title: Development of a humanized antibody with high therapeutic potential against dengue virus type 2.
abstract: BACKGROUND
  Dengue virus (DENV) is a significant public health threat in tropical and subtropical regions of the world. A therapeutic antibody against the viral envelope (E) protein represents a promising immunotherapy for disease control.
  
  
  RESULTS
  We generated seventeen novel mouse monoclonal antibodies (mAbs) with high reactivity against E protein of dengue virus type 2 (DENV-2). The mAbs were further dissected using recombinant E protein domain I-II (E-DI-II) and III (E-DIII) of DENV-2. Using plaque reduction neutralization test (PRNT) and mouse protection assay with lethal doses of DENV-2, we identified four serotype-specific mAbs that had high neutralizing activity against DENV-2 infection. Of the four, E-DIII targeting mAb DB32-6 was the strongest neutralizing mAb against diverse DENV-2 strains. Using phage display and virus-like particles (VLPs) we found that residue K310 in the E-DIII A-strand was key to mAb DB32-6 binding E-DIII. We successfully converted DB32-6 to a humanized version that retained potency for the neutralization of DENV-2 and did not enhance the viral infection. The DB32-6 showed therapeutic efficacy against mortality induced by different strains of DENV-2 in two mouse models even in post-exposure trials.
  
  
  CONCLUSIONS
  We used novel epitope mapping strategies, by combining phage display with VLPs, to identify the important A-strand epitopes with strong neutralizing activity. This study introduced potential therapeutic antibodies that might be capable of providing broad protection against diverse DENV-2 infections without enhancing activity in humans.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Pi-Chun
authors.initials: PC
authors.lastname: Li
authors.forename: Mei-Ying
authors.initials: MY
authors.lastname: Liao
authors.forename: Ping-Chang
authors.initials: PC
authors.lastname: Cheng
authors.forename: Jian-Jong
authors.initials: JJ
authors.lastname: Liang
authors.forename: I-Ju
authors.initials: IJ
authors.lastname: Liu
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Chiu
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Lin
authors.forename: Gwong-Jen J
authors.initials: GJ
authors.lastname: Chang
authors.forename: Han-Chung
authors.initials: HC
authors.lastname: Wu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D057134:Antibodies, Neutralizing / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000627:therapeutic use; D000998:Antiviral Agents / Q000627:therapeutic use*; D003715:Dengue / Q000276:immunology* / Q000628:therapy* / Q000821:virology; D003716:Dengue Virus / Q000276:immunology*; D004195:Disease Models, Animal; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D016019:Survival Analysis; D010948:Viral Plaque Assay
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000998:Antiviral Agents