Functional and immune response to respiratory syncytial virus infection in aged BALB/c mice: A search for genes determining disease severity

ABSTRACTBackground. Recent studies have demonstrated that respiratory syncytial virus (RSV) is a significant cause of morbidity and mortality in the elderly. The cellular mechanisms that determine the host's susceptibility and severity of the disease are not well understood. In this study, we sought a mouse model of human respiratory disease by studying the functional and cellular response to RSV in aged animals. Methods. Aged BALB/c mice (>10 months of age) were infected with human RSV (strain A2) and compared with sham-infected mice. Clinical progress of the illness was monitored by daily assessment of weight changes and mortality. The animals were sacrificed four days postinfection. Lung pathology was obtained and viral titers were measured by plaque assay. Gene expression profiles were studied from lung tissue RNA using gene array. Results. RSV produced significant clinical illness in aged mice as evidenced by a 15% weight loss and a 10% mortality rate. Lung pathology revealed inflammatory changes wit...