The Differential Anti-HIV Effect of a New Humic Substance-Derived Preparation in Diverse Cells of the Immune System.

The anti-HIV activity of a new humic substance-derived preparation has been studied in individual pools of immune cells (CD4+ T lymphocytes, macrophages, dendritic cells). Near-complete inhibition of the HIV infection (by more than 90%) was achieved by treating each of the abovementioned cell types with non-toxic concentrations of the preparation. The inhibitory effect demonstrates the possibility of preventing the depletion of a significant portion of functionally important immune cells. A comparative study of infection inhibition in individual cell pools has allowed us to reveal the differences in the preparation's effectiveness in each of the cell populations. A R5-tropic HIV-1 infection in macrophages exhibited maximum sensitivity to the preparation: 90% and 50% inhibition of the infection were observed in the presence of concentrations as low as 1.4 and 0.35 µg/ml, respectively. A 15- and 19-fold higher concentration was required to achieve the same extent of inhibition in dendritic cells infected with the same strain. The effectiveness of the drug in CD4 + T lymphocytes is quite comparable to its effectiveness in macrophages. The drug is universally effective for both the T- and M-tropic variants of HIV-1.

[Rapid spread of the HIV-1 circular recombinant CRF02-AG in Russia and neighboring countries].

The spread of the HIV-1circular recombinant CRF02-AG in countries of the former Soviet union (Commonwealth of Independent States, CIS) was studies using partial and full genome sequences. The full-genome sequence of the CRF02-AG recombinant circulating in Russia was obtained for the first time. A Global phylogenetic tree of CRF02-AG full-genome sequences was constructed. Three distinct groups of the sequences were detected as clustered by the geographical location (CIS, South Korea, and France), which is indicative of the single-virus introduction in each of the regions mentioned above. The CIS cluster exhibiting minimum genetic diversity was, therefore, relatively young. The phylogenetic analysis of the env gene sequences within the CIS cluster made it possible to clearly discriminate three branches: two of Russian and one of Uzbek origin. The low genetic diversity within the two Russian subclusters provides evidence of at least two recent independent introductions of the CRF02-AG recombinant from Central Asia into Russia. This work was performed within the framework of the 7th Federal Research Program (FP&), Project EURIPRED (European Research Infrastructures for Poverty Related Diseases), grant agreement No.312661.

[Molecular epidemiology of HIV-1 strains in the Moscow Region].

The Moscow Region is one of the HIV-1-affected subjects of the Russian Federation; there were 34613 HIV-1-infected subjects as of October 31, 2009. To characterize the molecular epidemiology of HIV-1 in the Moscow Region, the investigators obtained and studied HIV-1 variants from 61 infected subjects of the region, who were major risk groups: intravenous drug users (IDUs) and hetero- and homosexually infected persons. Genetic analysis of HIV-1 variants was carried out by sequencing the gag genes (729 nucleotides in length, including full-length protein p17 and partial p24) andlor env (270 nucleotides in length, V3 region) with further phylogenetic analysis. The findings demonstrated that HIV-1 subtype A variants are dominant in the Moscow Region and detectable in 93.5% of IDUs and 100% of heterosexually infected persons. Phylogenetically (and accordingly epidemiologically) unrelated HIV-1 subtype B strains were revealed in 4 patients, including 2 IDUs.

Dehydrogenase activity of infected cells and biological properties of HIV-1 variants.

Changes in dehydrogenase activity of some continuous cell lines were studied during the response to acute infection in vitro with HIV-1 variants having different biological features. Soon after infection, the dehydrogenase activity of infected cells increased, and this increase was greater and more prolonged with the HIV-1 r/h variant than with the HIV-1 s/l variant. Later stages showed decreased dehydrogenase activity of HIV-1-infected cells compared to the noninfected control; this is a manifestation of the cytodestructive effect of the virus. The changes increased monotonously (but not in direct proportion) with an increase in the infecting dose.

[New approaches to the chemotherapy of HIV infection]. / Novye podkhody k khimioterapii VICh-infektsii.

