We also identified several E-DI-II specific mAbs with high to no neutralizing activity. Serotype-specific mAbs (DB2-3 and DB23-3) with potent neutralizing activity were found to recognize E-DI-II of DENV-2 ( Figure 2 and Table 1 ). Some studies have identified highly neutralizing and protective antibodies against JEV and Figure 5 . Construction and characterization of humanized DB32-6 mAb. (A) Amino acid sequences of humanized DB32-6 (hDB32-6). FR, framework region; CDR, complementarity determining region. Red residues represent the different amino acids from murine DB32-6 (mDB32-6). (B) mDB32-6 and hDB32-6 mAbs recognized DENV-2-infected BHK-21 cells by IFA. Cells were counterstained with DAPI (blue) and observed at 4006 magnification. (C) Binding activity of hDB32-6 mAbs. Three stable clones of hDB32-6 (hDB32-6-30, hDB32-6-48 and hDB32-6-51) recognized DENV-2infected C6/36 cells and recombinant E-DIII of DENV-2 by ELISA. (D) Various concentrations of mDB32-6 and hDB32-6-48 mAbs were reactive to DENV-2 and recombinant E-DIII of DENV-2 but not to mock control. NMIgG and NHIgG were used as negative controls. (E) Binding affinities of mDB32-6 and hDB32-6-48 to E-DIII of DENV-2. mAbs affinity analysis was performed by surface plasmon resonance (SPR). Binding affinity was tested at the mAb concentrations ranging 0 to 4 nM. Binding curves and kinetic parameters are shown. doi:10.1371/journal.pntd.0001636.g005