Journal: bioRxiv

Article Title: CD47 predominates over CD24 as a macrophage immune checkpoint in cancer

doi: 10.1101/2024.11.25.625185

Figure Lengend Snippet: A, Histograms depicting cell surface expression of CD24 and CD47 by flow cytometry on mouse cancer cell lines. B, Correlation of CD24 and CD47 surface expression of cell lines shown in A by geometric MFI. Data shown as mean ± SD of 3 technical replicates. Simple linear regression was performed to assess correlation. C, Representative plots showing quantification of CD45+ phagocytic primary mouse macrophages co-cultured with CFSE+ KPCA.C. Co-cultures were exposed to vehicle control (PBS) or 10 ug/ml of monoclonal antibodies against mouse CD47, CD24, or the combination for 2 hours. Phagocytosis is represented as CD45+ macrophages that had engulfed CFSE+ KPCA.C cells as a percentage of the total macrophage population. D, Quantification of phagocytosis for cell lines in A . Cell lines are organized based on expression levels of each surface marker. Data represent mean ± SD of 3 technical replicates. E, Correlation of cell surface expression levels of CD47 and CD24 compared to phagocytosis upon treatment with the corresponding antibodies for each cell line. Data points depict mean ± SD from 3 replicates for each experiment. Correlation was assessed by simple linear regression. F, Representative microscopy images of GFP+ KPCA.C cells when co-cultured with primary mouse macrophages upon treatment with vehicle control (PBS), 10 ug/mL anti-CD47, 10 ug/mL anti-CD24, or the combination for 6.5 days. Top row depicts raw images of GFP+ fluorescence. Bottom row depicts purple GFP+ mask for above images used for quantification of cancer cell growth. Scale bar, 800 µm. G, Quantification of fluorescent well area from co-culture experiments for multiple cell lines after 6.5 days, organized by surface expression of CD24. Cancer cells were quantified by either green (KPCA.C, 3LL ΔNRAS, MC38) or red (238N1) fluorescent area based on their fluorophore expression. Data and means shown from one (3LL ΔNRAS, MC38) or two (238N1, KPCA.C) independent experiments with 3 technical replicates per experiment. D,G, statistical significance ns, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 determined by two-way ANOVA with Holm-Sidak multiple comparison test.

Article Snippet: Antibodies used for experiments included: InVivoMAb anti-mouse/human/rat CD47 (IAP) clone MIAP410 (BioXCell BE0283), InVivoMAb anti-mouse CD24 clone M1/69 (BioXCell BE0360), InVivoMAb anti-human CD47 clone B6.H12 (BioXCell BE0019-1), anti-human CD24 clone ML5 (Biolegend 311102), anti-human CD24 clone SN3 (GeneTex GTX74945), cetuximab (Selleckchem A2000).

Techniques: Expressing, Flow Cytometry, Cell Culture, Control, Marker, Microscopy, Fluorescence, Co-Culture Assay, Comparison

Journal: bioRxiv

Article Title: CD47 predominates over CD24 as a macrophage immune checkpoint in cancer

doi: 10.1101/2024.11.25.625185

Figure Lengend Snippet: A, Representative histograms demonstrating cell surface expression of CD47 and CD24 on knockouts of KPCA.C and knockdowns of 238N1 by flow cytometry. B, Representative gating of phagocytic APC CD45+ mouse macrophages when co-cultured with the indicated CFSE+ KPCA.C knockouts treated with vehicle control (PBS) for 2 hours. Phagocytic macrophages are calculated as CD45+ cells that have engulfed CFSE+ cancer cells after 2 hours as a percent of all macrophages. C,D, Quantification of phagocytosis as a percentage of the maximum phagocytic response of macrophages using KPCA.C knockout cells ( C ) or 238N1 knockdown cells ( D ) treated with vehicle control (PBS), anti-mouse CD47 antibody, anti-mouse CD24 antibody, or the combination. Data represents mean ± SD of 3 technical replicates. E,F, Quantification of fluorescent well area as a measure of GFP+ KPCA.C knockout cells ( E ) or mCherry+ 238N1 knockdown cells ( F ) growth after co-culture with primary mouse macrophages and the indicated antibodies on day 6.5. Data represents mean ± SD from two independent experiments of 3 technical replicates each. G,H, Quantification of phagocytosis using CFSE+ MC38 ( G ) or 3LL ΔNRAS ( H ) cancer cells that overexpress CD24 after co-culture with primary mouse macrophages and the indicated antibodies. Data represent mean ± SD from 3 individual experiments each containing 3 technical replicates. I, Quantification of phagocytosis using StayGold+ KPCA.C cancer cells treated with vehicle control (PBS), or anti-mouse CD24 antibody, in the absence or presence of FcR blocking reagents (Fc1, anti-mouse Truestain clone 93; Fc2, anti-mouse CD16/CD32 clone 2.4G2). Data represents mean ± SD of 3 technical replicates. ( C-H ) ns, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 by two-way ANOVA with Holm-Sidak multiple comparison test.

