The isolation of the human delta chain gene and its expression in normal T cells and T cell leukemias.

In this paper we describe a gene that lies 85 kb 5' of the constant region of the human alpha chain and some 30-50 kb 3' of the alpha chain V region (H. Griesser, unpublished observation). This gene undergoes somatic recombination and is transcribed in thymocytes, PHA-stimulated peripheral blood T cells, and some T cell leukemic cell lines. Sequence analysis revealed that the gene has a structure similar to that of immunoglobulin and other T cell antigen receptor genes. Comparison of the sequence to a mouse gene found in a similar location revealed 80% homology at the protein level. Recently, M. Davis and A. Weiss (personal communication) have demonstrated that the protein product of the mouse gene is the delta chain gene. Thus, the gene described in this paper represents the human homolog of the delta chain gene of the T cell antigen receptor.