Functional analysis and quantitative determination of the expression profile of human parvovirus B19.

Comprehension of the pathogenetic potential of human parvovirus B19 requires the definition of the complete spectrum of cellular tropism and a functional analysis of the viral genome in infected cells. In this study, we carried out a systematic functional analysis of B19 virus genome in the course of infection of susceptible bone marrow mononuclear cells and myeloblastoid UT7/EpoS1 cells, in terms of dynamics of nucleic acid synthesis. A PCR array was designed and a comprehensive analysis was performed by quantitative PCR and RT-PCR, yielding extended information on the presence and abundance of the diverse classes of viral nucleic acids, on the temporal regulation of genome expression and on its relationship with the cell cycle. The analysis performed indicate that the synthesis of viral nucleic acids is correlated to the progression through the S phase of the cell cycle, that an extended pattern of transcriptional activity occurs throughout the course of infection, with a maximal rate of transcription preceding the onset of S-phase dependent replication of the viral genome, and that utilization of transcript processing signals is relatively constant throughout the course of infection. The information obtained led to the definition of a unified model of functional and expression profiling of parvovirus B19 genome.