Oral Epithelial Cells Expressing Low or Undetectable Levels of Human Angiotensin-Converting Enzyme 2 Are Susceptible to SARS-CoV-2 Virus Infection In Vitro
Laith Ebraham,
Chuan Xu,
Annie Wang,
Cyril Hernandez,
Nicholas Siclari,
Divino Rajah,
Lewins Walter,
Salvatore A. E. Marras,
Sanjay Tyagi,
Daniel H. Fine,
Carlo Amorin Daep,
Theresa L. Chang
Affiliations
Laith Ebraham
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Chuan Xu
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Annie Wang
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Cyril Hernandez
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Nicholas Siclari
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Divino Rajah
Global Technology Center, Colgate-Palmolive Company, Piscataway, NJ 08855, USA
Lewins Walter
Global Technology Center, Colgate-Palmolive Company, Piscataway, NJ 08855, USA
Salvatore A. E. Marras
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Sanjay Tyagi
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Daniel H. Fine
Department of Oral Biology, School of Dental Medicine, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
Carlo Amorin Daep
Global Technology Center, Colgate-Palmolive Company, Piscataway, NJ 08855, USA
Theresa L. Chang
Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
The oral cavity is thought to be one of the portals for SARS-CoV-2 entry, although there is limited evidence of active oral infection by SARS-CoV-2 viruses. We assessed the capacity of SARS-CoV-2 to infect and replicate in oral epithelial cells. Oral gingival epithelial cells (hTERT TIGKs), salivary gland epithelial cells (A-253), and oral buccal epithelial cells (TR146), which occupy different regions of the oral cavity, were challenged with replication-competent SARS-CoV-2 viruses and with pseudo-typed viruses expressing SARS-CoV-2 spike proteins. All oral epithelial cells expressing undetectable or low levels of human angiotensin-converting enzyme 2 (hACE2) but high levels of the alternative receptor CD147 were susceptible to SARS-CoV-2 infection. Distinct viral dynamics were seen in hTERT TIGKs compared to A-253 and TR146 cells. For example, levels of viral transcripts were sustained in hTERT TIGKs but were significantly decreased in A-253 and TR146 cells on day 3 after infection. Analysis of oral epithelial cells infected by replication-competent SARS-CoV-2 viruses expressing GFP showed that the GFP signal and SARS-CoV-2 mRNAs were not evenly distributed. Furthermore, we found cumulative SARS-CoV-2 RNAs from released viruses in the media from oral epithelial cells on day 1 and day 2 after infection, indicating productive viral infection. Taken together, our results demonstrated that oral epithelial cells were susceptible to SARS-CoV-2 viruses despite low or undetectable levels of hACE2, suggesting that alternative receptors contribute to SARS-CoV-2 infection and may be considered for the development of future vaccines and therapeutics.
