Alpha-Fetoprotein as a Factor of Differentiation and Functional Activity of Myeloid-Derived Suppressor Cells.

We studied the role of alpha-fetoprotein (AFP) in regulation of differentiation and functional activity of human myeloid-derived suppressor cells (MDSC) in vitro. To obtain MDSC, CD11b+ cells were isolated from the peripheral blood of healthy donors followed by cytokine induction (IL-1ß+GM-CSF) into the MDSC phenotype. The cell functions were assessed by the expression of indoleamine 2,3-dioxygenase (IDO) and arginase-1 (Arg1) and cytokine profile of the cell cultures. Native AFP did not affect the total number of MDSC and the percentage of polymorphonuclear MDSC (PMN-MDSC), but increased the number of monocytic MDSC (M-MDSC). AFP did not change the expression of Arg1, but in low concentrations (10 and 50 U/ml) increased the number of IDO-containing cells. AFP modulated the cytokine profile of CD11b+ cells: it reliably decreased the level of IL-19 (50 and100 U/ml) and showed a tendency to decrease the levels of IL-34, MMP-2, sCD163, CHI3L1, OPN and to increase the levels of IL-29, IL-32, APRIL, PTX3, and sTNF-R1. Thus, we have demonstrated a regulatory effect of native AFP at the level of MDSC generated from CD11b+ cells under conditions of cytokine induction in vitro.

In HIV-Infected Immunological Non-Responders, Hepatitis C Virus Eradication Contributes to Incomplete Normalization of Systemic Inflammation Indexes, but Does Not Lead to Rapid CD4+ T-Cell Count Recovery.

In HIV-positive individuals taking antiretroviral therapy, coinfection with hepatitis C virus (HCV) increases systemic inflammation, which interferes with the CD4+ T-cells regeneration. This study evaluated the effect of HCV eradication on systemic inflammation and CD4+ T-cell regeneration in patients who gave poor response to antiretroviral therapy, the so-called "immunological non-responders" (INRs). HIV-infected patients who received a course of direct-acting antivirals for treating hepatitis C were examined. The control groups included HIV/HCV-coinfected INRs and relatively healthy volunteers. It was established for the first time that HCV eradication is not accompanied by a complete suppression of systemic inflammation, but improves the T-cell pool composition: in INRs, the blood CD4+/CD8+ T-lymphocyte ratio increases and approaches those of healthy individuals. Apparently, in INRs treated for hepatitis C, the immune system recovery takes time and may be incomplete.

Risk Factors and Mechanisms of Cardiovascular Diseases in Posttraumatic Stress Disorder Model in Wistar Rats as Dependent on Stress Resistance and Age.

The article focuses on the pathogenetic mechanisms of posttraumatic stress disorder (PTSD), which is associated with psychological stress because of the coronavirus pandemic. The molecular mechanisms responsible for disease susceptibility in some individuals and stress resistance in others are amongst crucial research interests of experimental and clinical medicine. Priority data were obtained to indicate that distortions of synthesis and metabolism and, most significantly, a switch between two energy transport forms, glucose and lipids, underlie myocardial dysfunction in young and old stress-sensitive Wistar rats in a PTSD model. Histochemistry and polarization microscopy showed energy deficit in cardiomyocytes and signs of ischemic and hypoxic areas emerging in the myocardium as a result of an accumulation of NADH and NADPH, which initiate excessive production of reactive oxygen species.

Effect of Alpha-Fetoprotein on Differentiation of Myeloid Supressor Cells.

The effect of recombinant alpha-fetoprotein (AFP) on human myeloid suppressor cell (MDSC) differentiation was studied in vitro in the presence of cytokines IL-6 (10 ng/mL) and GM-CSF (10 ng/mL). It was found that AFP at concentrations of 50 and 100 IU/mL increased the number of MDSC (CD33+ HLA-DR-/lowCD11b+) in culture. Analysis of MDSC subpopulations showed that the increase was due to monocytic M-MDSC (HLA-DR-/lowCD33+CD11b+CD14+CD66b-). There was no modulating effect of AFP on granulocytic PMN-MDSC (HLA-DR-/lowCD33+CD11b+CD14-CD66b+). The effects of recombinant AFP on MDSC differentiation were thus demonstrated for the first time.

Metabolic Features of Activated Memory CD4+ T-Cells Derived from HIV-Infected Immunological Non-responders to Highly Active Antiretroviral Therapy.

