GEOOtherMus musculusOtherhttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE315742GEOGSEfalseCTLA-4 blockade enhances germinal center reactions in lymph nodes that drive glioma-specific IgG production and glioma clearanceHumoral immunity, which is mediated by B cells that mature in germinal centers (GCs) in lymph nodes (LNs), is essential for adaptive immune responses. However, the involvement of B cell responses in anti-tumor and immunotherapy responses remains largely unexplored. Here, we show that activation of B cells in GCs of tumor-draining deep cervical LNs (dcLNs) is necessary for the efficacy of CTLA-4 immune checkpoint blockade in glioma in vivo. We demonstrate that anti-CTLA-4 therapy enhances follicular helper T cell (Tfh) expansion in dcLNs, leading to GC B cell formation, class switching to IgG, and the generation of glioma-specific antibodies. Glioma-bearing mice lacking antibody-secreting cells did not benefit from CTLA-4 blockade. Furthermore, using our new in vivo reporter system, we show that distally-secreted glioma-specific IgG infiltrates the tumor microenvironment and triggers glioma cell phagocytosis. Our study uncovers a previously unknown B cell–dependent mechanism underlying anti-CTLA-4 mediated control of glioma, which could be harnessed to treat other tumor types.2026/05/28GSE315742GSM9436131GSM9436132GSM9436123GSM9436124GSM9436125GSM9436126GSM9436127GSM9436128GSM9436129GSM943613016417315742Mus musculus