Peripheral blood monocytes (PBMCs) display innate antiviral response to rhinovirus (RV) infected bronchial epithelial cells (133.44)

Abstract

Rhinovirus (RV) infection is an important trigger of acute asthma and COPD. Study objectives; were to characterise the response of PBMCs and CD8 lymphocytes when exposed to RV infected bronchial epithelial cells. Methods; Human Calu3 cells were used as a model for bronchial epithelial cells and infected with RV-43 and RV-1B. PBMCs were obtained from healthy individuals and separated by Ficoll-Paque centrifugation. CD8 lymphocytes were identified as CD3+, CD8+ by flow cytometry. PBMCs were exposed to infected Calu3 cells, cells exposed to UV inactive RV, PHA and TLR3 agonist PolyI:C. Response was measured by ELISA for release of interferon(IFN)-γ and TNF-α. CD8 activation with expression of perforin or proliferation measured by carboxyfluorescein succinimidyl ester assay. Results: Exposure of PBMCs to Calu3 cells infected with both RV led to significant release of IFN-γ and TNF-α, smaller release was seen in response to UV inactive RV. Exposure to PolyI:C also led to a similar release. CD8+ cells were found to be the primary source of IFN-γ release. CD8+ cells did not show an increase in perforin expression or evidence of proliferation. Conclusions; exposure of PBMCs and CD8+ cells to an RV infected bronchial epithelium alone results in an innate immune response mediated by TLR3 without evidence of a CD8 adaptive immune response.