Interferon-responsive neutrophils and macrophages extricate SARS-CoV-2
Omicron critical patients from the nasty fate of sepsis
Abstract
The SARS-CoV-2 Omicron variant is characterized by its high
transmissibility, which has caused a worldwide epidemiological event.
Yet, it turns ominous once the disease progression degenerates into
severe pneumonia and sepsis, presenting a horrendous lethality. To
elucidate the alveolar immune or inflammatory landscapes of Omicron
critical-ill patients, we performed single-cell RNA-sequencing
(scRNA-seq) of bronchoalveolar lavage fluid (BALF) from the patients
with critical pneumonia caused by Omicron infection, and analyzed the
correlation between the clinical severity scores and different immune
cell subpopulations. In the BALF of Omicron critical patients, the
alveolar violent myeloid inflammatory environment was determined. ISG15
+ neutrophils and CXCL10 +
macrophages, both expressed the interferon-stimulated genes (ISGs), were
negatively correlated with Clinical Pulmonary Infection Score (CPIS),
while septic CST7 + neutrophils and inflammatory VCAN
+ macrophages were positively correlated with
Sequential Organ Failure Assessment (SOFA). The percentages of ISG15
+ neutrophils were associated with more protective
alveolar epithelial cells, and may reshape CD4 + T
cells to the exhaustive phenotype, thus preventing immune injuries. The
CXCL10 + macrophages may promote plasmablast/plasma
cell survival and activation as well as the production of specific
antibodies. As compared to the previous BALF scRNA-seq data from
SARS-CoV-2 wild-type/Alpha critical patients, the subsets of neutrophils
and macrophages with pro-inflammatory and immunoregulatory features
presented obvious distinctions, suggesting an immune disparity in
Omicron variants. Overall, this study provides a BALF single-cell atlas
of Omicron critical patients, and suggests that alveolar
interferon-responsive neutrophils and macrophages may extricate
SARS-CoV-2 Omicron critical patients from the nasty fate of sepsis.