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Updated: Aug 12, 2026

Generation of Human Alloantigen-specific T Cells from Peripheral Blood
Published on: November 21, 2014
Regulation of T cell receptor beta allelic exclusion at a level beyond accessibility
Annette Jackson1, Hrisavgi D Kondilis, Bernard Khor
1The Department of Immunology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Abstract:
Allelic exclusion of V(beta)-to-DJ(beta) recombination depends on asynchronous rearrangement of alleles of the gene encoding T cell receptor beta in double-negative thymocytes and feedback inhibition that is maintained in double-positive thymocytes. Feedback is thought to be enforced through downregulation of V(beta) accessibility. In an attempt to override this negative regulation, we introduced the enhancer of the gene encoding T cell receptor alpha into the V(beta) gene cluster downstream of V(beta)12. In double-negative thymocytes, the introduced enhancer had no measurable effect on accessibility, but V(beta)12 rearrangement was stimulated and V(beta)12 allelic exclusion was partially subverted. In contrast, double-positive thymocytes showed increased V(beta) transcription and accessibility, but feedback inhibition of V(beta)-to-DJ(beta) recombination remained intact. Our results indicate additional regulatory constraints on V(beta)-to-DJ(beta) recombination that operate beyond the accessibility barrier.
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