title: Isolation of a CD8alphaalpha+ CD4- tumour T-cell clone with cytotoxic activity from a CD4+ CD8- cutaneous T-cell lymphoma.
abstract: BACKGROUND
  We have previously established tumour T-cell lines, both from the skin and from the blood of patients with a cutaneous T-cell lymphoma (CTCL). In one patient, the tumour cells and the derived cell lines had a CD3+ CD4+ CD8- phenotype and a trisomy of chromosome 7. They expressed three T-cell receptor (TCR) beta-chain transcripts, but only one was productively rearranged and expressed at the cell membrane.
  
  
  OBJECTIVE
  In the present study, we tried to isolate a fast-growing new tumour T-cell line from the same patient.
  
  
  METHODS
  We performed direct cell cloning of the skin tumour lymphocyte population, which led to the isolation of an interleukin-2-dependent highly proliferative T-cell subclone, named Cou-L3, with a CD3+ TCR-Vbeta13+ CD4- CD8alphaalpha+ phenotype.
  
  
  RESULTS
  We demonstrated that Cou-L3 was identical to the original clonal tumour CD3+ Vbeta13+ CD4+ CD8- cells, as it expressed the same rearranged TCR-Vbeta13 chain. We further studied the functional activity of these CD8alphaalpha+ Vbeta13+ Cou-L3 cells. We found that these cells exhibited CD3-redirected cytotoxic activity.
  
  
  CONCLUSIONS
  An immunophenotypic shift, with a change from a CD4+ to a CD8+ phenotype, has been already reported in association with disease progression in CTCL. However, in these cases, there has been no demonstration that the phenotypic change involved the same T-cell clone. The present study is the first report of the phenotypic heterogeneity of the tumour clonal cell population in CTCL.
authors.affiliation: INSERM U448, Department of Dermatology, Hôpital Henri Mondor, 94010 Créteil, France.
authors.forename: M
authors.initials: M
authors.lastname: Nikolova
authors.forename: H
authors.initials: H
authors.lastname: Echchakir
authors.forename: J
authors.initials: J
authors.lastname: Wechsler
authors.forename: L
authors.initials: L
authors.lastname: Boumsell
authors.forename: A
authors.initials: A
authors.lastname: Bensussan
authors.forename: M
authors.initials: M
authors.lastname: Bagot
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000473:pathology*; D008297:Male; D009182:Mycosis Fungoides / Q000473:pathology; D014411:Neoplastic Stem Cells / Q000276:immunology / Q000473:pathology; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell