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

MACHICOTE A; PAPA GOBBI RODRIGO; LEVY ESTRELLA; ROCCA ANDRES; ALICIA SAMBUELLI; MARTÍN YANTORNO; CORREA GUSTAVO; POMBO M TERESA; DOCENA GUILLERMO; FAINBOIM L

MAR DEL PLATA

Congreso; Congreso anual de la Sociedad Argentina de Inmunología, en el marco del congreso conjunto SAIC-SAI-SAFIS; 2018

Background: We previously described a natural human CD8+HLA-DR+ Treg subset acting through cellular contact, CTLA-4 and the PD-1/PD-L1 axis. The present study aimed to evaluate the role of the axis PD-1/PD-L1 in the intestinal mucosa of Colorectal Cancer (CRC) and Inflammatory Bowel Disease (IBD) patients, focusing on the regulation of PD-L1 expression within epithelial tissues. Methods: Cells and tissue from healthy controls samples (HC; n=41), IBD (n=36) and CRC patients (n=31) were obtain from colonic biopsies or surgical specimens. Lamina propria (LP) CD8+HLA-DR+ cells were assessed by flow cytometry. BIN1 mRNA expression levels were analyzed by RT-qPCR. PD-L1 immunofluorescence and immunohistochemistry were performed in paraffin slides.Results: In LP from HC samples, CD8+HLA-DR+ cells represented a 22.8±1.4% of the CD8 subset, and they highly expressed PD-1 (CD8+HLA-DR+ 52.4±4.5% vs. 31.5±3.6% within CD8+HLA-DR-;p