title: Molecular cloning of two CD7 (T-cell leukemia antigen) cDNAs by a COS cell expression system.
abstract: The human CD7 antigen (gp40) is a cell surface glycoprotein found on thymocytes and mature T-cells. It is one of the earliest antigens to appear on cells of the T-lymphocyte lineage, and the most reliable clinical marker of T-cell acute lymphocytic leukemia. This report describes the isolation and nucleotide sequence of a full length CD7 cDNA, and of a cDNA for an unusual intron-bearing precursor. The DNA sequence of the clone predicts a highly glycosylated membrane protein with homology to members of the immunoglobulin superfamily, and no relationship to known oncogenes. Over-expression of CD7 RNA was observed in only one T-cell tumor line, and genomic DNA rearrangement was not observed in any lines. Prompted by a recent suggestion that CD7 plays a role in IgM binding, COS cells expressing CD7 were tested and found not to bind IgM or IgM immune complexes.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics*; D000954:Antigens, Surface / Q000276:immunology*; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D006023:Glycoproteins / Q000235:genetics; D006801:Humans; D008562:Membrane Glycoproteins; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection
chemical_list: D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D006023:Glycoproteins; D008562:Membrane Glycoproteins; C028388:thymus-leukemia antigens; D004247:DNA