ABSTRACT
Neutrophilic granulocytes (NG) are the main drivers of pathological inflammation in COVID-19. Objective. To specify the mechanisms of immunopathogenesis of COVID-19 based on a comparative immunological study of the number and phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets with an assessment of their effector functions against changing profile of NG-associated cytokines IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma. Patients and methods. In patients with moderate-to-severe and severe COVID-19, we determined IL-1beta, TNFalpha, IL-6, IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma (ELISA), the phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets, NF-kappaB-NG (CYTOMICS FC500), phagocytically active NG (%), neutrophil extracellular traps (NETs), NG in apoptosis, and the activity of NADPH oxidase. Results. In COVID-19 against the background of IFNalpha and IFNgamma production blockade and high levels of NG-associated IL-8, IL-18, IL-17A, VEGF-A, a reduction in the number of mature and functionally active CD16brightSD62LbrightCD11bbrightCD63-NG subsets was revealed, as well as an increase in the number of CD16dimSD62LdimSD11bbrightCD63-NG subsets with an immunosuppressive phenotype and CD16brightSD62LbrightSD11bbrightCD63bright-NG subsets with high cytotoxic activity and ability to form NETs, a decrease in the percentage of phagocytically active NG and an increase in the activity of NADPH oxidase, NETs, and NG in apoptosis. Conclusion. IFNalpha deficiency provokes a hyperergic response of NG-associated cytokines, which leads to the formation of uncontrolled immune inflammation involving NG subsets with an immunosuppressive and cytotoxic phenotype, exacerbating the course of COVID-19. The use of recombinant IFNalpha-2b with antioxidants (Viferon) in the early stages of the disease can help to restore immune homeostasis, normalize the level of NG-associated cytokines, reduce NERTs, and achieve good clinical efficacy.Copyright © 2022, Dynasty Publishing House. All rights reserved.
ABSTRACT
Neutrophilic granulocytes (NG) are the main drivers of pathological inflammation in COVID-19. Objective. To specify the mechanisms of immunopathogenesis of COVID-19 based on a comparative immunological study of the number and phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets with an assessment of their effector functions against changing profile of NG-associated cytokines IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma. Patients and methods. In patients with moderate-to-severe and severe COVID-19, we determined IL-1beta, TNFalpha, IL-6, IL-8, IL-18, IL-17A, VEGF-A, IFNalpha, and IFNgamma (ELISA), the phenotype of CD16+SD62L+CD11b+CD63- and CD16+SD62L+CD11b+CD63+ subsets, NF-kappaB-NG (CYTOMICS FC500), phagocytically active NG (%), neutrophil extracellular traps (NETs), NG in apoptosis, and the activity of NADPH oxidase. Results. In COVID-19 against the background of IFNalpha and IFNgamma production blockade and high levels of NG-associated IL-8, IL-18, IL-17A, VEGF-A, a reduction in the number of mature and functionally active CD16brightSD62LbrightCD11bbrightCD63-NG subsets was revealed, as well as an increase in the number of CD16dimSD62LdimSD11bbrightCD63-NG subsets with an immunosuppressive phenotype and CD16brightSD62LbrightSD11bbrightCD63bright-NG subsets with high cytotoxic activity and ability to form NETs, a decrease in the percentage of phagocytically active NG and an increase in the activity of NADPH oxidase, NETs, and NG in apoptosis. Conclusion. IFNalpha deficiency provokes a hyperergic response of NG-associated cytokines, which leads to the formation of uncontrolled immune inflammation involving NG subsets with an immunosuppressive and cytotoxic phenotype, exacerbating the course of COVID-19. The use of recombinant IFNalpha-2b with antioxidants (Viferon) in the early stages of the disease can help to restore immune homeostasis, normalize the level of NG-associated cytokines, reduce NERTs, and achieve good clinical efficacy.Copyright © 2022, Dynasty Publishing House. All rights reserved.
