[The purification and concentration of the rabies virus by a diafiltration concentration method]. / Ochistka i kontsentrirovanie virusa beshenstva metodom diafil'tratsionnogo kontsentrirovaniia.

Purified concentrates of rabies virus were prepared by both microfiltration chromatography and diafiltration methods. The diafiltration concentrate had a high level of protective activity and was not inferior to the microfiltration chromatographic one. The infectious activity was better retained after diafiltration, the chromatographic purity of both preparations was similar. It is concluded that diafiltration presents a good alternative to the currently used methods for purification and concentration of viruses.

[A comparison of 2 T-lymphoid cell lines persistently infected with the human immunodeficiency virus (HIV-1) with different productive capacities]. / Sravnenie dvukh T-limfoidnykh kletochnykh linii, persistentno infitsirovannykh virusom immunodefitsita cheloveka (VICh-1), s razlichnoi produktivnoi sposobnost'iu.

T-lymphoid cell lines (H9/CBL-4 and CEM/CBL-4) persistently infected with HIV-1 were observed simultaneously for 6.5 months. The virus activity was characterized by such parameters as the number of infected cells determined by fluorescent antibody technique, the total level of virus--specific protein synthesis determined by immune blotting method, and the capacity to infect H9 and CEM cells. A comparative analysis of the two cell lines helped define the evaluation criteria for high and low productivity cultures. It was shown that a short-term virus persistence could exist in high-productivity cultures and long-term persistence in low-productivity cultures. The cytopathic activity of virus in cultures could be judged by accumulation of virus protein p24 in cell-free supernatants, this being one of the factors defining the efficacy of infection of H9 and CEM T-lymphoid cells.

[The isolation and characteristics of hybridomas producing monoclonal antibodies to the structural proteins of the Vnukovo-32 strain of the rabies virus]. / Poluchenie i kharakteristika gibridom, produtsiruiushchikh monoklonal'nye antitela k strukturnym belkam virusa beshenstva, shtamm Vnukovo-32.

A series of hybridomas secreting monoclonal antibodies (MCA) to glycoprotein and nucleocapsid proteins of rabies virus strain Vnukovo-32 was selected as a result of fusion of splenocytes from immune BALB/c mice with cells of myeloma line Sp2/OAq14, screening and cloning by limiting dilution methods in semi-liquid agar. Four hybridomas secreted MCA to glycoprotein in high titres (5.0 x 10(5)-2.2 x 10(6)) and had marked virus-neutralizing and therapeutic properties. Eight hybridomas produced MCA to the nucleocapsid complex: five hybridomas secreted MCA of the G class in high titres (2.4 x 10(5)-1.6 x 10(6)) and three hybridomas secreted MCA of the M class in low titres.

[Group- and type-specific antibodies to the gag-gene protein p26 of the human immunodeficiency virus immunological type 2 in infected patients]. / Gruppo- i tipospetsificheskie antitela k belku p26 gena gag virusa immunodefitsita cheloveka 2-go immunologicheskogo tipa u infitsirovannykh.

The immunoreactivity of serum samples from HIV-2 infected persons was studied by radioimmunoprecipitation assay (RIPA) in homo- and heterotypic variants. In homotypic RIPA all sera studied have precipitated the viral glycoprotein with the high molecular weight, gp170. Some samples were active for gag-gene products, p57 and p26 in homotypic RIPA. Most these samples were also active for heterotypic gag-protein of HIV-1 serotype, p55 and p24. On the other hand anti-gag reactivity of one sample was limited only by homotypic activity. Some causes of this phenomena as well as its significance for serodiagnosis of HIV infection are discussed.

[A radioimmunoprecipitation method in the serodiagnosis of HIV infection: the development of the optimal conditions for its performance and the evaluation of the possibilities for its use]. / Metod radioimmunopretsipitatsii v serodiagnostike VICh-infektsii: razrabotka optimal'nykh uslovii postanovki i otsenka vozmozhnostei ispol'zovaniia.

The optimum conditions for using the method of radioimmunoprecipitation (RIP) for the detection of human immunodeficiency virus (HIV) in serum samples have been established. Out of several available cell lines persistently infected with HIV, specially selected line 17 has been chosen. The characteristic feature of this is the high and stable (under the conditions of prolonged cultivation) accumulation of virus-specific proteins in infected cells. The optimum conditions for making the test and its evaluation have also been established. The data of literature on the advantages of the method of RIP over such traditional methods as the enzyme immunoassay and immunoblotting have been confirmed. Thus, the presence of specific antibodies in several serum samples registered as false negative has been established. The intertypical reactivity of two serotypes of the virus, HIV-1 and HIV-2, has been studied. Cross reactivity of antibodies with respect to the HIV gene gag, but not with respect to viral glycoproteids, has been established. Ideas on the expediency and prospects of using RIP for the serological control of HIV infection are presented.

