V gamma 3 T cell receptor rearrangement and expression in the adult thymus.
Rearrangement and expression of the V gamma 3-J gamma 1 TCR has been found in murine dendritic epidermal cells (DEC) and fetal thymus. By using the polymerase chain reaction technique, V gamma 3-J gamma 1 rearrangements and RNA expression were detected in the murine adult thymus. Individual genomic and cDNA junctions were cloned and sequenced. In genomic DNA, 55% (16/29) of V gamma 3-J gamma 1 junctional sequences had N regions ranging in length from 1 to 12 nucleotides resulting in considerable junctional diversity. Only 5% (2/42) of cDNA sequences had N regions. The canonical DEC sequence represented 36% (15/42) of the cDNA sequences. Thus, fetal-type V gamma 3-J gamma 1 rearrangements lacking N regions were preferentially expressed in adult thymocytes, some of which may be DEC precursors. The developmental stages in which V gamma 3-J gamma 1 rearrangements are generated were studied by using polymerase chain reaction to detect circular rearrangement products. Active V gamma 3-J gamma 1 rearrangement was detected in thymuses from fetal, newborn, and 2-wk-old mice but not in 5-wk or 8-wk-old (adult) mice. V gamma 2, one of the most common V gamma rearrangements in the adult, was found to be actively rearranging to J gamma 1 in the adult thymus. However, V gamma 2-V gamma 3 replacement rearrangement was not found. These results support the hypotheses that adult thymocytes with rearranged V gamma 3-J gamma 1 are persistent from earlier developmental stages and represent a separate lineage from those with V gamma 2-J gamma 1 rearrangements.
Aguilar
L K
LK
Department of Microbiology and Immunology, Baylor College of Medicine, Houston, TX 77030.
Belmont
J W
JW
D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D005786:Gene Expression Regulation; D015334:Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor / Q000235:genetics*; D015698:Genomic Library; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013950:Thymus Gland / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*
D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta