Molecular characterization of human T cell receptor α chains including a Vδ1‐encoded variable segment

Publisher Website
Google Scholar
Abstract
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 α/β framework epitope, and by the A13 mAb, putatively specific for an epitope encoded by the Vδ1 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 Vδ1 gene (one of the two major Vδ genes) was transcribed with the Cα gene segment. In the T2 polyclonal cell line, distinct Vδ1/Cα transcripts were all found to include the same Jα segment suggesting the existence of “hybrid” TcR α/δ chains encoded by unique Vδ1/Jα rearrangements. The present study was designed to characterize further the Vδ1/Jα 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 Jα segments were used in the 20 Vδ1JαCα transcripts which have been studied. Together, these data indicate that Vδ1 is a “mixed” (i.e. α/δ) TcR V segment which can join with most (if not all) J segments in the α/δ locus. In addition, it can be definitely concluded that the A13 mAb recognizes a Vδ1‐encoded antigenic determinant and not a Vδ1J epitope (i.e. it can be defined and used as an anti‐Vδ1 mAb, as opposed to reagents such as for example δ‐TCS‐1).