Biased V beta usage in immature thymocytes is independent of DJ beta proximity and pT alpha pairing.
During thymus development, the TCR beta locus rearranges before the TCR alpha locus. Pairing of productively rearranged TCR beta-chains with an invariant pT alpha chain leads to the formation of a pre-TCR and subsequent expansion of immature pre-T cells. Essentially nothing is known about the TCR V beta repertoire in pre-T cells before or after the expression of a pre-TCR. Using intracellular staining, we show here that the TCR V beta repertoire is significantly biased at the earliest developmental stage in which VDJ beta rearrangement has occurred. Moreover (and in contrast to the V(H) repertoire in immature B cells), V beta repertoire biases in immature T cells do not reflect proximity of V beta gene segments to the DJ beta cluster, nor do they depend upon preferential V beta pairing with the pT alpha chain. We conclude that V gene repertoires in developing T and B cells are controlled by partially distinct mechanisms.
Wilson
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A
Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland.
Maréchal
C
C
MacDonald
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HR
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D005810:Multigene Family / Q000235:genetics / Q000276:immunology; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D013950:Thymus Gland / Q000737:chemistry / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D008562:Membrane Glycoproteins; D011498:Protein Precursors; D016693:Receptors, Antigen, T-Cell, alpha-beta; C090377:pre-T cell receptor alpha