Effect of PEGylated Graphene Oxide Nanoparticles on the Metabolism of Jurkat Cells

The effect of graphene oxide (GO) nanoparticles of 100-200 nm in size coated with linear (LP-GO) and branched (BP-GO) polyethylene glycol at concentrations of 5 and 25 μg/mL on the metabolism of Jurkat tumor cells was studied. It was found that LP-GO nanoparticles at a concentration of 25 μg/mL can enhance basal glycolysis of Jurkat T-lymphocyte tumor cell line cells, while LP-GO and BP-GO at the same concentration can reduce the indicators of compensatory glycolysis. Despite this, GO nanoparticles coated with linear and branched PEG at a concentration of 5 μg/mL do not have pronounced effects on oxidative phosphorylation and glycolysis of Jurkat cells and could therefore be safe for activated T cells.

Effect of Short PSG Peptides on Inflammatory Markers in Allogeneic Bone Marrow Cell Transplantation in Wistar Rats

Short linear peptide fragments of placental trophoblastic β1-glycoprotein (PSG) (YECE, YQCE, YVCS, and YACS) were studied in the context of their immunomodulatory effects at the level of inflammatory markers. The original host-versus-graft model was used in male Wistar rats without prior conditioning of recipient bone marrow. A composition of PSG peptide fragments was injected to animals after allogeneic transplantation of bone marrow cells in a dynamic experiment, inflammatory markers α1-acid glycoprotein (AGP, orosomucoid), α2-macroglobulin (α2M) were assayed by ELISA, and biochemical parameters (total protein, glucose, creatinine, and urea) were measured. The levels of α2M and AGP increased in response to allotransplantation, whereas administration of PSG peptides normalized serum α2M levels by the end of the experiment. The decrease in α2M level coincided with the independent effect of PSG peptide administration. The levels of total protein, glucose, creatinine, and urea in rat serum after allotransplantation were reduced throughout the experiment. Administration of PSG peptides contributed to normalization of serum total protein, creatinine, and urea levels by the end of the experiment. Administration of PSG peptides after allogeneic transplantation of bone marrow suspension contributed to normalization of the levels of α2M, total protein, creatinine, and urea, which can be interpreted as an anti-inflammatory effect of these peptides.

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-1β+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.

Interaction of Graphene Oxide Nanoparticles with Human Mononuclear Cells in the Cell-IQ System

The interaction of graphene oxide nanoparticles with human peripheral blood mononuclear cells was studied using the Cell-IQ continuous monitoring system for living cells. We used graphene oxide nanoparticles of various sizes coated with linear or branched polyethylene glycol (PEG) in concentrations of 5 and 25 μg/ml. After 24-h incubation with graphene oxide nanoparticles, the increase in the number of peripheral blood mononuclear cells at visualization points decreased; nanoparticles coated with branched PEG more markedly suppressed cell growth in culture. In the presence of graphene oxide nanoparticles, peripheral blood mononuclear cells retained high viability in culture after daily monitoring in the Cell-IQ system. The studied nanoparticles were engulfed by monocytes and the type of PEGylation had no effect on this process. Thus, graphene oxide nanoparticles reduced the increase in peripheral blood mononuclear cell mass during dynamic observation in the Cell-IQ system without reducing their viability.

[Antiviral and virucidal activity of sodium deoxyribonucleate and its complex with iron against viruses of different kingdoms and families]

INTRODUCTION

The urgent problem of modern medicine is the fight against acute respiratory viral infections (ARVI). To combat ARVI, drugs of wide antiviral potency are needed, as well as immunomodulating drugs. Such antiviral and immunomodulatory effects has sodium deoxyribonucleate (DNA-Na) and its complex with iron (DNA-Na-Fe) developed on the basis of double-stranded DNA of natural origin.

AIM OF THE STUDY

To assess antiviral and virucidal activity of DNA-Na and DNA-Na-Fe against viruses of different kingdoms and families.

MATERIALS AND METHODS

Antiviral and virucidal activity of DNA-Na and DNA-Na-Fe was assessed in cell cultures infected with viruses.

