FIG 5.

Histone H3K9me3 associated with HERV-W elements during influenza A virus infection. At 24 h postinfection, ChIP experiments were performed with rabbit IgG, antitrimethylated histone H3K9, H3, and SETDB1 antibodies on chromatin from uninfected and influenza A/WSN/33 virus-infected (MOI = 0.5) CCF-STTG1 cells. Precipitated chromatins were determined by qPCR with assays specific for ERVWE1 (A) and solo LTRs integrated in intronic regions of the ZNF277 and C9orf85 genes and proviruses integrated in intronic regions of the KYNU and ACOT13 genes (B). (C) Relative levels of transcripts encoding SETDB1 were measured in uninfected and virus-infected (MOI = 0.5) CCF-STTG1 cells at 24 h postinfection. (D) Levels of five HERV-W elements relative to the levels of GAPDH in input chromatin and in chromatin immunoprecipitated with anti-influenza A/WSN/33 virus antiserum from virus-infected (MOI = 0.5) CCF-STTG1 cells. ChIP data are presented as means ± SEMs from five independent experiments. *, P < 0.05; **, P < 0.01.