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;


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.


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.


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. 


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.