Detection of spliced and unspliced forms of germline TCR-Vβ transcripts in extrathymic lymphoid sitesMolecular Immunology (2008)
AbstractGermline TCR-Vβ transcription is commonly considered an event coupled with rearrangement of TCR genes in T cells. The extent of germline Vβ transcription is studied here in a range of cell types and in several mouse strains. A sensitive semi-quantitative RT-PCR method was developed to specifically detect germline and not rearranged transcripts. Germline transcription of a range of different Vβ genes was detected along with rearranged transcripts in bone marrow, thymus, mesenteric lymph node and spleen. Some transcripts were also detected in low level in non-lymphoid tissues including heart, liver and brain. Expression was also studied in the C57BL/6J-β2microglobulin−/− (C57BL/6J-β2M−/−) mouse model that lacks NK1.1 T cells and predominantly utilises Vβ8.2 in the formation of a TCR. β2M−/− mice, which lack both CD1-dependent NK1.1 T cells and CD8+ T cells, showed germline TCR-Vβ8 transcription in most tissues indicating that germline transcription is not specifically related to CD1-dependent NK1.1 T cells. In many tissues, multiple transcripts were amplified representing both spliced and unspliced forms of germline Vβ. For most Vβ genes, the expression of spliced and unspliced forms was equivalent. Given an abundance of unspliced transcripts, the presence of alternative ORFs encoding a novel protein was investigated within the TCR-Vβ genes. Sequence analysis of ORFs showed only genes with a high level of similarity to TCR-β. All data reflect the prevalence of germline transcripts in vivo and raise questions about their functional role.
- T cells,
- T cell receptor,
- germline transcription
Citation InformationJanice L Abbey and Helen C O'Neill. "Detection of spliced and unspliced forms of germline TCR-Vβ transcripts in extrathymic lymphoid sites" Molecular Immunology Vol. 45 Iss. 4 (2008)
Available at: http://works.bepress.com/helen_oneill/35/