Human Cysteine Cathepsins Degrade Immunoglobulin G In Vitro in a Predictable Manner

Area of Science:

• Immunology
• Biochemistry
• Computational Biology

Background:

• Cysteine cathepsins are vital for adaptive immunity, epitope generation for HLA presentation, and autoantigen degradation.
• Immunoglobulin variable regions are immunogenic, with T cell reactivity studied in diseases and against therapeutic antibodies.
• The processing of immunoglobulins/B cell receptors in antigen-presenting cells remains poorly understood.

Purpose of the Study:

• To investigate the role of cysteine cathepsins in processing monoclonal antibodies and CNS proteins.
• To elucidate the generation of peptides presented by HLA class II molecules from these proteins.
• To develop predictive models for immunoglobulin degradation.

Main Methods:

• In silico analysis using neural network models.
• In vitro experimental proteomics.
• Cellular models of antigen presentation.

Main Results:

• Cysteine cathepsins S, L, and B generate peptides from monoclonal antibodies and CNS proteins, including autoantigens.
• Peptide generation is dependent on immunoglobulin heavy chain variable families.
• Neural network models combined with proteomics predict this degradation process.

Conclusions:

• Cysteine cathepsins play a significant role in generating HLA class II-presented peptides from antibodies and autoantigens.
• Predictive tools for this degradation can be developed and improved.
• Findings impact biotherapeutic drug design and understanding of autoimmune diseases.