HFF were inoculated as above with DgH virions that had been incubated for 18 hrs in the presence or absence of PNGase. Glycosylated and deglycosylated DgH virions stimulated a 2.23 and 2.28 fold increase in IFN-a transcription, respectively. These results suggest that glycosylation has no impact on the interferogenic properties of DgH virions, unlike the glycoproteins of MHV and TGEV, which appear to stimulate Type I IFN through There was a degree of correlation between the change in expression determined by microarray studies and those confirmed by real-time PCR, particularly for genes under the control of NF-kB. Note: rel and nfkbib were not present on the original signalling-specific microarray, but were included in the real-time analysis, as they are known to be up-regulated as part of the NF-kB feedback mechanism. doi:10.1371/journal.pone.0009560.t003 a lectin-like action, HSV-1 gD may trigger IFN up-regulation through a different mechanism, possibly analogous to that used to stimulate other signalling pathways. Five interferon-stimulated genes were chosen to examine whether they were differentially expressed by virion binding. IFN-induced protein 54 (ISG54) transcripts are routinely used as a marker of ISG induction. Binding by DgB, DgD or DgH virions was insufficient to cause changes in the transcript abundance of interferon regulatory factor-1, -3, -7, -9 or ISG54 (Table 4) .