ABSTRACT The spike (S) polypeptide of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) consists of the S1 and S2 subunits and is processed by cellular proteases at the S1/S2 boundary that contains a furin cleavage site (FCS), 682 RRAR↓S 686 . Various deletions surrounding the FCS have been identified in patients. When SARS-CoV-2 propagated in Vero cells, it acquired deletions surrounding the FCS. We studied the viral transcriptome in Vero cell-derived SARS-CoV-2-infected primary human airway epithelia (HAE) cultured at an air-liquid interface (ALI) with an emphasis on the viral genome stability of the FCS. While we found overall the viral transcriptome is similar to that generated from infected Vero cells, we identified a high percentage of mutated viral genome and transcripts in HAE-ALI. Two highly frequent deletions were found at the FCS region: a 12 amino acid deletion ( 678 TNSP RRAR↓S VAS 689 ) that contains the underlined FCS and a 5 amino acid deletion ( 675 QTQTN 679 ) that is two amino acids upstream of the FCS. Further studies on the dynamics of the FCS deletions in apically released virions from 11 infected HAE-ALI cultures of both healthy and lung disease donors revealed that the selective pressure for the FCS maintains the FCS stably in 9 HAE-ALI cultures but with 2 exceptions, in which the FCS deletions are retained at a high rate of >40% after infection of ≥13 days. Our study presents evidence for the role of unique properties of human airway epithelia in the dynamics of the FCS region during infection of human airways, which is likely donor dependent.
【저자키워드】 Transcriptome, SARS-CoV-2, furin cleavage site, human airway epithelia, 【초록키워드】 coronavirus, Infection, Lung disease, stability, Culture, Deletion, patients, Donor, Amino acid, Air-liquid interface, Evidence, Vero, viral genome, viral transcriptome, HAE, acute respiratory syndrome, subunit, human airways, Vero cells, virion, selective, upstream, while, S1/S2 boundary, cellular protease, primary human airway, transcript, epithelia, S1 and S2, healthy, unique, maintain, mutated, retained, released, processed, FCS, 【제목키워드】 Human, Dynamics, Site,