Immunology

At the level of immune response, the demonstration that IKEPLUS immunization boosts IL-12 p40 and IFN-γ production suggested that enhanced TH1 cell responses were involved in the increased levels of protective immunity after Mtb challenge. Indeed, mice immunized with either IKE or IKEPLUS showed rapid induction of IL-12 p40 and IFN- γ expression within the first two days of high-dose intravenous challenge with Mtb. These data suggested that the protective responses elicited by IKEPLUS immunization were associated with the induction of TH1-type adaptive immunity, which was supported by the finding that Rag1−/− and IL-12 p40-deficient mice showed no significant change in their high susceptibility to Mtb challenge after immunization with IKEPLUS.