Rhinovirus C infection of human airway epithelial cells causes transient replication‐dependent changes in cellular architecture and barrier function

Abstract

RATIONALEInfections with human rhinovirus (HRV)‐C strains are associated with more severe exacerbations and increased hospitalizations in children with asthma. Although the replication cycles of HRV‐A and B strains have been extensively studied using cells of non‐airway origin (e.g. HeLa cells), HRV‐C replication within human airway epithelial cells (HAE) remains poorly understood as HRV‐C exclusively infects highly‐differentiated HAE. We have recently shown that HRV infections can be completely cleared from HAE without any requirement for immune cells. Our data suggest that mechanism of epithelial clearance involves a combination of shedding of infected cells, and antiviral responses, culminating in re‐differentiation. We are now seeking to elucidate the mechanisms by which HRV‐C remodels HAE cellular architecture during replication. We have focused on the modulation of cytoskeletal signaling pathways and resulting transient loss of barrier function.METHODSHighly differentiated air‐liquid interface (ALI) cultures of HAE, isolated from normal non‐transplanted human lungs, were infected with HRV‐C15 and monitored at 24, 48, 72, 96, 120, 144 hours post‐infection. HRV‐C15 replication kinetics were evaluated by serial apical washes every 24h to assess shed virus levels and cell lysates to quantify intracellular viral RNA by RT‐PCR. Studies of changing cytoskeletal architecture and intercellular junctions were performed using immunofluorescence staining for ZO‐1 and f‐actin. Other stimuli include replication‐deficient HRV, poly(I:C) (a mimic of the double‐stranded RNA produced during HRV replication), ROCK inhibitors, cytochalasin D (actin disruptor), and paclitaxel (microtubule stabilizer). Barrier function studies in Ussing chambers used FITC‐dextran (permeability) and measured real‐time transepithelial electrical resistance (TEER).RESULTSHRV‐C15 causes dramatic remodeling of highly‐differentiated HAE that follows the time course of viral replication and clearance from 24h to 144h. These changes include co‐localization of dsRNA‐positive cells with apically expressed ZO‐1 (indicative of infected cell shedding). Transient loss of barrier function is prominent at peak viral levels 24h post‐infection, but recovers with re‐differentiation within 144h. Preliminary data suggests that cytoskeletal inhibitors diminish the ability of HRV‐C15 to replicate and HAE shedding to occur; indicating a critical role for cytoskeletal signaling in HRV‐C15 replication.CONCLUSIONWe conclude that a HRV‐C serotype induces altered cellular architecture in HAE that is associated with disruption of the actin cytoskeleton and intercellular junctions. Future studies will evaluate the role of Rho GTPase signaling in HRV‐C replication or HAE shedding.Support or Funding InformationThis study was supported by grant number PJT‐159635 from the Canadian Institutes of Health Research (CIHR).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.