IL-12-Independent Th1-Type Immune Responses to Respiratory Viral Infection: Requirement of IL-18 for IFN-γ Release in the Lung But Not for the Differentiation of Viral-Reactive Th1-Type Lymphocytes

We demonstrated that IL-12 was induced during primary or secondary pulmonary adenoviral infection in wild-type (wt) mice. However, cellular responses were not compromised in the lungs of IL-12-/- mice. The level of IFN-gamma in the lung was similar in wt and IL-12-/- mice during pulmonary viral infection. Upon Ag stimulation in vitro, lymphocytes from draining lymph nodes or spleen of infected IL-12-/- mice released large amounts of IFN-gamma, …