In Vitro Antiviral Activity of a New Indol-3-carboxylic Acid Derivative Against SARS-CoV-2.

The coronavirus disease (COVID-19) pandemic has brought into sharp relief the threat posed by coronaviruses and laid the foundation for a fundamental analysis of this viral family, as well as a search for effective anti-COVID drugs. Work is underway to update existent vaccines against COVID-19, and screening for low-molecular-weight anti-COVID drug candidates for outpatient medicine continues. The opportunities and ways to accelerate the development of antiviral drugs against other pathogens are being discussed in the context of preparing for the next pandemic. In 2012-2015, Tsyshkova et al. synthesized a group of water-soluble low-molecular-weight compounds exhibiting an antiviral activity, whose chemical structure was similar to that of arbidol. Among those, there were a number of water-soluble compounds based on 5-methoxyindole-3-carboxylic acid aminoalkyl esters. Only one member of this rather extensive group of compounds, dihydrochloride of 6-bromo-5-methoxy-1-methyl-2-(1-piperidinomethyl)-3-(2-diethylaminoethoxy) carbonylindole, exhibited a reliable antiviral effect against SARS-CoV-2 in vitro. At a concentration of 52.0 µM, this compound completely inhibited the replication of the SARS-CoV-2 virus with an infectious activity of 106 TCID50/mL. The concentration curves of the analyzed compound indicate the specificity of its action. Interferon-inducing activity, as well as suppression of syncytium formation induced by the spike protein (S-glycoprotein) of SARS-CoV-2 by 89%, were also revealed. In view of its synthetic accessibility - high activity (IC50 = 1.06 µg/mL) and high selectivity index (SI = 78.6) - this compound appears to meets the requirements for the development of antiviral drugs for COVID-19 prevention and treatment.

[The problem of the use of interferons in the novel coronavirus disease COVID-19 (Coronaviridae: Coronavirinae: Betacoronavirus: Sarbecovirus)].

By the end of 2021, about 200 studies on the effect of interferons (IFNs) on the incidence and course of the new coronavirus infection COVID-19 (Coronaviridae: Coronavirinae: Betacoronavirus: Sarbecovirus) have been reported worldwide, with the number of such studies steadily increasing. This review discusses the main issues of the use of IFN drugs in this disease. The literature search was carried out in the PubMed, Scopus, Cochrane Library, Web of Science, RSCI databases, as well as in the Google Scholar preprint database using the available search queries «MeSH for coronavirus¼, «SARS-CoV-2¼, «IFN drugs¼, and «COVID-19¼. Interferon therapy is indicated for early administration (within the first 5 days of patient admission) in cases of mild to moderate COVID-19 to take advantage of the narrow therapeutic window of IFNs action. Control and suppression of viral replication requires therapy with IFNs and other effective antiviral agents that inhibit the reproduction of SARS-CoV-2 and induce several interferon-stimulated genes (ISG). Type I IFNs (IFN-I) exhibit potent pro-inflammatory properties and activate a wide variety of different cell types that respond to IFNs stimulation and pathogen entry. IFN-III confer local mucosal antiviral immunity without inducing the strong systemic pro-inflammatory responses associated with IFN-I. The use of IFNs drugs in the therapy of new coronavirus infection requires a cautious and differentiated approach, because in severe cases they can aggravate viral pathogenesis by causing excessive intensity of inflammatory reactions. The unique biological properties of substances of this class allow us to consider them as therapeutic agents with significant potential for use in patients with COVID-19.

[Interferon-regulating activity of the CelAgrip drug and its influence on the formation of reactive oxygen species and expression of innate immunity genes in Burkitt's lymphome cells cultures.]

