A novel method for efficient generation of antigen-specific effector T-cells using dendritic cells transduced with recombinant adeno-associated virus and p38 kinase blockade

The inefficacy of standard therapeutic strategies for ovarian cancer is reflected by the enduring poor prognosis of this malignancy. Due to the potential for exquisite specificity, sensitivity and long-term memory, immunotherapy offers an alternative modality for durable control of the disease, provided appropriate antigens can be identified and presented in the right context. We tested a novel dendritic cell vaccine formulation to reprogram autologous antigen-specific T-cells in vitro, in vivo in a murine model of ovarian cancer, and ex vivo using human cells from patients. We show that dendritic cells (DCs) treated with a p38 MAPK inhibitor and transduced with a recombinant adenovirus associated vector (AAV) expressing Sperm protein (Sp) 17 are highly effective in generating antigen-specific T-cell cytotoxic response against ovarian cancer cells. Additionally, these DCs enhanced the differentiation of effector T-cells while reducing the frequency of Foxp3 T-reg cells in vitro. This work provides a rationale for translation of pharmacologically reprogrammed DCs into clinical trials for prevention of tumor recurrence and progression in high-risk ovarian cancer patients.