[Production and characterization of a panel of monoclonal antibodies to Toxoplasma gondii antigens]. / Poluchenie i kharakteristika paneli monoklonal'nykh antitel k antigenam Toxoplasma gondii.

A representative collection was obtained containing 68 monoclonal antibodies (MAB) to Toxoplasma gondii antigens, which was characterized by the binding with the below fractions of tochizoites in the immune-enzyme assay (IEA) and immunoblotting (IB): membrane (MEM), somatic (water-soluble, SOM) and excretory-secretory (ES). Most of MABs were produced to MEM antigens (43), 6 MABs reacted with the somatic fraction, and 3 MABs reacted with both fractions. Two MABs to ES antigen were detected in the latter group. An analysis of MABs in concurrent IEA and IB revealed the immune-dominant proteins of the MEM and SOM fractions of antibodies to T. gondii tochizoites (p30 and p27, respectively). The presence of 2 non-overlapping antigenic determinants was shown for p30. Further research would detect MABs that could be used in the diagnosis of toxoplasmosis.

[Construction and study of antigenic characteristics of recombinant salmonella strain producing TBI protein]. / Konstruirovanie i issledovanie antigennykh svoistv rekombinantnogo shtamma sal'monelly, produtsiruiushchego belok TBI.

A recombinant strain producing TBI protein (artificial protein containing HIV-1 B and T cell epitopes) was constructed on the base of attenuated Salmonella typhimurium SL7207 strain and BALB/c mice were immunized with this strain in a dose of 10(9) live cells orally or rectally. A single immunization with the recombinant salmonella strain induced humoral and cellular immune response to HIV-1; hence, this strain is a promising candidate for vaccine against HIV.

[Molecular construction of experimental combined vaccines]. / Molekuliarnye konstruktsii éksperimental'nykh kombinirovannykh vaktsin.

A method for designing molecular constructions of combined artificial immunogens mimicking viral particles is proposed. Using this method, it is possible to expose antigenic determinants of any viral protein on the surface of such particles and to deliver plasmids containing genes encoding the synthesis of protein antigens to target cells. This approach was used to create the constructions of combined artificial immunogens inducing the production of specific antibodies to HIV-1 and to evaluate the extent and duration of B-cellular immune response depending on the way of antigen exposure to immunocompetent cells.

[Recombinant antibodies to tick-borne encephalitis virus]. / Rekombinantnye antitela k virusu kleshchevogo éntsefalita.

A gene encoding the dimeric form of single-chain antibody fragments (scFv) was designed on the basis of the artificial gene coding monomeric scFv to tick-borne encephalitis glycoprotein E. The sequence encoding histidine oligomer was added to 3'-ends of the genes encoding the monomeric and dimeric forms of scFv antibodies. Escherichia coli strains were constructed for the production of monomeric and dimeric antibodies. These antibodies were purified using Ni-NTA resin. The specificity of the purified monomeric and dimeric antibodies in the binding reaction with tick-borne encephalitis virus was shown by ELISA and Western-blot analysis. The identity of glycoprotein E epitope bound by monomeric and dimeric scFv and parental monoclonal antibodies E6B was confirmed by competitive immunoassay.

[Comparative study of the effectiveness of HBcAg presentation to the immune system using attenuated Salmonella strains, serovars S.enteritidis and S.typhimurium]. / Sravnitel'noe issledovanie éffektivnosti predstavleniia immunoi sisteme HBcAg s pomoshch'iu attenuirovannykh shtammov Salmonella serovarov S.enteritidis i S.typhimurium.

In this work the results of obtaining HBcAg-producing attenuated Salmonella strains, serovars S. enteritidis and S. typhimurium, and their comparative study is presented. As revealed in this study, attenuated S. enteritidis strain E-23 and S. typhimurium strain T-10, producing HBcAg, induce cell-mediated and humoral immune response to HBcAg after injected into anovals. After injection S. typhimurium strain T-10 induces a much higher titer of specific antibodies than S. enteritidis strain E-23. The level of specific antibodies induced by recombinant HBcAg seems to correlate with the capacity of salmonellae for survival inside macroorganisms.

[Isolation and study of recombinant strains of Salmonella typhimurium SL 7207, producing HBcAG and HBcAG-HBs]. / Poluchenie i issledovanie rekombinantnykh shtammov Salmonella typhimurium SL 7207, produtsiruiushchikh HBcAg i HBcAg-HBs.

Recombinant strains producing hepatitis B virus (HBcAg) core protein and chimeric core protein exposing on its surface the major immunogenic epitope of HBsAg (HBcAg-HBs) were constructed on the base of attenuated S. typhimurium SL 7202 strain. The resultant Salmonella strains produced proteins which were capable of self-assembly into virus-like particles and showed antigenic properties of both core and surface hepatitis B proteins. A single rectal immunization with recombinant S. typhimurium induced humoral and cellular immune response to HBcAg and HBsAg. Specific anti-HBcAg were detected in animal sera and intestinal tissues, which indicated the formation of specific mucosal immunity.

[Expression of the gene for vaccinia virus 36K nonstructural protein in Escherichia coli and study of the protective properties of expression products]. / Ekspressiia gena nestrukturnogo belka 36K virusa ospovaktsiny v Escherichia coli i izuchenie protektivnykh svoistv produktov ékspressii.

The nonstructural 36K protein of vaccinia virus (VV) mapped in HindIII-P and HindIII-J fragments of VV strain L-IVP has been expressed in E. coli as a fusion protein. The products of 36K gene preserved the antigen homology with the native protein 36K and the capacity to bind specific immunoglobulins of rabbit antiVV serum. The protective properties of 36K gene products and their joint effect with the immunodominant protein 35K were investigated. The non-structural 36K gene products showed no protective activity, but increased the production of specific antibodies in mice immunized with a mixture of both protein preparations, this increase being compatible with that observed after immunization with the inactivated virus preparations.

[Changes in antigenic properties of the p35 protein of vaccinia virus in various protein fractions of the virion with the use of monospecific antisera]. / Izmenenie antigennykh svoistv belka P35 virusa ospovaktsiny v sostave razlichnykh belkovykh fraktsii viriona s pomoshch'iu monospetsificheskikh antisyvorotok.

Three monospecific antisera to the major 35 kD (p35) surface protein of vaccinia and ectromelia viruses have been obtained. Two of them are obtained to p35 protein isolated by electrophoresis in the presence of sodium dodecylsulfate from the protein fractions of vaccinia virus, soluble in NP40 and NP40 with dithiothreitol (NP40 and DTT-fractions). The third serum is obtained to NP40-fraction of ectromelia virus, containing practically only p35 protein. The obtained antisera were compared in the reactions with the different fractions of viral proteins in two versions of solid phase radioimmunoassay. The effect of such reagents as sodium dodecylsulfate, NP40, 2-mercaptoethanol, ethanol on the antigenic properties of p35 protein from vaccinia virus is discussed.