title: Evidence supporting a zoonotic origin of human coronavirus strain NL63.
abstract: The relationship between bats and coronaviruses (CoVs) has received considerable attention since the severe acute respiratory syndrome (SARS)-like CoV was identified in the Chinese horseshoe bat (Rhinolophidae) in 2005. Since then, several bats throughout the world have been shown to shed CoV sequences, and presumably CoVs, in the feces; however, no bat CoVs have been isolated from nature. Moreover, there are very few bat cell lines or reagents available for investigating CoV replication in bat cells or for isolating bat CoVs adapted to specific bat species. Here, we show by molecular clock analysis that alphacoronavirus (α-CoV) sequences derived from the North American tricolored bat (Perimyotis subflavus) are predicted to share common ancestry with human CoV (HCoV)-NL63, with the most recent common ancestor between these viruses occurring approximately 563 to 822 years ago. Further, we developed immortalized bat cell lines from the lungs of this bat species to determine if these cells were capable of supporting infection with HCoVs. While SARS-CoV, mouse-adapted SARS-CoV (MA15), and chimeric SARS-CoVs bearing the spike genes of early human strains replicated inefficiently, HCoV-NL63 replicated for multiple passages in the immortalized lung cells from this bat species. These observations support the hypothesis that human CoVs are capable of establishing zoonotic-reverse zoonotic transmission cycles that may allow some CoVs to readily circulate and exchange genetic material between strains found in bats and other mammals, including humans.
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Huynh
authors.forename: Shimena
authors.initials: S
authors.lastname: Li
authors.forename: Boyd
authors.initials: B
authors.lastname: Yount
authors.forename: Alexander
authors.initials: A
authors.lastname: Smith
authors.forename: Leslie
authors.initials: L
authors.lastname: Sturges
authors.forename: John C
authors.initials: JC
authors.lastname: Olsen
authors.forename: Juliet
authors.initials: J
authors.lastname: Nagel
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Johnson
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Agnihothram
authors.forename: J Edward
authors.initials: JE
authors.lastname: Gates
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Frieman
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Baric
authors.forename: Eric F
authors.initials: EF
authors.lastname: Donaldson
mesh_terms: D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D015153:Blotting, Western; D002460:Cell Line; D002685:Chiroptera / Q000821:virology*; D019295:Computational Biology; D018352:Coronavirus Infections / Q000635:transmission*; D058957:Coronavirus NL63, Human / Q000235:genetics*; D019143:Evolution, Molecular; D005243:Feces / Q000821:virology; D005455:Fluorescent Antibody Technique; D006801:Humans; D016013:Likelihood Functions; D008396:Maryland; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014779:Virus Replication / Q000502:physiology; D015047:Zoonoses / Q000821:virology*