Discovery of Artificial Interleukin Receptors Uncovers Methods to Design and Engineer Immune Responses

Strategic Insights -

Scientists at Colorado State University have unveiled a breakthrough in the field of Immunology, detailing the creation of artificial interleukin receptors that can be designed and engineered to elicit specific immune responses. This research, published in the Proceedings of the National Academy of Sciences, marks a significant step forward in understanding the diversity of Toll/interleukin-1 receptor (TIR) domain functions and their role in plant immunity.

The study reveals that plant genomes can encode hundreds of TIR-domain containing proteins, many of which confer important agricultural disease resistance. However, the natural variation in these proteins and how it influences TIR enzymatic output and immunity-associated cell death remained largely unexplored. To address this, researchers assayed a complete collection of the TIR domains of Arabidopsis thaliana Col-0 (the 'AtTIRome') and discovered that roughly half of the AtTIRome triggered cell death in transient assays.

Key Takeaways:

  • The study identified a collection of 578 unique TIR domains in Arabidopsis thaliana Col-0, known as the AtTIRome, which displayed a range of cell death phenotypes in transient assays.
  • Artificial TIR proteins designed based on consensus sequences of the AtTIRome's cell death phenotypic classes revealed polymorphisms controlling variation in TIR cell death elicitation and metabolite production.
  • The research demonstrated that natural variation in the 'BB-loop', a flexible region overlying the catalytic pocket, determines differences in function across Arabidopsis TIR-containing proteins.
  • Artificial TIRs were shown to be functional on an NLR chassis and that BB-loop variation can tune the activity of a natural TIR-NLR protein.
  • The findings provide methods to design and engineer TIR-based immune receptors and shed light on the diversity of TIR outputs.

Statistics:

  • 578 unique TIR domains were identified in the AtTIRome, which displayed a range of cell death phenotypes in transient assays.
  • Roughly half of the AtTIRome (294 domains) triggered cell death in transient assays.
  • 33 artificial TIR proteins were designed, which revealed polymorphisms controlling variation in TIR cell death elicitation and metabolite production.
  • 15 of the artificial TIR proteins were functional on an NLR chassis.

Sources:

  • (1) The Arabidopsis Tipome Informs the Design of Artificial Tip (Toll/interleukin-1 Receptor) Domain Proteins. Proceedings of the National Academy of Sciences, 2025; 122(37).
  • (2) NewsRx. New Interleukin Receptors Data Have Been Reported by Researchers at Colorado State University [The Arabidopsis Tipome Informs the Design of Artificial Tip (Toll/interleukin-1 Receptor) Domain Proteins]. Life Science Weekly. October 21, 2025; p 3224.