The preclinical analysis of the effectiveness of AZT and new compounds (sulphatized derivate of chitosan (Sch) and adamantileted Sch, contents 10 and 18% of adamantine) prepared on the basis of chitosan (Ch), carried out with the use of the experimental clinical test system (the in vitro model of peripheral blood mononuclears of a concrete patient) developed in laboratory, is presented. Both combinations in concentration 0.01 mkg/ml are decreased HIV antigens till 6.4 and 8.6% accordingly, while whilst initial Sch hare caused less effect in 4-5 fold.

[A replaceable nonfrictional membrane filter for the prevention of cell culture contamination]. / Smennyi nefriktsionnyi membrannyi fil'tr dlia predotvrashcheniia kontaminatsii keltiochnykh kul'tur.

A changeable membrane filter preventing the friction between moving parts and the membrane during tight screwing of a culture flask is proposed.

[Biological properties of primary HIV-1 isolates with varying serotype]. / Biologicheskie svoistva pervichnykh izoliatov VICh-1 razlichnykh serotipov.

Russian HIV variants with common (rapid/high SI and slow/low NSI) and rare (slow/low SI and rapid/high NSI) phenotypes are described. SI variants demonstrate a higher p24 concentration level than serotype-independent NSI. The majority of SI variants belonging to A, B, and C serotypes were isolated from patients with mainly stage B3. At stages B2 and C2, when the majority of viruses are characterized by NSI phenotype, serotype D isolates are characterized only by SI phenotype. The spectrum of cell tropism was wide for all rapid/high strains and narrow for all slow/low ones.

[Culturing T-lymphoblastic cell lines in media containing growth proteins]. / Kul'tirovanie T-limfoblastoidnykh kletochnykh linii v sredakh, soderzhashchikh rostovye proteiny.

Two optimal variants of growth medium with different content of growth proteins obtained from cattle and porcine blood sera are recommended for culturing lymphoblastoid cells. Use of growth proteins helps optimize the conditions of cell culturing by ruling out the toxic effect and Mycoplasma contamination and ensures the standardization of virological experiments due to the absence of gamma-globulin fraction.

[Identification of immunoreactive epitopes in proteins coded by gag, env, and pol genes of the type I human T-lymphotropic virus (HTLV-I) using synthetic peptides]. / Identifikatsiia immunoreaktivnykh épitopov v belkakah, kodiruemykh genami gag, env i pol T-limfotropnogo virusa cheloveka tipa I (HTLV-I) s ispol'zovaniem sinteticheskikh peptidov.

Reactivity of 26 synthetic peptides that comprise 12 to 26 amino acid residues corresponding to segments of the gag p19, env gp46, and pol proteins of human T-lymphotropic virus type I toward 31 positive sera was studied using enzyme-linked immunosorbent assay. Specific reactivity with high titers of antibodies (presented in reciprocal dilution values) was detected for the synthetic peptides corresponding to fragments 110-130 and 100-130 (titers up to 4050) of p19, 174-197 (up to 800), 186-201 (up to 4050), 191-215 (up to 1350), 242-257 (up to 800), and 272-292 (up to 450) of gp46. Immunoreactivity of seven peptides, fragments of pol-proteins, was weak. New linear epitopes in the regions 145-158, 272-277, and 292-300 of gp46 were detected. In addition, location of the known linear epitopes in p19 and gp46 was refined on the basis of comparative study of overlapping peptides from these proteins.

[The detection of provirus in lymphocyte DNA. The monitoring of HIV infection at the genetic level]. / Detektsiia provirusa v DNK limfotsitov. Monitoring VICh-infektsii na geneticheskom urovne.

The presence of HIV provirus in the cell culture and in the patients' blood was studied by polymerase chain reaction followed by hybridization in solution. It was shown that: (i) the hybridized product could be detected both by gel electrophoresis and by binding on hydroxyapatite; (ii) the detection level achieved was no more than 10 infected lymphocytes per million; (iii) the hybridization signal and sensitivity of detection could be enhanced by the transcription of PCR product by the phage T7 RNA polymerase. The observed lack of complete correlation between the amount of provirus and of the p24 antigen in the patients' blood possibly reflects the peculiarities of HIV infection.

