Tuberculosis (TB) is the leading cause of death due to a pathogen. The live-attenuated BCG vaccine is the only approved vaccine to prevent TB, but it fails to confer long-term protection. We hypothesi Show more
Tuberculosis (TB) is the leading cause of death due to a pathogen. The live-attenuated BCG vaccine is the only approved vaccine to prevent TB, but it fails to confer long-term protection. We hypothesize that the immunosuppressive cytokine IL-27 may contribute to the inefficacies of the BCG vaccine. IL-27 is elevated in neonates, the population most commonly administered BCG, and levels increase further upon vaccination. IL-27 interferes with the phagolysosomal pathway, suggesting it may limit the diversity of antigens processed and presented to T cells. We hypothesized that in the absence of IL-27 signaling, BCG vaccination induces antigen-specific T cells that recognize a greater number of antigens and provide enhanced protection during M. tuberculosis (Mtb) challenge. CD3 Show less