We analyzed the expression of T-cell receptor (TcR) α, β, γ, and δ chain genes in 18 T-cell leukemic cell lines. In addition, 11αβ T-cell lines with the deletion of Jδ-Cδ locus were analyzed, using 5 kinds of Vδ gene segments. It is indicated that MOLT15, HsB2, and KE37 are at pre-αβ cell level of T-cell development, showing the specific characteristics as follows; negative expression of TcR α chain gene, deletion of Jδ-Cδ segment, residual Vδ1 and Vδ5 genes on chromosomes, volume of γ chain expression between γδ T-cell and αβ T-cell, and full length β chain message. Our results also show that the human genomic structure in TcR δ-α gene locus is 5'-Vα-Vδ4-Vαn -Vδ1-Vδ5-δRec-Vδ2-Dδ-Jδ-Cδ-Vδ3-JΨ 3'.
