Molecular dissection of box jellyfish venom cytotoxicity highlights an effective venom antidote

Man-Tat Lau,Thang M Khuong,John Manion,David T Nguyen,Jamie B Littleboy,Jamie E Seymour,Daniel Hesselson,G Gregory Neely,Qiao-Ping Wang,Lisa Oyston

doi:10.1038/s41467-019-09681-1

Abstract

The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection of a jellyfish venom-induced cell death pathway by screening for host components required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis. We identify the peripheral membrane protein ATP2B1, a calcium transporting ATPase, as one host factor required for venom cytotoxicity. Targeting ATP2B1 prevents venom action and confers long lasting protection. Informatics analysis of host genes required for venom cytotoxicity reveal pathways not previously implicated in cell death. We also discover a venom antidote that functions up to 15 minutes after exposure and suppresses tissue necrosis and pain in mice. These results highlight the power of whole genome CRISPR screening to investigate venom mechanisms of action and to rapidly identify new medicines.

Highlights

The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure
We found that venom isolated from C. fleckeri rapidly killed human cells in a concentration-dependent manner by resazurinbased cell viability assay (Fig. 1b) and similar results were obtained by evaluating Lactate dehydrogenase (LDH) release or ATP depletion (Supplementary Fig. 1a, b)
To validate a role for sphingolipids in venom-induced cell death, we focused on SGMS1, a top-ranked hit (Fig. 2d) which encodes a key enzyme for sphingomyelin synthesis- sphingomyelin a Biological process b

Summary

Introduction

The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. We discover a venom antidote that functions up to 15 minutes after exposure and suppresses tissue necrosis and pain in mice These results highlight the power of whole genome CRISPR screening to investigate venom mechanisms of action and to rapidly identify new medicines. The bacterial clustered regularly interspaced short palindromic repeats (CRISPR)-Cas[9] system has been shown effective for genome-scale loss of function screens in mammalian cells[12,13] This approach is suited to identify genes required for drugs or toxins to trigger cell death, and has been used to characterise cell death in response to cancer drugs[12,13], bacteria toxins[14] and viral infection[15]. Our molecular insights directly informed a rational drug repurposing strategy that identified a new box jellyfish venom antidote that can suppress tissue destruction and attenuate the excruciating pain associated with envenoming

Methods

Results

Conclusion