Secreted proteases are functional for Hemagglutinin cleavage.

<p>Cultures of differentiated human epithelial cells were exposed to either 0.4ppm of ozone or air for 4 h. A) 24 h post-exposure, cells were infected with influenza A/Malaya/302/1954. 24 h post-infection, total cellular lysates were analyzed for intracellular cleavage of the viral HA protein by Western blot. B) 24 h post-exposure, apical supernatants were collected and incubated with influenza A/Malaya/302/1954. Cleavage of the viral HA protein was analyzed by Western blot. C) Cultures of differentiated human epithelial cells were exposed to either 0.4ppm of ozone or air for 4 h. 24 h post-exposure, apical supernatants were immunoprecipitated (IP) with anti- HAT, anti- TMPRSS2, or an isotype control (IgG). Protein levels were analyzed by Western blot. D) Apical supernatants of differentiated human epithelial cells, were immunoprecipitated (IP) with anti- HAT, anti- TMPRSS2, or an isotype control (IgG) followed by incubation with influenza A/Malaya/302/1954. Cleavage of the viral HA protein was analyzed by Western blot. NECs were obtained from four healthy volunteers (n = 4). Densitometry was used to quantitate the amounts of cleaved H2 protein, and the numbers below the gel indicate the ozone/air ratio.</p>