Coinfection of influenza A and B and human OC43 coronavirus in normal
human bronchial epithelial cells
Background Influenza viruses and seasonal coronaviruses are pathogens
transmitted via an airborne route that can cause respiratory diseases in
humans that have similar symptoms such as fever, cough, and pneumonia.
These two viruses can infect similar human tissues, such as the
respiratory tract and nasal, bronchial, and alveolar epithelial cells.
Influenza virus and seasonal coronavirus coinfections are poorly
understood. Methods Here, we coinfected normal human bronchial
epithelial (NHBE) cells with influenza A/California/04/09 (IAV) or
B/Victoria/504/2000 (IBV) strains and the seasonal human
beta-coronavirus OC43 and evaluated viral replication capacities. We
also examined changes in the expression of various cytokines/chemokines
by qPCR and Luminex assay. Results We observed that replication of IAV
and IBV was not affected by coinfection with OC43. However, coinfection
reduced OC43 titers (~ 3-fold) compared to infection
with OC43 alone. Select cytokine/chemokine expression was increased in
coinfected cells compared to all single infections with greater
differences seen between coinfected cells and cells infected with OC43
alone compared to IAV- or IBV-infected cells. In addition, IL-8 and
IL-1RA showed the highest expression among a panel of 22 cytokines by
Luminex. Conclusions As the rate of influenza and seasonal coronavirus
coinfection continue to increase, our findings may help set guidelines
for the treatments of the individuals coinfected with both viruses.