[Study of certain indicators of immunity upon infecting CBA/Calac line mice with Lassa virus]. / Izuchenie nekotorykh pokazatelei immuniteta pri zarazhenii myshei linii CBA/Calac virusom lassa]

Some immunity parameters (interferon, tumor necrosis factor, interleukin 1, etc.) were studied in CBA/Calac mice infected with Lassa virus. The results permit a hypothesis that a pathologic inflammatory reaction is responsible for the death of animals in experimental Lassa fever. One of the components of this reaction is endogenous shock involving a manifest production of immune response mediators, such as interferon, interleukin 1. and tumor necrosis factor.

[Immunization of rabbits with Lassa virus]. / Immunizatsiia krolikov virusom Lassa.

The parameters of humoral and cell-mediated immunity after inoculation of the infectious and inactivated antigen of Lassa virus to rabbits which are insusceptible to this infection were studied. Lassa virus antigen was demonstrated to induce synthesis of specific antibodies in rabbits the level of which was proportional to the dose of inoculation and the time of immunization. The results of leukocyte blastogenesis test and delayed type hypersensitivity test confirm the development of sensitization to inactivated Lassa virus in immune rabbits.

[Characteristics of the immune response in mice immunized with the inactivated Lassa virus]. / Kharakteristika immunnogo otveta u myshei, immunizirovannykh inaktivirovannym virusom Lassa.

The influence of humoral and cell-mediated immunity on the formation of resistance in mice immunized with inactivated Lassa virus was evaluated. As a result of immunization, both nonspecific and specific immune response developed, the main rule in the formation of resistance belonging to specific immunity.

[Effect of immunosuppression on the development and outcome of an acute infection in mice caused by administration of the Lassa virus]. / Vliianie immunosupressii na razvitie i iskhod ostroi infektsii, vyzyvaemoi u myshei vvedeniem virusa Lassa.

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. Cyclosporin A in various doses exerted no effect on the outcome of the acute infection. The adoptive transfer of splenocytes from mouse donors inoculated intraperitoneally prevented the development of lethal disease symptoms and death of mice-recipients. It is suggested that immunocompetent cells are involved in the development and outcome of experimental infection of mice with Lassa virus.