Engineering HeLa Cells to Better Support Rhinovirus C Infection In Vitro

Abstract

Human rhinoviruses (RVs) are non-enveloped, positive-sense, single-stranded RNA viruses that target the respiratory tract for infection, leading to common cold-like symptoms, bronchiolitis, or, in some cases, pneumonia. RVs are classified into three phylogenetically distinct groups: RV-A, RV-B, and RV-C, with RV-C being identified most recently, in 2006. However, while RV-A and RV-B viruses have been studied for decades in HeLa cells, RV-C does not naturally infect conventional cell lines and thus, it has been difficult to propagate and study in the lab. Further, no assay currently exists to quantify infectious RV-C particles, such as a plaque assay or limiting dilution assay. It has been demonstrated that cadherin-related family member 3 (CDHR3) is a critical cellular entry receptor for RV-C, and further, that RV-C may depend on the stimulator of interferon genes (STING) for viral genome replication. To investigate the roles of these proteins in RV-C infectivity, inducible human STING (hSTING) was transfected into HeLa cells that stably express CDHR3. Elevated STING expression was then confirmed in these cells after induction with Doxycycline (Dox). Ongoing studies seek to further explore how the expression of additional ciliated cell-specific host factors - such as Prominin-1 (PROM1) - in HeLa cells impact virus infection in this cell line. The hypothesis is that the combined expression of CDHR3, PROM1, and STING in HeLa cells will enhance entry and replication, facilitating amplification of RV-C in the laboratory and aiding detection of infection via antibody-mediated staining or enhanced cytopathic effects. These engineered HeLa cells would thereby constitute a novel cell line that is more amenable to the establishment of a plaque assay or limiting dilution assay to quantify infectious virus.