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E protein binding at the Tcra enhancer promotes Tcra repertoire diversity.

ABSTRACT: V(D)J recombination of antigen receptor loci is a highly developmentally regulated process. During T lymphocyte development, recombination of the Tcra gene occurs in CD4⁺CD8⁺ double positive (DP) thymocytes and requires the Tcra enhancer (Eα). E proteins are known regulators of DP thymocyte development and have three identified binding sites in Eα. To understand the contribution of E proteins to Eα function, mutants lacking one or two of the respective binding sites were generated. The double-binding site mutant displayed a partial block at the positive selection stage of αβ T cell development. Further investigation revealed loss of germline transcription within the Tcra locus at the Jα array, along with dysregulated primary and impaired secondary Vα-Jα rearrangement. Eα E protein binding increases Tcra locus accessibility and regulates TCRα recombination, thus directly promoting Tcra repertoire diversity.

SUBMITTER: Mihai A

PROVIDER: S-EPMC10358851 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature

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E protein binding at the Tcra enhancer promotes Tcra repertoire diversity.

Mihai Ariana A Roy Sumedha S Krangel Michael S MS Zhuang Yuan Y

Frontiers in immunology 20230706

V(D)J recombination of antigen receptor loci is a highly developmentally regulated process. During T lymphocyte development, recombination of the Tcra gene occurs in CD4+CD8+ double positive (DP) thymocytes and requires the Tcra enhancer (Eα). E proteins are known regulators of DP thymocyte development and have three identified binding sites in Eα. To understand the contribution of E proteins to Eα function, mutants lacking one or two of the respective binding ...[more]

PMID: 37483636

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