Inhibition of human immunodeficiency virus type 1 (HIV-1) penetration into target cells by synthetic peptides mimicking the N-terminus of the HIV-1 transmembrane glycoprotein.

To investigate the mechanism of action of the 22-amino-acid HIV fusion peptide on HIV infection, we studied its influence on virus adsorption and HIV-induced syncytium formation. The effect of the peptide preparations on the synthesis of viral antigens in HIV-infected cell cultures was determined by antigen capture assay, and the inhibition of proviral DNA synthesis was detected by hybridization with a HIV-specific oligonucleotide probe after PCR amplification. Fusion peptides inhibited HIV-induced syncytium formation and antigen production in lytic infected cells, and this effect was increased in conjugation with bovine serum albumin or with synthetic net-charged polymer by its C-terminus. The association of peptide with carrier by N-terminus, or with positive-charged polymer or gelatin completely abolished its effect on HIV infection. No peptide preparations influenced HIV-1 chronically infected cells. Because peptide preparations blocked the HIV-specific DNA synthesis 2 hr after infection without influencing virus adsorption and reverse transcription, we concluded that the block of infection occurred during the penetration of virions through the cell membrane. On the basis of results obtained we propose that our peptide preparations could be used for anti-HIV chemotherapy. The possibility of the existence of receptors for gp41 N-terminal region on target cell membrane is discussed.

[Inhibition of reproduction of the human immunodeficiency virus in cell culture by 2',3'-dideoxynucleoside-5'-phosphites]. / Ingibirovanie reproduktsii virusa immunodefitsita cheloveka v kul'ture kletok 5'-fosfitami 2'-3'-didezoksinukleosidov]

5'-Phosphites (5'-hydrogenphosphonates) of 2',3'-dideoxynucleosides (T, A, G, C) were synthesized and studied as inhibitors of human immunodeficiency virus type 1 (HIV-1) in MT4 and CEM13 cell cultures. It was shown that all 5'-phosphites effectively inhibit the production of viral antigens and protect cells from the cytotoxic effect of HIV infection. 5'-Phosphites were more active antiviral compounds than the corresponding nucleosides.

[The ajoene blockade of integrin-dependent processes in an HIV-infected cell system]. / Blokada adzhoenom integrinzavisimykh protsessov v sisteme kletok, infitsirovannykh VICh.

Ajoene, (E,Z)-4,5,9-trithiadodeca-1,6,11-triene-9-oxide, isolated from extracts of garlic (Allium sativum) has been previously shown to inhibit platelet aggregation by inactivating allosterically the platelet integrin, GP IIb/IIIa. The structural and functional similarity of integrins led the authors to suggest that ajoene may also inhibit adhesive interactions and fusion of leukocytes. Synthetic stereoisomers of ajoene synthesized by the authors exhibited equal antiaggregatory activities (IC100 approximately 50 microM for platelets; IC100 approximately 10 microM for fMLP-stimulated neutrophils). Racemic ajoene inhibited the fusion of H9 cells with HIV-infected H9:RF cells (IC50 approximately 45 microM; 16 h of incubation) and also exhibited a degree of antiviral activity (IC50 approximately 5 microM as assessed by inhibition of HIV-1/CEM/Lav 1 Bru replication in CEM13 cells; m. o. i. 0.1; 72 h). A considerable increase in the latter became evident when the compound was administered in aliquots of 50 microM per 12 h of incubation (inhibition by 30%; total concentration 0.25 microM; 72 h).(ABSTRACT TRUNCATED AT 250 WORDS)

[Suppression of the human immunodeficiency virus in cultured cells by 5'-phosphites of 3'-azido-2',3'-dideoxynucleosides]. / Podavlenie virusa immunodefitsita cheloveka v kul'ture kletok 5'-fosfitami 3'-azido-2',3'-didezoksinukleozidov.

