Controversial role of neutrophilic granulocytes in the immunopathogenesis of COVID-19: correlation with imbalance of pro-inflammatory neutrophil-associated cytokines and interferon alpha deficiency.

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.

Controversial role of neutrophilic granulocytes in the immunopathogenesis of COVID-19: correlation with imbalance of pro-inflammatory neutrophil-associated cytokines and interferon alpha deficiency.

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.

Defects in the interferon system associated with a deficiency of natural killers and T-cells in patients with COVID-19

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.

Effects of recombinant IFN-α2b on the phenotype of neutrophil granulocyte subpopulations in patients with COVID-19

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.