A Bivalent Recombinant BCG Expressing the S1 Subunit of the Pertussis Toxin Induces a Polyfunctional CD4 T Cell Immune Response.

A recombinant BCG strain expressing the genetically detoxified S1 subunit of pertussis toxin 9K/129G (rBCG-S1PT)， previously constructed by our research group， demonstrated the ability to develop high protection in mouse models of pertussis challenge which correlated with the induction of a Th1 immune response pattern. The Th1 immune response induced by rBCG-S1PT treatment was also confirmed in the murine orthotopic bladder cancer model， in which the intravesical instillation of rBCG-S1PT resulted in an improved antitumor effect. Based on these observations， we hypothesize that the reengineering of the S1PT expression in BCG could increase the efficiency of the protective Th1 immune response in order to develop a new alternative of immunotherapy in bladder cancer treatment.