CYTIP is rapidly down-regulated in HSV-1-infected DCs. (A) Total mRNA was isolated from HSV-1 EGFP-infected (MOI of 1, black columns) and mock-infected (white columns) DCs at the indicated time points. The RNA was labeled and hybridized to Affymetrix Human Genome U133A arrays. The expression profile of CYTIP (top graph) shows a dramatic down-regulation 8 and 24 hours after infection compared with mock-infected cells. The expression profile of GAPDH (bottom graph) is shown as control; no significant influence on gene expression could be observed. (B) DCs were mock-infected or infected with HSV-1 at a MOI of 1 and harvested at the indicated time points after infection (pi). Western blot analyses with antibodies against CYTIP (top panel), cytohesin-1 (middle panel), and β-actin as loading control (bottom panel) show that CYTIP is rapidly down-regulated in HSV-1-infected DCs, whereas cytohesin-1 is only slightly influenced by infection. Small arrows indicate the appearance of additional CYTIP bands with higher molecular masses. (C) Exact quantification of CYTIP expression in mock-infected DCs (white columns), cells treated with UV-inactivated HSV-1 virions (gray columns), and HSV-1-infected DCs (MOI of 1, black columns) by intracellular flow cytometry illustrates that CYTIP is down-regulated with fast kinetics only after infection with HSV-1. Error bars represent ± SD. ***P < .001. **P < .01. Gene profiling by Affymetrix analysis (A) was performed once. Experiments B and C were repeated at least 3 times independently. (B) One representative experiment is shown.