[Masking of HIV antigen by specific antibodies in a model experiment]. / Maskirovanie antigena virusa immunodefitsita cheloveka spetsificheskimi antitelami v model'nom éksperimente.

An immuno-diagnostic test system of competitive EIA detecting HIV antigen in a concentration up to 1 ng/ml has been developed. Using this system, a phenomenon of binding of HIV antigen by antibody in sera from infected persons consisting in masking of antigenic determinants was demonstrated. The "undetectability" of HIV antigen in the system of competitive EIA caused by this phenomenon is considered to be a model of clearance of antigen at the excess of antibody in vitro. The experimental results are in agreement with the suggestion that repeated HIV antigenemia occurs as a result of exhaustion of specific immune responses.

[The low frequency of false positive results in the serological detection of infectivity with the human immunodeficiency virus in collectives of healthy young people]. / Nizkaia chastota lozhnopolozhitel'nykh rezul'tatov pri serologicheskom vyiavlenii infitsirovannosti virusom immunodefitsita cheloveka v kollektivakh zdorovykh molodykh liudei.

Among 1002 foreign students examined in Odessa 11 subjects with antibody to HIV, i.e. infected with HIV, were detected. A complete agreement of the results of the enzyme immunoassay and immune blotting test was observed. The reasons of this are discussed. A specific regional distribution of seropositive subjects by their permanent residence places was revealed.

[Preparative isolation of purified antigens of the herpes simplex virus type I and a study of their immunogenic properties]. / Preparativnoe poluchenie ochishchennykh antigenov virusa prostogo gerpesa tipa I i izuchenie ikh immunogennykh svoistv.

The HSV-I-containing material prepared in chick embryo fibroblast cultures was concentrated on nuclear filters followed by chromatography on a column with large-pore silica. The MESK detergent was used for isolation of glycoproteins. The glycoprotein preparation was highly immunogenic in experimental animals.

[Expert diagnosis of infectivity with the AIDS virus using immune blotting: the development of a system and assessment of its parameters]. / Ekspertnaia diagnostika infitsirovannosti virusom SPID s pomoshch'iu immunnogo blotinga: razrabotka sistemy i otsenka ee paranetrov.

A system for serodiagnosis of infection with AIDS viruses by means of immune ("western") blotting has been developed. The system has been found to be highly sensitive and suitable for expert serodiagnosis of AIDS disease and infection with human AIDS viruses.

[Use of microfiltration and gel filtration technics for purifying and concentrating the Venezuelan equine encephalomyelitis virus]. / Primenenie mikrofil'tratsionnoi i gel'-fil'tratsionnoi tekhniki dlia ochistki i kontsentrirovaniia virusa venesuél'skogo éntsefalomielita loshadei.

A system for purification and concentration of Venezuelan equine encephalomyelitis (VEE) virus omitting large-scale ultracentrifugation was developed. The first step consists in prefiltration through large pore nuclear filters (NF) to remove large particle admixtures from the virus-containing fluid. In the second step, the resulting filtrage undergoes concentrating microfiltration through small pore NF. In this way the virus, but not total protein, is concentrated approximately 30-fold without any loss of biological activity. For VEE virus purification the next step uses gel filtration chromatography in a column with chemically modified macropore silica. In this stage, the purification factor by protein is approximately 100-fold and virus yield reaches 40%. It is suggested that the procedure used be applied for purification and concentration of a wide range of enveloped viruses.

[Preparative isolation of myxovirus glycoproteins and the study of their immunogenic properties]. / Preparativnoe poluchenie glikoproteinov miksovirusov i izuchenie ikh immunogennykh svoistv.

Preparative isolation of glycoproteins from ortho- and paramyxoviruses is described. The purified concentrated virus has been treated with nonionic detergent MESK with subsequent removal of viral cores by centrifugation. Supernatant was sterilized by filtration through the nuclear filters and cleared from detergent by dialysis. Glycoproteins obtained have not contained contaminating cellular or core viral proteins or viral shell lipids. In the absence of detergent, glycoproteins have formed the peculiar mycelial complexes. Biological activity of glycoproteins was kept at high level. Glycoproteins output at isolation from different strains of influenza viruses A, B and Sendai virus varied from 75 to 98%. Immunogenetic study of the preparations obtained has demonstrated their capability to stimulate the formation of antibodies against both viral glycoproteins comparable with the capability of intact virus. The obtained level of immunity was enough to protect organism against homologous infection. Samples of glycoproteins obtained are up to standards for subunit vaccines, and the technique of their preparation is perspective as far as the production of vaccine preparations is concerned.