Infection and Propagation of Human Rhinovirus C in Human Airway Epithelial Cells

Human rhinovirus species C (HRV-C) was recently discovered using molecular diagnostic techniques and is associated with lower respiratory tract disease, particularly in children. HRV-C cannot be propagated in immortalized cell lines, and currently sinus organ culture is the only system described that is permissive to HRV-C infection ex vivo. However, the utility of organ culture for studying HRV-C biology is limited. Here, we report that a previously described HRV-C derived from an infectious cDNA, HRV-C15, infects and propagates in fully differentiated human airway epithelial cells but not in undifferentiated cells. We demonstrate that this differentiated epithelial cell culture system supports infection and replication of a second virus generated from a cDNA clone, HRV-C11. We show that HRV-C15 virions preferentially bind fully differentiated airway epithelial cells, suggesting that the block to replication in undifferentiated cells is at the step of viral entry. Consistent with previous reports, HRV-C15 utilizes a cellular receptor other than ICAM-1 or LDLR for infection of differentiated epithelial cells. Furthermore, we demonstrate that HRV-C15 replication can be inhibited by an HRV 3C protease inhibitor (rupintrivir) but not an HRV capsid inhibitor previously under clinical development (pleconaril). The HRV-C cell culture system described here provides a powerful tool for studying the biology of HRV-C and the discovery and development of HRV-C inhibitors.