title: A human homolog of the mouse CD8 molecule, Lyt-3: genomic sequence and expression.
abstract: The CD8 antigen is a marker for those cytotoxic T cells that recognize antigen in the context of class I major histocompatibility antigens (MHC) and has now been identified in many species. In rodents the CD8 antigen is a heterodimer of two distinct chains, Lyt-2 and Lyt-3 in the mouse and OX-8 Mr 32,000 and 37,000 chains in the rat. Human CD8 has consistently been described as a homodimer/homomultimer on mature T cells made up of one chain homologous to the Lyt-2 and OX-8 Mr 32,000 chains. This paper identifies a human equivalent of the second rodent CD8 chain (Lyt-3 and OX-8 Mr 37,000 chains) at the genomic level and shows that this gene is transcribed in human thymocytes and in some acute leukemic T-cell lines. The existence of a human Lyt-3 homolog raises the possibility that human CD8, like mouse CD8, may exist as a heterodimer.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000235:genetics*; D000954:Antigens, Surface / Q000235:genetics*; D001483:Base Sequence; D005786:Gene Expression Regulation; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic / Q000502:physiology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D046911:Macromolecular Substances; D012333:RNA, Messenger