[The antiviral action of recombinant forms of the human T-lymphocyte CD4 receptor]. / Protivovirusnoe deistvie rekombinantnykh form CD4-retseptora T-limfotsita cheloveka.

A recombinant protein containing the first 179 N-terminus amino acids of human T-lymphocyte CD4-receptor was synthesized in E. coli cells. This recombinant protein was shown to interact with OKT4A and Leu3a monoclonal antibodies competing with HIV gp120 glycoprotein for binding with the native CD4 receptor. Experiments in vitro in human T-lymphocyte cultures showed that the recombinant CD4-protein in concentrations of 1 to 10 micrograms/ml inhibited the virus-induced syncytium formation, HIV replication in cell culture, synthesis of HIV reverse transcriptase and other virus-specific proteins, that is, behaved as a HIV inhibitor.

[The isolation and characteristics of monoclonal antibodies to recombinant proteins of HIV-1 and HIV-2--the env and gag gene products]. / Poluchenie i kharakteristika monoklonal'nykh antitel k rekombinantnym belkam VICh-1 i VICh-2--produktam genov env i gag.

Ten hybridomas secreting monoclonal antibodies (Mab) against recombinant HIV-1 and HIV-2 antigens were produced (3 Mab anti-gag protein, 2 anti-env1, and 5 anti-env2). In the immunoblotting assay all the anti-gag Mabs reacted with HIV capsid protein p24, whereas one of them reacted also with p55 protein and with 7 other polypeptides. Another anti-gag Mab cross-reacted with the antigen of subpopulation of human peripheral blood lymphocytes. The third one interacted with the antigen of both HIV-1 and HIV-2. All the 10 Mabs interacted with natural HIV antigens and can be used for identification and differentiation of HIV-1 and HIV-2.

[Characteristics of Namalwa cells--a substrate for production of human interferon]. / Kharakteristika kletok Namalwa--substrata dlia polucheniia chelovecheskogo interferona.

The properties of lymphoid Namalwa cell line propagated at the USSR Academy of Medical Sciences Research Institute of Viral Preparations for interferon production are described. The scanning and transmissive electron microscopy studies of the cells showed their morphological stability and the absence of microbial contamination. The 46-48-chromosome cells comprised 85% of the population, hypodiploid cells (44-45 chromosomes), 9%, tetraploid and hypertetraploid cells, 3%. Spontaneous aberrations were detected in 3% of the chromosome. Inoculation of the cells into unsuppressed laboratory animals (rabbits, guinea pigs, adult or suckling mice) or chick embryos did not cause the development of any pathological process. Namalwa cells were shown to produce interferon after multiple (up to 4 times) induction with Newcastle disease virus.

[Isolation of purified and concentrated human interferon from Namalwa cells]. / Poluchenie ochishchennogo i kontsentrirovannogo chelovecheskogo interferona iz kletok liniii Namal'va.

The interferon produced in the cultured Namalwa cells was purified and concentrated according to the method of K. Cantell and S. Hirvonen developed for purification of leukocyte interferon. A preparation concentrated 500-fold had the antiviral activity of 10(6) IU/ml at a specific activity of 1-3 X 10(6) per 1 mg of protein. The amount of protein in the preparation was approximately 0.6 mg/ml, that of cell DNA less than 100 ng/ml. The experiments demonstrated that the virus inducer of interferon and possible contaminant viruses were removed on purification. The preparation had no oncogenic potency on inoculation of newborn Syrian hamsters, was harmless by intraperitoneal inoculation of mice and on multiple inoculations on rabbit eye cornea, was not toxic in cell cultures.

[A new rabies vaccine in public health practice in the USSR]. / Novaia antirabicheskaia vaktsina v praktike zdravookhraneniia SSSR.

A new antirabies vaccine prepared on the basis of virus grown in the ovine brain, purified from 85-90% of brain-tissue ballast substances and inactivated with beta-propilactone has been developed at the Moscow Research Institute of Viral preparations (USSR Acad. Med. Sci.). The preparation produces no neuro-allergenic effect in tests on guinea pigs. When injected to humans, the vaccine shows much lower reactogenicity than Fermi vaccine. High antigenic and immunogenic activity of the new vaccine has made it possible to work out a less intensive immunization schedule in comparison with that used for immunization with Fermi vaccine and nonconcentrated tissue-culture vaccine, viz. doses of 3 ml for 12 days or doses of 3 ml for 20 days with two booster immunizations. The preparation has been introduced into medical practice.

Preparation of Hybridomas producing monoclonal antibodies against human interferon.

