为33.5、36.5、40、49和52 kD的五种非细胞角蛋白蛋白质抗原共享，分子量较高的多肽可能是33.5 - kD蛋白质的前体。相比之下，B17 - 21表位无法通过免疫印迹检测到，可能是构象型的。在长期培养的角质形成细胞中，只有当表皮片层在形态上分化时才表达这些抗原。在没有胎牛血清（FCS）和表皮生长因子（EGF）的情况下，表达会增强。G36 - 19和B17 - 21抗原参与了角质桥粒 - CLE超结构，该结构可能与角质形成细胞的黏附有关，并部分负责角质层的机械抗性。这些抗原是研究表皮分化和脱屑过程中桥粒成熟的相关标志物。
