DETECTION OF A NOVEL BORNA-DISEASE VIRUS-ENCODED 10 KDA PROTEIN IN INFECTED-CELLS AND TISSUES

Borna disease (ED) is a transmissible, progressive polioencephalomyeli tis; primarily of horses and sheep, The genomes of two cell-adapted st rains of Borna disease virus (BDV), the aetiological agent of ED, have been cloned and sequenced. According to the structural characterizati on achieved so far, BDV contains a non-segmented negative-sense 8.9 kb single-stranded RNA genome, In this paper we report the expression, p urification and intracellular tracing of a novel non-glycosylated BDV- specific protein with a molecular mass of approximately 10 kDa (BDV p1 0 protein), The successful isolation of the corresponding mRNA from in fected cells, amplification of the genetic region by RT-PCR and its ef ficient expression as a glutathione S-transferase (GST) fusion protein demonstrated that antibodies specific for the BDV p10 protein are ind uced in infected animals. In addition, we have produced monospecific a ntisera against the GST-p10 fusion protein in rabbits. This monospecif ic antiserum recognized the BDV p10 protein in brain cells of naturall y and experimentally infected animals as well as in persistently BDV-i nfected cells. Antibody-mediated affinity-chromatography using the ant i-p10 serum could successfully be applied to purify a ca. 10 kDa antig en from infected animal cells to such an extent that glycosylation of this component could be ruled out.