Distinct Roles for CXCR6+ and CXCR6- CD4+ T Cells in the Pathogenesis of Chronic Colitis: e65488

• Published in: PloS one Vol. 8; no. 6
• Main Authors: Mandai, Yasushi, Takahashi, Daisuke, Hase, Koji, Obata, Yuuki, Furusawa, Yukihiro, Ebisawa, Masashi, Nakagawa, Tomoo, Sato, Toru, Katsuno, Tatsuro, Saito, Yasushi
• Format: Journal Article
• Language: English
• Published: 01.06.2013
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0065488

CD4+ T cells play a central role in the development of inflammatory bowel disease (IBD) via high-level production of effector cytokines such as IFN- gamma and TNF- alpha . To better characterize the colitogenic CD4+ T cells, we examined their expression of CXCR6, a chemokine receptor that is expressed by T cells upon activation and is upregulated in several inflammatory diseases. We found that 80% of colonic lamina propria CD4+ T cells expressed CXCR6 in the CD45RBhigh T cell-transferred colitis model. CXCR6 expression was similarly upregulated in inflamed mucosa of patients with Crohn's disease. Although surface marker analysis demonstrated that both CXCR6+ and CXCR6- CD4+ T-cell subsets consist of the cells with effector and effector-memory cells, the more cells in the CXCR6+ subset produced IFN- gamma and TNF- alpha compared to CXCR6- subset, and only the CXCR6+ subset produced IL-17A. Nevertheless, adoptive retransfer of lamina propria CXCR6+ T cells into Rag1-/- recipients failed to induce the disease due to limited expansion of the transferred cells. By contrast, retransfer of CXCR6- cells evoked colitis similar to that observed in CD4+CD45RBhigh T cell-transferred mice, and resulted in their conversion into CXCR6+ cells. Collectively, these observations suggest that the CXCR6+CD4+ T-cell subset consists of terminally differentiated effector cells that serve as the major source of effector cytokines in the inflamed tissue, whereas CXCR6-CD4+ T-cell subset serves as a colitogenic memory compartment that retains the ability to proliferate and differentiate into CXCR6+CD4+ T cells.