MutantEscherichia colienterotoxin as a mucosal adjuvant induces specific Th1 responses of CD4+and CD8+T cells to nasal killed-bacillus calmette-guerin in mice

On single nasal immunization of mice with killed-bacillus calmette-guerin (BCG) plus a mutantEscherichia colienterotoxin, delayed-type hypersensitivity was induced and BCG-infection decreased. Spleen cells, particularly CD4+T cells among them produced IL-2, IFNγ and TNFα in response to the killed-BCG or purified protein derivatives. CD8+T cells including cytotoxic T lymphocytes produced IFNγ and TNFα. However, both types of T cells reacted a little to Ag85B. The mutant induces cellular immunity to nasal killed-BCG vaccine and decreases BCG-infection. CD4+and CD8+T cells produce cytokines effective for tuberculosis. Although killed-BCG loses some antigens like Ag85B, nasal killed-BCG plus the mutant is useful for tuberculosis.