INTRODUCTION: Interferons (IFN) and IFN inducers are effective in suppressing viral reproduction and correcting of the innate immunity mechanisms. The aim of the study was to test the hypothesis of the possible involvement of the IFN inducer CelAgrip (CA) as an activator or suppressor of antiviral effects in Burkitt's lymphoma (LB) cell cultures with different ability to produce Epstein-Barr virus antigens (EBV). MATERIAL AND METHODS: The kinetic analysis of the dynamics of reactive oxygen species (ROS) production and determination of gene group expression by real-time PCR in response to CA treatment were done in human cell lines LB P3HR-1 and Namalva, spontaneously producing and not producing EBV antigens. RESULTS AND DISCUSSION: When treating CA in Namalva cells, a decrease in the ROS activation index was found; in P3HR-1 cells, an increase was observed. After treatment with CA, there was no reliable activation of the IFN-α, IFN-ß and IFN-λ genes in Namalva cells, but the expression of the ISG15 and P53(TP53) genes was increased more than 1200 times and 4.5 times, respectively. When processing the CA of P3HR-1 cells, the expression of IFN-α genes increased by more than 200 times, IFN-λ - 100 times, and the ISG15 gene - 2.2 times. The relationship between IFN-inducing action of CA and the activity of ISG15 and ROS in LB cell cultures producing and not producing EBV antigens is supposed. CONCLUSION: In Namalva cells that do not produce EBV antigens the treatment of CA results in suppression of ROS generation and activation of the expression of genes ISG15 and P53 (TP53); in P3HR-1 cells producing EBV antigens, the opposite picture is observed - the formation of ROS and the expression of the IFN-α and IFN-λ genes are activated and the activity of the ISG15 and P53 (TP53) genes is suppressed.

[Interferon-regulating activity of the celagrip antiviral drug and its influence on formation of reactive oxygen species and expression of innate immunity genes in the follicular lymphoma patients].

INTRODUCTION: Medicines from the group of interferon inducers (IFNs) "swith on" the synthesis of type 1 interferons (IFN-I) and induce the expression of IFN-stimulated genes (ISGs) that regulate innate immunity reactions and protect the host from infectious agents and the tumour pathology.The purpose of the study was to determine the role of the drug celagrip (CA) in the activation of innate immunity genes and the effect on the production of reactive oxygen species (ROS) in patients with follicular lymphoma (FL). OBJECTIVES:  to study the intensity of ROS production and the level of expression of the IFN-α2, IFN-λ1, ISG15, BCL2, P53(TP53) and USP18 genes in response to the treatment of blood cells of patients with FL with the preparation of CA. MATERIAL AND METHODS: The study involved primary cancer patients diagnosed with follicular lymphoma (FL) and healthy volunteers. A kinetic analysis of the dynamics of production of reactive oxygen species (ROS) was performed in whose blood cells, and the expression of the group of genes was determined by real-time PCR in response to CA processing. RESULTS AND DISCUSSION: ROS production by blood cells of patients with FL and volunteers in the presence of CA significantly decreased (P < 0.05). The level of gene expression of ISG15, P53(TR53) and USP 18 in the group of patients with FL was significantly higher than that in the group of volunteers. When treating blood cells with CA, it becomes possible to divide patients with FL into groups with a positive and negative response in accordance with the level of expression of the USP18 gene. We divided FL patients into groups with a positive and negative response in accordance with the level of USP18 gene expression after treatment of blood cells with CA. CONCLUSIONS: The CA drug reduces the production of ROS and simultaneously stimulates the activity of the innate immunity genes ISG15, P53(TP53) and USP18 in the blood cells of patients with FL.

[Cytokine-regulating activity of anti-virus preparation CelAgripus in Burkitt's lymphoma stable B-cell lines.]

