IMMU-15. ALLOGENIC MACROPHAGES IMMUNOTHERAPY IN A MOUSE MODEL OF GLIOBLASTOMA. (23rd April 2019) - Zhang, Zijian Zhang
Abstract: Human glioma tumors are immunosuppressive, and evade immune response through a variety of inhibitory pathways. Major challenges in immunotherapy include glioma-associated immune resistance, central nervous system immune privilege, and tumor antigen-specific immune responses, and. Therefore, overcoming immune resistances plays a key role in developing effective immunotherapy. Allograft within the tumor site actively turns off tumor-associated immunosuppression and turns on therapeutic immune responses. We treated the glioblastoma mice with an advanced immunotherapy by inoculation of tumor antigen loaded allogenic macrophages into tumor site. Flow cytometry assay indicated that the increases of CD8+ and CD4+ T cells and CD11b+/Ly6c+ and CD11b+/CD11c+ macrophages in challenged hemisphere. Glioblastoma induced splenic CD4+CD25+Foxp3+ cells were diminished in treated glioblastoma mice. However, the suppressive activity of CD11b+Ly6C+ cells, and CD11b+LY6G, and CD11b+CD11c myeloid cells in bone marrow had an increase in glioblastoma mice with or without treatment. Importantly, the treated group exhibited no tumor growth or significant small tumors in the brain. Our aim is to study the immune rebalancing of allogeneic macrophage on the glioma-mediated immune resistance in a mouse model of glioblastoma.