Expression of a Highly Antigenic and Native-Like Folded Extracellular Domain of the Human α1 Subunit of Muscle Nicotinic Acetylcholine Receptor, Suitable for Use in Antigen Specific Therapies for Myasthenia Gravis

Abstract

We describe the expression of the extracellular domain of the human α1 nicotinic acetylcholine receptor (nAChR) in lepidopteran insect cells (i-α1-ECD) and its suitability for use in antigen-specific therapies for Myasthenia Gravis (MG). Compared to the previously expressed protein in P. pastoris (y-α1-ECD), i-α1-ECD had a 2-fold increased expression yield, bound anti-nAChR monoclonal antibodies and autoantibodies from MG patients two to several-fold more efficiently and resulted in a secondary structure closer to that of the crystal structure of mouse α1-ECD. Our results indicate that i-α1-ECD is an improved protein for use in antigen-specific MG therapeutic strategies.

Standardization of the experimental autoimmune myasthenia gravis (EAMG) model by immunization of rats with Torpedo californica acetylcholine receptors — Recommendations for methods and experimental designs

“…The T. californica AChR (tAChR) has been used in most EAMG studies because it provides a reliable antigen for the induction of EAMG for which we describe the immunization standards. However, some antigen-specific therapies may depend on the exact amino acid sequence of the human AChR, such as immunodominant T or B cell epitopes, or on conformational epitopes that are specific for human MG. Other antigens such as the human AChR α1/1–210 peptides ( Lennon et al, 1991 ), the recombinant chimeric Aplysia ACh-binding protein (AChBP) with human main immunogenic region ( Luo and Lindstrom, 2012 ) or ectodomains of human AChR subunits ( Niarchos et al, 2013 ) have also been used to induce EAMG. These human antigen models are clearly useful for answering specific research questions in exploratory studies.…”