ABSTRACT
Background: The hyperactivated subsets of neutrophilic granulocytes (NG) play a negative role on the development, course and outcome of the COVID-19. With this position, NG are interesting target for creation of new therapeutic approaches. Method(s): The study group (SG) included 31 patients with moderate COVID-19, aged 61(57;71)years. Before and after incubation of whole blood with HP (106 g/l, 60 min., 37degreeC) 2 NG subsets were tested: major -CD64- CD16+CD32+CD11b+, minor -CD64+ CD16+CD32+CD11b+ with detection of their phenotypes using MFI (FC 500, Beckman Coulter, USA). Phagocytic activity of NG against S. aureus was studied. Comparison group(CG) consisted 22 healthy volunteers 58 (57;70) years old. Result(s): In patients with COVID-19 the minor subset of NG CD64+CD16+CD32+CD11b+(% ) was significantly increased in 5-fold versus the CG (p <= 0.005) and had transformed phenotype: CD64dimCD16brightCD32midCD11bbright versus CD64midCD16dimCD32midCD11b brightin the CG (p <= 0.005). This transformed phenotype had high expression levels of receptors of activation: CD16 and CD11b, that suggested its negative hyperactivation. The % of the major subset NG did not change (p > 0.05), but an altered phenotype of CD64-CD16brightCD32midCD11bdimNG was determine against CD64-CD16dimCD32midCD11boNG in the CG. Defects of phagocytic activities of NG were found: the decrease of % an active phagocytic NG, absorbing and digesting abilities (p1 <= 0.005;p2 <= 0.005;p3 <= 0.005).The effects of HP in vitro were shown: the significant decreasing of NG minor subset (%) in comparison with it's level before HP influences (p <= 0.005) reached to the values of the CG (p > 0.05). In parallel, the phenotype of minor subset changed to CD64brightCD16dimCD32midCD11bo, with decreasing level of CD16 to normal (p > 0.05). The transformed phenotype of the major subset was changed to CD64-CD16midCD32brightCD11 bmidNG: a decrease in MFI CD16, an increase in MFI CD32 and MFI CD11b (p1 <= 0.005;p2 <= 0.005;p3 <= 0.005). The restoration of defective phagocytic function of NG was received. Conclusion(s): Immunomodulating effects of HP in vitro on NG in moderate COVID-19 were shown: positive remodeling of the phenotype of minor aggressive NG subset from hyperactivated to normal and the restoration of defective NG phagocytic function.
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.