Expression of the simian varicella virus glycoprotein L and H.

Simian varicella is used as a model to investigate varicella-zoster virus pathogenesis and to evaluate antiviral therapies. In this study, the simian varicella virus (SVV) glycoprotein L (gL) was characterized along with its association with glycoprotein H (gH). The SVV gL gene encodes a predicted 175 amino acid polypeptide that shares 43.5% and 27.9% amino acid identity with the VZV gL and HSV-1 gL, respectively. The SVV gL polypeptide sequence lacks a consensus glycosylation site and a typical signal sequence, but does possess an endoplasmic reticulum targeting sequence found commonly in chaperone proteins. Transcriptional analysis indicated that the SVV gL and the uracil DNA glycosylase (UDG) genes share a common 5' RNA start site and are co-expressed on a 2.0 kb transcript. gL and gH expression in SVV-infected Vero cells was demonstrated by immunofluorescence and immunoprecipitation analyses using specific antisera generated against gL and gH peptides. Similar to other herpesvirus gH and gL homologs, the SVV gL and gH form a complex within infected cells. gL and gH transcripts and antigens were detected in tissues of monkeys with acute simian varicella. The simian varicella model offers an opportunity to investigate the role of the gL and gH in viral pathogenesis.

Identification and characterization of the simian varicella virus uracil DNA glycosylase.

Simian varicella virus (SVV) infection of non-human primates is used as a model to study the pathogenesis and latency of varicella-zoster virus (VZV), the etiological agent of chickenpox and shingles. Uracil DNA glycosylase (UDG) is a DNA repair enzyme responsible for excision of uracil residues misincorporated into DNA. UDG is conserved throughout the herpesvirus family and may play an important role in viral pathogenesis. This study identified a 300 amino acid SVV UDG that shares 53.9% amino acid identity with the VZV UDG. The SVV UDG is expressed in infected Vero cells as determined by reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analysis. The SVV UDG is encoded on a 2.0 kb transcript which also appears to encode the SVV glycoprotein L (gL) and the VZV gene 58 homolog. The SVV UDG is enzymatically active as determined by the ability of a SVV UDG-maltose binding protein fusion construct to remove [(3)H]-uracil incorporated into DNA.