Figure 3. ADAM17 facilitates SARS‐CoV‐2 infection.

• A
  Western Blot (WB) analysis of A549‐ACE2 knock‐out (KO) lines. Two different KO lines were generated using distinct CRISPR guide RNAs for both ADAM10 and ADAM17. A non‐targeting control (NTC) guide RNA served as control. Shown are two replicates for each cell line. Mature (m) and immature (im) forms of ADAM10 and ADAM17 are indicated. ACE2 levels remained unaffected. α‐tubulin served as loading control. *: remaining, low amount of immature ADAM10 and ADAM17. The double KO (dKO) was generated from guide 1 of each ADAM10 and ADAM17.
• B
  Quantification of the abundance of mature ADAM10 and ADAM17 protein forms from (A). Data are normalized to loading control α‐tubulin and to NTC (N = 3–4). The band of mADAM17 runs very close to three unspecific bands (marked with arrowheads)—one closely above and two closely below mADAM17 (A). Thus, the quantification of remaining mADAM17 in the ADAM10 KO includes also these three unspecific bands. Two‐sided independent Student’s t‐test with Benjamini–Hochberg FDR correction.
• C
  RT‐qPCR quantification of viral RNA (SARS‐CoV‐2 N gene relative to RPLP0) upon infection of A549‐ACE2 NTC or KO cells with SARS‐CoV‐2. Cells were treated with BB94 (10 µM) or DMSO for 6 h prior to infection and RNA was isolated at 24 hpi. Two‐way ANOVA with the Tukey’s post hoc multiple comparison test. Data are normalized to NTC DMSO (N = 3).
• D–G
  UMAP of 63,103 cells from BAL fluid derived from infected individuals (Liao et al, ²⁰²⁰). (D) Individual cell types are indicated in color. (E) Normalized counts of SARS‐CoV‐2 reads, ADAM10, ADAM17, and TMPRSS2 gene expression levels. (F) Dot plot of ADAM10, ADAM17, and TMPRSS2 expression, grouped by disease severity. Expression levels are color‐coded, and the percentage of cells expressing the aforementioned genes is size‐coded. (G) Cells that are infected and additionally express ADAM17 (ADAM17⁺, red), ADAM10 (ADAM10⁺, blue), both ADAMs (ADAM10⁺ ADAM17⁺, purple), or TMPRSS2 (TMPRSS2⁺, orange) are indicated. See also Fig EV3.

Data information: Data from (B, C) are represented as mean ± 95% CI from at least three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001.

Source data are available online for this figure.