Proteoliposome-based ZnT8 self-antigen for type 1 diabetes diagnosis

A method of detecting ZnT8 antibodies in serum comprising:

• (a) providing a collection of proteoliposomes having an interior and an exterior wherein some proteoliposomes have protein sequences of a transmembrane domain (TMD) of a zinc transporter 8 (ZnT8) on its exterior and other proteoliposomes comprise protein sequences of a cytosolic domain (CTD) of a ZnT8 protein exposed on its exterior,
• wherein the protein sequences of a TMD and a CTD are part of a full length ZnT8 protein,
• wherein the full length ZnT8 protein is a 325R polymorphic variant of human ZnT8,
• wherein the collection of proteoliposomes is prepared by dehydrating soluble ZnT8-containing proteoliposomes followed by rehydration of the dehydrated ZnT8-containing proteoliposomes, and
• wherein the collection of proteoliposomes is bound to a plate or chip;
• (b) adding serum comprising antibodies targeting the protein sequences of TMD and/or CTD forming proteoliposomes bound to the antibodies;
• (c) adding a labelled secondary antibody that binds to the antibodies bound to the proteoliposomes;
• and
• (d) measuring the amount of antibodies targeting the protein sequences of TMD and/or CTD bound to the proteoliposomes.