Recombinant murine beta interferon enhances resistance of mice to systemic Mycobacterium avium infection

Abstract

Susceptible BALB/c mice were infected with Mycobacterium avium TMC 702. Groups of mice were then infused with 104 U (~400 U/h) of murine beta interferon (IFN-β) via a minipump system, and the progression of the infection was assessed. Mice infused with IFN-β showed superior resistance to infection, as determined by reduced bacterial growth in the livers and spleens of infected animals, (1-log reduction in bacterial CFU at 2 months postinfection; P < 0.001). This was corroborated by the fact that resident peritoneal macrophages treated with IFN-β in vitro (102 U/ml) were more bacteriostatic for M. avium TMC 702 than their untreated counterparts. Overall, these findings suggest an important role for IFN-β in mycobacterial infections.