A three monoclonal antibody combination potently neutralizes multiple botulinum neurotoxin serotype F subtypes.
Human botulism is primarily caused by botulinum neurotoxin (BoNT) serotypes A, B and E, with around 1% caused by serotype F (BoNT/F). BoNT/F comprises at least seven different subtypes with the amino acid sequence difference between subtypes as high as 36%. The sequence differences present a significant challenge for generating monoclonal antibodies (mAbs) that can bind, detect and neutralize all BoNT/F subtypes. We used repertoire cloning of immune mouse antibody variable (V) regions and yeast display to generate a panel of 33 lead single chain Fv (scFv) mAbs that bound one or more BoNT/F subtypes with a median equilibrium dissociation constant (KD) of 4.06 × 10-9 M. By diversifying the V-regions of the lead mAbs and selecting for cross reactivity we generated five mAbs that bound each of the seven subtypes. Three scFv binding non-overlapping epitopes were converted to IgG that had KD for the different BoNT/F subtypes ranging from 2.2×10-8 M to 1.47×10-12 pM. An equimolar combination of the mAbs was able to potently neutralize BoNT/F1, F2, F4 and F7 in the mouse neutralization assay. The mAbs have potential utility as diagnostics capable of recognizing the known BoNT/F subtypes and could be developed as antitoxins to prevent and treat type F botulism.
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Yongfeng
Y
Fan
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Consuelo
C
Garcia-Rodriguez
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Jianlong
J
Lou
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Weihua
W
Wen
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Fraser
F
Conrad
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
Wenwu
W
Zhai
Molecular and Translational Sciences Division, United States Army Medical Institute of Infectious Diseases (USAMRIID), Fort Detrick, Maryland, United States of America.
Theresa J
TJ
Smith
Medical Countermeasures Technology, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, United States of America.
Leonard A
LA
Smith
Department of Anesthesia and Perioperative Care, University of California, San Francisco, Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California, United States of America.
James D
http://orcid.org/0000-0003-0562-3517
JD
Marks
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000992:Antitoxins / Q000235:genetics / Q000276:immunology*; D001905:Botulinum Toxins / Q000276:immunology*; D001906:Botulism / Q000175:diagnosis / Q000628:therapy; D020134:Catalytic Domain / Q000276:immunology; D003014:Clostridium botulinum / Q000378:metabolism; D003429:Cross Reactions / Q000276:immunology; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics; D007114:Immunization; D051379:Mice; D012441:Saccharomyces cerevisiae / Q000235:genetics; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000992:Antitoxins; D000939:Epitopes; D057127:Single-Chain Antibodies; D001905:Botulinum Toxins; C096321:botulinum toxin type F