A MODEL OF LATENT ADENOVIRUS-5 INFECTION IN THE GUINEA-PIG (CAVIA-PORCELLUS)

A model of adenovirus 5 (Ad5) infection was developed in guinea pigs t o begin to study its role in the pathogenesis of peripheral lung infla mmation. Forty animals were inoculated intranasally with 10(10) pfu of AdS/animal, and 15 animals inoculated with sterile culture media serv ed as controls. Viral titres were 10(4.4), 10(6.1), 10(5.2), and 10(2. 9) pfu/animal, on days 1, 3, 4, and 7 after infection, respectively. I n situ hybridization to viral DNA and immunocytochemistry for Ad5 E1A protein localized the virus to airway and alveolar epithelial cells. H istologic examination showed an extensive inflammatory cell infiltrati on around the airways, with epithelial necrosis and an alveolar exudat e that caused localized alveolar collapse in the infected areas, Immun ocytochemistry identified the cells in the infiltrate as cytotoxic T c ells. Although all animals 20 and 47 days after infection had seroconv erted to Ad5, virus was not detected in these groups either by viral p laque assay or in situ hybridization. Ad5 E1A DNA was detected by poly merase chain reaction in five of six animals 20 days after infection a nd in five of five animals 47 days after infection. In these same anim als, E1A protein was detected 20 days after infection in two and 47 da ys after infection in one while persistent bronchiolitis was observed in four and three animals 20 and 47 days after infection, respectively . These results demonstrate that the guinea pig provides a useful mode l to study the role of Ad5 infection in chronic airway inflammation.