ABSTRACT
The role of neutrophil granulocytes (NG) in the pathogenesis of COVID-19 is associated with the NG recruitment into inflammatory foci, activation of their functions and enhanced formation of neutrophil extracellular networks (NETs). In this review, we analyzed a large body of scientific literature devoted to the features of developing NETs, their role in the COVID-19 pathogenesis, a role in emerging immunothrombosis, vasculitis, acute respiratory distress syndrome, cytokine storm syndrome, and multi-organ lesions. Convincing data are presented clearly indicating about a profound role of NETs in the COVID-19 immunopathogenesis and associated severe complications resulting from intensified inflammation process, which is a key for the course of SARS-CoV-2 virus infection. The presented role of NGs and NETs, along with that of other immune system cells and pro-inflammatory cytokines, is extremely important in understanding development of overactive immune response in severe COVID-19. The scientific results obtained available now allow to identify an opportunity of regulatory effects on hyperactivated NGs, NETosis at various stages and on limiting a negative impact of pre-formed NETs on various tissues and organs. All the aforementioned data should help in creating new, specialized immunotherapy strategies designed to increase the odds of survival, reduce severity of clinical manifestations in COVID-19 patients as well as markedly reduce mortality rates. Currently, it is possible to use existing drugs, while a number of new drugs are being developed, the action of which can regulate NG quantity, positively affect NG functions and limit intensity of NETosis. Continuing research on the role of hyperactive NG and NETosis as well as understanding the mechanisms of regulating NET formation and restriction in severe COVID-19, apparently, are of high priority, because in the future the new data obtained could pave the basis for development of targeted approaches not only for immunotherapy aimed at limiting education and blocking negative effects already formed NETs in severe COVID-19, but also for immunotherapy, which could be used in combination treatment of other netopathies, primarily autoimmune diseases, auto-inflammatory syndromes, severe purulent-inflammatory processes, including bacterial sepsis and hematogenous osteomyelitis.Copyright © 2023 Saint Petersburg Pasteur Institute. All rights reserved.
ABSTRACT
Objective. To clarify the features of the defect in the function of NK cells, T lymphocytes, the interferon system in patients with moderate and severe COVID-19. Patients and methods. Tests of the peripheral blood of 50 COVID-19 patients aged 61(57–71) and having the moderate and severe disease were performed. The following parameters were measured: the quantity of CD3+CD19–, CD3+CD4+, CD3+CD8+ T lymphocytes, NK – (CD3–CD16+CD56+), and TNK – CD3+CD16+CD56+ with expression density considered membrane receptors (MFI) (FC 500 Beckman Coulter, USA), the levels of IFN-α, IFN-γ, IL-6, TNF-α cytokines (IFA). Results. Combined immunodeficiency associated with quantitative and functional defects in NK, T lymphocytes and their subsets was revealed in moderate and severe COVID-19. An imbalance of cytokines has been established: blockade of the production of IFN-α and IFN-γ against the background of a significant increase in IL-6 and TNF-α, which negatively affects both the number and functionality of the participants in the immune response and is associated with a severe course and poor prognosis of COVID-19. Conclusion. The data obtained demonstrate the need to develop new strategies and tactics for the treatment of COVID-19, including replacement systemic therapy with recombinant IFN-α2b in combination with antioxidants (Viferon®) in adequate therapeutic doses, aimed at restoring the normal functioning of T lymphocytes, NK and the interferon system.
ABSTRACT
Investigation of molecular mechanisms associated with interferon (IFN) production and receptor function of neutrophil granulocytes (NGs) in COVID-19 is highly relevant because it can be promising in the search for new therapeutic strategies targeting NGs and their reactivity to restore and strengthen the innate immune response against SARS-CoV-2. Objective. To assess the effects of recombinant IFN-α2b on the phenotype of CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119–, and CD16+IFNα/βR1+CD119+ NGs from peripheral blood of patients with COVID-19 in an in vitro experiment. Patients and methods. We analyzed blood samples from 31 patients with a mean age of 61 years (range: 57;71 years) with moderate COVID-19. We assessed the number of CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119–, and CD16+IFNα/βR1+CD119+ NGs, receptor density (FC 500, ‘Beckman Coulter,’ USA), phagocytic activity of NGs before and after incubation with recombinant IFN-α2b. We also measured serum levels of several cytokines, including IFNα, IFNγ, IL-6, IL-8 (ELISA, ‘Vektor-Best’ LLC). The control group comprised 22 adult healthy individuals with a mean age of 58 years (range: 57;70 years). Results. Patients with moderate COVID-19 demonstrated low serum levels of IFNα and IFNγ along with elevated levels of IL-6 and IL-8. We observed transformation of 3 phenotypes among NG subpopulations: CD16+IFNα/βR1–CD119+, CD16+IFNα/βR1+CD119-, and CD16+IFNα/βR1+CD119+. We observed positive remodulating effects of recombinant IFN-α2b on the number and phenotype of NG subpopulations and their phagocytic activity in our in vitro experiment. Conclusion. Recombinant IFN-α2b demonstrated positive effects in in vitro experiments;therefore, it can be considered in the future as a potential therapeutic tool for moderate COVID-19. Restoration of type I IFN might be an effective treatment option for COVID-19, because it can promote faster virus elimination, restore normal functioning of the IFN system, and have positive regulatory effects on the phenotype of NG subpopulations.