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Protease-resistant human GAD-derived altered peptide ligands decrease TNF-alpha and IL-17 production in peripheral
Bernhard O Boehm1, Silke Rosinger, Guido Sauer
1Department of Internal Medicine I, University Medical Center Ulm and Center of Excellence, Germany.
Molecular Immunology
|June 10, 2009
Summary
New protease-resistant altered peptide ligands (prAPL) targeting glutamic acid decarboxylase 65 (GAD) reduce autoimmune responses in type 1 diabetes. These GAD-derived prAPL show potential for novel immunomodulatory therapies.
Area of Science:
- Immunology
- Endocrinology
- Biochemistry
Background:
- Glutamic acid decarboxylase 65 (GAD) and proinsulin are key autoantigens in type 1 diabetes (T1D), driving autoreactive T cell responses.
- Altered peptide ligands (APL) are investigated for their potential to modulate autoimmune reactions.
Purpose of the Study:
- To design and characterize protease-resistant APL (prAPL) derived from GAD.
- To evaluate the immunomodulatory effects of these GAD-derived prAPL on T cell responses in T1D.
Main Methods:
- GAD-derived prAPL were created through cleavage site-directed modification.
- Protease resistance, HLA-DRB1(*)0401 binding affinity, and serum half-life of prAPL were assessed.
- The impact of prAPL on cytokine secretion (IL-17, TNF-alpha, IL-6) from T cells of T1D patients was measured.
Main Results:
- GAD-derived prAPL demonstrated resistance to lysosomal and serum proteases.
- These prAPL exhibited high-affinity binding to HLA-DRB1(*)0401 and an extended serum half-life.
- GAD-derived prAPL significantly reduced pro-inflammatory cytokine secretion from GAD-specific T cells and T1D patient lymphocytes.
Conclusions:
- Protease-resistant APL targeting GAD can effectively mitigate autoreactive T cell responses, including Th17 cells.
- The development of high-affinity, protease-resistant APL offers a promising strategy for novel therapeutic interventions in autoimmune diseases like T1D.
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