[The dynamics of the formation of IgG subclasses in Balb/c and CBA mice infected with the LCM, Lassa and Mopeia viruses and their role in diagnosis]. / Dinamika obazovaniia podklassov IgG u myshei Balb/c i CBA pri zarazhenii virusami LKhM, Lassa, Mopeiia i ikh rol' v diagnostike.

The dynamics of the induction of individual IgG subclasses in BALB/c and CBA mice and their role on the diagnostics of arenaviruses LCM, Lassa and Mopeia was studied. The study demonstrated that in solid-phase enzyme immunoassay (EIA) isotypes IgG2a and IgG2b to virus Mopeia could be used for the differentiation of virus Mopeia from viruses LCM and Lassa, and the antigen of virus Mopeia could be used for the preparation of diagnostic EIA systems not only to nonpathogenic virus Mopeia, but also to pathogenic viruses LCM and Lassa.

[The localization and preliminary characteristics of antigenic sites (B epitopes) in the nucleocapsid protein of the Lassa virus]. / Lokalizatsiia i predvaritel'naia kharakteristika antigennykh saitov (B-épitopov) v belke nukleokapsida virusa Lassa.

Nucleocapsid protein of Lassa virus contains 4 epitope sites. Three of them were localized in amino acid position 123-1 27, 337-346, and 518-527. Monoclonal antibody 1108 specific to Lassa virus NP-protein reacted with 123-127 synthetic peptide in solid-phase ELISA and precipitated nucleocapsid proteins of Machupo, Tacaribe, and Mopeia arenaviruses in RIP.

[The immunogenic activity of the Lassa virus structural proteins]. / Immunogennaia aktivnost' strukturnykh belkov virusa Lassa.

The immunogenic properties of Lassa virus GP1, GP2, and NP polypeptides were studied in rabbits. Lassa virus NP polypeptide, in contrast to GP1 and GP2 polypeptides, was shown to induce the highest titres of antibodies determined by IFA and ELISA tests. Moreover, the antibody relative avidity experiment showed that the anti-NP antibodies has ELISA index of 0.63 whereas anti-GP1 and anti-GP2 antisera had those of 0.49 and 0.28, respectively.

[Monoclonal antibodies to the Machupo virus: their isolation and preliminary characteristics]. / Monoklonal'nye antitela k virusu Machupo: poluchenie i predvaritel'naia kharakteristika.

Six monoclonal antibody-producing hybridoma cell lines were generated by fusion of NS-1 myeloma cells with BALB/c immune splenocytes. Monoclonal antibodies (MCA) specific to Machupo virus NP protein were used to study cross-reactivity between pathogenic and nonpathogenic arenaviruses. It was shown that 3140 MCA cross-reacted in IFA with Lassa, Tacaribe, and Tamiami arenaviruses whereas 3101 MCA reacted with Machupo virus alone. It was assumed that these 3101 MCA could be used for differentiation of Machupo virus in IFA.

[The detection of the Marburg virus antigen by solid-phase immunoenzyme analysis]. / Vyiavlenie antigena virusa Marburg metodom tverdofaznogo immunofermentnogo analiza.

Comparative studies of two variants of the enzyme-linked immunosorbent assay (ELISA) were carried out to determine the sensitivity of the detection of Marburg virus antigens in Vero cells. Both competitive and two-antibody ELISA variants detected as little as 5 ng of Marburg virus antigen. The Vero cell monolayer was found to produce 5-50 ng/0.05 ml of the virus-specific proteins at 6 to 8 days postinfection.

[The production of antibody-producing hybridomas to the Lassa virus]. / Poluchenie antiteloprodutsiruiushchikh gibridom k virusu Lassa.

The work deals with obtaining hybrid cell lines producing monoclonal antibodies to Lassa arenavirus. To obtain preparations for the screening of hybridomas by indirect immunofluorescence techniques, the dynamics of the accumulation of Lassa virus antigen in cell cultures Vero and 4647 was studied. The maximum accumulation of the virus antigen in Vero cells was shown to occur on day 3 after inoculation with a dose of 1.0 PFU/ml. The influence of different doses of gamma radiation on the infectious and antigenic activity of the virus was studied. The expediency of using a dose of 20.0 kGy for the irradiation of the virus was shown. The optimum schedule for the immunization of BALB/c mice was worked out, which made it possible to obtain activated mouse spleen cells used for the construction of hybridomas. The capacity of hybrid cells, injected into syngeneic mice, for the generation of tumors was shown.

[Recombinant monoclonal antibodies to the Lassa virus: the formation of reactive paratopes]. / Rekombinantnye monoklonal'nye antitela k virusu Lassa: formirovanie reaktivnykh paratopov.

Eighteen hybrid lines secreting recombinant monoclonal antibodies to Lassa virus were produced by fusion of mouse splenocytes with antibody-secreting X-63 myeloma cells. Interrelations between the structure and reactivity of the antibodies were studied by different serological and immunochemical methods. Monoclonal antibodies were divided into different groups according to their serological properties and macromolecular structure. A comparative analysis of the structure and reactivity of the recombinant monoclonal antibodies showed that the light and heavy Ig-specific chains could form the reactive antibodies when the chains were present in different paratopes of Ig molecules.

[The isolation and characteristics of recombinant monoclonal antibodies to the Lassa virus]. / Poluchenie i kharakteristika rekombinantnykh monoklonal'nykh antitel k virusu Lassa.

Recombinant monoclonal antibodies to Lassa virus were produced. The reactivity of the monoclonal antibodies was studied by indirect fluorescence antibody (IFA) technique, enzyme-linked immunosorbent assay (ELISA), and radioimmunoprecipitation method. The observed reactivity did not correlate with IgG isotyping groups.

[Immunization of rabbits with Lassa virus]. / Immunizatsiia krolikov virusom Lassa.

The parameters of humoral and cell-mediated immunity after inoculation of the infectious and inactivated antigen of Lassa virus to rabbits which are insusceptible to this infection were studied. Lassa virus antigen was demonstrated to induce synthesis of specific antibodies in rabbits the level of which was proportional to the dose of inoculation and the time of immunization. The results of leukocyte blastogenesis test and delayed type hypersensitivity test confirm the development of sensitization to inactivated Lassa virus in immune rabbits.

[Characteristics of monoclonal antibodies against Lassa virus]. / Kharakteristika monoklonal'nykh antitel k nukleoproteidu virusa Lassa.

Some properties of monoclonal antibodies to the Lassa virus have been characterized. The competitive immunoenzyme analysis has revealed the presence of at least three antigens in the Lassa virus nucleoprotein.