ABSTRACT
The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors. The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors. Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations.Copyright © Svirshchevskaya E.V. et al., 2023 The article can be used under the Creative Commons Attribution 4.0 License.
ABSTRACT
The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors. The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors. Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations.Copyright © Svirshchevskaya E.V. et al., 2023 The article can be used under the Creative Commons Attribution 4.0 License.
ABSTRACT
Abstract: Potential nonameric epitopes of CD8+ T lymphocytes were selected from the composition of structural, accessory, and nonstructural proteins of the SARS-CoV-2 virus (13 peptides) and a 15-mer epitope of CD4+ T lymphocytes, from the S-protein, based on the analysis of publications on genome-wide immunoinformatic analysis of T-cell epitopes of the virus (Wuhan strain), as well as a number of clinical studies of immunodominant epitopes among patients recovering from COVID-19 disease. The peptides were synthesized and five compositions of 6–7 peptides were included in liposomes from egg phosphatidylcholine and cholesterol (~200 nm size) obtained by extrusion. After double subcutaneous immunization of conventional mice, activation of cellular immunity was assessed by the level of cytokine synthesis by splenocytes in vitro in response to stimulation with relevant peptide compositions. Liposomal formulation exhibiting the best result in terms of the formation of specific cellular immunity in response to vaccination was selected for further experiments. Evaluation of the protective efficacy of this formulation in an infectious mouse model showed a positive trend in the frequency of occurrence of hyaline-like membranes in the lumen of the alveoli, as well as a somewhat lower severity of microcirculatory disorders. The latter circumstance can potentially help reduce the severity of the disease and prevent its adverse outcomes. A method to produce liposome preparations with peptide compositions for long-term storage is under development. © 2022, Pleiades Publishing, Ltd.
ABSTRACT
Background: Both myocardial infarction (MI) and COVID-19 are characterized by cytokine storm in blood. Purpose: The objective of this study was to compare the concentration of 39 cytokines, chemokines, and growth factors in blood sera of patients with MI, COVID-19 (COV), and healthy donors. Methods: Patients' blood was collected within 1-2 days after hospitalization in the cardiovascular or COVID intensive care units. All COV patients were in a severe condition;all had increased C reactive protein, 86 and 95% had increased ferritin and D-dimers levels accordingly, 8-10 times decreased lymphocyte numbers. The analysis of the humoral factors in blood serum of MI (n=22), COV (n=23) and donors (n=27) was performed using a 39-plex cytometric analysis. Results: Among all factors analyzed TGFa, IL-1b, 2, 3, 5, 9, 13, 17A were almost not detectable both in patient and donor sera. The concentrations of the other 31 humoral factors in normal sera differed significantly from 0 to 22000 pg/mL. We divided them into house-keeping factors HKF ranged from 1000 to 22000 pg/mL;sentinel innate immunity factors SIF (30-200 pg/mL), and acute phase factors APF (0-30 pg/mL). HKF were detected in all samples. Among SIF and APF IL-1a, G-CSF, IFNa2, IL-7, MIP-1a, IL- 12, and IFNg were detected in 56-80% donor blood while IL-1RA, MCP-3, IL-2, 6, 10, 12, 15, FLT-3F, GM-CSF, TNF-b - only in 10-55%. At the same time all MI patients were 100% positive in all these factors showing extensive activation of blood secretome. Among low incidence APF cytokines in COV patients, percentage of IL-1RA, MCP-3, IFNa2, IL-6, 10, 15, FLT-3L negative sera decreased 3-5 times;and all sera were positive for MIP-1a and IL-12. At the same time TNF-a level decreased significantly from 0 in control to 85% of negative sera in COV patients. Summarized results are shown as the ratios of factor concentrations in MI or COV sera to normal control (Fig). Blood secretome of MI changed more significantly than of COV patients. The major factors (shown in red) in MI were IL-6, IL-12, IFNg, FLT-3L, GM-CSF, and IL-15, which increased 12, 9, 6, 6, 6, and 5 times accordingly. In COV sera IL-6, IL-10, IP-10, and MCP-3 increased by 28, 12, 10, and 9 times accordingly. Less expressed however significant increases are marked with asterisks. Conclusions: Acute MI is characterized by severe disturbances in blood secretome with an increased level of 25 out of 39 factors studied. Contrary to it, in COV patients the levels of IL-6, 10, IP-10, and MCP-3 were more enhanced while only 15 out of 31 exceeded normal levels.