IMMU-06. REDUCTION OF CD4+ T CELLS NEGATIVELY AFFECTS SURVIVAL IN OLD BUT NOT YOUNG MICE WITH GLIOBLASTOMA

Abstract OBJECTIVE Previous work indicates poorer survival outcomes for older glioblastoma (GBM) patients ≥ 65 years of age as compared to younger < age. The cellular mechanisms associated with this age-dependent difference remain elusive. Here we evaluated the overall young and old immunocompetent mice intracranial brain tumors that were depleted specific immune cell populations. METHODS Young 6-8 weeks vs 80+ C57BL/6 treated up 3 either IgG isotype control antibodies or depleting against murine CD4, CD8, NK1.1, beginning at days prior to- every post-intracranial injection mouse tumor lines, GL261 CT-2A. Overall was between groups. Additionally, absolute peripheral blood mononuclear (PBMC) counts CD3+ T cells, CD4+ CD8+ cells analyzed aneurysm control- GBM-patients. RESULTS Older adult mice, but not CT-2A cell-based have a significantly decreased when control-treated group, well groups T- NK-cells (P 0.05). Coincidently, GBM fewer patient counterparts CONCLUSIONS data suggest levels play more important roles in subjects than subjects. A mechanistic understanding cell-dependent benefit is ongoing.