de Waal R M, Bogman M J, Maass C N, Cornelissen L M, Tax W J, Koene R A
Nature. 1983;303(5916):426-9. doi: 10.1038/303426a0.
Ia antigens are membrane-bound glycoproteins that play a part in antigen recognition and subsequent cell-cell interactions in the immune response. In the mouse they are coded for by the I region of the major histocompatibility complex H-2 and have been demonstrated on B lymphocytes, monocytes, activated T cells, macrophages and dendritic cells, including Langerhans cells. Ia-like antigens have also been detected on the vascular endothelium in man and on epidermal keratinocytes in rats but expression on the latter cells was induced by a graft-versus-host reaction or by contact hypersensitivity. In the mouse, previous studies have suggested that Ia antigens in skin are restricted to epidermal Langerhans cells and it was thought that these were the targets for Ia-dependent rejection of skin allografts. The results presented here show that Ia antigens in mouse allografts are also present on the vascular endothelium but their expression is variable and dependent on the immunological status of the recipient. These findings suggest that vascular endothelial cells can act as targets in Ia-incompatible skin allograft rejection.
Ia抗原是膜结合糖蛋白，在免疫反应中的抗原识别及随后的细胞间相互作用中发挥作用。在小鼠中，它们由主要组织相容性复合体H-2的I区编码，并且已在B淋巴细胞、单核细胞、活化的T细胞、巨噬细胞和树突状细胞（包括朗格汉斯细胞）上得到证实。在人类的血管内皮细胞以及大鼠的表皮角质形成细胞上也检测到了Ia样抗原，但后者细胞上的表达是由移植物抗宿主反应或接触性超敏反应诱导的。在小鼠中，先前的研究表明皮肤中的Ia抗原仅限于表皮朗格汉斯细胞，并且人们认为这些细胞是Ia依赖性皮肤同种异体移植排斥反应的靶标。此处给出的结果表明，小鼠同种异体移植中的Ia抗原也存在于血管内皮细胞上，但其表达是可变的，并且取决于受体的免疫状态。这些发现表明，血管内皮细胞可作为Ia不相容性皮肤同种异体移植排斥反应中的靶标。
