抄録
Mycobacterium avium complex (MAC) constitutes one of the most important agents of nontuberculous mycobacteria. It is difficult to eradicate, because most strains of MAC are resistant to antimicrobial agents. MAC is a facultative intracellular microorganism that mainly infects and multiplies within macrophages. Host defense mechanisms against nontuberculous mycobacterial infections are poorly understood. Cellmediated immunity plays an important role in the host defense. Interleukin-12 (IL-12), a cytokine produced mainly by macrophages, is a critical component in the development of cellmediated immunity.
In the present study, by using a mouse model of disseminated M. avium infection, we have demonstrated that treatment with recombinant murine IL-12 (0.25 μg intraperitoneally/day) reduces significantly the number of viable bacteria in infected mice. IL-12 itself, however, could not inhibit mycobacterial growth in vitro.
Thus, IL-12 exerts a potent antimycobacterial activity in vivo, probably by enhancing host defense mechanisms against the infection. There were relatively few IL-12 toxicities at the dose. IL-12 may prove to be of therapeutic value by promoting cellmediated immunity to infection with MAC.
