A Three Monoclonal Antibody Combination Potently Neutralizes Multiple Botulinum Neurotoxin Serotype E Subtypes
Consuelo Garcia-Rodriguez,
Ali Razai,
Isin N. Geren,
Jianlong Lou,
Fraser Conrad,
Wei-Hua Wen,
Shauna Farr-Jones,
Theresa J. Smith,
Jennifer L. Brown,
Janet C. Skerry,
Leonard A. Smith,
James D. Marks
Affiliations
Consuelo Garcia-Rodriguez
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Ali Razai
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Isin N. Geren
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Jianlong Lou
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Fraser Conrad
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Wei-Hua Wen
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Shauna Farr-Jones
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Theresa J. Smith
Molecular and Translational Sciences Division, United States Army Medical Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD 21702, USA
Jennifer L. Brown
Ke’aki Technologies LLC, United States Army Medical Institute of Infectious Diseases, (USAMRIID) Fort Detrick, MD 21702, USA
Janet C. Skerry
Ke’aki Technologies LLC, United States Army Medical Institute of Infectious Diseases, (USAMRIID) Fort Detrick, MD 21702, USA
Leonard A. Smith
Medical Countermeasures Technology, USAMRIID, Fort Detrick, MD 21702-5011, USA
James D. Marks
Zuckerberg San Francisco General Hospital and Trauma Center, Room 3C-38, Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Avenue, San Francisco, CA 94110, USA
Human botulism is most commonly caused by botulinum neurotoxin (BoNT) serotypes A, B, and E. For this work, we sought to develop a human monoclonal antibody (mAb)-based antitoxin capable of binding and neutralizing multiple subtypes of BoNT/E. Libraries of yeast-displayed single chain Fv (scFv) antibodies were created from the heavy and light chain variable region genes of humans immunized with pentavalent-toxoid- and BoNT/E-binding scFv isolated by Fluorescence-Activated Cell Sorting (FACS). A total of 10 scFv were isolated that bound one or more BoNT/E subtypes with nanomolar-level equilibrium dissociation constants (KD). By diversifying the V-regions of the lead mAbs and selecting for cross-reactivity, we generated three scFv that bound all four BoNT/E subtypes tested at three non-overlapping epitopes. The scFvs were converted to IgG that had KD values for the different BoNT/E subtypes ranging from 9.7 nM to 2.28 pM. An equimolar combination of the three mAbs was able to potently neutralize BoNT/E1, BoNT/E3, and BoNT/E4 in a mouse neutralization assay. The mAbs have potential utility as therapeutics and as diagnostics capable of recognizing multiple BoNT/E subtypes. A derivative of the three-antibody combination (NTM-1633) is in pre-clinical development with an investigational new drug (IND) application filing expected in 2018.
