Harris A J, Dean D, Burge S, Wojnarowska F
Department of Dermatology, Oxford Radcliffe Hospital Trust, UK.
Clin Exp Dermatol. 1997 May;22(3):128-33.
The CD44 family of cell surface glycoproteins is widely expressed in epithelial, mesothelial and haemopoietic tissues and is thought to function primarily as adhesion molecules. The molecule has an intracellular, a transmembrane and an extracellular domain. The membrane proximal region of the extracellular domain is of variable structure depending on which of 10 variable exons are involved in coding for this region. Both in vitro stimulated T cells and cytokine stimulated keratinocytes are known to express certain isoforms. In this study we have investigated whether specific isoforms of the CD44 molecule are expressed on epithelial cells and lymphocytes in the course of two inflammatory skin diseases, namely lupus erythematosus and lichen planus. Monoclonal antibodies, specific to the epitopes of the CD44 molecule encoded by v3, v4/5, v6 and v8/9 variable exons and a pan CD44 marker, were used on 10 lupus and 8 lichen planus frozen skin samples and compared with normal skin from 9 different body sites. Results failed to show detectable levels of variant isoforms of CD44 on lymphocytes in either inflammatory skin disease, despite evidence of T cell activation. All CD44 variant isoforms were reduced on the keratinocytes in some sections of lupus and lichen planus. The results are discussed in the context of the current models for the role of CD44 in the immune response.
细胞表面糖蛋白CD44家族广泛表达于上皮组织、间皮组织和造血组织，主要发挥黏附分子的功能。该分子具有一个胞内结构域、一个跨膜结构域和一个胞外结构域。胞外结构域的膜近端区域结构可变，取决于参与该区域编码的10个可变外显子中的哪一个。已知体外刺激的T细胞和细胞因子刺激的角质形成细胞都表达某些异构体。在本研究中，我们调查了在两种炎症性皮肤病（即红斑狼疮和扁平苔藓）的病程中，上皮细胞和淋巴细胞上是否表达CD44分子的特定异构体。针对由v3、v4/5、v6和v8/9可变外显子编码的CD44分子表位的单克隆抗体以及一种泛CD44标记物，被用于检测10份红斑狼疮和8份扁平苔藓的冰冻皮肤样本，并与来自9个不同身体部位的正常皮肤进行比较。结果显示，尽管有T细胞活化的证据，但在这两种炎症性皮肤病的淋巴细胞上均未检测到可检测水平的CD44变异异构体。在红斑狼疮和扁平苔藓的一些切片中，角质形成细胞上的所有CD44变异异构体均减少。我们将结合目前关于CD44在免疫反应中作用的模型来讨论这些结果。
