COMPARATIVE LUNG PATHOLOGY OF INBRED STRAINS OF MICE RESISTANT AND SUSCEPTIBLE TO SENDAI VIRUS-INFECTION

BALB/cA, DBA/2N and CDF1 (BALB/cA x DBA/2N) mice were inoculated intranasally with the Mol strain of Sendai virus (SV), and their mortality and histopathological lung lesions were compared. BALB/cA and CDF1 were resistant and DBA/2N was susceptible in terms of mortality. The lung lesions of the resistant strains were mild and focal, and limited to the bronchial regions, whereas those of the susceptible stain were severe and diffuse, extending to the alveoli, SV antigen was found mainly in the bronchial epithelium in the resistant strains, but in the susceptible strain, the antigen was found also in many alveolar epithelial cells and alveolar macrophages. SV antigen was detected in neither regenerated bronchial epithelium nor endothelial cells. Tumor necrosis factor (TNF) was detected immunohistologically in edematous perivascular regions and in some mononuclear cells infiltrating to the regions, suggesting that TNF is involved in the development of lung lesions by SV infection in the three mouse strains.