[Antigenic activity of human herpes virus type 8 proteins coding orfK8.1 and orf65].

A peptide scanning of the sequences of human herpes virus type 8 (HHV-8) proteins coding orfK8.1 and orf65 was made. The antigenic activity of peptides was evaluated by ELISA.

[Study of the diagnostic potential of various regions of tick-borne encephalitis virus glycoprotien E].

Bioinformation techniques were used to analyze envelope glycoprotein of tick-borne encephalitis virus in order to determine the potential diagnostically significant antigenic clusters. Five selected regions of the amino acid sequence of protein E were retranslated to nucleic sequences, by employing the optimum code for E. coli.

[Comparison of the diagnostic value of recombinant antigens and synthetic peptides that mimic the immunogenic epitopes of the envelop protein gp41 in the enzyme immunodetection of HIV-1 antibodies].

The study was undertaken to comparatively examine the efficiency of HIV antibody detection by enzyme immunoassay using recombinant antigens and synthetic peptides containing the most immunodominant region of the human immunodeficiency virus envelop protein gp41-cytotoxic T-lymphocytic (CTL) epitope. The application of the synthetic peptides that mimic this region has been to be inadequately effective. The recombinant proteins that contain the CTL epitope may be successfully used for the diagnosis of HIV-1, by using enzyme immunoassay as they show a higher sensitivity in detecting antibodies than do the synthetic peptises.

[Test for specific antibodies to virus hepatitis delta based on synthetic peptides].

Solid-phase synthesis of three linear peptides overlapping the major immunodominant epitope of HDAg, which located within amino acid (aa) segment 53-108, and peptide aa 167-179 was carried out. The structure of the peptides corresponded to the sequences of isolates HDV type I. Their antigen reactivity was studied by indirect enzyme immunoassay with sera from patients with hepatitis D and from asymptomatic carriers of anti-delta antibodies.

Characterization of monoclonal antibodies and epitope mapping of the NS4 protein of hepatitis C virus.

Recombinant DNA containing sequences of HCV NS4 protein was expressed in Escherichia coli cells. Six hybridoma clones producing monoclonal antibodies (MAB) to recombinant NS4 protein (rNS4), aa 1677-1756, were developed. Mapping with a panel of 33 peptides and reciprocal competitive EIA have shown that MAB obtained revealed five antigen determinants, not described earlier: MAB 3F11 and 3F12-one genotype-independent epitope of NS4A (aa 1700-1707) common for genotypes 1, 2 and 3; MAB 1D11-genotype-independent epitope (aa 1713-1728) and MAB 1D3-genotype (subtype 1b)-specific epitope of NS4B (aa 1711-1731); MAB 6B11 and C1-two conformation-dependent determinants in 5-1-1 region.

[Determination of type-specific synthetic peptide antibodies to hepatitis delta virus ].

Nine peptides from immunodominant (53-68 and 65-80 aa) and hypervariable (201-213 aa) regions derived from delta antigen sequences corresponding to 3 HDV genotypes were synthesized. Type specificity of antibodies to the resultant peptides was evaluated by indirect enzyme immunoassay with sera from patients with hepatitis D and asymptomatic carriers of anti-delta antibodies. Analysis of the results showed that HDV circulating in the Central Volga region belongs to type I in the majority of cases.

[Diagnostic possibilities of an immunoenzyme test-system for determining the spectrum of antibodies to structural and nonstructural hepatitis C virus antigens].

A new enzyme immunoassay EIA-HCV-Spectr test system constructed on the base of recombinant proteins and synthetic peptides allows separate detection of antibodies to E1/E2, core, HS3, NS4, and NS5 antigens of hepatitis C virus (HCV). The system is highly specific and more sensitive than the test systems used in screening studies, which allows its use as a final test for antiHCV antibodies. Antibodies to various HCV antigens were analyzed using this test system in patients with acute and chronic hepatitis C and asymptomatic donors with antiHCV.

[Determination of hepatitis G virus markers in various risk groups].

Study of prevalence of hepatitis G virus (HGV) markers in different risk groups showed the presence of HGV RNA in 3.2% blood donors, 24.2% patients with hepatitis C (HCV), and 28% patients with hemophilia.

[Antigenic activity of delta-antigen peptides corresponding to three genotypes of the delta hepatitis virus].

Six synthetic peptides from immunodominant region 65-80 aa derived from the sequences of delta-antigen corresponding to 3 HDV genotypes were obtained. Their antigenic activities were assessed by indirect enzyme immunoassay with sera of patients with hepatitis D and of asymptomatic carriers of anti-delta antibodies. Differences in antigenic characteristics of full-size 65-80 and truncated 71-80 aa peptides corresponding to three HDV genotypes were revealed.