[Isolation and cloning of gene for hepatitis delta antigen. The use of recombinant antigen for serodiagnosis of delta infection]. / Vydelenie i klonirovanie gena antigena virusa gepatita del'ta. Ispol'zovanie rekombinantnogo antigena dlia serodiagnostiki del'ta-infektsii.

Hepatitis delta virus antigen was isolated from a patient by reverse transcription and polymerase chain reaction. Gel-purified cDNA was cloned in E. coli expression vectors. High expression of the recombinant HDAg in bacteria was observed. The minor and major forms of HDV antigens were simultaneously expressed in bacterial strains carrying SupE mutation. A laboratory method is developed for detecting anti-HD in patients' blood. It is based on the use of minor and major forms of recombinant HDV antigen immobilized on the same membrane filter. The method can be used for creating an original highly specific test system.

[Determination of nucleotide sequences of Russian isolates of delta hepatitis virus]. / Opredelenie nukleotidnykh posledovatel'nostei rossiiskikh izoliatov virusa gepatita del'ta.

Genome RNA of hepatitis Delta virus (HDV) was isolated from the blood sera of 4 independently infected patients. The genome fragment of 901-1265 was obtained for each isolate by the RT-PCR. The resultant sequences showed that all isolates belonged to HDV genotype I. Russian isolates were shown to be closely related to an Italian one (98.1-97.5% and 97.1-95.1% identity for the nucleic acid and amino acid levels, respectively); they may represent an extra subtype within genotype I. No appreciable differences between the Russian strains were found, which fact may reflect a possible homogeneity of HDV population in North-Western Russia.

[The comparative characteristics of test systems for the diagnosis of viral hepatitis D]. / Sravnitel'naia kharakteristika test-sistem dlia diagnostiki virusnogo gepatita D.

Three Russian enzyme immunoassay kits for the detection of antibodies to hepatitis D virus (delta virus) in the blood serum were compared. Labsystems test kit was the control. Two of the examined kits were found sufficiently sensitive and specific, comparable with those of the imported agent.

[The frequency of antibodies against delta virus in patients with HBs positive hepatitis]. / Chastota antitel k del'ta-virusu u bol'nykh HBs-pozitivnym gepatitom.

Patients with HBsAg-positive hepatitis were screened for antibodies to HDV and HCV. The incidence of anti-HDV was 12.5% in a sample of 265 patients. The values differed appreciably in men and women, patients with chronic and acute hepatitis, narcomaniacs and subjects taking no narcotics. Antibodies to HDV were more incident in anti-HCV-positive than in anti-HCV-negative patients. The age-specific structure of the sampling has been analyzed and the distribution of HDV, HCV, narcomania, and chronic hepatitis markers for age groups has been determined. A high incidence of mixed (double and triple) infections with hepatotropic viruses has been revealed.

[Oligomeric forms of recombinant interleukin-2]. / Oligomernye formy rekombinantnogo interleikina 2.

Human recombinant interleukin 2 produced by Escherichia coli gives rise to oligomeric forms that are stable to complete denaturation. The appearance of these forms is preceded by the formation of oligomers sensitive to reduction. These processes depend on the cell status and seem to be associated with aggregation of the reaction product.

[Molecular chaperones: new proteins--new functions]. / Molekuliarnye shaperony: novye belki--novye funktsii.

A new class of cellular proteins named "molecular chaperones" has been described recently. Chaperones prevent from improper interactions either within or between polypeptide chains, which could produce incorrect structures. Chaperones assist in assembly or disassembly of oligomeric structures and in protein transport across membranes. There are three conservative families of chaperones and a few unrelated members. Some of them appeared to be stress proteins with yet unknown function. Mechanism of action and specificity of chaperone binding are under investigation now.

[A study of the intracellular fate of recombinant human interleukin 2 in Escherichia coli]. / Issledovanie vnutrikletochnoi sud'by rekombinantnogo chelovecheskogo interleikina 2 v Escherichia coli.

The expression of the human IL-2 recombinant gene in E. coli cells was studied. The processes which take place during thermo-induced expression and effect the state of the product were investigated. Experimental data on the membrane localisation of IL-2, the formation of aggregates (inclusion bodies) and polymers were obtained. It was determined that temperature significantly influence the kinetics of the processes of intracellular IL-2 production and IL-2 stability. It is supposed that the cell membrane state plays a determining role in these processes via temperature mediation. Thus, the formation of inclusion bodies described for a number of E. coli recombinant strains is probably stipulated not only by recombinant polypeptides properties, but also by cellular interactions.