Noble metals strip peptides from class II MHC proteins

Area of Science:

• Immunology
• Biochemistry
• Drug Discovery

Background:

• Class II major histocompatibility complex (MHC) proteins are crucial for immune function and autoimmune responses.
• Current methods to disrupt MHC-peptide interactions are challenging due to strong binding affinities.

Purpose of the Study:

• To identify small molecules that can disrupt MHC-peptide interactions.
• To explore a novel therapeutic strategy for autoimmune diseases.

Main Methods:

• High-throughput screening assay to discover peptide-stripping compounds.
• Biochemical experiments to elucidate the mechanism of action.
• Antigen-presenting cell assays to evaluate T cell activation inhibition.

Main Results:

• Discovery of noble metal complexes that allosterically strip peptides from human class II MHC proteins.
• Identification of a 'peptide-empty' conformation resembling the transition state of peptide loading.
• Demonstration that these metal inhibitors block T cell activation by antigen-presenting cells.

Conclusions:

• A novel allosteric mechanism for peptide removal from MHC proteins has been identified.
• This mechanism may explain the therapeutic effects of gold(I) drugs in rheumatoid arthritis.
• The findings provide a basis for developing new anti-autoimmune drugs targeting MHC-peptide interactions.