[Experimental study of the role of male ixodid ticks in the circulation of the tick-borne encephalitis virus]. / Eksperimental'noe izuchenie roli samtsov iksodovykh kleshchei v tsirkuliatsii virusa kleshchevogo éntsefalita.

Regular transmission of the tick-borne encephalitis virus by Ixodidae males feeding on laboratory animals is demonstrated. The virus titres in the male saliva were 0.1-1.5 lgLD50/0.03 ml. It was established that such doses didn't produce tense viremia in white mice or clinical tick-borne encephalitis.

[Dependence of the synthesis of virion structures in the tick-borne encephalitis virus on the cell culture type]. / Zavisimost' sinteza virionnykh struktur virusa kleshchevogo éntsefalita ot vida kletochnykh kul'tur.

Variations in synthesis of antigenic structures are observed in tick-borne encephalitis virus replication in cell cultures of different origin. In a number of cell cultures: pig and Syrian hamster embryo kidney cells, as well as in Chinese striped hamster cells and Tasmanian rat kangaroo cells, virion antigens (VA) are synthesized which differ in the direction of movement in the electric field, namely, anode and cathode VA. In other cell cultures: green monkey kidney, barking deer kidney, and human fibroblasts, only cathode VA is synthesized. In chick embryo fibroblast cultures, in addition to the above-mentioned VA, considerable amounts of a VA which does not move in the electric field are synthesized. In all the cultures, a low molecular nonvirion antigen (NA) is actively produced, the virus-containing fluids of human fibroblast cultures and Chinese striped hamster kidney cell cultures contain lower amounts of high molecular NA, while rat kangaroo and green monkey kidney cell cultures have no high-molecular NA of tick-borne encephalitis virus.

[Changes in the synthesis of the virion antigen of the tick-borne encephalitis virus after passage through ixodid ticks and small mammals]. / Izmeneniia sinteza virionnogo antigena virusa kleshchevogo éntsefalita posle passirovaniia cherez iksodovykh kleshchei i melkikh mlekopitaiushchikh.

Large-plaque strains of tick-borne encephalitis (TBE) virus possess a high peripheral activity, and in acute infection in continuous pig embryo kidney cells (PEK) synthesize a virion antigen (VA) whose subpopulations differ in their mobility in agarose gel electrophoresis: the bulk portion of VA moves towards the cathode and a small one towards the anode. After long-term passages of these strains in Ixodid ticks they lose their peripheral activity and produce only small plaques. In reproduction in PEK cells the amount of the infectious virus remains the same but VA synthesis changes significantly. There is almost no synthesis of VA moving towards the cathode and that of VA moving towards the anode remains unchanged or decreases insignificantly. The decrease in the synthesis of the major portion of VA is accompanied by the reduction of the hemagglutinating properties of the strains and retention of the nonvirion antigen production. Reversion to the initial properties of the strains passaged in ticks occurs after their inoculation into natural hosts of tick-borne encephalitis virus: small mammals (bank vole and common vole).

[Sexual transmission of the tick-borne encephalitis virus in ixodid ticks (Ixodidae)]. / Polovaia peredacha virusa kleshchevogo éntsefalita u iksodovykh kleshchei (Ixodidae).

Sexual transmission of tick-borne encephalitis virus from infected ixodid males to noninfected females is shown: in Ixodes persulcatus in 50% (6 of 12) and in Hyalomma anatolicum in 6.2% (1 of 16). The sexual transmission of tick-borne encephalitis virus is shown to provide a transmissible transfer of the virus into eggs in ixodid ticks. Electron microscope studies of the sexual system of ixodid males infected with the virus have revealed numerous morphologically mature virus particles in lumens of endoplasmic reticulum, in vacuoles of Golgi complex of spermatocytes and in association with tubular elements of spermatids.