Efficient functional neutralization of lethal peptide toxins in vivo by oligonucleotides

Tarek Mohamed Abd El-Aziz,Michel Ronjat,Jordi Molgo,Michel De Waard,Corinne Ravelet,Mahmoud Fadl,Muriel Amar,Simon Pale,Denis Servent,Germain Sotoing Taiwe,Jérôme Dejeu,Emmanuelle Fiore,Sawsan Al-Khoury,Eric Peyrin

doi:10.1038/s41598-017-07554-5

Abstract

Medical means to save the life of human patients affected by drug abuse, envenomation or critical poisoning are currently limited. While the compounds at risks are most often well identified, particularly for bioterrorism, chemical intervention to counteract the toxic effects of the ingested/injected compound(s) is restricted to the use of antibodies. Herein, we illustrate that DNA aptamers, targeted to block the pharmacophore of a poisonous compound, represent a fast-acting and reliable method of neutralization in vivo that possesses efficient and long-lasting life-saving properties. For this proof of concept, we used one putative bioweapon, αC-conotoxin PrXA, a marine snail ultrafast-killing paralytic toxin, to identify peptide-binding DNA aptamers. We illustrate that they can efficiently neutralize the toxin-induced (i) displacement of [125I]-α-bungarotoxin binding onto nicotinic receptors, (ii) inhibition of diaphragm muscle contraction, and (iii) lethality in mice. Our results demonstrate the preclinical value of DNA aptamers as fast-acting, safe and cheap antidotes to lethal toxins at risk of misuse in bioterrorism and offer hope for an alternative method than donor sera to treat cases of envenomation.

Highlights

With more than 100,000 deaths and 400,000 amputations, envenomation has been added by the World Health Organization[1] onto the list of tropical diseases neglected by global public health organizations[2]
For proof of concept that aptamers have the ability to neutralize dangerous animal toxins, we focused on a fast-killing paralytic α-conotoxin[23, 24]
While this report is of interest to the field of toxinology, we believe that it sets the trend for any poisonous compound that puts human life at risk, including drug abuse, phytochemicals or viral infection

Summary

Introduction

With more than 100,000 deaths and 400,000 amputations, envenomation has been added by the World Health Organization[1] onto the list of tropical diseases neglected by global public health organizations[2]. Compared to antibodies (i) they have a small size, (ii) their production is easy, reproducible and cost-effective, (iii) they can be stored at ambient temperature, and (iv) they are poorly immunogenic and lack toxicity[15, 16] They should be able to bind toxins for which no immune response can be triggered. For proof of concept that aptamers have the ability to neutralize dangerous animal toxins, we focused on a fast-killing paralytic α-conotoxin[23, 24] These compounds have been listed by the USA Center for Disease Control and Prevention as potential bioweapons in agreement with the Public Health Security and Bioterrorism Preparedness and Response Act of 200225, 26. While this report is of interest to the field of toxinology, we believe that it sets the trend for any poisonous compound that puts human life at risk, including drug abuse, phytochemicals or viral infection

Methods

Results

Conclusion