Epitopes

An epitope is the part of an antigen that is recognized by the immune system.   Epitopes are relatively short sequences of amino acids and a typical full-length protein contains many different epitopes to which antibodies can bind.  Epitopes of protein antigens are divided into two categories, conformational epitopes and linear epitopes, based on their structure and interaction with the paratope, the region of an antibody to which an epitope binds.   The immune system is divided into innate and adaptive categories, adaptive immunity is only present in vertebrates and highly selectively recognises, destroys and remembers invading pathogens in a process mediated by T- and B-cells. B- and T-cells do not recognize pathogens as a whole, but instead recognize epitopes within these antigens. Epitopes are classified as B cell epitopes or T cell epitopes on the basis of the types of cellular response they elicit. There is great interest in identifying epitopes in antigens in order to understand disease etiology, for immune monitoring, to develop diagnosis assays, and to design epitope-based vaccines.

Further reading

Huang and Honda (2006) CED: a conformational epitope database. BMC Immunol. 7 7 PMID: 16603068

Sanchez-Trincado et al (2017) Fundamentals and Methods for T- and B-Cell Epitope Prediction J. Immunology Research Article ID 2680160 PMID: 29445754

Tian et al (2018) A Review on T Cell Epitopes Identified Using Prediction and Cell-Mediated Immune Models for Mycobacterium tuberculosis and Bordetella pertussis. Front. Immunology 9 2778 PMID: 30555469