Venom is a complex cocktail of biologically active proteins, salts, and organic molecules. The venom toxin-coding genes in animals have convergently originated from endophysiological protein-coding genes via gene duplication, followed by accelerated evolution. Venom research has primarily focussed on snake venoms because of their remarkable compositional variation and the negative impact of snakebites on human health. Research has highlighted that conventional antivenom, the mainstay treatment for snakebites, is ineffective in countering the inter and intraspecific variations in snake venoms. Therefore, in the first chapter of my thesis, I will employ our understanding of venom evolution to design a broadly effective snakebite therapy. With the help of comparative venom gland transcriptomics and evolutionary analysis, I will identify regions in the major venom toxins that remain conserved across populations, regions and even species. I will then synthesise sequences coding these epitopes and undertake DNA immunisation of small mammals (e.g., mice and rabbits). I will employ advanced technologies in antibody discovery, including B cell sorting and yeast display selection, to discover and recombinantly express neutralising antibodies. By targeting such conserved epitopes in the major venom toxins, particularly the three-finger toxins (3FTx) and snake venom metalloproteases (SVMP) from multiple species of elapid and viperid snakes, I aspire to achieve a broad breadth of neutralisation against the most medically important snakes of the Indian subcontinent.

In addition to the evolutionary design of antibodies, I will explore the potential use of animal immunisation with specific toxin families in discovering broadly neutralising antibodies (bNAbs). In Chapter II, I will attempt to discover bNAbs from large mammals immunised with the major venom toxin families from snakes in India and sub-Saharan Africa. Since the immune systems of these animals only get exposed to the major snake venom toxins, it greatly enhances our chance of discovering bNAbs against snakes across continents.

In addition to claiming the lives of over 58,000 Indians annually, snakebites result in over a hundred thousand immutable injuries each year. Research demonstrates that conventional antivenoms are ineffective in countering the morbid effects of snake envenoming. Unfortunately, very limited research has been undertaken towards solving this socioeconomic problem. Therefore, in the third chapter of my thesis, I will undertake an antibody discovery campaign to discover and recombinantly express neutralising antibodies against toxins that inflict morbid symptoms. I will exploit the unique properties of the camelid single heavy chain antibodies (VHH), which offer several advantages over mammalian immunoglobulins, including smaller size, greater tissue penetration potential, and thermostability. As these VHH antibodies are easy to manipulate and humanise, they will greatly reduce the adverse effects of snakebite treatment. 

Overall, with the broadly neutralising antibodies discovered against 3FTx and SVMPs - the two major toxin families in India’s medically most important snakes - I hope to save the lives, limbs and livelihoods of India’s 100,000 annual snakebite victims. In addition to advancing snakebite therapeutics, the findings of my thesis will shed light on the evolution of this highly adaptive complex cocktail.