The Airway Epithelium: Barrier Against Foreign Pathogens
The human airway (including the trachea and bronchi) is lined by a single layer epithelium that serves as the interface between the external and internal environments. It also provides a physical barrier and mucous layer to protect against infection from foreign pathogens like respiratory viruses. The differentiated cell types of the airway epithelium include ciliated cells, goblet cells, and basal cells. Respiratory epithelial cells are the targets of respiratory viruses such as influenza, and experience inflammation in conditions like asthma.
Lifeline® provides airway epithelial cells from the human airway, including:
Lifeline® airway cell types can be used to study normal respiratory cell function, and disease conditions such as asthma, COPD, and viral infection. They are optimized for growth in BronchiaLife™ Epithelial Airway Medium.
Recent Research Featuring Lifeline® Airway Epithelial Cells
Influenza infection stimulates an interferon (IFN) response, primarily by IFNl, in infected respiratory epithelial cells. One of the factors that is activated in response to IFNl is indoleamine 2, 3-dioxygenase (IDO), a metabolic enzyme that has been implicated in immune suppression. In a 2015 study, Fox et al. investigated the role of IDO in the context of influenza infection of respiratory epithelial cells. They found that influenza infection stimulates IDO1 expression and activity in Lifeline® human normal bronchial epithelial (NHBE) cells. Furthermore, they demonstrated that IDO1expression and activity was induced following IFNl treatment of NHBE cells, and IFNl neutralizing antibodies abrogates this effect in influenza-infected cells. Finally, the researchers illustrated that IDO inhibition in influenza-infected cells decreases virus production and increases cell death. Together, the results of this study suggest that IFNl directly induces IDO1 activity in response to influenza infection and that IDO activity may be important for persistent viral infection and replication.
Coronaviruses (CoVs) cause respiratory infections that are mostly mild, but can cause more serious conditions, including SARS. CoVs infect host airway epithelial cells following binding to host cell receptors by the viral spike (S) glycoprotein. It is the S protein that mediates virulence and is a potential target for vaccines. Therefore, information about S protein binding to host receptors can inform vaccine development. Qian et al. developed a series of six monoclonal antibodies and tested their abilities to neutralize human b-CoV HKU1. They found that two of the six monoclonal antibodies effectively neutralized HKU1 infection of and production by Lifeline® human bronchial/tracheal epithelial cells. Additionally, they were able to map the binding sites on the HKU1 S protein and determined that these two monoclonal antibodies were so efficient at neutralization because they bound to the S protein receptor binding domains, effectively blocking the interaction between the S protein and its host receptor. Together, the results from this study provide new information about the virulence of HKU1, its ability to infect host cells, and how to neutralize its action.
Lifeline® cells are being used to study homeostasis, disease, engineering assays, and much more! How are YOU using Lifeline® cells? Tell us and your study could be featured here on our blog!