Structural Basis for Differential Neutralization of Ebolaviruses

Viruses

Shridhar Bale¹  Joao M. Dias¹  Marnie L. Fusco¹  Takao Hashiguchi¹  Anthony C. Wong⁴  Tong Liu²  Ana I. Keuhne³  Sheng Li²  Virgil L. Woods²  Kartik Chandran⁴  John M. Dye³ 

[1] Dept. of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA;Dept. of Medicine, University of California San Diego, La Jolla, CA 92093, USA;Virology Division, United States Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702, USA;Dept. of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461, USA;

关键词: Filovirus;    Ebola;    ebolavirus;    Sudan virus;    neutralization: glycoprotein;    antibodies;    structure;   

DOI  :  10.3390/v4040447

来源: mdpi

【 摘 要 】

There are five antigenically distinct ebolaviruses that cause hemorrhagic fever in humans or non-human primates (Ebola virus, Sudan virus, Reston virus, Taï Forest virus, and Bundibugyo virus). The small handful of antibodies known to neutralize the ebolaviruses bind to the surface glycoprotein termed GP_1,2. Curiously, some antibodies against them are known to neutralize in vitro but not protect in vivo, whereas other antibodies are known to protect animal models in vivo, but not neutralize in vitro. A detailed understanding of what constitutes a neutralizing and/or protective antibody response is critical for development of novel therapeutic strategies. Here, we show that paradoxically, a lower affinity antibody with restricted access to its epitope confers better neutralization than a higher affinity antibody against a similar epitope, suggesting that either subtle differences in epitope, or different characteristics of the GP_1,2 molecules themselves, confer differential neutralization susceptibility. Here, we also report the crystal structure of trimeric, prefusion GP_1,2 from the original 1976 Boniface variant of Sudan virus complexed with 16F6, the first antibody known to neutralize Sudan virus, and compare the structure to that of Sudan virus, variant Gulu. We discuss new structural details of the GP₁-GP₂ clamp, thermal motion of various regions in GP_1,2 across the two viruses visualized, details of differential interaction of the crystallized neutralizing antibodies, and their relevance for virus neutralization.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.