Assessment of IgE response and cytokine gene expression in pulmonary efferent lymph collected after ovalbumin inhalation during experimental infection of calves with bovine respiratory syncytial virus

摘要

Objective-To assess IgE response and cytokine gene expressions in pulmonary lymph collected from bovine respiratory syncytial virus (BRSV) infected calves after ovalbumin inhalationAnimals-Thirteen 7- to 8-week-old calvesProcedures-The efferent lymphatic duct of the caudal mediastinal lymph node of each calf was cannulated 3 or 4 days before experiment commencement Calves were inoculated (day 0) with BRSV (n = 7) or BRSV-free tissue culture medium (mock exposure 6) via aerosolization and exposed to aerosolized ovalbumin on days 1 through 6 and day 15 An efferent lymph sample was collected daily from each calf on days 1 through 16 CD4+ and CD8+ T lymphocyte subsets in lymph samples were enumerated with a fluorescence-activated cell scanner Expressions of several cytokines by efferent lymphocytes and lymph ovalbumin-specific IgE concentration were measured Each calf was euthanized on day 16 and then necropsied for evaluation of lungsResults-Mean fold increase in ovalbumin-specific IgE concentration was greater in BRSV infected calves than in mock-infected calves At various time points from days 4 through 10 percentages of T lymphocyte subsets and CD4+ CD8+ T lymphocyte ratios differed be tween BRSV-infected calves and day 1 values or from values in mock-infected calves On days 3 through 5 IL4 and IL13 gene expressions in BRSV infected calves were increased compared with expressions in mock-infected calves Lung lesions were consistent with antigen exposureConclusions and Clinical Relevance-In response to the inhalation of aerosolized ovalbumin BRSV infection in calves appeared to facilitate induction of a T helper 2 cell response and ovalbumin-specific IgE production (Am J Vet Res 2011 72 134-145)