RESULTS AND DISCUSSION

DNA-Na and DNA-Na-Fe had antiviral activity against adenovirus at concentrations of 2501000 mcg/ml. Antiviral effect of both drugs was not detected in case of poliovirus. DNA-Na and DNA-Na-Fe had antiviral activity against coronavirus in all administration schemes. EC50 for DNA-Na ~ 2500 mcg/ml, for DNA-Na-Fe ~ 1000 mcg/ml. In cells treated with DNA-Na-Fe, secretion of following proinflammatory cytokines was detected: Interleukin (IL) 1, IL-2, IL-6, IL-18, interferon- (IFN-), IFN-, as well as anti-inflammatory cytokines: IL-4, IL-10, antagonist of IL-1 receptor. Evidently, DNA-Na and DNA-Na-Fe have antiviral effect, but mechanism of action does not seem to be associated with specific effect on viral replication. Presence of virucidal activity of drugs against representatives of Coronaviridae, Adenoviridae, Picornaviridae, Retroviridae, Herpesviridae in vitro test in range of 1.03.0 lg TCID50 was identified.

CONCLUSION

Presence of simultaneous antiviral and virucidal activity of DNA-Na and DNA-Na-Fe against adeno- and coronaviruses shows their prospects for prevention and treatment of ARVI.

The Role of Recombinant Glycodelin in the Differentiation of Regulatory T-Lymphocytes

The effect of recombinant glycodelin (GdA) on the number of T-regulatory lymphocytes (Treg) in a culture of activated CD4⁺ lymphocytes was investigated, while simultaneously assessing the proliferative status of the cells. Recombinant GdA from E. coli and from HEK293 cells were used in the study at concentrations of 0.2; 2 and 10 µg/mL. It was found that only a low concentration (0.2 μg/mL) of recombinant GdA of bacterial origin reduced the number of proliferating CD4⁺ lymphocytes as well as the number of Treg (CD4⁺CD25^highCD127^-/low) in the experimental system in vitro.

Interaction of Human Dendritic Cells with Graphene Oxide Nanoparticles In Vitro

We studied the effect of graphene oxide nanoparticles on the differentiation of human dendritic cells and uptake of nanoparticles by these cells in vitro. The objects of the study were mononuclear cells from healthy donors induced into the phenotype of dendritic cells by cytokines (IL-6 and GM-CSF). We used graphene oxide nanoparticles of different sizes functionalized with linear or branched PEG (P-GO or bP-GO) in concentrations of 5 and 25 μg/ml. It was found that graphene oxide nanoparticles did not affect the viability and percentage of dendritic cells in the culture. However, P-GO nanoparticles (25 μg/ml) suppressed the expression of CD83 on the surface of dendritic cells in cultures, thereby suppressing cell differentiation. Dendritic cells internalized P-GO nanoparticles, particles in high concentration were more actively engulfed, but the size of the particles and the type of PEG did not affect the intensity of this process. In general, P-GO nanoparticles in a concentration of 25 μg/ml can regulate differentiation of dendritic cells by suppressing their maturation.

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.

Graphene Oxide Nanoparticels Interaction with Jurkat Cell Line in Cell-IQ System

In recent years, materials based on graphene oxide (GO) have been actively studied for their use in biomedicine. The aim of our study was to investigate the increase in cell mass and viability of Jurkat tumor line T cells during 24 h of contact with GO nanoparticles in the Cell-IQ system of intravital observation. We used nanoparticles of different sizes coated with linear or branched polyethylene glycol (PEG) at concentrations of 5 and 25 μg/mL. It was shown for the first time that direct contact with GO nanoparticles reduced the growth in cell mass at the visualization points by more than twofold, regardless of nanoparticle size and concentration. Moreover, the number of live cells in the culture decreased by 5-9% after 24 h of monitoring. Thus, PEG-coated GO nanoparticles were found to suppress the proliferation and viability of Jurkat cell line T lymphocytes.

[Antiviral activity of extracts of basidiomycetes and humic compounds substances against Human Immunodeficiency Virus (Retroviridae: Orthoretrovirinae: Lentivirus: Human immunodeficiency virus 1) and Herpes Simplex Virus (Herpesviridae: Simplexvirus: Human alphaherpesvirus 1)]

INTRODUCTION

One of the most urgent problem of modern medicine is the fight against the disease caused by the Human Immunodeficiency Virus (HIV) - HIV infection. The chemical compounds have improved the situation for infected people, but they are toxic, disrupt the metabolism and cannot eliminate the integrated virus from the body. The emergence of resistant HIV strains makes these treatments ineffective. Often, the death of HIV-infected people occurs as a result of the development of opportunistic infections caused by viruses of the Herpesviridae family. Therefore, the search for new therapeutic and preventive drugs that are less toxic and active against several viruses at the same time is relevant. Basidiomycetes, higher fungi, are a source of medicinal compounds that have antimicrobial properties, as well as antiviral ones. Humic compounds (HS) of various nature also have antiviral activity.The aim of the study was to obtain nontoxic compounds from the basidiomycete Inonotus obliquus and humic compounds from brown coals and to test their activity against viruses that are pathogenic to humans: HIV and Herpes Simplex Virus (HSV).

