[Alphavirus reproduction in cultures of transplantable human lymphoblastoid cells during persistent infections]. / Reproduktsiia al'favirusov v kul'turakh perevivaemykh limfoblastoidnykh kletok cheloveka pri persistiruiushchei infektsii.

The results of virological investigations of alphavirus persistence in human B-cell lines Raji and L-101 are presented. The formation of persisting infection was shown to depend both on the cell line and on the virus type. Productive persistent infection of Raji cells with Venezuelan equine encephalitis virus was followed for 11 months. The presence of the virus was confirmed by electron microscopic and immunofluorescent examinations. Infectious virus production varied from 0.001 to dozens PFU/cell, and the content of viable cells from 100,000 to 300,000 in 1 ml of the culture fluid. Virus infectivity in the culture medium varied within the range of 5-7 lg PFU/ml. Human lymphoblastoid cells Raji persistently infected with Venezuelan equine encephalitis virus were examined cytologically, karyologically, and electron microscopically. The long-term presence of the virus resulted in profound alterations in the cell population. Morphology of the cells and processes of division were changed, the mitotic index decreased, the rate of 3H-thymidine incorporation into cellular DNA increased. The mechanisms of persistence are discussed.

[Use of continuous human lymphoblastoid cell lines (T- and B-origin) to produce persistent tick-borne encephalitis virus and Venezuelan equine encephalomyelitis virus infections]. / Ispol'zovanie perevivaemykh limfoblastoidnykh linii kletok cheloveka (T- i B-proiskhozhdeniia) dlia polucheniia persistentnoi infektsii virusa kleshchegogo éntsefalita i virusa venesuél'skogo éntsefalomielita loshadei.

Persistent infection with tick-borne encephalitis virus (TBE) was established in experimentally infected continuous lymphoblastoid human cell lines Raji, L-101 (of B-origin) and 1387 (T-origin) and with Venezuelan equine encephalomyelitis (VEE) virus in Raji and 1387 lines. The persistently infected lines produced infectious virus, the cells showed specific fluorescence in immunofluorescent tests, and electron microscopic examinations revealed TBE and VEE virions in sections.

[Alphavirus reproduction in cultures of transplantable human lymphoblastic cells in acute infection]. / Reproduktsiia al'favirusov v kul'turakh perevivaemykh limfoblastoidnykh kletok cheloveka pri ostroi infektsii.

The results of investigations of acute infection of continuous human B- and T-cells with typical members of the alphavirus group--Semliki Forest, Sindbis, and Venezuelan equine encephalomyelitis viruses, are presented. Virus amplification was shown to pass through the typical phases: eclipse, logarithmic growth, plateau. Infectious virus production per one cell was from 10 to 10,000 PFU in various cultures. Cell infection results in interferon production. Replication of the viruses under study in lymphoblastoid cell cultures is not accompanied by the active cytocidal effect. The regularities determining the sensitivity of lymphoblastoid cells to viruses in general and alphaviruses in particular are discussed. Proceeding from the results of the study of alphavirus replication in human continuous B- and T-cells it is suggested that this system be used as a model for the analysis of antiviral activity of interferon, its inducers, and chemopreparations in special cells. Lymphoblastoid and fibroblast interferon are as active in B-cells and show no antiviral activity in continuous T-cells, as interferon inducer.

[Stimulation of interferon formation by natural and synthetic inducers in cultures of human tonsil cells]. / Stimuliatsiia interferonoobrazovaniia prirodnymi i sinteticheskimi induktorami v kul'turakh kletok mindalin cheloveka.

Conditions of interferon production stimulation were studied in human tonsillar cell cultures exposed to natural and synthetic inducers : poly(I) . poly(C), phage f2 RNA replicase, phytohemagglutinin and the low-molecular inducer gossypol (beta-aminoethyl sulfoxide Na). It has been shown that being inferior in the productivity per one cell to the continuous lymphoblastoid Raji and Namalva cell liness the tonsillar cell cultures, due to their high density, produce rather high interferon titers reaching hundreds of IU50/ml. The viability of the tonsillar cell cultures and their incubation at 37 degrees C during 24 hours are rather important for adequate interferon production.

[Viral interaction with stimulated and nonstimulated human tonsil cells]. / Vzaimodeistvie virusov so stimulirovannymi i nestimulirovannymi kletkami mindalin cheloveka.

Interferon induction and the course of infection with paramyxovirus (Newcastle disease virus) and alphaviruses (Venezuelan equine encephalomyelitis, Sindbis, Semliki forest viruses) in human tonsillar cell cultures were studied in comparison with continuous Burkitt lymphoma, Raji, and Nawalva cells. The virus inducers stimulated production of dozens and hundreds IU50/ml of interferon in tonsillar cell cultures. No virus replication could be detected either in intact or phytohemagglutinin-stimulated tonsillar cells. Phytohemagglutinin treatment may lead to blocking of interferon production induced by Newcastle disease virus.

[Antiviral activity of interferon and its inducers in human lymphoblastoid and somatic cells]. / Protivovirusnaia aktivnost' interferona i ego induktorov v limfoblastoidnykh i somaticheskikh kletkakh cheloveka.

The antiviral effect of interferon inductors, such as poly-I--poly-C, phage f2 RNA replicative form and low molecular inductor GSN and their influence on cellular DNA synthesis were studied in the cultures of lymphoblastoid (inplanting lines Raji Namalva) and somatic human cells. The Semliki forest virus used as the test organism multiplicated well in cells Raji accumulating up to 9 lg BOU/ml. The two-strand RNA was less active in the lymphoid cells than in the somatic ones. GSN was 10 times more active and less toxic in cells Raji as compared to the fibroblasts. The lymphoblastoid interferon had higher antiviral activity as compared to the fibroblast interferon in the system of Raji--Semliki forest virus than in the system of the human embryon fibroblast--Venezuela Horse Encephalytic Virus. Romantadin actively inhibited (100 times) production of the alfavirus in both the somatic and lymphoblastoid cells.