INTRODUCTION: Cytokines activated in response to immunosuppressive viral infections can directly or indirectly affect the neoplastic transformation of B cells. In this study, we studied a new substance designed to produce the antiviral drug CelAgrip (CA, CelAgripus), which exhibits interferon (IFN) and cytokine-inducing activity and, apparently, can be used as an activator of antiviral immunity. Purpose - is to evaluate the cytokine-regulating effect of CA in Burkitt's lymphoma (LB) cell lines latently infected with the Epstein-Barr virus (EBV). OBJECTIVES: to study the CA-induced expression of the cytokine genes IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17, IL-18, IFN-α, IFN -γ, IFN-ß, IFN-λ1, IFN-λ2, IFN-λ3, TNF-α in normal and EBV transformed LB cells. MATERIAL AND METHODS: Cell line: the human embryo fibroblasts (HEF), Namalva, Daudi, Raji, P3HR-1. Preparations: CA, gossypol-acetic acid (GAA), sodium carboxymethyl cellulose (Na-CMC). METHODS: RT-PCR and methods for assessing cytotoxicity (MTT and Scepter 2.0 Merck cell counter). RESULTS: The effect of the CA preparation on the expression of IFN-λ, IL-1ß, IL-6, IL-8 and IL-10 genes was revealed. DISCUSSION: We observed the activation of gene expression of IFN-λ, IL-1ß, IL-6, IL-8 and suppression of IL-10 gene activity when treatment CA of LB cells. CONCLUSION: The substance CA has new effects on the activation of the expression of a number of key cytokine genes in stable Burkitt lymphoma cell lines.

[Ophthalmic drug films in the therapy of experimental herpetic keratoconjunctivitis.]

INTRODUCTION: The complexity of the treatment of herpetic keratoconjunctivitis is due to the severity of the disease, complications, the transition to chronic relapsing forms and the insufficient effectiveness of the drugs used, which leads to a steady increase in the number of patients. The aim of the study was to evaluate the therapeutic efficacy of the eye drug films «GlazAvir¼ in the experimental model of acute herpetic eye infection in rabbits. RESEARCH OBJECTIVES: to study the specific activity of «GlazAvir¼ and compare the long-term indicators of the level of manifestation of individual clinical signs of keratoconjunctivitis. MATERIAL AND METHODS: In the work we used rabbits of the Chinchilla breed, the herpes simplex virus type 1 and the eye drug films «GlazAvir¼. A model of ophthalmic herpetic infection was formed by infection of rabbits with virus-containing material of a pre-scarified eye cornea against the background of local anesthesia. Аnimals were treated with the drug «GlazAvir¼ - 1 application per day for 7 days. Animals were observed daily for 15 days, then every 3 days until the 25th day of observation. The effectiveness of the drug was evaluated at the peak of the development of the pathological process. RESULTS AND DISCUSSION: There was a decrease in mortality from 50 to 20%, and an increase in average life expectancy by 27.87%, compared with the control in animals treated with «GlazAvir¼. It was noted after activation of herpetic keratoconjunctivitis on the 2nd - 5th day, at the peak of the disease (6-9th day) a statistically significant decrease in the activity of the pathological process (p<0.05) by rabbits treated with the «GlazAvir¼ ophthalmic drug films. The tendency to normalization by the rabbits treated with the «GlazAvir¼ preparation was observed until the 14th day. CONCLUSION: The data obtained indicate the pronounced effectiveness of the «GlazAvir¼ preparation in the treatment of experimental herpesvirus keratoconjunctivitis.

Polyprenyl Phosphates Induce a High Humoral and Cellular Response to Immunization with Recombinant Proteins of the Replicative Complex of the Hepatitis C Virus.

The search for new adjuvants remains the critical task for the creation of hepatitis C vaccines due to the weak immunogenicity of biotechnological products. When immunizing mice with the recombinant proteins NS3 and NS5B of the hepatitis C virus (HCV), the adjuvant activity of three immunomodulators was compared. Phosprenyl® on the basis of polyprenyl phosphate (PPP), chemically synthesized analogue of the bacterial cell wall glucosaminyl muramyl dipeptide (GMDP), and IFN-α recombinant protein were tested. GMDP increased the activity of IgG1 antibodies 4-6 times but did not stimulate the production of IFN-γ; IFN-α has not shown any adjuvant properties. The introduction of recombinant HCV proteins together with PPP in low doses increased the activity of IgG2a isotype antibodies 4-7 times and increased IFN-γ secretion 3 times. Thus, it was first shown that PPP polarizes the immune response to Th1-type and is a promising adjuvant for the development of a vaccine against hepatitis C.

