[Antibodies against alpha-2 and gamma-interferons affect the course of juvenile respiratory papillomatosis in children treated with alpha-2 interferon preparations]. / Vliyanie antitel k alfa-2 i gamma-interferonam na techeniye yuvenil'nogo respiratornogo papillomatoza u detey, poluchayushchikh lecheniye preparatami alfa-2 interferona.

1-year or longer treatment of juvenile respiratory papillomatosis (JRP) with alpha-2 interferons (A21) leads to emergence of antibodies to A21 in 54.3% of the patients. The greatest percentage of the antibody positives (94.4%) was found among JRP patients treated with intramuscular recombinant human A21 (reaferon). The proportion of the antibodies carriers fell to 15.4% if reaferon was used as a component of the new preparation viferon. JRP patients have also autoantibodies to A21 and gamma-interferon (8.74 and 33.3%, respectively). Patients with autoantibodies to gamma-interferon responded well to treatment with A21. Antibodies to A21 seem to have no negative effect on interferon therapy of JRP. Reaferon and viferon can be effectively used in JRP treatment.

Autologous enhancement by interferon of natural killer activity of human peripheral blood lymphocytes.

The in vitro action of interferon (IFN)-alpha and IFN-gamma from six healthy donors and ten patients with multiple sclerosis (MS) on natural killer (INK) activity of peripheral blood lymphocytes (PBL) was studied in an autologous system. The NK activity of PBL was detected by a cytotoxic test using (3)H-uridine human erythromyeloblast K562 cells. Autologous IFN-alpha and IFN-gamma did not augment NK activity of PBL from healthy donors in vitro, whereas in samples from MS patients the IFNs strongly stimulated NK cell cytotoxic function. This stimulation suggests the existence of an inhibitor of regulatory IFN action, that is produced in healthy donors simultaneously with IFN in response to IFN induction, but which is lacking in commercial IFN preparations. The factor-containing supernatants from healthy donors reduced the stimulatory action of autologous IFNs in patients with MS almost until complete blockade. Because this inhibitor was absent in patients with MS, deficiency of an inhibitor of IFN regulatory action in MS could open the way to treatment of this compartment of the immune system.

Properties of virions and ribonucleoproteins of Venezuelan equine encephalomyelitis virus.

The physicochemical properties of Venezuelan equine encephalomyelitis (VEE) virus and of its ribonucleoprotein (RNP) were studied. Upon purification in a discontinuous or linear sucrose gradient, the losses of infectivity were small (25%), and 96% of cellular proteins were removed. The purified virus was homogeneous with respect of sedimentation rate (s20, w = 265 S). The CsCl gradient was unsuitable for purification of infectious virus because the latter was destroyed at high CsCl concentrations. Buoyant density of the virus in CsCl after formaldehyde fixation was 1.21--1.22 g/cm3. Treatment of the virus with 1% Nonidet P-40 proved to be the most effective method for isolation of the RNP. The structures thus obtained contained practically all of the viral RNA and about 20% of viral proteins, and were homogeneous with respect of sedimentation rate (153 S) and buoyant density (1.40--1.42 g/cm3 in CsCl after formaldehyde fixation). The RNPs were sensitive to ribonuclease.

The effect of combination of different inducers on the refractory state in interferon production.

A second injection of 100 mug poly (rI) poly (rC) per mouse at 6 and 24 hours after the first injection stimulated additional peaks of interferon production. The dynamics of the process of accumulation and disappearance of interferon was similar to that after a single injection of poly (rI). poly (rC). Injection of the above dose 12 hours after the first injection induced no interferon production as it apparently coincided with the refractory state in interferon production. After pretreatment of poly (rI) poly (rC) with DEAE-dextran, the refractory phase occurred in 6 hours. Inoculation of Venezuelan equine encephalomyelitis virus as a second interferon inducer resulted in a repeated stimulation of interferon production both in animals and in tissue culture; however, interferon titres in this case were low. The use of an inactivated virus as a second interferon inducer stimulated interferon production to higher titres (5120 IU/ml) than a single injection of DEAE-dextran-treated poly (rI). poly (rC). It is possible that a combined use of poly (rI). poly (rC) and noninfectious virus as a second interferon inducer eliminates the development of the refractory state.

The dynamics of development of cell resistance to viruses induced by synthetic polynucleotides.

The dynamics of interaction of complexes of synthetic polynucleotides (polyinosinic and polycitidylic acid--poly (rI)-poly (rC), and polyguanylic and polycytidylic acid--poly (rG)-poly (rC)) with cells as well as the dynamics of interferon accumulation and development of antiviral effect against some RNA viruses were studied in primary chick embryo cell (CEC) cultures. Four phases were observed in the development of the antiviral effect of synthetic polynucleotides: adsorption, increase, marked antiviral effect and waning. The duration and extent of the antiviral effect depended upon the activity and the dose of the preparation and less so upon virus type. At the same time, the dynamics of the development of the antiviral effect in early stages differed significantly depending on the virus model.

On the synthesis of viral ribonucleic acids and ribonucleoproteins in the submitochondrial system completely free of interfering cytoplasmic contaminations.

The synthesis of virus-specific macromolecules was studied in the reconstituted system containing inner membrane-matrix fraction from rat liver mitochondria and infectious RNA of Venezuelian equine encephalomyelitis (VEE) virus. In a series of preliminary experiments it was shown that isolated submitochondrial fraction was completely free of interfering cytoplasmic contaminations and particularly, of cytoplasmic 80S ribosomes. VEE RNA when added to submitochondrial system caused significant stimulation of RNA and protein synthesis. These processes were resistant to actinomycin D which inhibited profoundly the synthesis of proper mitochondrial macromolecules. The stimulating effect of VEE RNA in experiments with submitochondrial system was about three times higher than that with intact mitochondria. The stimulation of 14C-amino acid incorporation increased as a function of incubation time; a certain lag-period being observed. The newly formed virus-specific RNA's and ribonucleoproteins were identified with the aid of sedimentation analysis. In particular, radioactive RNA's with sedimentation coefficients 40S and 26-18S were isolated from the incubated system. These RNA's are similar respectively to VEE genome RNA and double-stranded VEE replicative RNA. In double labelling experiments with 3H-uridine and 14C-amino acids it was shown that VEE RNA induced synthesis of ribonucleoproteins containing newly formed RNA and protein. These RNP possessed sedimentation coefficients 60-80S, 140S and 300S in sucrose gradient and buoyant densities 1.32 and 1.50 g/cm3 in cesium chloride gradients. These properties of ribonucleoproteins synthesized de novo in submitochondrial system are close to those of RNP intermediates of VEE virus reproduction in the infected cells. We concluded that viral RNA could program virus-specific synthesis in the submitochondrial system under conditions that eliminated the contribution of cytoplasmic ribosomes.

Morphogenesis of Venezuelan equine encephalomyelitis virus.

Morphogenesis of Venezuelan equine encephalomyelitis virus was studied by means of electron microscopy. Virus-specific structures (factories, viroplasts) were found at early stages of infection; these structures were composed of fibrillar and cylindrical formations, aggregates of ribosomes, and viral nucleoids. The latter emerged from fibrillar and cylindrical structures. Aggregates of viral nucleoids were found in the cytoplasm and occasionally in the nuclei of virus-infected cells. Viral envelopes and mature virions were formed on the cell membranes and on the membranes of intracellular vacuoles. Anomalous forms of virions (both polygenomic and oligogenomic) were observed.