A Paradigm Shift in Snakebite Envenoming Therapy: From Conventional Antivenoms to Rationally Designed, Broadly Neutralizing Combination Therapies

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  A Paradigm Shift in Snakebite Envenoming Therapy: From Conventional Antivenoms to Rationally Designed, Broadly Neutralizing Combination Therapies Abstract For over a century, polyclonal antivenom has been the cornerstone of snakebite therapy, saving countless lives. However, the current production method, based on immunizing large animals, has inherent limitations in terms of safety, stability, and supply reliability, thereby creating a pressing need for alternative technologies. This review charts the rise of next-generation antivenoms built on recombinant antibody engineering. We systematically survey the strategies for discovering and developing these molecules, from humanized monoclonal antibodies and VHHs to computationally designed proteins. Our central thesis is that achieving broad-spectrum neutralization against complex venoms requires a shift from single-agent approaches to rationally designed, oligoclonal “cocktail” therapies (defined mixtures of a few select therapeut...

Role of the complement system in kidney cell death induced by Loxosceles venom Sphingomyelinases D

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Role of the complement system in kidney cell death induced by Loxosceles venom Sphingomyelinases D

Abstract

Envenomation by Loxosceles spiders can result in local and systemic pathologies. Systemic loxoscelism, which can lead to death, is characterized by intravascular hemolysis, platelet aggregation, and acute kidney injury. Sphingomyelinase D (SMase D) in Loxosceles spider venom is responsible for both local and systemic pathologies, and has been shown to induce metalloprotease activity. As the complement system is involved in many renal pathologies and is involved in hemolysis in systemic loxoscelism, the aim of this study was to investigate its role and the role of complement regulators and metalloproteases in an in vitro model of Loxosceles venom induced renal pathology. We investigated the effects of the venom/SMase D and the complement system on the HK-2 kidney cell line. Using cell viability assays, western blotting, and flow cytometry, we show that human serum, as a source of complement, enhanced the venom/SMase D induced cell death and the deposition of complement components and properdin. Inhibitors for ADAM-10 and ADAM-17 prevented the venom induced release of the of the complement regulator MCP/CD46 and reduced the venom/SMase D induced cell death. Our results show that the complement system can contribute to Loxosceles venom induced renal pathology. We therefore suggest that patients experiencing systemic loxoscelism may benefit from treatment with metalloproteinase inhibitors and complement inhibitors, but this proposition should be further analyzed in future pre-clinical and clinical assays.

Okamoto, C.K., van den Berg, C.W., Pohl, P.C. et al. Role of the complement system in kidney cell death induced by Loxosceles venom Sphingomyelinases D. Arch Toxicol (2024). https://doi.org/10.1007/s00204-024-03711-8