Investigation of 3D Primary Human Airway Cell Culture as a Viable and Successful Model for Study of Respiratory Syncytial Virus Infection and Antiviral Drug Treatment.

Abstract

Respiratory Syncytial Virus is almost universally experienced by the human population, infecting the airway and posing a significant risk to the very young and elderly populations in addition to immunocompromised individuals. Resulting in a Th2 immune response, RSV is most commonly associated with upper and lower respiratory tract infection and bronchiolitis in addition to coinfections such as influenza or pneumonia. EpiAirway, a 3D cell culture model of primary human tracheal and bronchial epithelial cells from MatTek, was used to test 5 laboratory and clinical strains of RSV. Four antiviral compounds with different mechanisms of action were tested in this model; PC786, GS-5806, RSV-604, and ALS-8112, with treatment given at the time of infection or delayed by 6 or 72 hours. qRT-PCR readout of viral load was the endpoint for all experiments, and cytokine concentration was measured using multiplex assays, both measured 5 days after addition of drug. Infection treated with RSV-604 or PC786 had a greater viral load reduction than treatment with GS-5806 or ALS-8112 across all viral strains tested. Delaying drug treatment appeared to decrease this reduction, and a similar trend was seen in tissue from asthmatic donors compared to normal tissue. These results were compared to similar viral testing run in 2D cell culture using a HEp-2 cell line, wherein comparable compound efficacy trends were seen when treatment was applied at the time of infection. After infection in EpiAirway tissue, IL-6, IP-10, and RANTES concentration levels increased in both normal and asthmatic samples. All cytokines tested with the exception of TSLP and RANTES were higher in asthma tissue than normal tissue. Overall the EpiAirway system presents a useful and applicable 3D cell culture model to study RSV and offers numerous paths for future study to understand both the infection process and the efficacy of antiviral compounds.