Pathological observations of lung inflammation after administration of IP-10 in influenza virus- and respiratory syncytial virus-infected mice.

Pneumonia is a common complication of influenza virus infection and a common cause of death of patients. The aim of this study was to test the hypothesis that interferon-γ-inducible protein-10 (IP-10) is an important chemokine in the development of airway inflammation caused by certain viruses. Mice were infected with influenza virus after administration of murine IP-10 and the severity of pneumonia was compared with the group which was infected with influenza virus alone. Another mice group was infected with respiratory syncytial virus (RSV) after injection of IP-10 and also the severity of pneumonia was compared to the group which was infected with RSV alone. The mice infected with influenza virus or RSV after administration of IP-10 presented with more fulminant and necrotizing diffuse alveolar and bronchiole damage with lymphocyte infiltration. Our results indicate that IP-10 is an important chemokine and is associated with the severity of pneumonia caused by certain viruses.