Live attenuated oral Salmonella platform for effective T- and B-cell targeting of PD-L1.

74Background: Significant progresses have been recently achieved in cancer vaccines, yet novel immunization solutions to deliver efficiently tumor-associated antigens to professional antigen-presenting cells, and to overcome the peripheral tolerance and the immunosuppressive tumor microenvironment that prevent the eradication of cancer in most of patients, are urgently needed. VAXIMM is developing a unique and versatile oral T-cell vaccination platform based on the FDA-approved live-attenuated Salmonella Typhi strain Ty21a vaccine Vivotif, capable of delivering tumor-associated antigens encoded in DNA expression construct to the gut-associated lymphoid tissue, breaking immune tolerance and inducing effective anti-tumor immunity. Methods: This study summarizes the immunogenicity and antileukemia efficacy of VXM10 vaccines based on the live-attenuated Salmonella Typhimurium strain SL7207, transformed with a eukaryotic expression plasmid encoding different variants of the murine PD-L1 protein. Results: The a...