Fig 5. LRRC15 expression is enriched in the fibroblasts of COVID-19 patients and associated with reduced SARS-CoV-2 viral burden.

(A, B) Cell type–specific expression of ACE2 and LRRC15, assessed by scRNA-seq of lungs from deceased COVID-19 patients (A) Delorey and colleagues [44] or (B) Melms and colleagues [43]. (C) Tukey boxplots (IQR boxes with 1.5 × IQR whiskers) of the relative frequencies of fibroblast subtypes among total fibroblasts, comparing COVID-19 patients (blue) to non-COVID-19 controls (red). Statistical significance was assessed by two-tailed unpaired Mann–Whitney test. (D) Volcano plot of differentially expressed genes in the lungs of deceased COVID-19 patients, comparing samples with high vs. low SARS-CoV-2 RNA levels at the time of death [46]. Genes with positive log₂ fold changes are associated with high viral burden, while genes with negative log₂ fold changes are associated with low viral burden. (E) LRRC15 expression in lung cell lines (A549, A549-ACE2, Calu-3), comparing mock controls vs. SARS-CoV-2-infected samples. Data represent means ± SEM. Statistical significance was assessed by two-tailed unpaired Welch’s t test. For underlying data, see S2 Data. ACE2, angiotensin-converting enzyme 2; COVID-19, Coronavirus Disease 2019; IQR, interquartile range; LRRC15, leucin-rich repeat-containing 15; SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2; scRNA-seq, single-cell RNA-sequencing.