MATERIAL AND METHODS

The antiviral activity of melanin extracts obtained from the culture of the chaga fungus Inonotus obliquus and HS from the brown coal of the Kansko-Achinsk Deposit was studied using a model of MT-4 lymphoblastoid cells infected with HIV type 1 (HIV-1) strains and a monolayer culture of Vero cells infected with HSV type 1 (HSV-1) using virological and statistical research methods.

RESULTS AND DISCUSSION

It was found that all the studied compounds did not have a cytotoxic effect on cells at a concentration of 100 mcg/ml. It was shown that extracts of basidiomycetes and HS have antiviral activity against HIV-1 and HSV-1. EC 50 (50%-effective concentration) for HIV-1 was 3.7-5.0 mcg/ml, selectivity index 28-35. Antiherpetic activity was detected at a dose of 50-100 mcg/ml. The antiviral effectiveness of melanin compounds was established both in the «preventive» (2 hours before cell infection) and in the «therapeutic» regimen of drug administration, both for HIV-1 and HSV-1. The presence of antiviral activity of melanin and HS in relation to the RNA-containing HIV-1 virus and DNA-containing HSV-1 virus in our study coincides with the results of a number of authors in relation to influenza viruses, herpes virus, HIV, hepatitis B virus, Coxsackievirus, smallpox vaccine virus, which suggests that the type of nucleic acid in the virus does not play a fundamental role in the antiviral action of these drugs. It is also clear that HS is effective against both enveloped and non-enveloped viruses.

CONCLUSION

In general, it can be concluded that melanin and humic compounds are characterized by low toxicity in the presence of both virucidal and antiviral activity. This allows us to consider the studied compounds as the basis for creating safe medicines that are effective against pathogens of various viral infections.

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.

[The role of alpha-fetoprotein in regulation of the cytokine profile of activated T-helpers and their conversion in Th17 phenotype]

We studied the effect of the native (non-recombinant) alpha-fetoprotein (AFP) on differentiation, proliferation, and cytokine profile of activated helper T cells 17 (Th17). The object of the study was a culture of isolated by immunomagnetic separation helper T cells (CD4+), induced into the Th17 phenotype by using TCR-activator and proinflammatory cytokines (IL-1β and IL-6). AFP had not significant effect on the frequency of Th17 cells (ROR-γτ+) in the helper T cell culture, and did not affect proliferation of these cells, as measured by Ki-67 expression. Evaluation of the cytokine profile of culture supernatants by using the Luminex xMAP technology, revealed that AFP did not affect the levels of IL-4, IL-5, IL-7, IL-8, IL-10, IL-17, IFN-γ and TNF-α, but at concentrations of 50 IU/ml and 100 IU/ml it increased IL-2 production by activated helper T cells. At the same time, AFP suppressed the synthesis of G-CSF and GM-CSF (10 IU/ml), but stimulated the production of CCL4/MIP-1β (100 IU/ml) and CCL2/MCP-1 chemokines (10 IU/ml and 50 IU/ml).

Development of an Immunosorbent for Solid-Phase NMR-Based Assay

The conditions for constructing an immunosorbent reagent for solid-phase NMR analysis were optimized. For this purpose, we increased the area of ​​the sensitized portion of the membrane to fit the relaxometer coil size and added the agent sorption buffer. This provided the penetration of the anti-ligand molecules into the membrane thickness and their uniform distribution.

[The influence of chorionic gonadotropin on phenotype conversion and hTERT gene expression by T-lymphocytes of different degrees of differentiation]

The effects of chorionic gonadotropin (hCG) on the expression of the hTERT gene in combination with the conversion of the phenotype of naive T-cells and T-cells of immune memory in vitro were studied. hCG inhibited expression of hTERT mRNA in naive T-cells (CD45RA+) and immune memory T cells (CD45RO+), causing a decrease in the replicative potential of the cells. The presence of hCG in the culture led to the conversion of the phenotype of T-lymphocytes. hCG reduced the number of proliferating T-cells of immune memory, estimated by phenotypic signs by differential gating. hCG (10 IU/ml and 100 IU/ml) inhibited expression of CD25 by the studied populations, but did not modulate expression of the CD71 proliferation marker. Thus, hCG inhibited the functional activity of naive T-cells and T-cells of immune memory, which, in the context of pregnancy, can contribute to the formation of immune tolerance to the semi-allogenic fetus.

