CD4-DISEASE - EVIDENCE FOR AN ANTIGEN-SPECIFIC RESPONSE( CELL OLIGOCLONALITY IN CROHNS)

To identify disease-specific T cell changes that occur in Crohn's dise ase (CD) the T-cell receptor (TCR) BV repertoires of lamina propria ly mphocytes (LPL) from both disease-active and disease-inactive colonic tissue of three CD patients were compared by a quantitative polymerase chain reaction (qPCR) and CDR3 length analysis. It was observed that the BV repertoires of LPL isolated from the disease-active and disease -inactive parts of the colon of the same individual were different, an d most of the differences occurred in CD4+ LPL with very few differenc es in the CD8+ populations of LPL. Although the pattern of BV segments that was increased in disease-active relative to disease-inactive tis sue was different for all three CD patients, there was an increase in the levels of BV11, 13S2, 15, 16, and 17 segments in the disease-activ e tissue of all three patients. Standard CD3 length analysis of BV11, 13S2, 15, 16, and 17 segments revealed that in two of the three CD pat ients there was a striking degree of TCR oligoclonality in the disease -active tissue that was absent from disease-inactive tissue of the sam e individual. Additional differences between the disease-active and di sease-inactive tissues a ere observed using a more refined method of C DR3 length analysis, which employs BV- and BJ-specific primers. These observations suggest char at least some of the inflammation in CD is t he result of responses by CD4+ T cells to specific antigens.