Structure and function analysis of therapeutic monoclonal antibodies against dengue virus type 2.
Dengue virus (DENV) is the most prevalent insect-transmitted viral disease in humans globally, and currently no specific therapy or vaccine is available. Protection against DENV and other related flaviviruses is associated with the development of antibodies against the viral envelope (E) protein. Although prior studies have characterized the neutralizing activity of monoclonal antibodies (MAbs) against DENV type 2 (DENV-2), none have compared simultaneously the inhibitory activity against a genetically diverse range of strains in vitro, the protective capacity in animals, and the localization of epitopes. Here, with the goal of identifying MAbs that can serve as postexposure therapy, we investigated in detail the functional activity of a large panel of new anti-DENV-2 mouse MAbs. Binding sites were mapped by yeast surface display and neutralization escape, cell culture inhibition assays were performed with homologous and heterologous strains, and prophylactic and therapeutic activity was evaluated with two mouse models. Protective MAbs localized to epitopes on the lateral ridge of domain I (DI), the dimer interface, lateral ridge, and fusion loop of DII, and the lateral ridge, C-C' loop, and A strand of DIII. Several MAbs inefficiently inhibited at least one DENV-2 strain of a distinct genotype, suggesting that recognition of neutralizing epitopes varies with strain diversity. Moreover, antibody potency generally correlated with a narrowed genotype and serotype specificity. Five MAbs functioned efficiently as postexposure therapy when administered as a single dose, even 3 days after intracranial infection of BALB/c mice. Overall, these studies define the structural and functional complexity of antibodies against DENV-2 with protective potential.
Sukupolvi-Petty
Soila
S
Department of Medicine,Washington University School of Medicine, 660 South Euclid Ave., Box 8051, St. Louis, MO 63110, USA.
Austin
S Kyle
SK
Engle
Michael
M
Brien
James D
JD
Dowd
Kimberly A
KA
Williams
Katherine L
KL
Johnson
Syd
S
Rico-Hesse
Rebeca
R
Harris
Eva
E
Pierson
Theodore C
TC
Fremont
Daved H
DH
Diamond
Michael S
MS
D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics* / Q000276:immunology* / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000235:genetics* / Q000276:immunology* / Q000627:therapeutic use; D001665:Binding Sites; D002460:Cell Line; D006224:Cricetinae; D003715:Dengue / Q000517:prevention & control / Q000628:therapy; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology*; D018604:Epitope Mapping; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D013329:Structure-Activity Relationship; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; C051821:E-glycoprotein, Dengue virus type 2; D014759:Viral Envelope Proteins