Immunological non-responders (INR) are HIV-infected subjects that fail to restore CD4+ T-cell counts despite undetectable HIV viral load, which is controlled by highly active antiretroviral therapy (HAART). In INR, impaired immune restoration is linked to low-productive proliferation of memory CD4+ T-lymphocytes. Taking into account that T-cell ability to divide depends on the activity of metabolic pathways, we aimed to determine rates of mitochondrial respiration and glycolysis in memory CD4+ T-cells of INR. Two groups of HIV-infected HAART-treated patients were studied: immunological non-responders and subjects with an adequate immunological response to therapy (immunological responders - IR). Control (C) group comprised uninfected volunteers. In both groups of HIV-infected patients glycolytic activity of memory CD4+ T-cells was lower than that in C. Mitochondrial respiration rate in memory CD4+ T-cells derived from IR was comparable to that of C at basal state, however, after stimulation IR failed to reach the values of uninfected subjects. INR had the lowest mitochondrial respiration rate both at basal state and after stimulation. Taken together, the data presented herein demonstrate that low regenerative potential of memory CD4+ T-cells derived from INR might be linked to diminished lymphocytes' metabolic activity.

New Morphofunctional Criteria for Resistance Profile in Post-Traumatic Stress Disorder Models as Adrenal Dysfunction Trigger.

For the first time in modeling posttraumatic stress disorder (PTSD), we have described the morphofunctional state of adrenal glands in Wistar rats resistant and sensitive to predator stress (rodent fear of the predator). Despite the evident signs of adrenal dysfunction in both phenotypes, we have discovered the thickening of undifferentiated cell zone and high indices of functional activity of stem cells in resistant animals, suggesting ample adaptation. The most important data demonstrate the direct relationship between the reduction of corticosterone and testosterone levels and adrenal dysfunction in PTSD models. The study results allow considering the adrenal stem cells as potential therapeutic targets.

[The Challenges of Vaccine Development Against Betacoronaviruses: Antibody Dependent Enhancement and Sendai Virus as a Possible Vaccine Vector].

To design an effective and safe vaccine against betacoronaviruses, it is necessary to elicit a combination of strong humoral and cell-mediated immune responses as well as to minimize the risk of antibody-dependent enhancement of viral infection. This phenomenon was observed in animal trials of experimental vaccines against SARS-CoV-1 and MERS-CoV that were developed based on inactivated coronavirus or vector constructs expressing the spike protein (S) of the virion. The substitution and glycosylation of certain amino acids in the antigenic determinants of the S-protein, as well as its conformational changes, can lead to the same effect in a new experimental vaccine against SARS-CoV-2. This review outlines approaches for developing vaccines against the new SARS-CoV-2 coronavirus that are based on non-pathogenic viral vectors. For efficient prevention of infections caused by respiratory pathogens the ability of the vaccine to stimulate mucosal immunity in the respiratory tract is important. Such a vaccine can be developed using non-pathogenic Sendai virus vector, since it can be administered intranasally and induce a mucosal immune response that strengthens the antiviral barrier in the respiratory tract and provides reliable protection against infection. The mucosal immunity and the production of IgA antibodies accompanying its development reduces the likelihood of developing an antibody-dependent infection enhancement, which is usually associated only with immunopathological IgG antibodies.

Role of α-Fetoprotein in Regulation of Proliferation and Functional Activity of Naïve T Cells and Immune Memory T Cells.

We studied the role of native α-fetoprotein preparation in the regulation of proliferation and functional activity of naïve T cells and immune memory T cells in vitro. The study was carried out on separated fractions of naïve T cells (CD45RA+) and immune memory T cells (CD45R0+) incubated with α-fetoprotein under conditions of TCR activation. At the level of naïve T cells, α-fetoprotein in a concentration of 100 U/ml reduced the expression of CD28, but increased the expression of CD25, while at the level of immune memory T cells α-fetoprotein (50 and 100 U/ml) only suppressed the expression of CD25. No effects of α-fetoprotein on the proliferative status of the studied lymphocyte subpopulations and on the expression of CD71 (proliferation marker) by these cells were detected. Addition of α-fetoprotein in a concentration of 100 U/ml increased the level of IL-2 in naïve T cell culture supernatants, while production of IL-2 by memory T cells remained unchanged. These data demonstrated the priority aspects of regulation of the functional activities of naïve T cells and immune memory T cells.

Changes in the Regulatory T-Lymphocyte Counts in HIV-Infected Patients with a Discordant Response to Antiretroviral Therapy.

