Development of synthetic immunological tools for Tasmanian devil research

The Tasmanian devil (Sarcophilus harrisii) is the world‚ÄövÑv¥s largest extant carnivorous marsupial. The wild population of devils has been decimated by two transmissible cancers, collectively named Devil Facial Tumour Disease (DFTD). Transmissible cancers are exceedingly rare and only three are found in mammalian species. The occurrence of two of these transmissible cancers in a single species raises a number of questions about the devil‚ÄövÑv¥s immune system and the pathogenesis of these diseases. Understanding the Tasmanian devil immune system and how it responds to these transmissible tumours is imperative for the continued conservation of this species. This research may also provide insight into the tumour - host immune system relationship in other cancers including human disease. Development of immune checkpoint immunotherapies and cancer vaccines have provided more targeted cancer therapies that are safer for patients and are in many cases more effective than traditional chemotherapy or radiotherapy. The understanding of immune system function and disease pathogeneses enhances the development of safe, effective, and rational therapies for disease. One of the major problems facing the field of wild immunology is the reagent gap. This refers to the lack of research tools and reagents available that specifically and reliably bind to non-human, non-model species targets. While thousands of antibodies are commercially available that bind to rodent or human targets, there are less than 30 that bind to Tasmanian devil targets, many of which have had to be developed in-house or custom ordered and are not commercially available. The development of specific, affordable, and reliable research tools will allow investigation into DFT pathogenesis, development of therapies, and analysis of therapy efficacy to be faster, more reliable, and more reproducible. A digital database of hybridoma derived anti-Tasmanian devil checkpoint molecule antibody sequences was designed and will provide a resource for the development of several novel antibodies and other affinity reagents for use in DFTD research, diagnoses, and therapies. Producing synthetic affinity reagents from known sequences is faster and cheaper than conventional antibodies without compromising specificity or affinity. Devilisation of hybridoma derived antibodies involves hybridising the mouse derived variable regions with devil derived constant regions. Compared to mouse derived antibodies, devilised reagents are less immunogenic and more appropriate for functional immune research and eventually, therapeutic applications. This thesis presents a method of producing anti-PDL1 devilised recombinant antibodies using a mammalian cell-based protein expression system.