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.

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.

The role of human chorionic gonadotropin in regulation of naïve and memory T cells activity in vitro

The role of human chorionic gonadotropin (hCG) in the regulation of molecular genetics factors determining the functional activity of human naïve and memory T cells in vitro was studied. It was found that hCG (10 and 100IU/ml) inhibited CD28 and CD25 expression on the naïve T cells (CD45RA+) and CD25 expression on the memory T cells (CD45R0+). hCG didn't affect the CD71 proliferation marker expression in total. Nevertheless, hCG reduced the percentage of proliferating memory T cells with simultaneous suppression of CD71 expression on proliferating CD45R0+cells. In parallel, expression of U2af1l4, Gfi1, and hnRNPLL genes, which are Ptprc gene alternative splicing regulators was evaluated. It was established that hCG stimulated the expression of U2af1l4 and hnRNPLL genes, responsible for the assembly of CD45R0 in memory T cells, but reduced the expression of Gfi1 in these cells. In general, hCG promotes the differentiation of memory T cells by increasing of CD45R0 expression, but inhibits proliferation and CD25 expression which reflects their functional activity.

Role of the pregnancy-specific glycoprotein in regulation of the cytokine and chemokine profiles of intact mononuclear cells

The effect of human pregnancy-specific glycoprotein (PSG) on the cytokine and chemokine production in vitro by intact mononuclear cells was studied by the method of flow fluorimetry. PSG inhibited production of the proinflammatory cytokines IL-6, IL-8, IL-17, IFN-γ, and TNF-α and chemokines CCL3/MIP-1α, CCL4/MIP-1β, CCL2/MCP-1; at the same time, PSG stimulated IL-12(p70) production. Simultaneously with increasing the VEGF level, PSG inhibited production of IL-9, IL-13, G-CSF, and GM-CSF. The PSG effect discovered can be interpreted as a contribution into the immune tolerance formation during pregnancy.

The effect of pregnancy-specific β1-glycoprotein 1 on the transcription factor FOXP3 expression by immunocompetent cells

The role of human pregnancy-specific β1-glycoprotein (PSG) in the regulation of expression of the transcription factor FOXP3 was studied. It is found that, under conditions of directed induction of phenotypic changes in CD4⁺ lymphocytes to regulatory T cells (Treg), PSG at high concentrations (10 and 100 μg/mL) increased FOXP3 expression. The evaluation of the spontaneous expression level of FOXP3 mRNA showed that PSG (1 and 100 μg/mL) stimulated the expression of this factor in mononuclear cells and isolated CD4⁺ lymphocytes. Thus, PSG stimulates FOXP3 expression in immunocompetent cells.

Effect of pregnancy-specific β1-glycoprotein on indoleamine-2,3-dioxygenase activity in human monocytes

The role of heterogenic human pregnancy-specific glycoprotein (PSG), obtained by the authors' technology, in the regulation of the indoleamine-2,3-dioxygenase (IDO) activity in female blood monocytes has been studied in vitro. PSG stimulated IDO activity under the conditions of induction of the monocytes by interferon-γ. Upon the induction of cell proliferation by lipopolysaccharides, the stimulating effect was obtained only with 10 μg/mL of PSG. Enhanced IDO activity is probably a factor of peripheral immunological tolerance and antimicrobial protection against intracellular infections in the gestation period.

Immunochromatographic system for diagnostics of pseudotuberculosis

We developed a model immunochromatographic test-system for serological express-diagnostics of pseudotuberculosis. Nitrocellulose membrane sensitized with species-specific antigen, Yersinia pseudotuberculosis thermostable toxin, was used as the immunosorbent. Detection of antibodies to the pathogen was performed using functionalized carbon nanoparticles. System performance was verified in testing of the reference pseudotuberculosis serum. Tests with salmonella, escherichia, and enteral yersinia diagnostic sera and blood serum from a healthy man demonstrated high specificity of the system.

