P164 HLA G expression is differentially expressed in infiltrating cells in inflammatory bowel disease and in healthy specimens

• Published in: Journal of Crohn's and colitis Vol. 14; no. Supplement_1; pp. S220 - S221
• Main Authors: Ferreira, S, Abiodoun Sadissou, I, Serafim Parra, R, Ribeiro Feitosa, M, Sanches Lizarte Neto, F, Pretti da Cunha Tirapelli, D, Naiara zambelli Ramalho, L, Feres, O, Ribeiro da Rocha, J J, Donadi, E A, de Almeida Troncon, L E
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 15-01-2020
• ISSN: 1873-9946; 1876-4479
• DOI: 10.1093/ecco-jcc/jjz203.293

Abstract
Background
Since HLA-G is an immune checkpoint molecule and since Crohn’s disease (CD) and ulcerative colitis (UC) exhibit immune-mediated mechanism deregulation, we aimed to evaluate HLA-G intestinal expression and soluble (sHLA-G) levels in CD/UC patients, stratified according to CD phenotype/localisation and UC extension.
Methods
HLA-G tissue expression was assessed by immunohistochemistry in biopsies collected from 151 patients (90 CD, 61 UC) and 24 healthy controls, and in surgical resections (28 CD, 12 UC). Plasma sHLA-G levels (97 CD, 81 UC and 120 controls) were evaluated using ELISA
Results
HLA-G expression was observed in intestinal epithelial cells of controls and CD/UC specimens, exhibiting closely similar profiles, and in lamina propria infiltrating cells, exhibiting differential patterns. In biopsies, CD/UC lamina propria plasma cells/lymphocytes presented: i) increased HLA-G expression compared with controls (p < 0.0001), ii) irrespective of the extent, UC cell staining was greater compared with CD cells (p = 0.0011), and iii) the inflammatory CD phenotype presented increased number of infiltrating cells compared with stenosing and fistulizing phenotypes (p = 0.0407). In surgical resections, CD/UC patients exhibited increased infiltrating cell HLA-G expression in lesion areas compared with margins. sHLA-G levels were increased in UC/CD patients (p < 0.0001) when compared with controls, but no difference was observed between patients.
Conclusion
Increased infiltrating cell HLA-G expression associated with increased sHLA-G levels in CD/UC patients may reflect host on-going strategies to suppress chronic inflammation.
References
Renan Garcia Gomes, Carlos Alexandre Antunes de Brito et al, (2018), HLA-G is expressed in intestinal samples of ulcerative colitis and Crohn’s disease patients and HLA-G5 expression is differentially correlated with TNF and IL-10 cytokine expression, Human Immunology, 79(6):477–484. doi: 10.1016/j.humimm.2018.03.006