Journal: iScience
Article Title: A crosstalk between adhesion and phagocytosis integrates macrophage functions into their microenvironment
doi: 10.1016/j.isci.2025.112067
Figure Lengend Snippet: Integrin-mediated phagocytic uptake is modulated by substrate stiffness hMDMs were seeded on fibronectin-coated polyacrylamide hydrogels or glass coverslips and incubated at 37°C for 4 h. Cells were pre-treated or not with 150 ng/mL PMA for 15 min, challenged with opsonized RBCs (iC3b-IgM-RBCs) and fixed immediately (time “0” min) or after 15 min at 37°C. Cells were then labeled with Alexa Fluor 488-conjugated phalloidin and a Cy3-labeled anti-rabbit antibodies that recognize the anti-sheep RBCs IgMs used to opsonize RBCs. (A) Representative wide-field images of macrophages seeded on 4 kPa, 12 kPa, or 25 kPa hydrogels or glass and incubated with iC3b-IgM-RBCs for 15 min. Opsonized RBCs are shown in cyan in the upper panel and phase contrast images are shown in the lower panel, where phagosomes are visible (examples of phagosomes are shown by the white arrows). Scale bar, 10 μm. (B and C) Quantification of RBC association at 0 min (B) and phagocytosis after 15 min (C) on the different substrates, with or without PMA pre-treatment. Association refers to both bound and internalized RBCs while phagocytosis only considers internalized RBCs. (D) Phagocytosis efficiency after 15 min on the different substrates, with or without PMA pre-treatment, calculated as the percentage of bound RBCs that are internalized. (E) Representative confocal images of macrophages seeded on 4 kPa, 12 kPa, or 25 kPa hydrogels or glass and incubated with iC3b-IgM-RBCs for 2 min. F-actin is shown in gray while RBCs are shown in cyan (white arrow shows one example of an actin cup). Scale bar, 10 μm. (F) Quantification of the number of actin cups formed by macrophages after 2 min. (B–D and F) Data from each donor is color coded: individual cells are represented as the smaller, lighter dots; means of all cells for each donor are shown as the bigger, darker dots with a black border. 25–30 cells were analyzed per condition and per donor. Horizontal bars represent the means of all donors. Ratio paired t tests were used to compare the means of all donors. ∗: p value < 0.05; ∗∗: p value < 0.01.
Article Snippet: Anti-sheep red blood cells (RBCs) rabbit IgMs , Gentaur , Cat#MBS524107.
Techniques: Incubation, Labeling