Pathogen-specific loss of host resistance in mice lacking the IFN-gamma-inducible gene IGTP

Interferon-gamma (IFN-gamma) is critical for defense against pathogens, but the molecules that mediate its antimicrobial responses are largely unknown . IGTP is the prototype for a family of IFN-gamma-regulated genes that enco de 48-kDa CTP-binding proteins that localize to the endoplasmic reticulum. We have generated IGTP-deficient mice and found that, despite normal immune cell development and normal clearance of Listeria monocytogenes and cytome galovirus infections, the mice displayed a profound loss of host resistance to acute infections of the protozoan parasite Toxoplasma gondii. By contra st, IFN-gamma receptor-deficient mice have increased susceptibility to all three pathogens. Thus, IGTP defines an IFN-gamma-regulated pathway with a s pecialized role in antimicrobial resistance.