Mechanistic Study of Broadly Neutralizing Human Monoclonal Antibodies against Dengue Virus That Target the Fusion Loop

作者:Costin Joshua M; Zaitseva Elena; Kahle Kristen M; Nicholson Cindo O; Rowe Dawne K; Graham Amanda S; Bazzone Lindsey E; Hogancamp Greg; Sierra Marielys Figueroa; Fong Rachel H; Yang Sung Tae; Lin Li; Robinson James E; Doranz Benjamin J; Chernomordik Leonid V; Michael Scott F; Schieffelin John S; Isern Sharon*
来源:Journal of Virology, 2013, 87(1): 52-66.
DOI:10.1128/JVI.02273-12

摘要

There are no available vaccines for dengue, the most important mosquito-transmitted viral disease. Mechanistic studies with anti-dengue virus (DENV) human monoclonal antibodies (hMAbs) provide a rational approach to identify and characterize neutralizing epitopes on DENV structural proteins that can serve to inform vaccine strategies. Here, we report a class of hMAbs that is likely to be an important determinant in the human humoral response to DENV infection. In this study, we identified and characterized three broadly neutralizing anti-DENV hMAbs: 4.8A, D11C, and 1.6D. These antibodies were isolated from three different convalescent patients with distinct histories of DENV infection yet demonstrated remarkable similarities. All three hMAbs recognized the E glycoprotein with high affinity, neutralized all four serotypes of DENV, and mediated antibody-dependent enhancement of infection in Fc receptor-bearing cells at subneutralizing concentrations. The neutralization activities of these hMAbs correlated with a strong inhibition of virus-liposome and intracellular fusion, not virus-cell binding. We mapped epitopes of these antibodies to the highly conserved fusion loop region of E domain II. Mutations at fusion loop residues W101, L107, and/or G109 significantly reduced the binding of the hMAbs to E protein. The results show that hMAbs directed against the highly conserved E protein fusion loop block viral entry downstream of virus-cell binding by inhibiting E protein-mediated fusion. Characterization of hMAbs targeting this region may provide new insights into DENV vaccine and therapeutic strategies.

  • 出版日期2013-1
  • 单位NIH