Fig 5.

ELISA binding titers to JRFL gp140-F trimers elicited by DNA EP of cell surface trimers and protein boosting. The presence of anti-Env-specific antibody in serum samples derived from the trimer-inoculated NHPs was detected by binding to trimeric JRFL gp140-F immobilized to the solid phase by ELISA. The sera from NHPs inoculated with PBS were included as negative controls (A034 and AP05), and there was no detectable binding of prebleed sera. Top left and right panels depict the ELISAs performed with antisera collected after 1 and 3 EP DNA immunizations, respectively. The bottom left and right panels show the results of ELISA performed with antisera collected after 3 DNA immunizations followed by 1 and 2 trimeric protein boosts, respectively. The symbols and the animal numbers shown on the right designate the individual NHPs from which serum was isolated.