Measles virus (MV) and interferon (IFN)-gamma induced IP-10 chemokine mRNA in U373 glioblastoma cells. The minimal response element for both MV and IFN-gamma was localized between nucleotide -231 and -153 of muIP-10 promoter, which contains an IFN-stimulated response element (ISRE) and the distal NF-kappa Bd site. Mutation of individual elements showed that ISRE and NF-kappa Bd were required to function together. DNA-protein binding profiles with the minimal response element showed that IFN-gamma induced a complex consisting of STAT1 while MV induced a complex consisting of p50 and p65 in the absence of new protein synthesis. IFN-gamma and MV also induced IRF-1 DNA binding activity which persisted for longer time periods with IFN-gamma stimulation. Despite the functional requirement of both ISRE and NF-kappa Bd elements, different combinations of DNA binding factors are used in the induction of IP-10 by MV or IFN-gamma.