Structural basis of tetanus toxin neutralization by native human monoclonal antibodies

• DOI: 10.1016/j.celrep.2021.109070
• Publication Date: 2021-05-04T14:28:58Z
• Authors: Yueming Wang; Changwen Wu; Jinfang Yu; Shujian Lin; Tong Liu; Lipeng Zan; Nan Li; Po Hong; Xiaoli Wang; Zhenxing Jia; Jason Li; Yao Wang; Ming Zhang; Xiaohui Yuan; Chengming Li; Wenwen Xu; Weihong Zheng; Xinquan Wang; Hua-Xin Liao
• Keywords: 0301 basic medicine; ganglioside; QH301-705.5; Antibodies, Monoclonal; native human monoclonal antibody; tetanus; 3. Good health; Mice; 03 medical and health sciences; toxin neutralization; Tetanus Toxin; Animals; Humans; Amino Acid Sequence; Biology (General); immunoglobulin; tetanus toxin

Four potent native human monoclonal antibodies (mAbs) targeting distinct epitopes on tetanus toxin (TeNT) are isolated with neutralization potency ranging from approximately 17 mg to 6 mg each that are equivalent to 250 IU of human anti-TeNT immunoglobulin. TT0170 binds fragment B, and TT0069 and TT0155 bind fragment AB. mAb TT0067 binds fragment C and blocks the binding of TeNT to gangliosides. The co-crystal structure of TT0067 with fragment C of TeNT at a 2.0-Å resolution demonstrates that mAb TT0067 directly occupies the W pocket of one of the receptor binding sites on TeNT, resulting in blocking the binding of TeNT to ganglioside on the surface of host cells. This study reveals at the atomic level the mechanism of action by the TeNT neutralizing antibody. The key neutralization epitope on the fragment C of TeNT identified in our work provides the critical information for the development of fragment C of TeNT as a better and safer tetanus vaccine.