THEORETICAL AND APPLIED ASPECTS OF THE INTERFERON SYSTEM: TO THE 60TH ANNIVERSARY OF THE DISCOVERY OF INTERFERONS.

The review contains a brief analysis of the 60-year history of the discovery, study and medical application of interferons, a new group of remarkable proteins that have found wide medical application in the therapy of virological, oncological, neurological, ophthalmic and other pathologies. Modern data on the classification of interferons and the mechanisms of their action are given. Particular attention is paid to the clinical use of medications of interferon and its inducers.

[Antiviral activity of phosprenyl and gamapren against infection caused by influenza a (H5N1) virus in cell culture].

The antiviral activity of Phosprenyl and Gamapren in vitro against highly pathogenic strain of avian influenza H5N1 virus was studied. Inoculation of the virus to the susceptible cell culture led to development of the cytopathogenic effect. Preliminary introduction of Phosprenyl and Gamapren an hour prior to infecting the cells with virus 10.0 TCID50 dose completely inhibited the cytopathogenic activity of the virus. At higher doses of virus (100.0 TCID50) significant inhibition of the infectious activity of the virus was observed: 70% of infected cells survived under the action of Phosprenyl, and 90% under the action of Gamapren. With the introduction of the preparations simultaneously with the infection of cells with virus at a dose of 10.0 TCID50 virtually 100% of infected cells survived, while in control cultures death of 100% of the cells occurred. After infection with the virus at a dose of 100.0 TCID50 Phosprenyl and Gamapren caused 50% protection of the cells. The antiviral effect of the drugs Phosprenyl and Gamapren may be associated not only with their virulicidal, but with anti-viral activity as well.

[Efficacy of polyprenyl phosphates in the experimental genital herpes model].

An experimental model of the primary genital herpes (herpes simplex type 2, HSV-2) in the female guinea pigs was suggested to study the infectious process activity of polyprenyl phosphates (PPP) and PPP+acyclovir (AC) complex treatment. The morphofunctional features of the guinea pig ovaries were studied in the control and experimental groups (the latter were inoculated with PPP and/or AC as a primary infection treatment) at the stage of the recurrent genital herpes aggravation. It was shown that in the case of combined PPP +AC use significant changes in the disease symptoms were observed, as well as a decrease in the infectious process activity and duration, and positive remote effect on the ovarian morphophysiology.

[TREATMENT OF PATIENTS WITH CHRONIC RECURRENT HERPES VIRUS INFECTION OF GENITAL LOCALIZATION: A CLINICAL STUDY OF FORTEPREN PREPARATION].

