Stanovení markerů exprese genů HLA II. třídy

• Main Author: Zajacová, Marta
• Other Authors: Černá, Marie
• Format: Dissertation
• Language: Slovak
• Published: 2010
• Online Access: http://www.nusl.cz/ntk/nusl-296617

BACKGROUND: HLA molecules play a central role in the immune response. HLA class II are involved in the selection of the T-cell repertoire in the thymus, and in presentation of antigenic peptides to antigen reactive CD4-positive T cells. The HLA class II act as restriction determinants in the presentation of antigens to T lymphocytes and their expression on the cell surface is necessary for triggering the immune responses. Regulated transcription of HLA class II genes is a complex system involving cis-acting sequence elements and trans-acting protein factors. It has been reported that allelic polymorphism exists in the regulatory regions of HLA class II DQA1, DQB1 and DRB1 genes. Most of the polymorphisms appear to be conserved within a haplotype. The hierarchy of sequence homology which exists among the structural genes is not paralleled among their promoter sequences. It is of interest that the most striking discrepancy was found for the DR4 linked alleles, DQB1*0301 and DQB1*0302, which were described as frequent risk factors for a variety of autoimmune diseases. The structural genes of these two alleles are the most closely related, but their regulatory sequences are the most heterogeneous among DQB1 variants. These sequence differences correspond to functional variation: The promoter strength...