UBC Theses and Dissertations
In vitro respiratory syncytial virus infection in guinea pig alveolar macrophages Kaan, Philomena Miewching
Respiratory syncytial virus (RSV) is the most common cause of acute bronchiolitis in infants. Alveolar macrophages (AM), cells which play major roles in lung defense mechanisms, are major targets for RSV infection in vivo and in vitro. This thesis examines the effects of cell maturation, age and sex of the host, and interaction of environmental particulates (PM10) on in vitro RSV infection of guinea pig AM. In addition, the expression of protein kinase in RSV-infected AM was studied. Electron microscopy localized immunogold labeled RSV antigens in the lysosomes of mature AM that restrict RSV replication while gold particles were observed in the cytoplasm of immature AM that support viral replication. Using RSV Yield as a measure of virus progeny per RSV immunopositive AM, immature AM from young animals showed a significantly higher RSV Yield compared to the same AM sub-population from adult animals. The data concerning animal gender showed that the distribution of AM sub-population from both sexes is similar but the RSV Yield of mature AM was greater from male than female guinea pigs. The introduction of PM10 during RSV infection of AM resulted in suppression of RSV Yield and RSV-induced cytokine production. The study of protein kinase expression identified Rsk, PKB and p70 S6K as potential candidates and MAPK and PKB as major pathways involved in RSV-mediated signal transduction in AM. In conclusion, the response of guinea pig AM to in vitro RSV infection is associated with expression of candidate protein kinases and is influenced by cell maturation, age and sex of the host animal, and interaction with extrinsic factors such as air pollution.
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