EXPRESSION OF prM/E STRUCTURAL PROTEINS OF TICK-BORNE ENCEPHALITIS VIRUSES BY RECOMBINANT PDXVIRUS VECTORS

Abstract

Viruses of the tick-borne encephalitis (TBE) complex cause thousands of cases of severe neurological disease annually. Genes coding for the structural glycoproteins (prM and E) of TBE complex viruses [Russian spring-summer encephalitis (RSSE) virus, central European encephalitis (GEE) virus and Langat (LGT) virus] were amplified from viral transcripts by FOR and cloned into vaccinia transfer vector plasmids. Expression of the prM/E proteins was demonstrated by detection of precipitable glycoproteins on SDS polyacrylamide gels, which established the fidelity of the cloned genes. Recombinant vaccinia viruses (VV) containing RSSE, GEE or LGT prM/E genes were isolated and used to generate extracellular virus-like particle structures containing E glycoprotein. Transfer vector plasmids containing prM/E genes were prepared for the isolation of host range-restricted, modified vaccinia strain Ankara (MVA) viruses expressing the prM and E proteins of either RSSE, GEE or LGT viruses. Transient expression of prM and E proteins from the transfer vector plasmids was evaluated to select candidate vectors for generating recombinant, attenuated poxviruses for future use as immunoprophylatic vaccines against TBE