P103 Identifying CES-1 positive myeloid cells with mass cytometry as a potential therapeutic target for Crohn’s disease
HagemanMD, I.(1);Elfiky, A.(2);Becker, M.(2);Joustra, V.(1);Buskens, C.(3);Li Yim, A.(2);Hakvoort, T.(2);Verhoeff, J.(4);Garcia Vallejo, J.(4);D'Haens, G.(1);Wildenberg, M.(2);De Jonge, W.(2);
(1)Academic Medical Center AMC University of Amsterdam, Department of Gastroenterology & Hepatology, Amsterdam, The Netherlands;(2)Academic Medical Center AMC University of Amsterdam, Tytgat Institute for Liver and Intestinal Research, Amsterdam, The Netherlands;(3)Academic Medical Center AMC University of Amsterdam, Department of Surgery, Amsterdam, The Netherlands;(4)Academic Medical Center AMC University of Amsterdam, Department of Molecular Cell Biology & Immunology- Amsterdam Infection & Immunity Institute and Cancer Center Amsterdam, Amsterdam, The Netherlands;
Background
Myeloid cells are key players in the sustained inflammatory process in Crohn’s disease (CD), and are therefore therapeutic targets. Human mononuclear myeloid cells express the cell selective expression of carboxylesterase 1 (CES-1). Esterase-sensitive motif (ESM) technology has been developed to specifically target ESM tagged small molecules on human mononuclear myeloid cells, based on their CES-1 expression, creating a larger therapeutic window with less side effects. This study investigates the presence of CES-1 expressing cells in PBMCs, intestinal biopsies and fistula cells of CD patients, highlighting the potential of ESM-technology in CD. This could benefit CD treatment in non-responsive patients or patients with a fistulizing phenotype.
Methods
Intestinal biopsies were collected from CD patients who underwent endoscopy. PBMCs were collected from CD patients who were receiving Vedolizumab (VDZ) treatment and categorized as responders or non-responders. Criteria for response was based on clinical (HBI ≤4) and biochemical (fecal calprotectine ≤250 µg/g) and/or endoscopic assessment (≥50% reduction in SES-CD score). Fistula tissue was of CD patients was obtained during surgery. CES1-positive cells were phenotyped by mass cytometry with a panel of 32-markers, including the myeloid markers CES-1, CD14, CD16, HLA-DR, CD11c, CD206.
Results
We demonstrated the presence of CD14+HLADR+CD11a+CD44+CD11b+ myeloid cells exclusively expressing CES-1 in intestinal biopsies of CD patients (n=7). CES-1 expression did not differ between inflamed and uninflamed tissue. In PBMCs of VDZ responders (n=5) and non-responders (n=6), we were able to identify different subsets of myeloid cells such as classical (CD14++CD16-), intermediate(CD14+CD16+) and non-classical (CD14-CD16++) monocytes, DCs and CD2+ DC precursors all demonstrating CES-1 expression. Percentage of CES-1 positive cells in inflamed PBMCs (or non-responders) was higher than in uninflamed PBMCs (responders) in all of the above-mentioned subsets. Furthermore, we demonstrated different myeloid populations within fistula cells (n=13) such as pDCs (CD123+CD68+HLA-DR+), DCs (CD11c+CD11b+HLA-DR+ CD44+) , CD141+DCs (CD141+CD49d+HLA-DR+) ,Macrophage (CD14+CD11c+CD11b+HLA-DR+CD44+) and M2 Macrophages (CD14+CD163+CD206+CD11c+CD11b+HLA-DR+CD44+), all expressing CES-1.
Conclusion
We demonstrated specific CES-1 positive myeloid cells within intestinal biopsies, PBMCs of non-responsive patients, and fistulae samples of CD patients. Targeting CES-1+ with ESM-technology could provide new therapeutic targets for CD.