Immunization with a murine cytomegalovirus based vector encoding retrovirus envelope confers strong protection from Friend retrovirus challenge infection
Fig 1
(A) Expression of F-MuLV Env from the MCMV.env vector was verified by immunoblot analysis of lysates of MEF cells infected with the MCMVΔm157-based vector MCMV.env or the non-transgene encoding control vector collected 4, 24 or 48 hours after infection. Uninfected MEF cells served as negative control, detection was performed with antibodies directed against the indicated proteins. (B) 2 × 105 PFU MCMV.env or MCMV, or different amounts of F-MuLV particles (1 × 105 FFU, 5 × 103 FFU, or 1 × 103 FFU) were subjected to SDS-PAGE and Western Blot. Presence of F-MuLV Env gp70 was probed with gp70-specific polyclonal antibody, detection of MCMV gB served as loading control. (C-F) For characterization of the growth kinetics of the MCMVΔm157-based vector MCMV.env in comparison to non-transgene encoding vector or to wildtype MCMV, in vitro (C) or in vivo (D-F) replication studies were performed. (C) MEF cells were infected with the indicated viruses, and plaque forming units (PFU) of input virus as well as of supernatants collected three days p.i. were analysed. (D-F) CB6F1 mice were infected with 2 × 105 PFU of the indicated viruses, and MCMV titers in spleen (D), kidney (E) and salivary gland tissue (F) were analyzed three and 21 days after infection. Data were obtained in one experiment, each dot indicates one infection (C) or one mouse (D-F), bars indicate median values. Data were analysed for statistically significant differences by One Way ANOVA on Ranks with the Dunn’s post test; no significant differences were observed.