AIM: Selection of optimal dosage regimen, length of treatment course (frequency of administration), safety, tolerance and clinical effectiveness evaluation of the medical preparation fortepren in patients with chronical recurrent herpes virus infection of genital localization. MATERIALS AND METHODS: The medical product of antiviral and immune modulating effect--fortepren (sodium polyprenyl phosphate) as a 4 mg/ml solution for injections combined with the base course of acyclic nucleoside acyclovir, 400 mg tablets, held studies. 40 male and female patients participated in the study. After a 10-day acyclovir course (400 mg x 3 times a day) for removing the acute phase, 4 groups of 10 individuals were formed: 1--5 ml (20 mg) of fortepren i/m once at day 13 ± 2 after the start of the study after the completion of the treatment of the acute phase of the disease; 2--5 ml (20 mg) fortepren i/m 3 times at an interval of 21 days; 3--2 ml (8 mg) fortepren i/m 3 times at an interval of 21 days; 4 (control)--5 ml of placebo i/m at remission stage 3 times at an interval of 21 days. Increase of the duration of inter-recurrence period, decrease of the severity of the recurrences, state of skin and mucous damage elements, improvements of immunologic parameters were considered during effectiveness evaluation. RESULTS: Significant differences in the frequency of recurrences of genital herpes were shown for 3 months of observation in experimental and control groups. A significant reduction of genital herpes recurrence frequency from 3.52 ± 0.09 (before treatment) to 2.89 ± 0.08 (after treatment) was noted in patients of group 3 (p < 0.001). The frequency of recurrences in the control group was 3.84 ± 0.10, that was higher than the parameters in all the experimental groups. A significant reduction of the rash area was noted in group 3, moreover, a redution of frequency of detection of clinical manifestations of genital herpes in the form of vesicle elements after treatment in groups 2 (p = 0.02) and 3 (p = 0.005) was found. Evaluation of local symptoms has established that burning have caused minimal discomfort for patients of groups 3 and 4 and itch and soreness--of groups 1 and 3. The least pronounced exacerbations were noted in patients of group 3. Intramuscular administration of fortepren preparation was established to result in the increase of titers of leukocyte virus-induced interferon for the whole duration of treatment. CONCLUSION: An intramuscular dose of 2 ml (8 mg) at recurrence stage 3 times at an interval of 21 days after the completion of the 10-day base course of treatment of the acute phase of chronical recurrent herpes virus infection of genital localization using acyclovir was accepted as an optimal dosage regimen. Analysis of the obtained results has shown an acceptable safety profile and a good level of tolerance for fortepren preparation.

[Usage of interferon inducers during viral infections].

Domestic researchers succeeded to create a group of original interferon inducers (II) with a high chemotherapeutic index and suitable for the prevention and treatment of viral infections and a number of other diseases. Clinical application of II concerns, first of all, a wide range of viral infections: influenza and other acute respiratory viral infections, herpes, hepatitis, encephalitis, rabies, slow and mixed infections, etc. The accumulated experience is generalized and the conclusion is made about the main advantages of II, which induce a balanced synthesis of endogenous interferon without antigenicity of its own. It is emphasized that a single injection of II "includes" synthesis of IFN in certain populations of cells and organs and provides a relatively long circulation of IFN at a therapeutic level and creation of long-term anti-virus resistance. It is concluded that, in general, interferon inducers with pronounced antiviral and immunomodulatory properties are currently used as effective tools for the prevention and treatment of a variety of diseases. The fact that II different in their chemical nature act at different stages of reproduction of viruses and affect various links of the innate and adaptive immunity explains the increased scope of the application of this group of drugs in medical practice.

Number of stromal precursors in mouse bone marrow and expression of cytokine genes in primary cultures of mouse bone marrow cells during various periods after immunization with S. typhimurium antigens.

Administration of S. typhimurium microbial mass to mice was followed by a significant increase (by 3-4 times) in the efficiency of cloning and number of stromal precursors in the femoral bone marrow. These parameters were maximum on days 1-3, but returned to normal by the 8th-15th day after immunization. As differentiated from intact animals, the expression of genes for proinflammatory cytokines IL-1ß (day 1 after immunization), IL-6 (days 1-3), TNF-α (days 1, 3, and 6), and IFN-α (days 1-3) was detected in bone marrow cultures from immunized mice. The expression of genes for IFN-γ, IL-18, and IFN-α was decreased on days 1, 3, and 6 after immunization of animals, respectively. Gene expression for the anti-inflammatory cytokine IL-4 was observed on day 6 after immunization. Therefore, this system was not characterized by a decrease in the immune response of stromal cells. The stromal component of hemopoietic and lymphoid organs has the vector of influences in response to bacterial antigens. This vector is directed to the stimulation and progression, but not to the suppression of immune reactions. Our results indicate that resident stromal cells play a role in the immune response of the body.

