Airway epithelial cells or AECs orchestrate the pulmonary immune responses to airborne viral infections and drive the successful resolution of infection. Among the immediate early responders that set the tone for innate immune response, we have identified that as early as half-an-hour of insult, the long noncoding RNA species (lncRNAs) are deployed by the AECs to modulate the epithelial inflammatory response. Specifically, in AECs, we identified a few novel lncRNAs that modulate the expression of inflammatory factors and of ligand/receptors that help recruit immune cells. As with the other acute viral infections, a balanced early epithelial response provides timely recruitment of appropriate immune cells to thwart the infection and resolve the lung tissue remodeling. However, hosts with hyperreactive or compromised lung mucosal immunity, suffer from higher lung tissue damage, impaired lung functions and overall poor health outcome, as noted in several cases of COVID- 19 patients. Overarching goal is to identify and characterize the early host immunomodulatory factors that might predispose to severe hyperinflammatory state to novel severe acute respiratory syndrome coronavirus-2 (SARS- CoV-2), the causative agent of COVID-19 disease. The studies proposed will provide novel insight into the immediate early susceptibility factors of upper airway epithelial cells to SARS-CoV-2 that contribute to a dysregulated inflammatory response. Specifically, the archived biological samples from COVID-19 patients will be analyzed to establish the association of expression levels of the novel lncRNA and SARS-CoV-2 receptors (ACE2 and TMPRSS2) among individuals with various degree of COVID-19 disease severity. The fixed cytospins and cell pellets will be analyzed for host cellular (lncRNA and receptors) and viral (Spike protein) factors; and will be validated by qPCR analysis. We will confirm the role of lncRNA by molecular gene editing in AECs cultured in-vitro and treated with a pseudovirions expressing SARS-CoV-2 S protein and validated in separate studies using SARS-CoV-2 clinical isolate for infection. Levels of inflammatory factors will be analyzed by multianalyte assays. This proof of concept study will help establish the association of novel lncRNAs with COVID-19 pathophysiology that could serve as early biological indicators (biomarkers) of airway immune dysregulation and other comorbidities. Molecular studies will also help determine whether targeting the novel lncRNA can help reduce or suppress SARS-CoV-2 mediated airway inflammatory responses.
The ongoing pandemic of COVID-19 has tested our limited understanding of the airway inflammatory responses to the opportunistic SARS-CoV-2 viral infection. Towards the overarching objective of delineating the pathophysiology of the underlying mechanisms, we propose that long noncoding RNAs could be the immediate early immunomodulators of the airway responses to viral assault. The proposed proof of concept studies will help establish the association of lncRNA expression with the severity of SARS-CoV-2 induced inflammation and COVID-19 disease conditions.
