Expression of the mucosal lymphocyte integrin alpha E beta 7 and its ligand E-cadherin in the synovium of patients with rheumatoid arthritis.

Abstract

The synovial expression of the mucosal lymphocyte integrin alpha E beta 7 and its ligand E-cadherin was analysed in order to study the relationship between T lymphocytes of the gastrointestinal tract and the synovium in patients with rheumatoid arthritis (RA). Immunohistochemical evaluation of synovium revealed that the alpha E beta 7-expression was detectable in 16 of the 38 samples examined. A concomitant examination on circulating lymphocytes by flow cytometry showed that alpha E beta 7-expressing lymphocytes occur less frequently in peripheral blood (PB). In vitro culture of lymphocytes increased the alpha E beta 7-expression on synovial lymphocytes six-fold, whereas PB lymphocytes expressed a two-fold increase. The addition of PHA to the culture medium did not dramatically increase the alpha E beta 7-expression on synovial lymphocytes, in contrast to PB lymphocytes where a 24-fold increase was detected. The addition of TGF-beta 1 to the culture of PB lymphocytes increased the alpha E beta 7-expression three-fold. E-cadherin expression was found in all synovial tissues analysed by immunohistochemistry. These results demonstrate that synovial T lymphocytes have the capacity to express the 'mucosal-type' integrin alpha E beta 7, possibly due to high levels of intra-articular TGF-beta 1. This expression might be of physiological importance since E-cadherin, the ligand for alpha E beta 7, is richly expressed by synoviocytes. In addition, the results indicate that a high in vivo expression of alpha E beta 7 is suppressed in the synovial tissue by a hitherto unknown mechanism.

• Authors: C Trollmo, I M Nilsson, C Sollerman, A Tarkowski
• Journal: Scandinavian journal of immunology (Scand J Immunol) Vol. 44 Issue 3 Pg. 293-8 (Sep 1996) ISSN: 0300-9475 [Print] England
• PMID: 8795724 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cadherins
• Integrins
• Ligands
• Transforming Growth Factor beta
• integrin alphaEbeta7

Topics

• Adult
• Arthritis, Juvenile (immunology)
• Arthritis, Rheumatoid (immunology)
• Cadherins (biosynthesis)
• Cells, Cultured
• Female
• Humans
• Integrins (biosynthesis)
• Leukocytes, Mononuclear (immunology)
• Ligands
• Male
• Middle Aged
• Synovial Membrane (immunology)
• T-Lymphocytes (cytology, drug effects, immunology)
• Transforming Growth Factor beta (pharmacology)