Discovery of broadly-neutralizing antibodies against brown recluse spider and Gadim scorpion sphingomyelinases using consensus toxins as antigens

Abstract

Broadly-neutralizing monoclonal antibodies are becoming increasingly important tools for treating infectious diseases and animal envenomings. However, designing and developing broadly-neutralizing antibodies can be cumbersome using traditional low-throughput iterative protein engineering methods. Here, we present a new high-throughput approach for the standardized discovery of broadly-neutralizing monoclonal antibodies relying on phage display technology and consensus antigens representing an average sequence of related proteins. We showcase the utility of this approach by applying it to toxic sphingomyelinases from the venoms of very distant orders of the animal kingdom, the recluse spider and Gadim scorpion. First, we designed a consensus sphingomyelinase and performed three rounds of phage display selection, followed by DELFIA-based screening and ranking, and benchmarked this to a similar campaign involving cross-panning against recombinant versions of the native toxins. Second, we identified two scFvs that not only bind the consensus toxins, but which can also neutralize sphingomyelinase activity in vitro. Finally, we conclude that the phage display campaign involving the use of the consensus toxin was more successful in yielding cross-neutralizing scFvs than the phage display campaign involving cross-panning.

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“…Another approach for the discovery of cross-reactive neutralizing agents involves the use of recombinantly produced consensus toxins. These artificial toxins are designed to resemble an average sequence of several related toxins and can be used for immunization [ 49 , 50 ] or as target antigens during phage display-based discovery campaigns [ 49 , 51 ]. Lastly, cross-reactive, high-affinity neutralizing agents can be discovered or optimized by applying recent advances within the field of artificial intelligence, next-generation sequencing, and machine learning [ 52 , 53 ].…”