Epitope mapping and validation
Epitope mapping is the process of identifying the specific peptide sequences on an antigen that elicit an immune response - either by binding to antibodies or MHC molecules. Epitope identification requires a systematic screening of the antigen, which can be difficult when the antigen has multiple conformations or binding domains. Since the development of therapeutics is dependent on having a detailed knowledge of these domains, peptide libraries are used to display multiple short, linear peptide fragments in parallel to deduce specific epitopes. The most common applications for epitope mapping are for T cells and antibodies.
T cell epitope mapping
T cell epitopes are components of proteins on antigen-presenting cells that elicit an immune response following T cell recognition and binding. Identification of these epitopes is critical for developing effective immune disease therapeutics. The peptide library is designed such that overlapping segments of the entire antigen are added to each well of a 96-well plate. T cell cultures or purified receptors are then added to the library and binding can be assessed by flow cytometry and other cellular assays. Epitope discovery by this method has been especially useful for developing vaccines for viral diseases and cancer.
Antibody epitope mapping
Antibody-epitope mapping provides novel insight into the specific binding interactions between proteins and antibodies. Similar to T cell mapping, antigenic peptides are screened following the addition of specific antibodies. If there is binding, then the peptide can be considered as "immunogenically fit," or capable of being immunogenic and promoting passive immunity. Binding events can be monitored in a variety of quantitative or qualitative methods, one of the most common being via ELISA. This screening technique has been used to identify the most effective monoclonal antibodies to treat multiple disorders and diseases, including muscular dystrophy and Alzheimer's disease.
Featured publication citing GenScript's peptide services for antibody-epitope mapping
Nikolaeva et al. Epitope mapping for monoclonal antibodies recognizing tuber necrotic isolates of Potato virus Y. Am J Potato Res. 2012 Apr; 89(2):121-128. Read more
Armistead et al. Antibodies to a Single, Conserved Epitope in Anopheles APN1 Inhibit Universal Transmission of Plasmodium falciparum and Plasmodium vivax Malaria. Infection and Immunity. 2014 Feb; 82(2): 818-829. Read more
Overview of peptide library applications for epitope mapping
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