The Aharoni laboratory utilizes protein engineering for applied and basic scientific research. Specifically, they use protein engineering approaches to generate novel proteins that can block the binding of proinflammatory cytokines to their endogenous receptors as autoimmune disease therapeutics. The Aharoni team also employs protein engineering to study enzyme-substrate recognition, focusing on enzymes catalyzing post-translational protein modifications, such as acetylation and methylation.
To generate these improved proteins, Prof. Aharoni and his group rely on directed protein evolution. Directed evolution methodologies are based on the generation of large mutant libraries, followed by screening assays designed to identify and isolate mutants with a higher binding affinity/catalytic activity than the native protein. For example, the researchers employ high-throughput screening for proteins with enhanced binding affinity using yeast surface display coupled to flow cytometry. This approach enables the screening of >107 mutants, enabling the enrichment of libraries for mutants with enhanced binding affinity towards a target protein.
To develop autoimmune disease therapeutics, the Aharoni team uses soluble receptors as starting points for the inhibition of cytokine-endogenous receptor interactions, focusing on the inhibition of IL-17A, involved in psoriasis, and TL1A (TNF-like cytokine), involved in Crohn’s disease. The researchers use protein engineering to enhance the stability and affinity of these soluble receptors to the target cytokines. The goal of the work being conducted by Prof. Aharoni and his laboratory is to further develop these improved extracellular receptor domains as novel therapeutic agents for autoimmune diseases in a series of biochemical, cellular, and animal studies.
Recently, antibodies targeting IL-17A proved to be highly efficient in the treatment of psoriasis in thousands of patients. The frequency of psoriasis in the world population is high (estimated to be 2-4%) and includes different forms of the disease. Prof. Aharoni hopes that the improvements made by his lab to the soluble receptors that targets IL-17A will complement current antibody therapy.