[The penetration of the Marburg virus into eukaryotic cells].

The early stages of infection of Vero-E6 cell culture with Marburg virus, a member of filovirus family, highly pathogenic for man, were studied. Virus multiplication was completely or significantly inhibited by lysosomotropic agents (LTA) of two types: weak base (ammonium chloride) and ionophore monensin. The level of the inhibiting effect was proportional to LTA concentration and was maximal when the drug was introduced into the culture medium before virus inoculation.

[pH-dependent fusion of eukaryotic cells, caused by arenaviruses, pathogenic and non-pathogenic for humans].

The conditions necessary for fusion from inside (FFWI) of the BHK-21 cell culture affected by the Lassa and Mopeya arenaviruses were studied. The fusion was shown to occur only in the slightly acid medium and at lower pH meanings for the Mopeya virus, than for the Lassa virus.

[Lysosomotropic agents inhibit the penetration of arenaviruses into a culture of BHK-21 and Vero cells].

Lysosomotropic agents (NH4Cl, amantadine, chloroquine, monensin) which prevent acidification of intracellular vacuoles, when introduced into the culture medium before or during inoculation of cells (BHK-21, Vero) with arenaviruses inhibit reproduction of these viruses completely or significantly. Mozambique virus proved to be 10 times more sensitive to the effect of lysosomotropic agents than Pichinde and Lassa viruses. Thus, arenaviruses have a pH-dependent stage at the beginning of the reproduction cycle which is indirectly indicative of their penetration into cells by receptor endocytosis.

[Effect of immunosuppression on the development and outcome of an acute infection in mice caused by administration of the Lassa virus].

In experimental infection of mice with Lassa virus, the infectious virus could be detected in all the organs and brain tissues tested. Histopathological lesions were demonstrated in cerebral and spinal cord tissues only. Roentgen irradiation in a dose of 500 R and cyclophosphamide protected mice against a lethal Lassa virus dose.