Protein-engineered molecules carrying GAD65 epitopes and targeting CD35 selectively down-modulate disease-associated...

Area of Science:

• Immunology
• Endocrinology
• Biotechnology

Background:

• Type 1 diabetes mellitus is an autoimmune disorder causing chronic hyperglycemia.
• Glutamic acid decarboxylase 65 (GAD65) is a key autoantigen, with autoantibodies contributing to pancreatic beta-cell destruction.
• Complement receptor type 1 (CD35) on lymphocytes can suppress immune cell activity.

Purpose of the Study:

• To investigate the potential of chimeric molecules to eliminate GAD65-specific B cells in type 1 diabetes.
• To develop a method for selectively delivering a suppressive signal to autoreactive B cells.

Main Methods:

• Constructed two chimeric molecules using GAD65-derived peptides and an anti-CD35 monoclonal antibody.
• Tested immunomodulatory activity in vitro on peripheral blood mononuclear cells (PBMCs) from type 1 diabetes patients.

Main Results:

• Observed a reduction in anti-GAD65 IgG antibody-secreting plasma cells.
• Noted an increased percentage of apoptotic B lymphocytes after treatment.
• Demonstrated selective modulation of GAD65-specific B lymphocytes and autoantibody production.

Conclusions:

• Engineered chimeric molecules effectively co-cross-linked CD35 and the B cell antigen receptor (BCR) on GAD65-specific B cells.
• This targeted approach shows promise for altering the autoimmune characteristics of B cells in type 1 diabetes.