PERIPHERAL CELL-MEDIATED IMMUNE-RESPONSE TO MYCOBACTERIAL ANTIGENS ININFLAMMATORY BOWEL-DISEASE

Citation
Ds. Rowbotham et al., PERIPHERAL CELL-MEDIATED IMMUNE-RESPONSE TO MYCOBACTERIAL ANTIGENS ININFLAMMATORY BOWEL-DISEASE, Clinical and experimental immunology, 102(3), 1995, pp. 456-461
Citations number
39
Categorie Soggetti
Immunology
ISSN journal
00099104
Volume
102
Issue
3
Year of publication
1995
Pages
456 - 461
Database
ISI
SICI code
0009-9104(1995)102:3<456:PCITMA>2.0.ZU;2-0
Abstract
A mycobacterial etiology has been proposed in Crohn's disease (CD). We have sought evidence of increased or modified T lymphocyte immune res ponses to Mycobacterium tuberculosis and Myco. paratuberculosis in pat ients with CD (n = 13), compared with ulcerative colitis (UC; n = 17) and controls (n = 17). Peripheral blood cells were cultured with phyto haemagglutinin (positive mitogen control), mycobacterial purified prot ein derivative (PPD) preparations, lysates, column fractions and whole , heat-killed bacteria. Responses of T cells and T eel subsets were as sessed by expression of activation markers (CD25, CD69), coupled with blastogenesis assays (H-3-thymidine uptake) and estimates of prolifera tion. Virtually all patients responded to Myco. paratuberculosis and M yco. tuberculosis antigens. There were no significant differences betw een patient groups, although there was a very high overall correlation (r = 0.95; P < 0.0001) between responses to the two mycobacterial spe cies. Most of the activation and proliferative responses resided in th e CD4(+) (T helper) subset. Although up to 15% of CD8(+) (suppressor/c ytotoxic) cells also became activated, the CD8(+) cells did not prolif erate subsequently. Cells expressing the alternate gamma delta form of the T cell receptor (TCR gamma delta(+)) did not activate or prolifer ate in response to mycobacterial antigens. There were no differences i n any of these parameters between patient groups. We conclude that the re is no specific increase or alteration in cell-mediated anti-mycobac terial immunity in inflammatory bowel disease (IBD). Thus our data do not support a mycobacterial etiopathology of Crohn's disease.