[Cytopathogenic properties of Yersinia pestis strains in an L-41 cell culture]. / Tsitopatogennye svoistva shtammov Yersinia pestis v kul'ture kletok L-41.

L-41 cell monolayer grown in cultural microplates was infected with Y. pestis strains of different virulence. The results evidenced a direct relationship between the strains' virulence for white mice and their ability to multiply in cellular system and to show cytopathogenic effect.

[Immunobiological properties of staphylococcal enterotoxins type A, B, C, D and E]. / Immunobiologicheskie svoistva stafilokokkovykh énterotoksinov tipov A, B, C, D, E.

Comparative study of mitogenic and interferonogenic properties of staphylococcal enterotoxins of different serotypes is done. It is revealed that preparations of enterotoxins are polyclonal mitogens and have interferon-inducing activity. It is stated that enterotoxin of D type has the highest mitogenic activity, which is shown by interferon-inducing activity of A type toxin.

[Effect of virus-induced interferon on mast cell resistance to the degranulating action of immune complexes]. / Vliianie virusindutsirovannogo interferona na rezistentnost' tuchnykh kletok k degranuliruiushchemu deistviiu immunnykh kompleksov.

Regularities of endogenous interferon (IFN) induction with Newcastle disease virus (NDV) in rats and the effect of this process of the resistance of mast cells to the degranulating effect of immune complexes are described. Increased resistance of mast cells to the damaging effect of immune complexes for 72 hours after a single induction of endogenous IFN with virus was demonstrated in experiments in vivo. Inoculation of rats with NDV treated at pH = 2.0 did not induce the production of endogenous IFN, and the mast cells from these animals underwent degranulation to the same extent as those from intact animals. Protection of mast cells by IFN from the degranulating effect of immune complexes was also demonstrated in in vitro experiments.

[Neutralizing antibodies to human gamma-interferon]. / Neitralizuiushchie antitela k chelovecheskomu gamma-interferonu.

Spleen lymphocytes from normal subjects who suddenly died were used as cells producing gamma-interferon. One spleen yielded (3-8) X 10(8) viable cells which made it possible to prepare from 3 to 81 of splenocyte suspension culture. Staphylococcal enterotoxin A (SEA) and B (SEB) were used as gamma-interferon inducers. Stimulation of splenocyte suspension culture with SEA and SEB resulted in production of gamma-interferon with an average activity of 640-2560 units/ml. A partially purified interferon preparation with an activity of 2 X 10(4) units/ml was obtained by sorption of gamma-interferon on porous glass CPG-200-240 followed by elution with a buffer containing 50% ethylene glycol and Sephadex G-25 gel chromatography. As a result of 11 successive intramuscular immunizations of rabbits at 2-week intervals with a partially purified and concentrated preparation of gamma-interferon with Freund's complete adjuvant, blood serum was obtained which was capable of neutralizing 32 units of gamma-interferon up to a dilution of 1:128. The serum was highly specific: it showed no specific interaction with antigenic determinants of either natural alpha- and beta- or plasmid alpha-F and alpha-F/D human interferons.

[Simple method of determining the antiproliferative activity of human interferons]. / Prostoi metod opredeleniia antiproliferativnoi aktivnosti chelovecheskikh interferonov.

A simple method for quantitative estimation of the antiproliferative activity of human interferon is described. The method is based on direct visual estimation (with the use of an inverted microscope) of various doses of interferon with respect to proliferation and colony formation of human transplantable tumor HeLa cells grown in Nells of plastic plates for microcultures. Single HeLa cells (target cells) are plated out on a monolayer of human embryo fibroblasts (HEF), which morphologically differ from the target cells (HeLa) and play the role of feeders. After that the cells are incubated at 37 degrees C in the atmosphere of 5 per cent of CO2 and humidity of 98 per cent for 4-5 days. With the use of this method for determining the anticellular activity of interferon it was shown that human gamma-interferon had a 30 times more pronounced antiproliferative activity than natural alpha- and beta-interferons and alpha-F and alpha-F/D plasmid interferons. The method provides also investigation of other aspects of the antiproliferative activity of interferon: it was shown that the physicochemical factors or antiinterferon sera inactivating the antiviral properties of the interferons were also the cause of simultaneous inhibition of their antiproliferative activity.

