Abstract 914 Poster Session IV, Tuesday, 5/4 (poster 172)

Herpesvirus gene expression proceeds according to carefully ordered transcription programs in which different viral genes are expressed at particular times during infections. The patterns of viral gene expression can offer useful insights into the pathogenic strategies used by the virus. Until recently no methods existed that could conveniently provide a comprehensive description of the transcription program of relatively large viruses such as the herpesviruses. Newly available technologies, notably cDNA microarrays, offer the potential to simultaneously determine the expression of 100s to 1000s of genes. We have constructed cDNA microarrays containing all the known ORFs of Human Herpesvirus 8 (HHV-8), a recently discovered gamma-herpesvirus epidemiologically and pathogenetically linked to Kaposi's sarcoma (KS), AIDS-related B cell lymphomas, and Castleman's disease, and are constructing microarrays, containing all the ORFs of HHV-6 and -7, etiologic agents of roseola. In order to better understand herpesvirus replicative strategy and the potential interactions between herpesviruses and host cells, we undertook experiments to compile a comprehensive description of the viral transcription programs. The microarray detectors for the known viral ORF and expressed messages were constructed using PCR products specified by primers designed on the basis of published, virtually complete viral sequences. RNA extracted at varying times after induction/infection was converted to fluor-labeled cDNA and hybridized to the microarrays. Hybridization and subsequent scanning of the arrays provided quantitative information concerning the levels of expression, offering a comprehensive overview of viral expression programs. Correlation of the known functions of some of the genes with their patterns of expression provides insight into herpesvirus pathogenic strategies.