Antigenic and transforming properties of the DB strain of the human polyomavirus BK virus

The analysis of the antigenic and transforming properties of the DB strain of the human polyomavirus BK Virus [BKV(DB)] is presented. Two genomes were molecularly cloned from a single virus preparation and were shown to represent viable virus; one clone [pBKV(DB)dl82] contained an 82 nucleotide deletion in the regulatory region relative to the second clone [pBKV(DB)]; pBKV(DB)dl82 demonstrated enhanced lytic and transforming activities relative to pBKV(DB). BKV(DB) is antigenically distinct from the prototype Gardner strain of BK Virus, and 50 to 60% of the population display serological evidence of BKV(DB) infection. Implications of the existence of antigenic variants on estimation of BK virus prevalence in the population are discussed.