We examined HIV-infected patients with different efficacies of immune system restoration during antiretroviral therapy. The study showed that against the background of low CD4+ T cell counts, subjects with a discordant immunologic response (patients with <350 CD4+ T cells per µL of blood after more than two years of treatment) develop a regulatory CD4+ T cell (Treg) deficiency. Furthermore, in these patients, the immunodeficiency is accompanied by an increase in the Treg frequency. Accumulation of regulatory T lymphocytes in the blood of HIV­infected subjects with discordant response to the treatment indicates a high viability of this T cell subset.

Physical Fatigue and Morphofunctional State of the Myocardium in Experimental Chronic Stress.

The relationship between the development of skeletal muscle fatigue of a specific type in male Wistar rats and morphofunctional alterations in the myocardium in the posttraumatic stress disorder (PTSD) model has been investigated for the first time. The aggravation of oxidative stress in the cardiomyocytes and the related transformation of the cell structural components and the depletion of energy reserves in PTSD has been identified as one of the main factors that accelerate the onset of musculoskeletal fatigue.

α-Fetoprotein Influence on the Conversion of Naïve T-Helpers into Memory T-Cell Effector Subpopulations.

The effect of native α-fetoprotein (AFP) on the conversion of naïve T-helpers into central memory T-cells (TCM) and effector subpopulations of the preterminally differentiated (TEM) and terminally differentiated (TEMRA) memory T-cells was studied. AFP was found to prevent the conversion of naïve T-helpers into effector subpopulations of memory T cells (TEM and TEMRA) while reducing the total production of IL-4 and IFN-γ by the studied cell populations. The data reveal a new role of AFP in the immune tolerance formation during pregnancy.

[Ocular lesions in HIV-infected patients of the ophthalmic hospitals]. / Porazhenie organa zreniia u VICh-infitsirovannykh patsientov oftal'mologicheskikh statsionarov.

PURPOSE: To analyze ophthalmic pathologies in HIV-infected patients of the ophthalmic hospitals of Perm city. MATERIAL AND METHODS: Medical records of 75 HIV patients registered in Perm Regional Centre for Prevention and Control of AIDS and Infectious Diseases who had received treatment in ophthalmic in-patient clinics of Perm in 2005-2015 years were analyzed retrospectively. Patient examination included traditional ophthalmological methods, as well as immunological (determination of CD4 cells and viral load), serological (detection of antibodies to herpes simplex virus, cytomegalovirus, chlamydia, toxoplasma), general clinical methods, and consultations by allied specialists. RESULTS: Ophthalmopathology requiring in-patient care was detected in 75 people (84 eyes). Men comprised 76%, women - 24%; average age was 32.82±8.68 years. The stage of HIV infection was known in 78.66% of patients: stage II - in 5% of cases, stage III - in 32%, stage IV - in 63%. Co-infection (hepatitis B and C, syphilis, tuberculosis) was detected in 81% of patients. HIV-related diseases (cytomegalovirus and herpes infection, candidiasis, toxoplasmosis) were observed in 48% of individuals. The time of emergence of ocular pathology from the time of HIV detection ranged from 1 day to 14 years. Inflammatory ocular diseases occurred in 55% of cases, dystrophic disorders - in 18%, eye traumas - in 24%, and strabismus - in 3% of patients. Reduced level of CD4 (less than 500 cells/mm3) was more prevalent (72.13%) among the study patients. As of the time of the study, only 36.4% of patients were receiving antiretroviral therapy. CONCLUSION: Among the studied individuals, eye lesion was mostly severe, inflammatory in nature; it occurred more frequently in stage IV HIV patients with reduced number of CD4 lymphocytes who was not receiving antiretroviral therapy.

CD8+ T cell expansion in HIV/HCV coinfection is associated with systemic inflammation.

High prevalence of non-AIDS-defining illnesses in treated HIV-infected patients is associated with increased peripheral CD8+ T cell counts. Hepatitis C virus (HCV) coinfection is an additional risk factor for the development of non-AIDS events. We found that, in HIV/HCV coinfection, the increased proportion of CD8+ T lymphocytes is due to the effector memory and terminal effector T cells gain. Moreover, in these patients, the accumulation of highly differentiated forms of CD8+ T lymphocytes was associated with increased concentrations of inflammatory indices.

Regulation of the peritoneal macrophage functional activity by the MP-5 and MP-6 myelopeptides under stress.

