Fig. (2) Caski cells do not express the HPV16 E2 protein. A) Caski cells were either not infected (NI) or infected with the GFP recombinant adenoviral vector (gfp) or the adenovirus expressing gfp-HPV16 E2 and were processed for immunofluorescence with the rabbit antibody raised against the HPV16 E2 protein previously described [10]. The expected MW for the untagged E2 protein is around 40Kd while the GFP tagged protein migrates at 66Kd [29]. B) Caski cells infected with the 2 recombinant adenoviruses, as indicated at the top of the pictures, were processed for immunofluorescence with the HPV16 E2 primary antibody and were revealed by secondary rabbit antibody coupled with Texas red (TR).