The role of BIN1 in the expression of PD-L1 in inflammatory bowel disease and colorectal cancer might explain a differential regulatory t cell activity through the PD-1/PD-L1 axis

RODRIGO PAPPA GOBI; BRUNO, LUISINA; ANDRÉS MACHICOTE; POMBO MARÍA TERESA; FAINBOIM, LEONARDO; LEVY, ESTRELLA MARIEL; DOCENA GUILLERMO

MAR DEL PLATA

Congreso; Reunión conjunta SAIC-SAI-SAFIS 2018; 2018

BACKGROUND: Inflammatory bowel diseases (IBD) are multifactorial pathologies characterized by a chronic and relapsing intestinal inflammation, probably due to an impairment of regulatory circuits. Peripheral blood CD8+ HLA-DR* were described as regulatory T cells with regulatory function acting through the checkpoints molecules CTLA-4 and PD-1 expressed by these cells. OBJETIVE: The aim of this work was to characterize CD8+HLA-DR+ T cells in the colonic mucosa, and to explore the role of the PD-1-PDL-1 axis in homeostasis and inflammation. METHOD: CD8+HLA-DR+ cells were assessed by flow cytometry at the colonic mucosa of healthy controls (HC) (n= 15) and IBD patients, (n= 10). Cells were also examined for the co-expression of CXCR3, CCR5, TIM-3, CD25, FoxP3, PD-L1, CD45 and PD-1 molecules. RESULTS: The frequency of CD8+HLA-DR+ T cells in the inflamed areas of IBD patients was 36.9 ± 4.6%. In comparison with non-inflamed areas of the same patients (22.8 ± 4.6%) or with HC samples (20.9 ± 1.4%) the difference was significant (p