Using acute infection of mice with lymphocytic choriomeningitis virus (LCMV) strain Armstrong, we show here that IRF9 limited early LCMV replication by regulating expression of interferon-stimulated genes and IFN-I and by controlling levels of IRF7, a transcription factor essential for IFN-I production.
Mice deficient in STAT1 but not STAT2 or IRF9 develop a lethal CD4+ T-cell-mediated disease following infection with lymphocytic choriomeningitis virus.