Journal: bioRxiv
Article Title: Targeting Siglec-10/α3β1 Integrin Interactions Enhances Macrophage-Mediated Phagocytosis of Pancreatic Cancer
doi: 10.1101/2025.05.06.652455
Figure Lengend Snippet: (a) Model illustrating the mechanism of Siglec-10-mediated inhibition of macrophage phagocytosis. Siglec-10 expressed on macrophages binds to its glycan ligands on PDAC cells, which are present on multiple proteins such as ITGA3, ITGB1, and CD24. This interaction induces inhibitory signaling in macrophages, suppressing phagocytosis (left panel). Blocking Siglec-10 with an antibody prevents inhibitory signaling, thereby enhancing macrophage phagocytic ability (right panel). (b) Screening of recombinant antibodies from the top clones for Siglec-10 binding using ELISA. Binding to immobilized Siglec-10 (blue) and Siglec-5 (gray) proteins is shown. (c) Flow cytometric analysis of clone selectivity, showing binding to CHO-K1 cells expressing either Siglec-10 (blue) or Siglec-5 (gray). (d) Area under the curve (AUC) analysis of an in vitro phagocytosis assay to screen the ability of Siglec-10 antibody clones, as well as the commercially available antibodies against CD24 and Siglec-10, to enhance the phagocytic activity of macrophages against AsPC-1 PDAC cells. (e) AUC analysis of the in vitro phagocytosis assay for the top-performing Siglec-10 antibody clone using macrophages differentiated from the monocytes of four donors. Statistical significance was determined using Friedman’s ANOVA test. (f) Time-course analysis of the in vitro phagocytosis assay for the top Siglec-10 blocking antibody clone (68A11A1, blue) compared to the isotype control (gray). Results are based on n=4 independent experiments. (g) ELISA-based binding analysis of the 68A11A1 recombinant antibody to immobilized recombinant Siglec-10 and Siglec-5 proteins at different dilutions. (h) Evaluation of the ability of anti-CD24 or recombinant Siglec-10 antibody (clone 68A11A1) to enhance macrophage-mediated phagocytosis of several PDAC cell lines (AsPC-1, MIA PaCa-2, and PANC-1). Phagocytosis was normalized to the isotype control for each antibody and conducted using macrophages differentiated from monocytes of 5–8 healthy donors. Each symbol represents data from an individual donor, and statistical analyses were performed using ratio paired t-tests compared to the isotype control. On the right, a representative image of the killing assays is shown (red indicates increased killing).
Article Snippet: PDAC cells were incubated with anti-human ITGA3 and ITGB1 antibodies (Clone ASC-1 and TS2/16, respectively, from Thermo Fisher Scientific) at a concentration of 1 μg/mL in 1× PBS at 4°C for 15 minutes.
Techniques: Inhibition, Glycoproteomics, Blocking Assay, Recombinant, Clone Assay, Binding Assay, Enzyme-linked Immunosorbent Assay, Expressing, In Vitro, Phagocytosis Assay, Activity Assay, Control