Influenza Virus-specific T Cells Lead to Early Interferon γ in Lungs of Infected Hosts: Development of a Sensitive Radioimmunoassay

A sensitive immunoradiometric assay for murine interferon γ (MuIFN-γ) has been developed and used reproducibly to measure low levels of MuIFN-γ in lung lavage samples from influenza-infected mice. In control infected mice, IFN-γ peaked on day 6, but transfer of virus-specific cytotoxic T cells or T helper cells, which reduced virus replication in vivo in infected hosts, resulted in an earlier peak on day 4.