title: Predominance of type 1 CD4+ T cells in human abdominal aortic aneurysm.
abstract: The functional repertoire of T cells in abdominal aortic aneurysm (AAA) and the exact nature of aortic wall adaptive cellular immune responses still remains a matter of debate. In this study, we sought to determine whether type 1 or type 2 responses occur predominantly in human aneurysmal aortic lesions. We first examined the phenotype and cytokine secretion profile of T lymphocytes freshly isolated from aneurysmal aortic wall for comparison with their circulating counterparts using flow cytometry. We found that both populations of infiltrating CD4(+) and CD8(+)T cells displayed a unique activated memory phenotype. In addition, we identified the presence in human aneurysmal aortic lesion of CD4(+)T cells producing high levels of interferon (IFN)-gamma but not interleukin (IL)-4, reflecting their type 1 nature. Quantitative analysis of cytokine gene expression confirmed increased IFN-gamma transcript levels in infiltrating cells compared to controls. We next analysed aortic wall responses using LightCycler-based quantitative real-time reverse transcription-polymerase chain reaction. Compared to control non-diseased aortic samples, we demonstrated that whole AAA tissues exhibited high mRNA levels of IFN-gamma but not IL-4. Overexpression of the transcription factor T-bet in the absence of significant GATA-3 expression further assessed the type 1 polarization of aortic wall immune responses. These findings indicate that type 1 CD4(+)T cells predominate in human AAA lesions. This study has important implications for the pathogenesis of aneurysm disease. Through the production of IFN-gamma, T cells may indeed contribute to orchestrate extracellular matrix remodelling.
authors.affiliation: Department of Immunology, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium. cgalle@ulb.ac.be
authors.forename: C
authors.initials: C
authors.lastname: Galle
authors.forename: L
authors.initials: L
authors.lastname: Schandené
authors.forename: P
authors.initials: P
authors.lastname: Stordeur
authors.forename: Y
authors.initials: Y
authors.lastname: Peignois
authors.forename: J
authors.initials: J
authors.lastname: Ferreira
authors.forename: J-C
authors.initials: JC
authors.lastname: Wautrecht
authors.forename: J-P
authors.initials: JP
authors.lastname: Dereume
authors.forename: M
authors.initials: M
authors.lastname: Goldman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000276:immunology; D001012:Aorta, Abdominal / Q000276:immunology; D017544:Aortic Aneurysm, Abdominal / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D015870:Gene Expression; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D007371:Interferon-gamma / Q000032:analysis / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D007378:Interleukins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D020825:T-Box Domain Proteins; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014157:Transcription Factors / Q000032:analysis / Q000276:immunology; D000098815:T-bet Transcription Factor
chemical_list: D015703:Antigens, CD; D007378:Interleukins; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D014157:Transcription Factors; D015847:Interleukin-4; D007371:Interferon-gamma