Article Snippet: Antibodies used for experiments included: InVivoMAb anti-mouse/human/rat CD47 (IAP) clone MIAP410 (BioXCell BE0283), InVivoMAb anti-mouse CD24 clone M1/69 (BioXCell BE0360), InVivoMAb anti-human CD47 clone B6.H12 (BioXCell BE0019-1), anti-human CD24 clone ML5 (Biolegend 311102), anti-human CD24 clone SN3 (GeneTex GTX74945), cetuximab (Selleckchem A2000).

Techniques: Expressing, Flow Cytometry, Cell Culture, Control, Knock-Out, Knockdown, Co-Culture Assay, Blocking Assay, Comparison

Journal: bioRxiv

Article Title: CD47 predominates over CD24 as a macrophage immune checkpoint in cancer

doi: 10.1101/2024.11.25.625185

Figure Lengend Snippet: Results of scRNA-seq of sorted CD45+ immune cells from experiments using CD24 or CD47 knockout tumors. ( A,C,E ) Comparison of CD47- tumors (KPCA.C CD47 knockout, 238N1 CD47 knockout) to wild-type tumors (KPCA.C control, 238N1 control). A, Relative frequencies of immune cells from CD47- versus wild-type tumors. C, UMAP showing identified cell clusters. E, Gene set enrichment analysis showing Normalized Enrichment Scores of top Hallmark pathways. ( B,D,F ) Comparison of CD24- tumors (KPCA.C CD24 knockout, 238N1 CD24 knockout) to wild-type tumors (KPCA.C control, 238N1 control). B, Relative frequencies of immune cells from CD24- versus wild-type tumors. D, UMAP showing identified cell clusters. F, Gene set enrichment analysis showing Normalized Enrichment Scores of top Hallmark pathways.

Article Snippet: Antibodies used for experiments included: InVivoMAb anti-mouse/human/rat CD47 (IAP) clone MIAP410 (BioXCell BE0283), InVivoMAb anti-mouse CD24 clone M1/69 (BioXCell BE0360), InVivoMAb anti-human CD47 clone B6.H12 (BioXCell BE0019-1), anti-human CD24 clone ML5 (Biolegend 311102), anti-human CD24 clone SN3 (GeneTex GTX74945), cetuximab (Selleckchem A2000).

Techniques: Knock-Out, Comparison, Control

Journal: bioRxiv

Article Title: CD47 predominates over CD24 as a macrophage immune checkpoint in cancer

doi: 10.1101/2024.11.25.625185

Figure Lengend Snippet: A, Diagram showing process for high-throughput development and functional evaluation of bispecific antibodies targeting macrophage immune checkpoints. Antibody sequences were transformed into scFvs and cloned into a knob-into-hole format using a human IgG1 Fc. Constructs targeting macrophage immune checkpoints (CD47, CD24, SIRPa, PD-1) were cloned into knob formats and crossed with tumor-binding constructs in a hole format. Bispecific antibodies (n = 77) were expressed in Expi293F cells and used for downstream biochemical and functional analysis. B, Growth of StayGold+ DLD-1 cells in co-culture with human macrophages and each bispecific antibody. Each curve represents the mean for an individual bispecific antibody from 4 replicates. Black curve with hashed lines represents mean and 95% CI of control wells . C, Anti-tumor efficacy of bispecific antibodies at approximately t = 6.5 days as evaluated by macrophage checkpoint category. *p<0.05, ****p<0.0001 by one-way ANOVA with Dunnett’s multiple comparisons test. D-F, Growth curves for each of the WTa2d1 constructs ( D ), CD24-3 constructs ( E ), or CV1 constructs ( F ). G, Representative whole-well imaging of co-cultures treated with different bispecific antibodies at approximately t = 6.5 day. Green signal depicts growth of StayGold+ DLD-1 cells. Rows contain different macrophage checkpoint arms, while columns contain different tumor-binding arms. H, Scatter plot showing binding of each bispecific antibody to human neutrophils versus red blood cells. I, Representative histograms showing binding of the indicated bispecific antibodies to human neutrophils and red blood cells.

Article Snippet: Antibodies used for experiments included: InVivoMAb anti-mouse/human/rat CD47 (IAP) clone MIAP410 (BioXCell BE0283), InVivoMAb anti-mouse CD24 clone M1/69 (BioXCell BE0360), InVivoMAb anti-human CD47 clone B6.H12 (BioXCell BE0019-1), anti-human CD24 clone ML5 (Biolegend 311102), anti-human CD24 clone SN3 (GeneTex GTX74945), cetuximab (Selleckchem A2000).

Techniques: High Throughput Screening Assay, Functional Assay, Transformation Assay, Clone Assay, Construct, Binding Assay, Co-Culture Assay, Control, Imaging