Tcrd Rearrangement Redirects a Processive Tcra Recombination Program to Expand the Tcra Repertoire.

Journal Article (Journal Article)

Adaptive immunity depends on diverse T cell receptor repertoires generated by variable, diversity, and joining (V[D]J) recombination. Here, we define the principles by which combinatorial diversity is generated in the murine Tcra repertoire. Tcra and Tcrd gene segments share the Tcra-Tcrd locus, with interspersed Vα and Vδ segments undergoing Vδ-Dδ-Jδ rearrangement in CD4-CD8- thymocytes and then multiple rounds of Vα-Jα rearrangement in CD4+CD8+ thymocytes. We document stepwise, highly coordinated proximal-to-distal progressions of Vα and Jα use on individual Tcra alleles, limiting combinatorial diversity. This behavior is supported by an extended chromatin conformation in CD4+CD8+ thymocytes, with only nearby Vα and Jα segments contacting each other. Tcrd rearrangements can use distal Vδ segments due to a contracted Tcra-Tcrd conformation in CD4-CD8- thymocytes. These rearrangements expand the Tcra repertoire by truncating the Vα array to permit otherwise disfavored Vα-Jα combinations. Therefore, recombination events at two developmental stages with distinct chromatin conformations synergize to promote Tcra repertoire diversity.

Full Text

Duke Authors

Cited Authors

  • Carico, ZM; Roy Choudhury, K; Zhang, B; Zhuang, Y; Krangel, MS

Published Date

  • June 6, 2017

Published In

Volume / Issue

  • 19 / 10

Start / End Page

  • 2157 - 2173

PubMed ID

  • 28591585

Pubmed Central ID

  • PMC5529038

Electronic International Standard Serial Number (EISSN)

  • 2211-1247

Digital Object Identifier (DOI)

  • 10.1016/j.celrep.2017.05.045


  • eng

Conference Location

  • United States