Researchers at UT Southwestern Medical Center report the identification of a new cellular source for an important disease-fighting protein used in the body's earliest response to infection. The protein interferon-gamma (IFN-γ) keeps viruses from replicating and stimulates the immune system to produce other disease-fighting agents. Neutrophils, the newly identified cellular source of the protein, are the major component of the pus that forms around injured tissue. The researchers also report that the neutrophils appear to produce IFN-γ through a new cellular pathway independent of Toll-like receptors (TLRs): the body's early warning system for invasion by pathogens. This finding indicates that...