Mice fed lipid-encapsulated Mycobacterium bovis BCG are protected against aerosol challenge with Mycobacterium tuberculosis

Abstract

Mice that consumed a single dose of 10(7) lipid-encapsulated Mycobacterium bovis BCG bacilli showed significant pulmonary and systemic protection against aerosol challenge with M. tuberculosis H37Rv. As an extension of previous challenge studies with virulent strains of M. bovis, this report describes a reduction in M. tuberculosis infection in mice vaccinated orally with lipid-encapsulated BCG comparable to that observed in mice vaccinated subcutaneously with BCG. These results are consistent with the induction of tuberculin-specific cell-mediated immune responses.

FIG. 1.

Effects of subcutaneously delivered BCG or orally delivered lipid-encapsulated BCG vaccination on cytokine production in PPD-stimulated murine splenocyte cultures. Data are means ± standard errors of the means for eight mice per group for IFN-γ (black bars) and IL-2 (white bars). Asterisks indicate values in vaccinated animals that were significantly different from corresponding values in control animals at a P value of <0.05 (Student's t test). N.V., nonvaccinated control animals (sham injection of PBS).