[Effect of T-activin on the production of immune interferon]. / Deistvie T-aktivina na produktsiiu immunogo interferona.

A study was made of the effect of T-activin on the biosynthesis of immune gamma-interferon. It was shown that in 27% of patients with chronic nonspecific pulmonary diseases, production of gamma-interferon by lymphocytes was substantially reduced during exacerbation of inflammatory process in the lungs. It was discovered that T-activin was not an interferon inductor but enhanced its synthesis in patients with a low capacity of producing immune interferon even at small doses of interferon inductor. The preparation does not produce any effect on this process in normal subjects and in patients showing the normal level of gamma-interferon. Thus T-activin can be used for stimulation of interferonogenesis.

[Human immune interferon: production and action]. / Chelovecheskii immunnyi interferon: produktsiia i deistvie.

The most marked production of immune interferon by human peripheral blood leukocytes and splenocytes stimulated with phytohemagglutinin (PHA) and staphylococcal enterotoxin A (SEA) was shown to be achieved when lymphoid cells are propagated under conditions of constant sparing mixing on roller apparatus at a temperature of 37 degrees +/- 0.5 degrees C. The resulting interferon was sensitive to low pH, thermolabile, inactivated by treatment with trypsin, and not neutralised by antisera to human alpha- and beta-interferons. The antiviral properties with regard to vesicular stomatitis and Semliki Forest viruses were practically similar in PHA- and SEA-induced interferon and human alpha- and beta-interferons. The capacity to inhibit colony formation by HeLa cells was 30 times higher in gamma-interferon than the antiproliferative activity of alpha- and beta-interferons.

[Purification and identification of mRNA of immune (gamma) interferon from human splenocytes]. / Ochistka i identifikatsiia informatsionnoi RNK immunnogo (gamma) interferona iz splenotsitov cheloveka.

The isolation of total RNA from primary culture of human splenocytes and its physico-chemical and biological properties are described. Human splenocytes are characterized by a high content of mRNA of human immune interferon, low content of total RNA and an extremely high activity of RNAases. Therefore it was necessary to elaborate conditions for the isolation of mRNA without DNA contaminants in the presence of extensive inhibitors of the RNAase activity. These include cell homogenization, separation of cytoplasm at -10 degrees C and treatment by RNAase inhibitors--ribonucleoside-vanadyl complexes or a combination of aurin-tricarboxylic acid with dithiothreitol. The resulting preparations of total RNA were purified by chromatography on oligo (dT)-cellulose and translated in a cell-free system from rabbit reticulocytes. These preparations were free of nonspecific translation inhibitors which are normally present in the lymphoid cells mRNA. In a cell-free system mRNA of human splenocytes induced with staphylococcal enterotoxin A code the synthesis of biologically active interferon which was identified as immune (gamma) human interferon, using a serological analysis. The preparations of immune interferon mRNA obtained under the conditions described above can further be used for cloning of the corresponding gene in bacterial cells.

[Effect of preliminary treatment with homologous interferon (priming) on the production of human immune interferon]. / Vliianie predvaritel'noi obrabotki gomologichnym interferonom (praiming) na produktsiiu chelovecheskogo immunnogo interferona.

Pretreatment of the cultures of human peripheral blood leukocytes and splenocytes with the incubation medium of the mitogen-stimulated human lymphoid cells containing various concentrations of lymphokines (including 10 to 1280 units/ml of immune interferon) resulted in increased (by at least 4 times) production of interferon, induced by staphylococcal enterotoxin A, phytohemagglutinin and mitogen from Phytolacca americana (PWM), as well as in intensification of DNA synthesis in the producing cells. A more pronounced specific binding of the inductor labeled with radioactive iodine to the producing cells was also observed.

Binding of staphylococcal enterotoxin A (SEA) with human splenic lymphocytes.

1. The presence of specific binding of [125I]SEA with human splenocytes is established. 2. The association of toxin at 4 C is characterized by saturation, reversibility and a great affinity to a receptor (Kd = 4.0 x 10(-7) M). 3. The number of binding sites on a cell is equal to 6000. 4. At 23 C the binding of labelled toxin with a cell described by a biphasic curve. 5. Priming increases the association of SEA with the splenocytes and correspondingly increases the production level of gamma-interferon.

