Abstract 3136: Adoptive transfer of bone marrow T cells induces antitumor immune responses in murine models of melanoma and neuroblastoma

Abstract

Abstract Bone marrow (BM) serves as a reservoir for a unique population of memory T cells. Tumor-specific T cells have been identified in the bone marrow of cancer patients. However, few direct functional analyses of tumor-specific responses in T cells isolated from BM have been performed. In this study, we investigated the ability of bone marrow T cells to induce anti-tumor immunity in mice bearing neuro2A neuroblastoma or B16 melanoma. To demonstrate the presence of antigen-specific T cells in BM, we first examined the percent of antigen-specific CD8+ T cells in vaccinated mice. The overall percent of antigen-specific CD8+ T cells was much higher in BM compared to spleen and lymph nodes of vaccinated mice. To investigate the ability of antigen-specific BM T cells to induce cytotoxic function, BM T cells were isolated from mice vaccinated with OVASIINFEKL peptide pulsed dendritic cells (DC). Expanded BM T cells from DC vaccinated mice co-cultured with M05 or irrelevant tumor cells led to tumor-specific cytotoxicity (p<0.001). In B16 tumor-bearing mice, T cells isolated from BM produced IFN-gamma in response to gp100 peptide (1400+210 pg/ml). Adoptive transfer of BM T cells isolated from B16-bearing mice led to a delay in tumor growth compared to control groups (p<0.001). In the neuroblastoma model, T cells isolated from BM of neuro2A-bearing mice produced higher levels of IFN-gamma and were tumor-specific (250+90 pg/ml, p<0.01 compared to T cells cultured with irrelevant tumor cells). Adoptive transfer of expanded BM T cells and DC vaccination in the setting of BM transplant led to a significant delay in tumor growth and enhanced survival in neuro2A bearing mice compared to BM transplant + DC vaccination alone group (p<0.02). These studies demonstrate that tumor-specific T cells can be isolated from the BM of tumor-bearing mice. Adoptive transfer of T cells expanded from the BM can delay tumor growth and improve survival. These studies support the isolation and expansion of T cells from the BM for use in adoptive cell therapy strategies in patients with neuroblastoma and melanoma. Citation Format: Krithika N. Kodumudi, Amy Weber, Ellen Moore, Amod Sarnaik, Shari Pilon-Thomas. Adoptive transfer of bone marrow T cells induces antitumor immune responses in murine models of melanoma and neuroblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3136. doi:10.1158/1538-7445.AM2015-3136