Role of HLA and T lymphocytes in the immune response.

Human leukocyte antigens (HLA) play a role in the pathogenesis of diseases involving an immune response. Because HLA are strongly associated with ophthalmologic diseases such as Behcet's disease, VogtKoyanagi-Harada's disease and birdshot retinochoroidopathy, an understanding of HLA is essential in analyzing the immunogenetic mechanisms underlying many diseases. Recent advances in molecular biology have made it possible to characterize the HLA gene region at the DNA level. This paper provides a comprehensive overview of the etiology of various immunologic disorders with emphasis on the role of HLA, a self/not-self discrimination mechanism, and of T lymphocytes.