Stastny Peter, Zou Yizhou, Fan Yisun, Qin Zhiqiang, Lavingia Bhavna
Transplantation Immunology Division, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390-8886, USA.
Contrib Nephrol. 2009;162:99-106. doi: 10.1159/000170842. Epub 2008 Oct 31.
The major histocompatibility complex (MHC) encodes the HLA class I antigens expressed on the surface of most nucleated cells and the HLA class II antigens which are expressed mostly in B lymphocytes, monocytes and dendritic cells. Mismatched HLA antigens are the main source of the immune response that leads to the rejection of allografts. In some patients however, rejection may occur without a detectable response to donor HLA antigens. We have been interested in characterizing antibodies that develop in transplant recipients who do not appear to have antibodies against HLA. For this purpose, we focused our attention to antigens which are expressed on the surface of endothelial cells and are not found on peripheral blood lymphocytes. These include the MICA and MICB antigens, which are encoded by loci in the MHC; certain autoantigens expressed on the endothelium; and a family of polymorphic antigens expressed on endothelial cells which are distinct from HLA and elicit production of antibodies that appear also to be associated with graft failure. Antibodies against MICA have been associated with allograft rejection. MICB antibodies are only rarely found. The autoantibodies and the endothelial specific alloantibodies are being characterized in ongoing studies.
主要组织相容性复合体（MHC）编码大多数有核细胞表面表达的HLA I类抗原以及主要在B淋巴细胞、单核细胞和树突状细胞中表达的HLA II类抗原。不匹配的HLA抗原是导致同种异体移植物排斥的免疫反应的主要来源。然而，在一些患者中，即使对供体HLA抗原没有可检测到的反应，也可能发生排斥反应。我们一直对那些似乎没有针对HLA抗体的移植受者体内产生的抗体进行特征分析。为此，我们将注意力集中在内皮细胞表面表达且在外周血淋巴细胞上未发现的抗原上。这些抗原包括由MHC基因座编码的MICA和MICB抗原；内皮细胞上表达的某些自身抗原；以及在内皮细胞上表达的一组多态性抗原，它们与HLA不同，能引发抗体产生，这些抗体似乎也与移植物失败有关。针对MICA的抗体与同种异体移植物排斥有关。MICB抗体很少被发现。目前正在对自身抗体和内皮细胞特异性同种抗体进行特征分析。
