On November 27th, iGem Leiden will hold a talk about their past project called A.L.P.A.C.A. :
Nanobodies have been increasing in popularity because of their many benefits over conventional antibodies, but their potential remains untapped due to the lengthy and expensive process associated with their complex development. This is especially true for the animal immunisation and screening techniques that are employed in the process. To solve this, iGEM Leiden 2024 is introducing a more efficient, animal-free, and cost-effective pipeline for the development of nanobodies: ALPACA. This novel approach uses yeast surface display of bispecific nanobodies to screen a custom synthetic nanobody library for binders to an antigen of choice. Antigen-binding ability of library nanobodies is assessed, based on steric hindrance between the binding sites of library nanobodies and secondary GFP-binding nanobodies. This results in antigen-binding yeast cells with reduced green fluorescence that can be collected through fluorescence-activated cell sorting (FACS). Following this, DNA sequences encoding the antigen-binding nanobodies are easily retrieved for further development and production. Our ALPACA system supports the widespread implementation of nanobodies, removing the largest obstacles behind their development, and foregoing the need for animal testing entirely.