Morphofunctional changes in guinea pig ovaries in experimental chronic herpesvirus infection.

The ovaries of adult guinea pigs infected with herpesvirus-2 were examined by light microscopy under conditions of latent infection and relapse of infectious process. Morphofunctional changes in the ovarian follicles at all stages of folliculogenesis and in ovarian stroma were caused by the negative effects of type 2 herpes simplex virus.

Correlations between in vitro effects of preparations of interferon and its inducers on blood cells in patients with multiple sclerosis.

We studied in vitro production of interferon-alpha and interferon-gamma by peripheral blood leukocytes from 15 patients with multiple sclerosis. The priming effects of interferon preparations weakly correlated with interferon-alpha production by leukocytes from patients with multiple sclerosis, but negatively correlated with interferon-gamma production. The effects of interferon inducers in most cases positively correlated with its spontaneous production. We found a weak positive correlation between the priming effect of natural interferon-alpha and the effect of recombinant interferons. There were positive or strong positive correlations between the effects of recombinant interferons on leukocytes from patients with multiple sclerosis. The relationship between the effects of medicinal interferon inducers and interferon preparation varied from negative to strong positive correlations. These data suggest that correlation analysis can be used for dynamic control and elaboration of methods for combined immunotherapy of multiple sclerosis with various interferon preparations or interferon and its inducers.

Two pathways of the nitric oxide-induced cytotoxycal action.

Nitric oxide is a diffusible messenger with multiple biological functions. We show here that NO-generating compound, S-nitrosoglutathione (GSNO) induces apoptosis in human chondrocytes and causes necrosis-like cell death in human epithelial CaOv cell line. Pretreatment of chondrocytes with low-dose GSNO or with gamma-interferon enhances their tolerance to the second high-concentration GSNO exposure. On the contrary, in CaOv cells low-dose GSNO pretreatment diminishes the resistance and increases cytolysis at the second GSNO exposure. We conclude that human chondrocytes possess specific and inducible mechanism preventing cell killing by nitric oxide.

Alternative processing of the tryptophanyl-tRNA synthetase mRNA from interferon-treated human cells.

We have analysed the structure of mRNA isoforms of the human gene encoding tryptophanyl-tRNA synthetase (Trp-tRNA synthetase) expressed in the epithelial CaOv cells and MT-4 lymphocytes. The Trp-tRNA synthetase gene is induced by interferon-gamma in both lines and, in MT-4 lymphocytes, also by interferon-alpha. Four Trp-tRNA synthetase mRNA isoforms have different combinations of the first exons IA, IB and II. Two transcription initiation sites (P1 and P2) were detected 90 bp from each other. Processing of the primary transcript initiated from the P1 start site generates the mRNA isoform where exon IA joins to exon II. The other three isoforms are produced by alternative splicing of the primary transcript produced from the P2 start site. Isoform 2 has a 3'-end fragment of exon IA joined to exon II. Isoform 3 contains exons IA and IB. Isoform 4 contains exon IA and exon III and lacks exon II encoding the N-terminus of the Trp-tRNA synthetase. Therefore, the two primary transcripts of the Trp-tRNA synthetase gene differ only in the 5' flank sequence between P1 and P2, and this fragment regulates their processing. Both interferon-alpha and interferon-gamma induce exon IA-containing and exon IB-containing isoforms of the Trp-tRNA synthetase mRNA.

Phosprenyl: a novel drug with antiviral and immunomodulatory activity.

A novel antiviral drug with immunomodulatory activity (Phosprenyl) is presented. The main active ingredient of the preparation is polyprenyl phosphates. This medicine is highly efficient against a number of viruses, including HIV in vitro, and tick-borne encephalitis and rabies viruses in the experimental models in vivo. In veterinary practice Phosprenyl is now regarded as an effective therapeutic means for treatment of canine distemper, hepatitis, enteritis, etc.