IFN-α Boosting of Mycobacterium bovis Bacillus Calmette Güerin-Vaccine Promoted Th1 Type Cellular Response and Protection against M. tuberculosis Infection

Figure 2

(a) Schematic representation of the designed protocol used in this study. Seven- to eight-week-old adult BALB/c mice were primed with PBS (group a); 100 UI of IFN-α (group b); 5 × 10⁵ CFUs of BCG Pasteur (group c); and 5 × 10⁵ CFUs of BCG + 100 UI of IFN-α (group d). Four, six, and eight weeks after the priming, mice from groups a and c received PBS, while mice from groups b and d received IFN-α (100 UI), respectively. Two weeks after the third boost, mice were infected by aerosol route with a low dose (100 CFUs) of M. tuberculosis H37 Rv. Eight weeks after infection, mice were sacrificed to determine CFU counts in the lungs and spleen. (b-c) Cell culture of lymph node, spleen, and lung was stimulated in vitro with HBHA and cytokine production was measured by ELISA. Values are expressed in pg/ml and represent media ± SEM of samples tested in duplicate from each group of mice. Differences are significant at with respect to control PBS immunized mice () and with respect to BCG vaccination without boost ().

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