The Immune Repertoire
The diverse antigen receptors of T and B lymphocytes are produced by somatic recombination of a limited, but large number of gene segments. These gene segments: V (variable), D (diversity), J (joining), and C (constant), determine the binding specificity and downstream applications of immunoglobulins and T cell receptors (TCRs).
The rearranged V(D)J portion of the receptor, termed the V-region, is of great interest as it is responsible for epitope recognition. When the V(D)J is translated into the amino acid sequence, the V-region can be subdivided into several parts consisting of the leader sequence, framework (FR) 1, complementarity-determining region 1 (CDR1), FR2, CDR2, FR3, CDR3, FR4, and the C-domains (see figure below). The CDR3 is of particular interest because some studies have indicated that this region is associated with antigen-specificity.
Applying Next Generation Sequencing to the Immune Repertoire
Next-generation sequencing (NGS) of the immune repertoire allows for the sequencing of millions of V-regions (or V(D)J sequences) in parallel. However, many of the NGS platforms are limited by the read-length of the output sequencing reads. iRepertoire offers several reagent systems to take advantage of the various output sequencing read lengths, and ALL reagent systems cover the CDR3 portion. Please read more about the different read lengths on our 100/150 PER vs 250 PER page.
Depicted is an antibody with both heavy and light chain. The V-region, which is responsible for antigen binding and specificity, consists of both framework (FR) and complementarity regions (CDR). iRepertoire offers reagent systems and services that facilitate the next generation sequencing of this region of B cell and T cell receptors. All reagent systems provide CDR3 sequence information (at a minimum).