Fig. 1. MT-MMPs and ADAMs facilitate SARS-CoV-2 entry.

(A to C) Pseudovirus entry screening. 293T cells were cotransfected with ACE2 and the indicated transmembrane serine protease, MT-MMPs, or ADAMs and then challenged by (A) SARS-CoV-2-S (Wuhan-Hu-1 strain), (B) SARS-CoV-1-S, or (C) VSV-G pseudoviruses at 24 hours after transfection. Pseudoviruses entry was quantified by measuring the luciferase signal of the cell lysates at 24 hours after transduction (n = 6). The fold change was normalized with the ACE2 transfection group. (D) Single-cell RNA sequencing (scRNA-seq) analysis for the expression of identified transmembrane serine protease, MT-MMPs, or ADAMs in the various cell types of human upper and lower respiratory tract, including the nasal, proximal, intermediate, distal, and alveolar epithelium. (E) Bulk RNA sequencing analysis for the expression of the identified transmembrane serine protease, MT-MMPs, or ADAMs in different human organs, reported as log-transformed transcript per million mapped reads [log₁₀(TPM + 1)]. The experiments in (A) to (C) were repeated three times independently with similar results. Data represented means and SDs from the indicated number of biological repeats. Statistical significance between groups was determined with one-way analysis of variance (ANOVA). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.