Dataset Information

Antibody-dependent enhancement of toxicity of myotoxin II from Bothrops asper.

ABSTRACT: Improved therapies are needed against snakebite envenoming, which kills and permanently disables thousands of people each year. Recently developed neutralizing monoclonal antibodies against several snake toxins have shown promise in preclinical rodent models. Here, we use phage display technology to discover a human monoclonal antibody and show that this antibody causes antibody-dependent enhancement of toxicity (ADET) of myotoxin II from the venomous pit viper, Bothrops asper, in a mouse model of envenoming that mimics a snakebite. While clinical ADET related to snake venom has not yet been reported in humans, this report of ADET of a toxin from the animal kingdom highlights the necessity of assessing even well-known antibody formats in representative preclinical models to evaluate their therapeutic utility against toxins or venoms. This is essential to avoid potential deleterious effects as exemplified in the present study.

SUBMITTER: Sorensen CV

PROVIDER: S-EPMC10791742 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Antibody-dependent enhancement of toxicity of myotoxin II from Bothrops asper.

Sørensen Christoffer V CV Fernández Julián J Adams Anna Christina AC Wildenauer Helen H K HHK Schoffelen Sanne S Ledsgaard Line L Pucca Manuela B MB Fiebig Michael M Cerni Felipe A FA Tulika Tulika T Voldborg Bjørn G BG Karatt-Vellatt Aneesh A Morth J Preben JP Ljungars Anne A Grav Lise M LM Lomonte Bruno B Laustsen Andreas H AH

Nature communications 20240116 1

Improved therapies are needed against snakebite envenoming, which kills and permanently disables thousands of people each year. Recently developed neutralizing monoclonal antibodies against several snake toxins have shown promise in preclinical rodent models. Here, we use phage display technology to discover a human monoclonal antibody and show that this antibody causes antibody-dependent enhancement of toxicity (ADET) of myotoxin II from the venomous pit viper, Bothrops asper, in a mouse model ...[more]

PMID: 38228619

Similar Datasets

Project description:DM64 is a toxin-neutralizing serum glycoprotein isolated from Didelphis aurita, an ophiophagous marsupial naturally resistant to snake envenomation. This 64 kDa antitoxin targets myotoxic phospholipases A2, which account for most local tissue damage of viperid snakebites. We investigated the noncovalent complex formed between native DM64 and myotoxin II, a myotoxic phospholipase-like protein from Bothrops asper venom. Analytical ultracentrifugation (AUC) and size exclusion chromatography indicated that DM64 is monomeric in solution and binds equimolar amounts of the toxin. Attempts to crystallize native DM64 for X-ray diffraction were unsuccessful. Obtaining recombinant protein to pursue structural studies was also challenging. Classical molecular modeling techniques were impaired by the lack of templates with more than 25% sequence identity with DM64. An integrative structural biology approach was then applied to generate a three-dimensional model of the inhibitor bound to myotoxin II. I-TASSER individually modeled the five immunoglobulin-like domains of DM64. Distance constraints generated by cross-linking mass spectrometry of the complex guided the docking of DM64 domains to the crystal structure of myotoxin II, using Rosetta. AUC, small-angle X-ray scattering (SAXS), molecular modeling, and molecular dynamics simulations indicated that the DM64-myotoxin II complex is structured, shows flexibility, and has an anisotropic shape. Inter-protein cross-links and limited hydrolysis analyses shed light on the inhibitor's regions involved with toxin interaction, revealing the critical participation of the first, third, and fifth domains of DM64. Our data showed that the fifth domain of DM64 binds to myotoxin II amino-terminal and beta-wing regions. The third domain of the inhibitor acts in a complementary way to the fifth domain. Their binding to these toxin regions presumably precludes dimerization, thus interfering with toxicity, which is related to the quaternary structure of the toxin. The first domain of DM64 interacts with the functional site of the toxin putatively associated with membrane anchorage. We propose that both mechanisms concur to inhibit myotoxin II toxicity by DM64 binding. The present topological characterization of this toxin-antitoxin complex constitutes an essential step toward the rational design of novel peptide-based antivenom therapies targeting snake venom myotoxins.

Project description:DM64 is a toxin-neutralizing serum glycoprotein isolated from the South American opossum Didelphis aurita. This ophiophagous marsupial is naturally resistant to snake envenomation and has evolved such biochemical defense as a trophic adaptation. The endogenous antitoxin is a human α1B-glycoprotein homolog of 64 kDa, specifically targeting myotoxic phospholipases A2, which account for most local tissue damage associated with viper snakebites. This study investigated the noncovalent complex formed between native DM64 and myotoxin II, a myotoxic calcium-independent phospholipase-like protein from Bothrops asper venom. Analytical ultracentrifugation, size exclusion chromatography, and small-angle X-ray scattering (SAXS) data indicated that DM64 is monomeric in solution and binds equimolar amounts of the toxin. Initial attempts to solve the structure of DM64 experimentally failed due to technical limitations caused by N-glycan heterogeneity and low recovery of heterologous protein. Classical molecular modeling techniques were impaired by the lack of templates with more than 25% sequence identity with DM64. An integrative structural biology approach was then applied to generate a refined three-dimensional model of the inhibitor bound to myotoxin II. The five immunoglobulin-like domains of DM64 were individually modeled using the I-TASSER suite. Distance constraints generated by cross-linking mass spectrometry of the complex guided the docking of DM64 domains to the crystal structure of myotoxin II (1CLP), using the Rosetta docking suite. The model of the DM64-myotoxin II complex was successfully fitted to a SAXS envelope. Inter-protein cross-links and limited hydrolysis analyses shed light on the inhibitor's regions involved with toxin interaction, revealing the critical participation of the first, third, and fifth domains of DM64. Our data showed that the fifth domain of DM64 binds to myotoxin II’s amino-terminal and -wing regions. The third domain of the inhibitor acts in a complementary way to the fifth domain. Their binding to these toxin regions presumably interferes with dimerization, a critical step in the allosteric activation of myotoxic PLA2-like proteins. Additionally, the first domain of DM64 likely interacts with the functional site of the toxin putatively associated with membrane anchorage. We propose that both mechanisms concur to effectively inhibit myotoxin II toxicity by DM64 binding. In summary, we argue such topological characterization of this toxin-antitoxin complex to constitute an essential first step toward the rational design of novel peptide-based antivenom therapies targeting snake venom myotoxins.

Dataset Information

Antibody-dependent enhancement of toxicity of myotoxin II from Bothrops asper.

Publications

Antibody-dependent enhancement of toxicity of myotoxin II from Bothrops asper.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets