Journal: Nature Communications
Article Title: RAS/MEK/PI3K pathway inhibition augments response to CD40 agonism by targeting CD11b + Bregs thereby overcoming melanoma PD1-resistance
doi: 10.1038/s41467-025-67315-1
Figure Lengend Snippet: A , B Tumor growth, created in BioRender. Yan, C. (2026) https://BioRender.com/83jrya2 , exact p values are provided as a Source Data file, and ( C ) Mouse body weight of B16F10 NRAS wt BRAF wt melanoma in C57BL/6 female mice, n = 8 mice per group. Treatment with 200 μg/mouse αPD1 (lead-in 2 doses, every 3 days, intraperitoneal), followed by 30 μg/mouse aCD40 (every 3 days, intraperitoneal), with or without 300 mg/kg rigosertib (RGS, 5 days a week, oral gavage) and 1 mg/kg trametinib (T, 5 days a week, oral gavage), starts at day 8 post tumor cell inoculation. D Tumor samples were collected from each treatment group at day 20 of treatment and immune profiled by FACS analysis. No αPD1-prime groups, Veh + IgG, n = 6, RGS + T + IgG, n = 8, Veh + aCD40, n = 8, RGS + T + aCD40, n = 7 tumors; with αPD1-prime groups, Veh + IgG, n = 5, RGS + T + IgG, n = 5, Veh + aCD40, n = 8, RGS + T + aCD40, n = 8 tumors. Exact p values are provided as a Source Data file. E The baseline frequency of CD11b + B cells and CD8 + Tc cells in melanoma tumors at 1-month post tumor cell inoculation (1014 tumors, n = 5; B16F10 tumors, n = 3). Exact p values are provided as a Source Data file. F The lung colonization model was established by intravenously injecting 0.5 × 10 6 metastatic B16F10-Luc2 cells via the tail vein. Splenic B cells were treated with 12.5 μg/ml aCD40 for 2 days then CD11b + B cells were isolated by magnetic separation for adoptive transfer. Starting at day 2 post tumor cell inoculation, ~2 × 10 6 CD11b + B cells were intravenously injected via the tail vein (once a week) in 200 μl HBSS buffer. Treatment of 200 μg/mouse αPD1 (every 3 days, intraperitoneal) starts at day 2 post tumor cell inoculation ( n = 5 mice per group). Twenty-one days after tumor implantation, tumor lung was weighed and subtracted from tumor-free lungs in mice. Created in BioRender. Yan, C. (2026) https://BioRender.com/83jrya2 . Exact p values are provided as a Source Data file. G Flow cytometry, exact p values are provided as a Source Data file, and ( H , I ) Immunohistochemistry (IHC) staining of B16F10 melanoma lung metastatic tumors after 21 days of treatment. The percentage of positive red IHC staining cells of Ki67 and CD8 was quantified from 20 fields of each FFPE slide sample per group ( n = 5 tumors per group). Exact p values are provided as a Source Data file. Tc, CD8 + CD3 + cytotoxic T cells. Th, CD4 + CD3 + T helper cells.
Article Snippet: Three mouse melanoma tumor models were used in the study, including BRAF wt NRAS mut 1014, BRAF wt NRAS wt B16F10 (Cat#: CCL-6475, ATCC, RRID:CVCL_0159), and B16F10-Luc2 cells (Cat#: CRL-6475-Luc2, ATCC, RRID:CVCL_A4CJ).
Techniques: Isolation, Adoptive Transfer Assay, Injection, Tumor Implantation, Flow Cytometry, Immunohistochemistry