[Comparative study of the biological properties of plasmid and natural human interferons]. / Sravnitel'noe izuchenie biologicheskikh svoistv plazmidnykh i prirodnykh chelovecheskikh interferonov.

A comparative study of biological properties of natural and plasmid human interferons was carried out. Natural and leukocyte interferons: alpha (induced by Newcastle disease virus) and gamma (induced by staphylococcal enterotoxin A) as well as natural fibroblastic beta interferon induced by poly(I) X poly(C) were studied in comparison with plasmid interferons alpha-F and alpha-F/D obtained from recombinant bacteria. Antigenic determinants of plasmid interferons alpha-F and alpha-F/D were found to be identical with those of natural and alpha-interferon of man and to differ from those of natural human alpha- and beta-interferons. Both plasmid interferons demonstrated the kinetics of development of the state of resistance to viruses in a human diploid cell culture typical of alpha-interferon but not of gamma-interferon from human leukocytes. Plasmid and natural alpha-interferons have similar anticellular activity for human tumor HeLa cells, similarly activate natural human killer cells and are similarly stabilized in the presence of 0.01 M lantan chloride. All these data permit a conclusion that plasmid human interferons alpha-F and alpha-F/D are analogous and close to the total preparation of natural alpha-interferon from human leukocytes. On the other hand, the range of cells sensitive to the antiviral effect of alpha-F and alpha-F/D interferons is wider than for leukocyte alpha-interferon, and stability on storage and heating is higher.

[Determination of the species specificity of interferons in the translation of the their mRNA from various cell cultures]. / Opredelenie vidovoi spetsifichnosti interferonov pri transliatsii ikh mRNK iz razlichnykh kletochnykh kul'tur.

Interferons obtained on induction of human lymphocytes with Newcastle viruses and staphylococcal enterotoxin A and diploid fibroblast cells of human embryos with poly (I).poly (C), as well as translation products of interferon mRNA obtained from these cells were analysed serologically. It was shown that the main type of interferon produced by the cells depended on the cell culture and inductor nature. It was defined at the level of the respective gene depression. Effective translation of mRNA of the interferons of the 3 types makes possible production of cDNA and creation of bacterial plasmids coding the genetic information for the synthesis of human interferon.

[Effect of remantadine and ribavirin on the production and antiviral action of human interferon types I and II]. / Vliianie remantadina i ribavirina na produktsiiu i protivovirusnoe deistvie cheovecheskikh interferonov I i II tipa.

The results of using human interferon of types I (alpha- and beta-interferons) and II (gamma-interferon) in combination with chemotherapeutic drugs, such as remantadin and ribavirin for the study in human cell cultures are presented. Moderate doses of the drugs (25 microgram/ml) did not eliminate the interferon production. In higher doses (50 microgram/ml) they lowered the interferon production levels 2--3 times. In the presence of ribavirin the level of the interferon production lowering was higher. On the whole the effect of the drugs on production of interferons of types I and II was of a similar character despite the different means of interferon induction. The combined use of interferons of types I and II with the chemotherapeutic drugs in human embryo cultures infected with Semiliki forest virus (SFV) revealed an additive character of the antiviral effect in all combinations tested. The level of the antiviral activity of alpha-, beta- and gamma-interferons against the SFV was practically the same.

[Detection of a factor that intensifies leukocyte migration in chick embryo allantoic fluid infected with influenza virus and a study of its effect on the formation of humoral immunity in guinea pigs]. / Obnaruzhenie faktora, usilivaiushchego migratsiiu leikotsitov, v allantoisnoi zhidkosti kurinykh émbrionov, zarazhennykh virusom grippa, i izuchenie ego vliianiia na formirovanie gumoral'nogo immuniteta u morskikh svinok.

The allantoic fluid of influenza A/Hong Kong/1/68 virus-infected chick embryos was found to contain a factor enhancing guinea pig leukocyte migration. Intraperitoneal inoculation of guinea pigs with the allantoic fluid containing this factor inhibited synthesis of specific antibodies to influenza virus and sheep erythrocytes.