title: Development and characterization of v-myc/v-raf-transformed murine fetal thymocyte cell lines.
abstract: Transformed murine fetal thymocyte cell lines were derived by incubating fetal thymic organ cultures with a v-myc/v-raf-containing retroviral construct in order to model developmental stages within the early triple negative (CD3-CD4-CD8-) thymocyte population. The resulting 10 cell lines had a lymphoid morphology, were all CD44+, CD90+, and were triple negative by surface antigen analysis. The cell lines, however, were distinguishable by differences in the expression of T cell-associated and T cell-specific genes. The CD3 genes were observed to be discoordinately expressed, in that CD3 gamma chain gene expression was detected in 2 cell lines in the absence of CD3 delta and epsilon expression. Expression of the CD3 gamma chain gene was observed in cell lines without the expression of other T cell-specific genes or T cell receptor rearrangement and may be one of the earliest T cell-specific genes to be expressed. The transcription factor Ikaros was expressed in all 10 cell lines, whereas the transcription factor TCF1 alpha was expressed only in the 2 most differentiated lines. In 8 cell lines, expression of partial TCR beta and/or TCR alpha transcripts was observed by Northern blot. In several lines, expression of rearranged TCR alpha transcripts in the absence of TCR beta transcripts was demonstrated; however, TCR beta DJ rearrangements were observed by Southern blot in all but 1 of these cell lines. Thus, these cell lines, ordered based on the general pattern of additive gene expression observed, may reflect various stages of triple-negative thymocyte differentiation and provide an in vitro mechanism to elucidate some of the molecular events involved in early thymocyte development.
authors: Department of Cellular Pathology, Armed Forces Institute of Pathology, Washington, DC 20306, USA.
authors: J K
authors: JK
authors: Taubenberger
authors: A H
authors: AH
authors: Reid
authors: D
authors: D
authors: Izon
authors: S A
authors: SA
authors: Boehme
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D015152:Blotting, Northern; D015139:Blotting, Southern; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral / Q000235:genetics / Q000276:immunology; D005333:Fetus; D015329:Gene Rearrangement, T-Lymphocyte / Q000276:immunology; D016259:Genes, myc / Q000276:immunology*; D016130:Immunophenotyping; D051379:Mice; D009924:Organ Culture Techniques; D016133:Polymerase Chain Reaction; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D016662:Virus Integration / Q000276:immunology
chemical_list: D015703:Antigens, CD; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta