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Nonspecific endogenic DNAase has been isolated from biomass of Mycoplasma fermentans PG-18 cells and purified to the homogeneous state. The scheme of isolation consists of purification stages on columns with phosphocellulose, DNA-cepharose CL-8B and phenylcepharose. DNAase was not bound to phosphocellulose, its volume was equal to zero. Then this DNAase was passed through column with DEA-cepharose CL-6B (elution by gradient KCl from 0.1 to 1.8M): enzyme was eluted at KCl concentration in the eluting buffer from 0.1 to 1.2 M. The enzyme was purified to the homogeneous state on column with phenylcepharose (elution by linear gradient of ethylene glycol from 30 to 80%): enzyme was eluted at the concentration of ethylene glycol in the eluting buffer from 43 to 80%. According to data obtained using gel-electrophoresis, under the denaturing conditions molecular mass of enzyme in acrylamide gel was 34 kDa.

The synthesis of HIV-1 (IIIb isolate) structural protein in chronically (CI) and acutely infected (AI) MT4 cells was studied. During long-term cultivation the CI system was characterized by high involvement of the cells into infection (up to 100%), high level of virus-specific protein synthesis, moderate virus yield, but absence of any virus-induced cytopathic effects and normal growth potential of infected cells. AI cells demonstrated a similar level of synthesis of virus specific proteins, higher virus yield, and rapid progression of cytopathicity followed by total cell death. Most of the HIV gp160 protein molecules undergo rapid cleavage in the region between the point of conventional cleavage and the transmembrane domain, being removed from the physiologically competent pool, but a small portion of gp160s undergo apparently normal intracellular development. According to our data, the two HIV variants (normal and defective) persist in CI system and pathological cleavage of defective virus gp160 protein results most probably in chronization of infection.

HIV strains were isolated from HIV-infected patients and AIDS patients in CIS. A total of 81 HIV isolates were obtained. The isolates were identified by using immunofluorescence and enzyme immunoassay, by determining the activity of reverse transcriptase, immunoblot, electron microscopy, polymerase chain reaction. Of the 81 isolates 79 were HIV-1 and 2 HIV-2. The strains differed in their infectivity, the kinetics of virus antigen accumulation, and the spectrum of susceptible cell lines. The viruses isolated may be assigned as two groups: high and low infective. The biological properties of the national HIV isolates were shown to be similar to the prototype HIV strains isolated elsewhere.

The transient expression of the HIV-1 gag genes and a HIV-1 ++trans-activator protein (tat)-encoded was made in cultured CV-1 cells. In recombinant plasmids, the gag gene was under the control of HIV-1 ++trans-activator sequence (tar) and the tat gene was under the control of a 7.5-kd vaccinia promoter. Transactivation of gag gene expression, which was stimulated by a tat gene expression product, was observed in the presence of wild vaccinia virus. The transaction was immunologically evaluated from the binding to monoclonal anti-p17 and anti-p24 antibodies. The findings lead to the discussion whether the regulatory proteins of HIV-1 can express in vaccinia virus vectors.

During the experiments 4 murine and 3 rat hybridomas producing monoclonal antibodies (MAb) against the protein p24 of human immunodeficiency virus type 1 (HIV-1) have been obtained. Using the immunoblotting technique, it was established that all the species of MAb reacted with the same viral proteins which are derivatives of gag gene--p24 and p55. The properties of MAb have been studied in competitive binding. Their ability of binding to different fragments of the gag protein produced by the recombinant plasmids in E. coli cells have been investigated in ELISA. The analysis of the findings suggests that the HIV-1 protein p24 contains at least 3 antigenic epitopes. All species of MAb reacted with 3 different HIV-1 strains and 2 HIV-1 isolates, but failed with 2 different HIV-2 strains. The only MAb NS5E4 can be used as an immunosorbent in the antigenic capture reaction.

The comparative study of HIV-positive and clinically healthy persons has indicated that the antigens of M. pneumoniae, M. fermentans and U. urealyticum are encountered nearly twice more frequently in the blood of HIV-infected patients than in that of healthy individuals. Mycoplasma antibodies are detected in HIV-positive persons 12 times more frequently than in healthy ones. Among the HIV-infected persons there are those who have simultaneously antigens of some Mycoplasma species.

A chronically HIV-1-infected culture of continuous human monocytes producing infectious virus during long-term continuous cultivation (over 200 passages) without the addition of noninfected cells was generated. HIV-1 produced by this culture had typical morphology and complete set of virus-specific proteins. This cell line is proposed for use as an additional model for the evaluation of antiviral effects of various drugs.

Biological properties of an AIDS agent first isolated from a native citizen in the USSR are presented. The source of the virus was a young Byelorussian woman who in the near past had had sexual contacts with a citizen from one of the Central Africa countries. The isolate is thought to be of HIV-I type. It replicated perfectly in many continuous lymphocyte lines and had HIV-characteristic morphology. The protein spectrum of the isolate was gp120, gp41, p65/51, p55, p32, p24, p17. Reverse transcriptase activity was detected in the culture fluid of the virus-containing cell cultures. The isolate was designated HIV-IZ.

The authors have examined the effect of a Tr. rubrum infection on HIV reproduction in H9 cell culture. A statistically significant activation on HIV multiplication has been observed 24 hrs after cell culture infection with the fungus: the infected cells produced more viral particles than the reference cells. The number of HIV virions has been increased mainly at the sites of Tr. rubrum localization and near H9 cell sites containing phagocytized elements of the fungus. In case of a mixed infection abnormal HIV forms (minimal and giant ones) have been detected along with the common virions. The ability of HIV virions to adsorption on Tr. rubrum surface has been revealed.

The comparative study of the amino acid sequence of gp120 in human immunodeficiency virus (HIV) strains HTLV-III and ARV-2 and the amino end areas of the growth hormone receptors of human skin and the insulin receptors has been carried out, thus making it possible to predict the existence of two compact domains connected with an area of a peptide chain. This area is incapable of the formation of a compact globular structure due to a high content of the remnants of proline. The data obtained as the result of electron microscopic study in combination with image processing have confirmed the predicted three-dimensional structure of gp120. This study has also shown that the amino acid sequence of some regions in the domains of gp120 has a significant degree of homology with similarly located regions of the growth hormone and insulin receptors; in its turn, this amino acid sequence is homologous to the framework regions of the VH domain of immunoglobulin. Antibodies to this VH domain specifically react with recombinant HTLV-III antigen. On the basis of the data obtained in our experiments and from the analysis clinico-immunological information, we have come to the conclusion that AIDS is an autoimmune disease induced by HIV due to the structural homology of gp120 with highly important receptors of human cells.

The authors have investigated the antibody binding with individual HIV protein by "western" blotting method. The optimal condition for binding was incubation of nitrocellulose strips at 37 degrees C for 2 hrs followed by incubation at 4 degrees C overnight. Differences in the serologic activities of a number of sera in "western" blotting were shown by using two different antigens. It was concluded that mixing of different antigens before electrophoresis may be useful for more effective "western" blotting analysis.

The results of HIV virus isolation from patient A. T., resident of Central Africa, are discussed, in whom Kaposi sarcoma was diagnosed clinically and histologically, and immunological examinations revealed the acquired immunodeficiency syndrome (AIDS). Cocultivation of the peripheral blood leukocytes of the patient with normal donor leukocytes yielded a leukocyte culture in which HIV virus expression was demonstrated. The HIV antigen was detected in the ultracentrifugate of the cultures by means of indirect enzyme-immunoassay using sera to the virus from the standard kits of Organon (Netherlands) and Abbot (USA). HIV antigen was also detected on the surface of lymphocytes in the culture by indirect immunofluorescence using the same sera. Besides, reverse transcriptase activity was demonstrated in ultracentrifugates of the culture fluid by exogenous reverse transcription test using poly(zA)-oligo(dT) matrix.

The growing pandemia of AIDS, which resulted in about 40,000 AIDS patients and about 3 million infected persons by the end of 1986, demands for the urgent creation of methods for diagnosis, prevention and treatment of the disease. The present paper analyzes the main aspects of AIDS immunobiology, i. e. the molecular genetics of the virus, production of the viral components, construction of kits for immunoenzyme detection of antibodies to the virus, development of confirmatory immunoenzyme assays. The authors discuss the prospects of creating the synthetic antigens of the AIDS virus or producing them on the basis of genetic engineering both for the diagnosis and prophylaxis of the infection.