High-dimensional profiling reveals phenotypic heterogeneity and disease-specific alterations of granulocytes in COVID-19

Abstract

Since the outset of the COVID-19 pandemic, increasing evidence suggests that the innate immune responses play an important role in the disease development. A dysregulated inflammatory state has been proposed as key driver of clinical complications in COVID-19, with a potential detrimental role of granulocytes. However, a comprehensive phenotypic description of circulating granulocytes in SARS-CoV-2-infected patients is lacking. In this study, we used high-dimensional flow cytometry for granulocyte immunophenotyping in peripheral blood collected from COVID-19 patients during acute and convalescent phases. Severe COVID-19 was associated with increased levels of both mature and immature neutrophils, and decreased counts of eosinophils and basophils. Distinct immunotypes were evident in COVID-19 patients, with altered expression of several receptors involved in activation, adhesion and migration of granulocytes (e.g. CD62L, CD11a/b, CD69, CD63, CXCR4). Paired sampling revealed recovery and phenotypic restoration of the granulocytic signature in the convalescent phase. The identified granulocyte immunotypes correlated with distinct sets of soluble inflammatory markers supporting pathophysiologic relevance. Furthermore, clinical features, including multi-organ dysfunction and respiratory function, could be predicted using combined laboratory measurements and immunophenotyping. This study provides a comprehensive granulocyte characterization in COVID-19 and reveals specific immunotypes with potential predictive value for key clinical features associated with COVID-19.SignificanceAccumulating evidence shows that granulocytes are key modulators of the immune response to SARS-CoV-2 infection and their dysregulation could significantly impact COVID-19 severity and patient recovery after virus clearance. In the present study, we identify selected immune traits in neutrophil, eosinophil and basophil subsets associated to severity of COVID-19 and to peripheral protein profiles. Moreover, computational modeling indicates that the combined use of phenotypic data and laboratory measurements can effectively predict key clinical outcomes in COVID-19 patients. Finally, patient-matched longitudinal analysis shows phenotypic normalization of granulocyte subsets 4 months after hospitalization. Overall, in this work we extend the current understanding of the distinct contribution of granulocyte subsets to COVID-19 pathogenesis.

SARS‐CoV‐2‐specific humoral and cellular immunity persists through 9 months irrespective of COVID‐19 severity at hospitalisation

“…Twenty‐six hospitalised COVID‐19 patients were included in this study, ten of whom were treated at the infectious disease unit (IDU) and are referred to as moderate, while sixteen patients were treated at the intensive care unit (ICU) and are referred to as severe (Figure 1a; Table 1). The present patient cohorts were part of the Karolinska KI/K COVID‐19 Immune Atlas project, where characterisations of other immune cell subsets during acute COVID‐19 have been described 16–21 . When possible, these patients were sampled longitudinally at 5 and 9 months after symptom onset (Figure 1a; Table 1).…”

“…In addition, 17 patients were followed up at 5 months and 13 patients were followed up at 9 months since symptom onset (Figure 1a). This COVID‐19 patient cohort is part of the Karolinska KI/K COVID‐19 Immune Atlas project 16–21 . More clinical information and other related data can be found at covid19cellatlas.com.…”

“…The present patient cohorts were part of the Karolinska KI/K COVID-19 Immune Atlas project, where characterisations of other immune cell subsets during acute COVID-19 have been described. [16][17][18][19][20][21] When possible, these patients were sampled longitudinally at 5 and 9 months after symptom onset (Figure 1a; Table 1). Patients were predominantly male, with comparable age between moderate and severe groups (Figure 1b and c).…”

“…This COVID-19 patient cohort is part of the Karolinska KI/K COVID-19 Immune Atlas project. [16][17][18][19][20][21] More clinical information and other related data can be found at covid19cellatlas.com. Sixteen healthy age-and sex-matched SARS-CoV-2-seronegative controls from 2020 were included for flow cytometry, multiplex and serology experiments (Figure 1a).…”

Immunomodulation: Immunoglobulin Preparations Suppress Hyperinflammation in a COVID-19 Model via FcγRIIA and FcαRI

“…FcR blocking on primary cells revealed that even though the highly expressed FcgRIII is part of immune complex phagocytosis, the lower expressed of FcgRIIA is functionally of greater importance (81,82). Furthermore, neutrophils of severe COVID-19 patients exhibit lower levels of FcgRIII (83)(84)(85). This highlights the suitability of neutrophil-like HL60 cells as a model system for COVID-19.…”