To prepare hybridomas secreting monoclonal antibodies (MoAb) against human alpha-interferon (alpha-IFN), BALB/c mice were immunized with IFN produced in Namalwa cells. Native alpha-IFN, as well as partially purified or on cellulose adsorbed alpha-IFN preparations were used for immunization. Seven hybridomas continuously secreting IgG against human alpha-IFN were prepared by fusion of splenocytes from immunized donors with the mouse myeloma cells. MoAb reacted in ELISA as well as in neutralization test with human lymphoblastoid, leukocytic and recombinant alpha-IFN.

Interferonogenicity of rabies vaccines as related to their therapeutic and prophylactic activities.

Non-interferonogenic rabies vaccine prepared from a virus grown in sheep brain and devoid of neuroallergenic factor and an interferonogenic vaccine from the same virus strain cultured in Japanese quail embryo cells have been compared. In mouse experiments both preparations appeared to have identical therapeutic and prophylactic efficacy. It seems that interferonogenicity of rabies vaccines cannot be used as a criterion of their prophylactic or therapeutic effects. The effectiveness of exogenous and endogenous interferon (IFN) in mice infected by the highly pathogenic fixed rabies virus has been experimentally demonstrated. Combined application of the vaccine and IFN or its inducer exerted the most marked therapeutic effect. Administration of IFN inducer into mouse brain was much more effective than its extraneural inoculation.

Characteristics of cellular and humoral immune responses after immunization with different rabies vaccines.

Three rabies vaccines were compared: 1. the Fermi type vaccine, a phenol-treated suspension of brain tissue from infected sheep; 2. a virus grown in sheep brain, purified from the contaminating material to 85-90% and inactivated with beta-propiolactone; 3. and the MNIIP-74 strain cultured in Japanese quail embryo cells and inactivated with beta-propiolactone. A single immunization of mice with any of the preparations resulted in about 50% inhibition of splenocyte migration after 2 days; by day 15 the inhibition was 95-98%. By day 45 the migration index returned to the initial level. Increased ability to blast transformation in splenocytes was found by day 15, reached the maximum (160 to 212% of the control level taken for 100%) by day 30, and then began to decrease. The most marked change in blast transformation was brought about by the purified cerebral vaccine, while the less marked one by the tissue culture vaccine. The titre of virus-neutralizing antibodies reached a maximum after 15-30 days, 60 days after immunization it dropped twice. The resistance of mice to intracerebral infection with the rabies virus shortly after immunization might be due to cellular protective factors, while at later intervals it correlated with the level of virus-neutralizing antibodies.

[Results of human immunization with a new rabies vaccine containing no neuroallergenic brain tissue factor]. / Rezul'taty immunizatsii liudei novoi antirabicheskoi vaktsinoi, ne soderzhaschei neiroallergennogo faktora mozgovoi tkani.

Immunization with a vaccine prepared from sheep-brain-grown fixed rabies virus inactivated with beta-propiolactone was given to 146 subjects. The vaccine was by 80-90% purified from waste brain tissue substances (protein content less than 2 mg/ml) and showed no neuroallergenicity in guinea pig tests. Simultaneously 86 subjects were vaccinated with commercial Fermi vaccine. Immunization was performed according to the schedules accepted in the USSR. The new vaccine produced much fewer local reactions than Fermi vaccine (in 39.6% and 60.9% vaccinees, respectively) and 5 times as few systemic reactions (in 6.03% and 31.3% vaccinees, respectively). The antigenic potency of the new vaccine was as good as that of Fermi vaccine.

Rabies vaccine prepared from the virus grown in Japanese quail embryo cell cultures.

Fixed rabies virus strain MNIIVP-74 was grown in Japanese quail embryo cell cultures, concentrated by ultrafiltration and inactivated with beta-propiolactone. The resulting vaccine was markedly antigenic and immunogenic for laboratory animals. Human volunteers injected with 2.0 ml vaccine on days 0, 3, 7, 14, 30 and 90 exhibited more intensive and longer antibody production than those injected daily for 14 days.

Properties of rabies vaccine freed of neuroallergenic factor from brain tissue.

Fixed rabies virus in the form of infected sheep brain suspension was freed from approx. 80% of ballast proteins, inactivated by beta-propiolactone and lyophilized. The vaccine thus obtained was devoid of neuroallergenicity when tested on guinea pigs and was highly antigenic and immunogenic. The vaccine caused no generalized reactions in volunteers; local reactions were weak and of short duration. Antibody formation was intensive in all volunteers.