[Immunologic mechanisms of preventing persistence of tick-borne encephalitis virus in mice].

The occurrence of temporary immunosuppression at the time of inoculation of tick-borne encephalitis (TBE) virus increases 7-fold the frequency of development of asymptomatic virus carrier state in the brain of mice. This model was used to study the role of various populations and subpopulations of immunocompetent cells in prevention of persistent infection (PI). In adoptive transfer 24 hours after inoculation no protective effect was demonstrated with B-lymphocytes, unfixed macrophages, cytotoxic T-lymphocytes of TBE-virus-infected mice, effectors of the delayed type hypersensitivity of donors vaccinated against TBE virus, as well as relatively low doses of specific antiviral antibody (AVA). A marked protective effect was exerted by non-immune splenocytes mixed with low doses of AVA or relatively high doses of AVA. With such immunization schedule, the number of surviving animals increased 3-4-fold, and among them the frequency of PI development decreased 6-10-fold. The role of T-helpers in formation of humoral immunity in experiments TBE in mice was demonstrated.