Abstract B74: Development of Salmonella-based vaccine against mesothelioma

Abstract

Purpose: Salmonella-based vaccine can provide protection against different kinds of cancer, whether used alone or used as a vehicle to deliver heterologous proteins. In this study, the functionality of a live Salmonella-p24 vaccine as a prophylactic anti-tumor vaccine against murine mesothelioma was analyzed.

Experimental Design: Malignant murine mesothelioma cell was engineered to express GAG, an HIV capsid protein, regarding as an artificial tumor associated antigen. Attenuated Salmonella enterica serovar Typhimurium aroA strain was modifed to encode p24, derived from GAG. BalB/C mice were orally immunized with Salmonella-p24 vaccine thrice at 2-week interval. P24-specific humoral and cellular immune responses were examined by ELISA and ELISPOT, respectively. Protection against the challenge with GAG-expressing mesothelioma was also evaluated after immunization.

Results: P24 antigen was successfully expressed in the cytoplasm of an attenuated Salmonella enterica serovar thyphimurium aroA strain. Immunization of wild-type BalB/C by oral gavage could elicit specific anti-p24 humoral and cellular immune response. In vivo protection studies revealed that over 80% of the treated mice remained free of GAG-mesothelioma after challenge, whereas all mice in control group developed tumor growth.

Conclusions: This p24-Salmonella vaccine could efficiently prevent GAG-expressing mesothelioma tumor growth in mice.

Citation Format: Chen Xu. Development of Salmonella-based vaccine against mesothelioma. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr B74.