Deviated overexpression of TCR-beta, TCR-gamma, CD4, and CD8 on thymic lymphomas induced by 1-propyl-1-nitrosourea: destruction of the allelic exclusion of TCR-beta and expression of functional TCR-betagamma heterodimer on a lymphoma, cFTL53.
Thymic lymphomas (FTLs) induced by the chemical carcinogen 1-propyl-1-nitrosourea (PNU) in F344 rats showed deviated overexpression of TCR-beta, TCR-gamma, CD4, and CD8. Even though most FTLs were in the CD4+ CD8+ stage, all FTLs expressed TCR-beta mRNA with TCR-gamma mRNA, but without TCR-alpha mRNA or TCR-delta mRNA. One of the FTLs, cFTL53, expressed two kinds of TCR-beta mRNA and two kinds of TCR-gamma mRNA, but did not express any mRNA of TCR-alpha or TCR-delta. Both alleles of TCR-beta loci were rearranged on cFTL53. cDNA cloning and sequencing analysis showed that one TCR-gamma mRNA, Vgamma4-Jgamma1-Cgamma1, and both TCR-beta mRNA, Vbeta2-Dbeta2-Jbeta2.1 and Vbeta19-Dbeta2-Jbeta2.1-Cbeta2, on cFTL53 were in the productive form, while the other TCR-gamma mRNA, Vgamma1-Jgamma4-Cgamma4L, was not. Both TCR beta-chains and a TCR gamma-chain were expressed on cFTL53, making a novel set of TCR-betagamma heterodimer. Cross-linking of TCR-betagamma heterodimer on cFTL53 resulted in a calcium flux, indicating that TCR-betagamma works as a signal transduction receptor. Thus, there are four strange phenomena on FTLs; CD4 and CD8 are expressed without TCR-alphabeta or TCR-gammadelta, TCR-beta mRNA and TCR-gamma mRNA were expressed simultaneously without TCR-alpha and TCR-delta mRNA on FTLs, the allelic exclusion of TCR-beta was destroyed in cFTL53, and a novel set of functional TCR-betagamma heterodimer was expressed on cFTL53.
Kinebuchi
M
M
Department of Pathology, School of Medicine, Sapporo Medical University, Chuo-ku, Japan.
Matsuura
A
A
Ogiu
T
T
Kikuchi
K
K
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015704:CD4 Antigens / Q000096:biosynthesis / Q000276:immunology*; D016827:CD8 Antigens / Q000096:biosynthesis / Q000276:immunology*; D019281:Dimerization; D015972:Gene Expression Regulation, Neoplastic; D008223:Lymphoma / Q000139:chemically induced / Q000276:immunology*; D008969:Molecular Sequence Data; D009607:Nitrosourea Compounds; D051381:Rats; D011916:Rats, Inbred F344; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D013953:Thymus Neoplasms / Q000139:chemically induced / Q000276:immunology*
D015704:CD4 Antigens; D016827:CD8 Antigens; D009607:Nitrosourea Compounds; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; C020796:propylnitrosourea