IMGT Web resources

 Here you are: IMGT Web resources > IMGT Education > Questions and Answers

QUESTION 4:

How to make 108 different T cell receptor delta chains?

ANSWER to question 4:

From the TRD genes to the T cell receptor delta chains

The TRD V-D-J rearrangements (D-J rearrangement then V to D-J rearrangements) in the T cells create a combinatorial diversity of 36-2 24 recombinations. Two or even the 3 TRDD may be used in a V-D-J rearrangements leading to 192 or 224 potentiel recombinations, respectively. One important additional mechanism contributes to the T cell receptor chain diversity: the N diversity (N, for nucleotides) which results from deletion and/or addition of nucleotides at random by the terminal deoxynucleotidyl transferase and creates, at the V-D-J-JUNCTION, regions not encoded in the germline DNA. There are up to four N diversity regions in V-D-J-JUNCTIONs comprising 3 TRDD. In contrast to the immunoglobulin loci, there is no mechanism of somatic mutations in the T cell receptor loci.

Created: 11/06/2001
Last updated: Friday, 22-Sep-2023 18:15:36 CEST
Author: Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr
Editor: Elodie Foulquier