A targetable ‘rogue’ neutrophil-subset, [CD11b+DEspR+] immunotype, is associated with severity and mortality in acute respiratory distress syndrome (ARDS) and COVID-19-ARDS

Abstract

Neutrophil-mediated secondary tissue injury underlies acute respiratory distress syndrome (ARDS) and progression to multi-organ-failure (MOF) and death, processes linked to COVID-19-ARDS. This secondary tissue injury arises from dysregulated neutrophils and neutrophil extracellular traps (NETs) intended to kill pathogens, but instead cause cell-injury. Insufficiency of pleiotropic therapeutic approaches delineate the need for inhibitors of dysregulated neutrophil-subset(s) that induce subset-specific apoptosis critical for neutrophil function-shutdown. We hypothesized that neutrophils expressing the pro-survival dual endothelin-1/VEGF-signal peptide receptor, DEspR, are apoptosis-resistant like DEspR+ cancer-cells, hence comprise a consequential pathogenic neutrophil-subset in ARDS and COVID-19-ARDS. Here, we report the significant association of increased peripheral DEspR+CD11b+ neutrophil-counts with severity and mortality in ARDS and COVID-19-ARDS, and intravascular NET-formation, in contrast to DEspR[-] neutrophils. We detect DEspR+ neutrophils and monocytes in lung tissue patients in ARDS and COVID-19-ARDS, and increased neutrophil RNA-levels of DEspR ligands and modulators in COVID-19-ARDS scRNA-seq data-files. Unlike DEspR[-] neutrophils, DEspR+CD11b+ neutrophils exhibit delayed apoptosis, which is blocked by humanized anti-DEspR-IgG4S228P antibody, hu6g8, in ex vivo assays. Ex vivo live-cell imaging of Rhesus-derived DEspR+CD11b+ neutrophils showed hu6g8 target-engagement, internalization, and induction of apoptosis. Altogether, data identify DEspR+CD11b+ neutrophils as a targetable ‘rogue’ neutrophil-subset associated with severity and mortality in ARDS and COVID-19-ARDS.

“Rogue” [DEspR+CD11b+] neutrophil subset correlates with severity in spontaneous intracerebral hemorrhage

“…We validated our ex vivo analysis protocols of neutrophil subsets in patients with sICH guided by our prior analysis of neutrophil subsets in patients with ARDS ( 12 ). We determined optimal conditions for ex vivo analysis by flow cytometry and immunofluorescence cytology.…”

“…The correlation of DEspR+CD11b+ neutrophil counts with NLR in patients with sICH suggests that the DEspR+ neutrophil subset contributes to increased NLR in sICH given observed delayed apoptosis in ex vivo analysis of DEspR+CD11b+ neutrophils ( 12 ). The correlation of DEspR+CD11b+ neutrophil counts with NET+ neutrophil counts indicates a predisposition of DEspR+ neutrophils to intravascular NET formation.…”

“…We recently identified the DEspR+CD11b+ “rogue” neutrophil subset associated with mortality and worse sequential organ failure assessment (SOFA) scores in patients with acute respiratory distress syndrome (ARDS), the prime example of feed-forward neutrophil-mediated tissue injury ( 12 ). “Rogue” DEspR+CD11b+ neutrophils exhibit delayed apoptosis, which is inhibited by a humanized, anti-DEspR antibody, hu6g8, in ex vivo studies ( 12 ). Concordantly, in a hypertensive, spontaneous ICH (hsICH) rat model, we detected DEspR+ neutrophils in perihematomal brain regions with evidence of blood-brain barrier (BBB) disruption at acute sICH ( 13 ).…”

“Rogue” neutrophil-subset [DEspR+CD11b+/CD66b+] immunotype is an actionable therapeutic target for neutrophilic inflammation-mediated tissue injury – studies in human, macaque and rat LPS-inflammation models

“…Recently, we have identified a targetable “rogue” neutrophil subset expressing the dual endothelin-1/signal peptide receptor (DEspR) on activated CD11b+ neutrophils ( 23 ). DEspR+CD11b+ neutrophils were detected in ARDS lung parenchyma, microvasculature and intra-alveolar exudates on post-mortem lung tissue section immunohistochemistry-staining; and peripheral levels correlated with ARDS severity measures, same-day sequential organ failure (SOFA)-scores and day-28 intensive care unit-free days, in contrast to non-correlation of DEspR-negative (DEspR[-]) neutrophil levels ( 23 ). Ex vivo studies of ARDS patient peripheral neutrophils demonstrated increased survival of DEspR+ neutrophils which was decreased by humanized anti-DEspR antibody incubation ( 23 ).…”

The favorable impacts of silibinin polyphenols as adjunctive therapy in reducing the complications of COVID-19: A review of research evidence and underlying mechanisms

“…According to previous studies, patients with COVID-19 may exhibit a broad, unspecific spectrum of signs and symptoms, including fever, sore throat, nausea, vomiting, myalgia, and dizziness [5] , [6] . Although most COVID-19 patients recover within weeks, about five percent of patients may experience a severe lethal disease leading to multi-organ damage, ARDS, and death [7] , [8] . In addition, elder individuals or patients with various co-morbidities are susceptible to severe COVID-19 [9] .…”