IL-4, IL-5 AND IL-10 ARE NOT REQUIRED FOR THE CONTROL OF M-BOVIS-BCG INFECTION IN MICE

Mycobacterial infections in mice are normally characterized by a profo und Th1 cell-mediated immune response, in which T cells secrete large amounts of IFN-gamma. Recent evidence suggests that this response also includes a Th2 component. In order to investigate whether production of IL-4, IL-5, or IL-10 influenced the outcome of a Mycobacterium bovi s-bacille Calmette-Guerin (BCG) infection, we intranasally infected IL -4, IL-5, and IL-10 gene-deficient and control mice and monitored the resulting immune response and bacterial clearance. IL-4, IL-5, and IL- 10 deficient mice cleared the mycobacteria with the same kinetics as c ontrol mice. Furthermore, T cells of cytokine deficient and control mi ce produced similar levels of IFN-gamma following in vitro stimulation with purified protein derivative (PPD) from M. bovis. We conclude tha t the cytokines IL-4, IL-5 and IL-10 are not essential for and do not negatively influence the protective immune response against M. bovis-B CG in the lung of mice.