Refinement and Neutralization Evaluation of the F(ab’)2 Type of Antivenom against the Deadly Jellyfish Nemopilema nomurai Toxins

Abstract

Jellyfish stings threaten people’s health and even life in coastal areas worldwide. Nemopilema nomurai is one of the most dangerous jellyfish in the East Asian Marginal Seas, which not only stings hundreds of thousands of people every year but also is assumed to be responsible for most deaths by jellyfish stings in China. However, there is no effective first-aid drug, such as antivenoms, for the treatment of severe stings by N. nomurai to date. In this study, we prepared a N. nomurai antiserum from rabbits using inactivated N. nomurai toxins (NnTXs) and isolated the IgG type of antivenom (IgG-AntiNnTXs) from the antiserum. Subsequently, IgG-AntiNnTXs were refined with multiple optimizations to remove Fc fragments. Finally, the F(ab’)2 type of antivenom (F(ab’)2-AntiNnTXs) was purified using Superdex 200 and protein A columns. The neutralization efficacy of both types of antivenom was analyzed in vitro and in vivo, and the results showed that both IgG and F(ab’)2 types of antivenom have some neutralization effect on the metalloproteinase activity of NnTXs in vitro and could also decrease the mortality of mice in the first 4 h after injection. This study provides some useful information for the development of an effective antivenom for N. nomurai stings in the future.

Raising Awareness on the Clinical and Forensic Aspects of Jellyfish Stings: A Worldwide Increasing Threat

“…The only specific treatment for a cnidarian envenomation in use thus far is a Chironex fleckeri antivenom. Other antivenoms are still being developed but were not tested in humans [ 231 , 232 ]. Finally, the way in which the venom exerts its toxic effects on humans is yet to be fully clarified and that may help to develop targeted treatments for jellyfish stings.…”

Investigation of Best Practices for Venom Toxin Purification in Jellyfish towards Functional Characterisation

“…As such, some jellyfish have venom so benign to humans they are referred to as “non-venomous”, while others such as box jellyfish and Irukandji have venom so powerful, they are well known to cause death in humans within hours [ 7 ]. This wide range of bioactivities observed across both the proteinaceous and non-proteinaceous components of jellyfish venom is of emerging focus towards not only biodiscovery but also the development of more effective first aid and clinical treatments, involving the development of an anti-venom [ 8 , 9 , 10 , 11 ].…”