Molecular characterization of human T cell receptor alpha chains including a V delta 1-encoded variable segment.
Previously we have shown that a small fraction of human peripheral T cells expresses a surface receptor recognized both by the BMA031 mAb, specific for a TcR alpha/beta framework epitope, and by the A13 mAb, putatively specific for an epitope encoded by the V delta 1 gene segment. An interleukin 2-dependent polyclonal cell line (termed T2) was derived from such A13+BMA031+ circulating lymphocytes. The molecular characterization of the TcR chains expressed by T2 cells demonstrated indeed that the V delta 1 gene (one of the two major V delta genes) was transcribed with the C alpha gene segment. In the T2 polyclonal cell line, distinct V delta 1/C alpha transcripts were all found to include the same J alpha segment suggesting the existence of "hybrid" TcR alpha/delta chains encoded by unique V delta 1/J alpha rearrangements. The present study was designed to characterize further the V delta 1/J alpha rearranged genes expressed in A13+BMA031+ cells. Three additional cell lines were generated from peripheral blood of distinct adult healthy donors. Using the anchored polymerase chain reaction, it was found that 17 different J alpha segments were used in the 20 V delta 1J alpha C alpha transcripts which have been studied. Together, these data indicate that V delta 1 is a "mixed" (i.e. alpha/delta) TcR V segment which can join with most (if not all) J segments in the alpha/delta locus. In addition, it can be definitely concluded that the A13 mAb recognizes a V delta 1-encoded antigenic determinant and not a V delta 1J epitope (i.e. it can be defined and used as an anti-V delta 1 mAb, as opposed to reagents such as for example delta-TCS-1).
Miossec
C
C
Laboratoire d'Hémato-Immunologie, INSERM U 333, Institut Gustave-Roussy, Villejuif, France.
Caignard
A
A
Ferradini
L
L
Roman-Roman
S
S
Faure
F
F
Michalaki
H
H
Triebel
F
F
Hercend
T
T
D000328:Adult; D001483:Base Sequence; D004247:DNA / Q000032:analysis; D005803:Genes, Immunoglobulin; D006801:Humans; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013329:Structure-Activity Relationship
D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D004247:DNA