ABSTRACT
The situation with the COVID-19 pandemic in the world is still tense. Due to the peculiarities of its pathogens, there is a low efficiency in the use of available specific etiotropic drugs, which leads to the need to search for new active means of comba-ting this dangerous infectious disease. Since the function of T-cell immunity is significantly impaired in COVID-19, it is advisable to find out the effect of correcting this part of the immune response on the course of coronavirus infection. For this purpose, a screening study was conducted to determine the effectiveness of the thymus preparation thymalin in an experiment on laboratory mice infected with murine hepatitis virus, which belongs to the same subgroup of coronaviruses that includes SARS-CoV-2, the causative agent of the COVID-19 pandemic. It was found that the study drug significantly protected infected mice at the level of 45.0–60.0 % compared to the controls and increased the average life expectancy of the test animals by 2.6–5.6 days compared to the control group, which in percentage terms is 51–110 %. The results obtained can serve as the basis for conducting regulated clinical trials with the aim of using this official medicinal product in clinical practice for the prevention and treatment of coronavirus infections in humans, including COVID-19. © 2022. The Authors.
ABSTRACT
The paper presents the results of a standard and complex treatment method using the peptide drug thymus thymalin in patients with COVID-19. One of the mechanisms of the immunomodulatory effect of thymalin is considered to be the ability of this peptide drug to influence the differentiation of human hematopoietic stem cells (HSCs). It was found that, as a result of standard treatment, patients in the control group showed a decrease in the concentration of the pro-inflammatory cytokine IL-6, C-reactive protein, D-dimer. The addition of thymalin to standard therapy accelerated the decline in both these indicators and the indicators of the T cell system. This has helped reduce the risk of blood clots in COVID-19 patients. The revealed properties of the thymus peptide preparation are the rationale for its inclusion in the complex treatment of coronavirus infection. Peptideswith potential biological activity against SARS-CoV-2 virus [29]. Note: Nitrogen atoms are shown in blue, oxygen atoms - in red, carbon atoms - in gray, hydrogen atoms - in white, and phosphorus atoms - in yellow.
Subject(s)
COVID-19 Drug Treatment , Cell Differentiation/drug effects , SARS-CoV-2/drug effects , Thymus Hormones/therapeutic use , COVID-19/genetics , COVID-19/pathology , COVID-19/virology , Cytokines/genetics , Hematopoiesis/drug effects , Hematopoietic Stem Cells/drug effects , Humans , SARS-CoV-2/pathogenicity , Thymus Gland/metabolism , Thymus Hormones/genetics , Thymus Hormones/metabolismABSTRACT
Thymalin is a polypeptide complex isolated from the thymus and regulating the functions of the immune system. Thymalin is effective in therapy of acute respiratory syndrome, chronic obstructive bronchitis, and other immunopathology. Thymalin increases functional activity of T lymphocytes, but the targeted molecular mechanism of its biological activity requires further study. We studied the influence of thymalin on differentiation of human hematopoietic stem cells (HSC) and expression of CD28 molecule involved in the implementation of antiviral immunity in COVID-19 infection. It was found that thymalin reduced the expression of CD44 (stem cell marker) and CD117 (molecule of the intermediate stage of HSC differentiation) by 2-3 times and increased the expression of CD28 (marker of mature T lymphocytes) by 6.8 times. This indirectly indicates that thymalin stimulated differentiation of CD117+ cells into mature CD28+T lymphocytes. It is known that in patients with severe COVID-19, the number of CD28+, CD4+, CD8+T lymphocytes in the blood decreased, which attested to a pronounced suppression of immunity. It is possible that the antiviral effect of thymalin consists in compensatory stimulation of HSC differentiation into CD28+T lymphocytes at the stage of immunity suppression in unfavorable course of viral infection. Thymalin can be considered as an immunoprotective peptide drug for the prevention of COVID-19.