P100 CD161 levels are reduced in all subpopulations of T-cell colonic mucosal lymphocytes in inflammatory bowel disease
E. Tristan, A. Carrasco, A. Martín-Cardona, Y. Zabana, M. Aceituno, A. Raga, X. Andújar, B. Arau, P. Ruiz-Ramírez, L. Ruiz-Campos, F. Fernández-Bañares, M. Esteve
Gastroenterology Department, Hospital Universitari Mútua Terrassa, Universitat de Barcelona, Terrassa. Centro de Investigación Biomédica en red de enfermedades hepáticas y digestivas CIBERehd, Gastroenterology Department, Terrassa, Spain
Background
CD161 is a type C lectin expressed in NKs cells and peripheral T cells (TCRγδ and αβ, NKTs), enriched in intestinal populations. Its expression can be modulated by infections and inflammation. MAIT cells are a subset of innate antimicrobial T-cells abundant in the mucosa but their role in immunological regulation is still unknown.
Methods
To measure CD161 levels in subtypes of T-lymphocytes of intestinal mucosa: CD4+, CD8+, double positive (DP,CD4+CD8+), double negative (DN,CD4−CD8−), MAIT cells (CD161+TCRVα7.2+) and intraepithelial cells (CD103+)
Results
Twenty-six patients with active inflammatory bowel disease (IBD) without immunosuppressive treatment (
Conclusion
In healthy mucosa, we did not find differences related to location in any of CD161 subpopulations except for increase of CD3+CD161+CD103+ and decrease of CD3+CD161+CD103− in left colon compared with right colon and ileum. Regarding MAIT cells, a progressive decrease was observed in distal parts of intestine for CD3+MAIT+CD103+ while CD3+MAIT+CD103− subpopulation has a specular behaviour; CD3+CD8+MAIT+ was increased in ileum compared with colon (Table 1).
| CD3+CD161+CD103− | 43.2 (33.3-63.0) | 41.5 (26.4-55.8) | 26.0 (18.7-35.2) | 0.034 |
| CD3+CD161+CD103+ | 56.8 (42.2-66.6) | 58.4 (44.1-73.5) | 73.9 (64.7-81.1) | 0.029 |
| CD3+MAIT+CD103+ | 57.1 (41.2-63.5) | 42.7 (24.7-52.2) | 32.4 (22.4-43.7) | 0.042 |
| CD3+MAIT+CD103− | 45.6 (36.5-58.7) | 57.2 (47.7-75.2) | 67.5 (57.8-77.5) | 0.037 |
| CD3+CD8+MAIT+ | 3.2 (2.2-5.4) | 1.7 (1.2-2.5) | 1.8 (1.5-2.2) | 0.019 |
In ileal CD vs. healthy ileal mucosa, no differences were observed regarding CD3+CD161+ and CD3+MAIT+. A reduction of CD3+CD161+ was observed in colonic IBD compared with controls due to a reduction of CD3+CD4+CD161+, CD3+CD8+CD161+ and CD3+DN_CD161+ (Table 2).
| CD3_CD161 | 35.9 (28.1-42.7) | 39.8 (33.0-55.1) | 61.2 (57.7-67.5) | 0.004 |
| CD3+CD4+CD161+ | 39.1 (37.2-56.0) | 47.0 (38.3-62.5) | 71.8 (68.3-77.0) | 0.001 |
| CD3+CD8+CD161+ | 14.0 (12.3-25.3) | 21.5 (15.6-45.7) | 49.1 (33.3-56.9) | 0.013 |
| CD3+DN_CD161+ | 16.0 (12.2-24.3) | 18.4 (14.3-49.3) | 45.6 (23.4-57.8) | 0.008 |
There is a regional specialisation for the subset CD103+ of both CD161+CD103+ and MAIT_CD103+ cells in healthy intestine. CD3+CD161+ T cells are reduced in IBD colonic inflammation and could serve as a marker of active IBD but not to sort between CD and UC.