title: In vitro exposure system for study of aerosolized influenza virus.
abstract: Infection of adherent cell monolayers using a liquid inoculum represents an established method to reliably and quantitatively study virus infection, but poorly recapitulates the exposure and infection of cells in the respiratory tract that occurs during infection with aerosolized pathogens. To better simulate natural infection in vitro, we adapted a system that generates viral aerosols similar to those exhaled by infected humans to the inoculation of epithelial cell monolayers. Procedures for cellular infection and calculation of exposure dose were developed and tested using viruses characterized by distinct transmission and pathogenicity phenotypes: an HPAI H5N1, an LPAI H7N9, and a seasonal H3N2 virus. While all three aerosolized viruses were highly infectious in a human bronchial epithelial cell line (Calu-3) cultured submerged in media, differences between the viruses were observed in primary human alveolar epithelial cells and in Calu-3 cells cultured at air-liquid interface. This system provides a novel enhancement to traditional in vitro experiments, particularly those focused on the early stages of infection.
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States; Emory University, Atlanta, GA 30333, United States.
authors: Hannah M
authors: HM
authors: Creager
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States.
authors: Hui
authors: H
authors: Zeng
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States.
authors: Joanna A
authors: JA
authors: Pulit-Penaloza
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States.
authors: Taronna R
authors: TR
authors: Maines
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States.
authors: Terrence M
authors: TM
authors: Tumpey
authors: Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States. Electronic address: jax6@cdc.gov.
authors: Jessica A
authors: JA
authors: Belser
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D053124:Influenza A Virus, H5N1 Subtype / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D064766:Influenza A Virus, H7N9 Subtype / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D007251:Influenza, Human / Q000635:transmission / Q000821:virology*; D014779:Virus Replication
chemical_list: D000336:Aerosols; C510527:CALU protein, human; D002135:Calcium-Binding Proteins
keywords: Aerosols; Avian viruses; Cell culture; Influenza; Viral replication