Induction of XBP-1 KO in primary MEFs prior to MCMV infection decelerates viral growth and protein expression.

<p>Primary MEFs derived from RERT/XBP-1^f/f mice were treated with vehicle (EtOH) or 4-OHT for 48 h and infected with MCMV-GFP atMO1 = 0.1 (A) and MOI = 1 (B). Culture supernatants were collected at indicated time points and titers were determined using standard plaque assay. (C) The expression of virus-derived GFP in RERT/XBP-1^f/f (C) and RERT/XBP-1^WT/WT (D) was monitored using flow cytometry. GFP positive cells were gated and considered as infected cells. (E, F) DNA was extracted from described cells and the genomic deletion of XBP-1 following EtOH or 4-OHT treatment was demonstrated using PCR analysis. Upper band represents deleted allele. (G) The expression of intrinsic viral proteins Immediate Early 1 (IE1), Early 1 (E1) and a 48 kDa late protein was measured by Western blot analysis. Cellular p97 served as loading control. (H) Total protein synthesis was assessed by radioactive pulse labeling and quantified using ImageJ. Data is from one experiment out of two (D, H), or three performed (C, G). (A, B) Results are shown as mean ±SEM of at least three replicates. * P<0.05, ** P<0.01.