5'-Phosphites (5'-hydrogenphosphonates) of 3'-azido-2'-, 3'-dideoxynucleosides are shown to be effective inhibitors of the human immunodeficiency virus (HIV-1) in MT4 cell culture. 5'-Phosphite of 3'-azido-2', 3'-dideoxythymidine was the most active among these compounds and even a little more active as compared to the well-known anti-AIDS drug 3'-azido-2',3'-dideoxythymidine; at the same time 5'-phosphites of 3'-azido-2',3' -dideoxynucleosides with adenine, guanine and cytosine bases were more active than the corresponding nucleosides. The toxicity of all four phosphites was comparatively low and the equimolar mixture of all four phosphites was 2-3 fold less toxic than each of them separately. Data on the decreased toxicity of the phosphite mixture are explained from the viewpoint of a decreased pool disbalance of natural 2'-deoxynucleoside 5'-triphosphates in cells; a significant pool disbalance is developed in the case of 3'-azido-2',3'-dideoxythymidine action.

[Isolation and characteristics of endocytic vacuoles containing the influenza virus]. / Vydelenie i kharakteristika éndotsitarnykh vakuolei, soderzhashchikh virus grippa.

Endocytic vacuoles (receptosomes) containing influenza virus were isolated from the cytoplasm of Ehrlich ascitic carcinoma cells and characterized. In the sucrose density gradient, the virus-containing material was detected in two peaks with a buoyant density of 1.175-1.16 and 1.155-1.135 g/cm3 with which the activity of marker enzymes of cell plasma membranes was associated. The virus was present in receptosomes in morphologically and electrophoretically intact condition. Examinations for the lipid composition of endocytic vacuoles showed the presence in their membranes of large amounts of cholesterol and glycolipids, particularly asialo-GM1 which, according to some authors may enhance the fusion of viral and cell membranes.

[Varying nature of the cell receptors for influenza and para-influenza viruses]. / Raznaia priroda kletochnykh retseptorov dlia virusov grippa i paragrippa.

A comparative study of receptors for influenza virus, fowl plague virus, and human parainfluenza type 3 virus was carried out. Natural receptors of guinea pig erythrocytes were destroyed with neuraminidase, and individual gangliosides GM1, GD1a, and GT1b were inserted into their membranes. The labeled virus was adsorbed on the erythrocytes modified in this manner, and the degree of restoration of the receptor activity of erythrocytes lost after neuraminidase treatment was determined. Two gangliosides, GD1a and GT1b, were found to be capable of functioning as specific receptors for influenza virus. Both gangliosides restored completely the virus adsorption on erythrocytes. In contrast, none of the three gangliosides used did not restore parainfluenza virus adsorption. It is concluded that the nature of influenza and parainfluenza virus receptors is different.

[Structural organization and proteins of the human type-3 para-influenza virus]. / Strukturnaia organizatsiia i belki virusa paragrippa cheloveka tipa 3.

The structure of human parainfluenza type 3 virus was studied by electron microscopy and virion fractionation by treatment with a detergent and high ionic strength. The protein spectrum of the virus was studied. The presence of 6 structural proteins was revealed of which two, HN and F, are glycoproteins. Intracellular cleavage of F0 protein into F1+2 proteins was demonstrated in a pulse-chase experiment. A tighter binding of HN protein than of F protein with the virus lipoprotein membrane was observed which may be useful for obtaining purified F protein preparations.

[pH-dependent hemolytic and neuraminidase activity of remantadine-sensitive and -resistant variants of influenza virus]. / pH-zavisimost' gemoliticheskoi i neiraminidaznoi aktivnosti chuvstvitel'nykh i ustoichivykh k remantadinu variantov virusa grippa.

A comparative study of pH-dependence of hemolytic and neuraminidase activities of four remantadin-sensitive influenza A virus strains CAPV (classical avian plague virus) (H7N7), USSR/090/77 (H1N1), Ann Arbor (H2N2), and Texas (H3N2) and their remantadin-resistant variants was carried out. The original strains were shown to produce hemolysis in a narrow pH range (5.0 and 5.5) and to have maximal neuraminidase activity at the same pH values. In remantadin-resistant variants the optimal pH values for hemolytic and neuraminidase activities were higher by 0.5-1.0 than for the sensitive variants.