Nassir, NasnaTambi, RichaBankapur, AsmaAl Heialy, SabaKaruvantevida, NoushadZehra, BinteBegum, GhausiaHameid, Reem AbdelAhmed, AwabShabestari, Seyed Ali SafizadehKandasamy, Richard KLoney, TomTayoun, Ahmad AbouNowotny, NorbertHachim, Mahmood YaseenBerdiev, BakhromAlsheikh-Ali, AlawiUddin, Mohammed2022-03-172022-03-172021204-2021.174https://repository.mbru.ac.ae/handle/1/916Summary: Understanding host cell heterogeneity is critical for unraveling disease mechanism. Utilizing large-scale single-cell transcriptomics, we analyzed multiple tissue specimens from patients with life-threatening COVID-19 pneumonia, compared with healthy controls. We identified a subtype of monocyte-derived alveolar macrophages (MoAMs) where genes associated with severe COVID-19 comorbidities are significantly upregulated in bronchoalveolar lavage fluid of critical cases. FCGR3B consistently demarcated MoAM subset in different samples from severe COVID-19 cohorts and in CCL3L1-upregulated cells from nasopharyngeal swabs. In silico findings were validated by upregulation of FCGR3B in nasopharyngeal swabs of severe ICU COVID-19 cases, particularly in older patients and those with comorbidities. Additional lines of evidence from transcriptomic data and in vivo of severe COVID-19 cases suggest that FCGR3B may identify a specific subtype of MoAM in patients with severe COVID-19 that may present a novel biomarker for screening and prognosis, as well as a potential therapeutic target.enFCGR3BCOVID-19SARS-CoV-2Article