Journal: Neuro-Oncology
Article Title: MIF-CD74 signaling drives immune modulation in medulloblastoma
doi: 10.1093/neuonc/noag020
Figure Lengend Snippet: Inhibition of CD74 via the lateral ventricle demonstrates immune-modulation and decreased tumor burden in primary and relapsed MB. (A) IHC of treatment-naïve primary (top row) and radiation-treated (bottom row) GTML allografts displaying H&E, CD74, and MIF expression within the tumor. Results representative of 3 independent replicates. Much of the tumor outside the cerebellum was removed for downstream RNA sequencing analyses, Scale bar, 100 µm. (B) Experimental schematic for evaluating the CD74-MIF blocking peptide C36L1. GTML primary or relapse cells expressing firefly luciferase were allografted into the cerebellum of FVBNRJ mice. C36L1 was administered either intraperitoneally or locoregionally through the lateral ventricle at time of engraftment and 1-week after, C36L1 vehicle was used as a control. Bioluminescence imaging was conducted to monitor tumor engraftment, progression, and/or regression up to 14 days post-therapy. At the endpoint, the tumor and CNS were harvested and assessed for immune infiltration and tumor burden. (C) Growth rate of mice bearing primary GTML allografts ( n = 3-4 per group) treated with vehicle control (black), C36L1 peptide through the lateral ventricle (red), or C36L1 peptide intraperitoneally (blue) was determined by calculating the slope of tumor growth between day 7 and 14 (endpoint). Line represents mean growth rate with individual points representing individual mice. Points below the dashed line indicate tumor regression. Statistical significance was calculated by two-way ANOVA with Tukey’s post-test. (D) UMAP projection of flow cytometry analysis of tumor/cerebellum of mice treated vehicle control or the C36L1 peptide via the lateral ventricle. The left panel display cells colored by experimental group (Control - black, C36L1 delivered via lateral ventricle - red, C36L1 delivered intraperitoneally - blue), highlighting the distribution and intensity target expression across different cell populations within the tumor and cerebellum of treated and control mice. The visualization provides insights into the immune cell infiltration and its association with the treatment groups. (E) UMAP projection of flow cytometry results, colored by the expression of CD74. (F) UMAP projection of flow cytometry results, colored by the expression of MHCII. (G) UMAP projection of flow cytometry results, colored by the expression of CD11b. (H) IHC of control (top row) and peptide-treated (bottom row) GTML primary tumor allografts displaying H&E, CD3, F4/80 and CD74 within the tumor. Results representative of 3 independent replicates, Scale bar, 100 um. (I) Growth rate of mice bearing recurrent GTML allografts ( n = 5 per group) treated with vehicle control (black) or C36L1 peptide through the lateral ventricle (blue) was calculated by calculating the slope of tumor growth between day 7 and 14 (endpoint). Line represents mean growth rate with individual points representing individual mice. Points below the dashed line indicate tumor regression. Statistical significance was calculated by two-way ANOVA with Tukey’s post-test. (J) Bar chart to illustrate the proportion of tumor-associated immune cells identified as microglia. A higher proportion of microglia is observed in the TME of CD36L1 peptide treatment versus scrambled control. (K) Bar chart to illustrate the level of CD74 expression in the TME of mice treated with CD36L1 versus scrambled control. (L) Bar charts displaying the proportion of CD38+ cells in the microglia population. Statistical analysis was performed using a two-way ANOVA with Tukey’s post-test to compare the groups. Error bars represent the SD. Significant differences between groups are indicated by * P < .05, ** P < .01, and *** P < .001.
Article Snippet: In brief, tissue sections were incubated in Tris-EDTA buffer (cell conditioning 1; CC1) at 95 ̊C for 1-h to retrieve antigenicity, followed by incubation with CD74 antibody (Origene CF507339 ) at 1:500 for 1-h.
Techniques: Inhibition, Expressing, RNA Sequencing, Blocking Assay, Luciferase, Control, Imaging, Flow Cytometry