Role of the type 5 adenovirus gene encoding the early region 1B 55-kDa protein in pulmonary pathogenesis

Comparison of the inflammatory response of Sigmodon hispidus cotton rats to pulmonary infection with wild-type 5 adenovirus (Ad5) or with a viral mutant, in which the early region 1B gene encoding a 55-kDa protein, Ad5dl110 (dl110), was deleted, indicated that the inflammation in animals infected with dl110 was markedly reduced compared with the inflammation in animals infected with wild-type Ad5, although both viruses replicated to the same extent. Comparable experiments done with C57BL/6 mice yielded identical results, even though only the early phase of gene expression essential for viral replication occurs in mice. Cytokine analysis of infected mouse lungs indicated that tumor necrosis factor-α and IL-6 were produced in relatively large quantities in wild-type Ad5-infected mice and at significantly lower levels in dl110-infected mice during the early stages of infection.