Analysis of cDNA clones specific for human T cells and the α and β chains of the T-cell receptor heterodimer from a human T-cell line

Abstract

We report the isolation and characterization of 19 classes of nonrearranging T cell-specific cDNA clones and two cDNA clones encoding the α and β chains of the T-cell antigen receptor from a human T-cell line, Jurkat. Results indicate that the human α-chain gene, like its β-chain counterpart, undergoes somatic rearrangement in T cells. In addition, it shows sequence homology to its β-chain counterpart and immunoglobulin, indicating that the human α chain is also a member of the immunoglobulin supergene family. Sequence comparison suggests that the α chain also may be composed of variable (V), diversity (D), joining (J), and constant (C) region gene segments. The protein deduced from the cDNA sequence has a molecular weight of 29,995 and possesses six potential N-glycosylation sites. The availability of α- and β-chain genes of the T-cell receptor from the same T-cell line provides tools to study their possible roles in recognition of antigens and major histocompatibility complex products by the human T-cell receptor.