[Application of diagnosticum based on functionalized carbon nanoparticles for monitoring of affine immunoglobulin purification]

A diagnostic reagent application based on carbon nanoparticles covalently functionalized by streptococcus G-protein was investigated in order to construct a system for the monitoring and optimization of the affinity purification technology of rabbit polyclonal antibodies to alpha-fetoprotein. The developed system allows semiquantitative assessment ofthe immunoglobulin content (IgG) of most higher animals and human beings in blood serum samples and eluate in a short time (45 min). IgG detection sensitivity using the carbon-G-protein diagnosticum was 80 ng/mL. Approaches to stabilizing the components of the analysis system, which ensures the preservation of their functional properties during long storage, were developed. The storage life of the diagnosticum was more than 20 years, and that of immunosorbents was more than year and a half. A technique of long-term immunosorbent storage, used in the analysis, was developed. Application of the test-system is possible without the presence of registration equipment.

[A panel of the drug-resistance HIV-1 clinical isolates]

A panel of 16 HIV-1 isolates was designed. Those isolates were isolated from patients undergoing HAART and developing resistance to the antiretroviral drugs. It was shown that the isolates were resistant to nucleoside RT inhibitors (retrovir, epivir) and non-nucleoside inhibitors (viramun). Isolates had stable replication activity. Average rate of cells expressing viral Ag was 14-20%. The infectious titer was 2.4 Ig TCID50. The sequencing showed that all isolates were of the subtype A dominating in the major part of Russian Federation. This panel could be used as the biotechnological base for studying antiretroviral drugs of new generation and for the design of experimental vaccines.

[The epidemic of human immunodeficiency virus-caused infection among users of psychotropic preparations in Russia]

The development of the epidemic of HIV infection among the intravenous injecting users of psychotropic substances in Russia in 1994-1999 is described on the basis of the data provided by territorial centers for the prevention and control of AIDS. In addition, the results of the screening in individual groups of the population of Russia for antibodies to HIV, carried out at the period of 1994 to the first half of 1999, are presented. In 1999 a considerable rise in the number of newly detected cases of HIV infection, mainly among persons injecting psychotropic drugs intravenously for non-medical purposes, was noted. The conclusion was made that the spread of HIV among drug addicts led to its passage to other groups of the population, mainly by heterosexual transmission.

[Sensitivity of Russian HIV-1 isolates to anti-HIV agents]

HIV strains isolated from HIV patients hospitalized at the Central Research Institute of Epidemiology in 1991-1993 are analyzed. HIV-1 strains isolated at different stages of the illness were referred to subtypes A and B. The biological properties of the isolates of both subtypes were virtually the same. The majority of the isolated HIV-1 strains were relatively resistant to azidothymidin, no matter whether the patients were previously treated with this drug or not. Study of strains repeatedly isolated from the same patients showed an increase of the cytodestructive characteristics of the isolates. Strains isolated from the same epidemiological chain were characterized by the same properties and sensitivity to the tested antiHIV agents. The resistance of the virus to antiHIV drugs with different mechanisms of action may be an indicator of the terminal stage of the illness.

[Morphological analysis of a cell system, infected with different strains of the human immunodeficiency virus]

Cell systems infected with 63 strains of types 1 and 2 HIV virus (HIV-1 and HIV-2) were examined under electron microscope. HIV virions were most frequently detected near the cell membrane or budding from it. In the cytoplasm HIV occurred only in vacuole-like formations. Accumulations of mature virions were seen in the cell-to-cell space. Mature particles of HIV-1 and HIV-2 differed by their morphology from oncoviral C particles and were similar rater to the Visna/Medi type Lentiviruses. Morphological analysis of HIV strains isolated in Russia demonstrated their similarity to be foreign HIV strains.

[The characteristics of human immunodeficiency virus strains isolated from HIV-infected persons on the territory of the USSR]

Fifty-seven HIV-1 strains were isolated from peripheral blood lymphocytes of 102 HIV-infected persons involved in epidemic outbreaks in different cities of the USSR. The effectiveness of isolation was 29.1% in asymptomatic infection, 51.7% in cases with generalized lymphadenopathy, and 82.6% in persons with severe clinical manifestations. Identification of the isolates by indirect immunofluorescence, ELISA, reverse transcriptase activity, Western blot, electron microscopy, and polymerase chain reaction showed them to belong to HIV-1 type. Reproduction of the isolates in cell cultures was accompanied by cytopathic effect and syncytium formation. The isolated strains can be divided into two groups: (1) the poorly growing isolates with low or negative RT and ELISA results and (2) the isolates with high infectivity, broad spectrum of cell tropism, and high levels of RT and ELISA. These data show the correlation of biological properties of HIV-1 strains isolated in the USSR with those of HIV strains previously isolated in Europe, USA, and Africa.