IFNG and infection: After the infection of L. monocytogenes-immunized animals with M. tuberculosis, a higher number of IFN-γ- and perforin-producing Vδ2 T cells in the airway of the immunized animals was observed compared to the HMBPP-deficient L. monocytogenes strain, which contributed to the inhibition of the intracellular M. tuberculosis growth.