Biology subjects
Publications and source records attributed to Kohanski, M. A..
Abstract/Key PointsO_LIA novel human olfactory epithelial organoid model has been generated from primary cell culture. C_LIO_LIHuman olfactory organoids exhibit immunostaining and gene expression for olfactory cells. C_LIO_LIOlfactory organoids mobilize Ca2+ in response to odorants, a surrogate for neuronal function. C_LI
Coronaviruses are adept at evading host antiviral pathways induced by viral double-stranded RNA, including interferon (IFN) signaling, oligoadenylate synthetase-ribonuclease L (OAS-RNase L), and protein kinase R (PKR). While dysregulated or inadequate IFN responses have been associated with severe coronavirus infection, the extent to which the recently emerged SARS-CoV-2 activates or antagonizes these pathways is relatively unknown. We found that SARS-CoV-2 infects patient-derived nasal epithelial cells, present at the initial site of infection, induced pluripotent stem cell-derived alveolar type 2 cells (iAT2), the major cell type infected in the lung, and cardiomyocytes (iCM), consistent with cardiovascular consequences of COVID-19 disease. Robust activation of IFN or OAS-RNase L is not observed in these cell types, while PKR activation is evident in iAT2 and iCM. In SARS-CoV-2 infected Calu-3 and A549ACE2 lung-derived cell lines, IFN induction remains relatively weak; however activation of OAS-RNase L and PKR is observed. This is in contrast to MERS-CoV, which effectively inhibits IFN signaling as well as OAS-RNase L and PKR pathways, but similar to mutant MERS-CoV lacking innate immune antagonists. Remarkably, both OAS-RNase L and PKR are activated in MAVS knockout A549ACE2 cells, demonstrating that SARS-CoV-2 can induce these host antiviral pathways despite minimal IFN production. Moreover, increased replication and cytopathic effect in RNASEL knockout A549ACE2 cells implicates OAS-RNase L in restricting SARS-CoV-2. Finally, while SARS-CoV-2 fails to antagonize these host defense pathways, which contrasts with other coronaviruses, the IFN signaling response is generally weak. These host-virus interactions may contribute to the unique pathogenesis of SARS-CoV-2. SignificanceSARS-CoV-2 emergence in late 2019 led to the COVID-19 pandemic that has had devastating effects on human health and the economy. Early innate immune responses are essential for protection against virus invasion. While inadequate innate immune responses are associated with severe COVID-19 diseases, understanding of the interaction of SARS-CoV-2 with host antiviral pathways is minimal. We have characterized the innate immune response to SARS-CoV-2 infections in relevant respiratory tract derived cells and cardiomyocytes and found that SARS-CoV-2 activates two antiviral pathways, oligoadenylate synthetase-ribonuclease L (OAS-RNase L), and protein kinase R (PKR), while inducing minimal levels of interferon. This in contrast to MERS-CoV which inhibits all three pathways. Activation of these pathways may contribute to the distinctive pathogenesis of SARS-CoV-2.
Airway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways from the nose down to small bronchi. We tested if serous cells from human nasal turbinate glands secrete bicarbonate (HCO3-), important for mucus polymerization, during stimulation with the cAMP-elevating agonist vasoactive intestinal peptide (VIP) and if this requires CFTR. Isoalted serous cells stimulated with VIP exhibited a ~20% cAMP-dependent decrease in cell volume and a ~0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl- and HCO3- secretion, respectively. Pharmacology, ion substitution, and studies using cells from CF patients suggest serous cell HCO3- secretion is mediated by conductive efflux directly through CFTR. Interestingly, we found that neuropeptide Y (NPY) reduced VIP-evoked secretion by blunting cAMP increases and reducing CFTR activation through Gi-coupled NPY1R. Culture of primary gland serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3- secretion. Moreover, VIP enhanced secretion of antimicrobial peptides and antimicrobial efficacy of gland secretions while NPY reduced antimicrobial secretions. In contrast, NPY enhanced the release of cytokines during inflammatory stimuli while VIP reduced cytokine release through a mechanism requiring CFTR conductance. As levels of VIP and NPY are up-regulated in disease like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control airway mucus rheology and inflammatory responses through gland serous cells.