Binding and neutralizing serum activities.

<p>(A) Sera collected from the WT <i>(left)</i> and NLGS-3 Core <i>(right)</i> prior to immunization <i>(blue)</i>, following the DNA/Protein Boost 1 <i>(orange)</i>, and following the DNA/Protein Boost 2 <i>(red)</i> were tested for antibody reactivity to autologous rEnv immunogens. * <i>indicates p value < 0</i>.<i>01</i>, ** <i>p value < 0</i>.<i>001</i>, or *** <i>p value < 0</i>.<i>0001</i>. (B) Reciprocal IC50 serum neutralization titers following the DNA/Protein Boost 1 immunization (Post-DP1) and the Post DNA/Protein Boost 2 immunization (Post-DP2). Neutralizing activities were determined against viruses expressing WT 426c envelope and 426c envelope NLGS variants with mutations in Loop D and V5. NLGS-1 lacks the NLGS at position 276 in Loop D, NLGS-2 lacks two NLGS in V5 at positions 460 and 463, while NLGS-3 lacks all three NLGS.