In mice, two-hour immobilization stress inhibited zymosan-induced production by macrophages of the oxygen radicals and cytokine IL-1ß. After myelopeptides MP-5 and MP-6 were administered into mice, the stress-induced inhibition of the reactive oxygen species (ROS) and IL-1ß was abrogated. MP-5 peptide stimulated spontaneous ROS production by macrophages and reduced IL-10 production under stress. Thus, under in vivo conditions and under stress, the effect of MP-5 and MP-6 myelopeptides modulates the peritoneal macrophage activity.

HCV coinfection of the HIV-infected patients with discordant CD4+ T-cell response to antiretroviral therapy leads to intense systemic inflammation.

The level of proinflammatory markers was assessed in HIV-infected patients that were coinfected with hepatitis C virus (HCV) and had failed to restore the CD4+ T cell counts (immunological nonresponders, INR) during the antiretroviral therapy (ART). Among four patient groups (HIV+HCV- and HIV+HCV+ subjects with the concordant response to ART; HIV+HCV- and HIV+HCV+ subjects that were INR), the greatest systemic inflammation was in the latter group. The maximum difference was between the subjects HIV+HCV-INR and HIV+HCV+ INR: the blood of coinfected patients contained significantly higher concentrations of the IP-10, sCD163, sTNF-RI, and sTNF-RII and of bacterial lipopolysaccharide. Systemic inflammation in HIV/HCV coinfected patients with the discordant response to ART is probably caused by a breach of hepatic barrier for the intestine products.

Role of α-fetoprotein in differentiation of regulatory T lymphocytes.

The effect of native α-fetoprotein (AFP) on the expression of T-regulatory lymphocyte (Treg) markers by activated CD4+ lymphocytes with different proliferative status was studied. α-Fetoprotein did not affect the ratio of proliferating and non-proliferating activated CD4+ cells. In the study of Treg differentiation, it was found that AFP at concentrations of 50 and 100 µg/mL significantly inhibited the number of nonproliferating CD4+FOXP3+ and CD4+FOXP3+HELIOS+ lymphocytes without affecting the expression of Treg markers by proliferating CD4+ lymphocytes.

Systemic inflammation and liver damage in HIV/hepatitis C virus coinfection.

OBJECTIVES: Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined. METHODS: Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated. RESULTS: Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163. CONCLUSIONS: Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.

Effect of Hepatitis C Virus Coinfection on the Content of CD4(+) and CD8(+) T Cell Subpopulations in HIV-Infected Patients Receiving Antiretroviral Therapy.

We studied the effect of hepatitis C virus coinfection on T cell subpopulations in HIV-infected patients receiving antiretroviral therapy. Coinfection with hepatitis C virus was followed by a decrease in the number of naive CD4(+) T cells and an increase in the count of central CD8(+) memory T cells in these patients. Hepatitis C virus had no effect on the number of CD4(+) memory T cells (main target for HIV). This can explain the absence of strong negative effect of hepatitis C virus on the course of HIV infection.

2-Morpholino-5-Phenyl-6H-1,3,4-Thiadiazine Corrects Metabolic Disorders during the Development of Alloxan Diabetes Mellitus in Rats.

Metabolic disorders were evaluated in rats with alloxan diabetes mellitus after administration of 2-morpholino-5-phenyl-6H-1,3,4-thiadiazine (compound L-17). Administration of L-17 reduced the severity of metabolic disorders associated with diabetes mellitus. At the end of the experiment, the concentration of glucose, glycated hemoglobin, malonic dialdehyde, and catalase activity were significantly higher and peroxidase activity was significantly lower in the group of animals receiving L-17. The decrease of glycemia, glucose concentration, and glycated hemoglobin content was reached by the 3rd-4th week of the experiment. These data suggest that correction of biochemical parameters in rats with alloxan diabetes was reached after administration of L-17 for at least 3 weeks.

Immune complexes that contain HIV antigens activate peripheral blood T cells.

Uninfected donor T cells were treated in vitro by model immune complexes that contained either HIV or hepatitis C virus (HCV) antigens. Unlike HCV antigen-containing complexes, the immune complexes that contained HIV antigens have been shown to activate peripheral blood T cells of uninfected donors under in vitro conditions. Both the antiviral antibodies and HIV antigen were involved in the activation process. The unique properties of the immune complexes formed by HIV antigens and antiviral antibodies are believed to result from the virus-specific antibody properties and molecular conformation of the antigen-antibody complex.