title: Differential susceptibility of mouse Lyt-2 and Lyt-3 genes to negative regulation.
abstract: Hybrids of Lyt-2/Lyt-3-positive class I-specific cytotoxic T lymphocytes (CTLs) with the BW5147 thymoma cell line (Lyt-2/Lyt-3-negative) are known to be Lyt-2/Lyt-3-negative due to shutoff of transcription of the CTL's Lyt-2 gene. Hybrids of a constitutively Lyt-2-positive transfectant of BW5147 (3B2) with a long term CTL line, 2C, and with CTLs generated in a mixed leucocyte reaction (MLR) shut off the CTL's Lyt-2 gene as expected but express the CTL's Lyt-3 gene product as a heterodimer with the product of the transfected Lyt-2 gene. Thus the Lyt-3 gene is not subject to the same negative regulatory influences as the Lyt-2 gene. That expression of Lyt-2 is not necessary for Lyt-3 gene transcription to continue is demonstrated by the finding that hybrids of MLR-generated CTLs with either BW5147 (Lyt-2-negative) or 3B2 (Lyt-2-positive) cells express Lyt-3 RNA. Southern hybridization and structural analysis of DNA fragments generated using the polymerase chain reaction demonstrated that hybrids contain several species of Lyt-3 RNA, one of which lacks the exon encoding the extracellular V-like domain and appears to be the product of an alternatively-spliced RNA transcript.
authors.affiliation: Department of Microbiology, University of Texas, Austin 78712.
authors.forename: I
authors.initials: I
authors.lastname: Hwang
authors.forename: J J
authors.initials: JJ
authors.lastname: Gu
authors.forename: P D
authors.initials: PD
authors.lastname: Gottlieb
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000950:Antigens, Ly / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D004277:DNA, Single-Stranded; D005786:Gene Expression Regulation; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D004277:DNA, Single-Stranded