Beschreibung:
<jats:p>Transrearrangements between the T‐cell receptor (TCR) VγI family and JβCβ loci occur at increased frequencies in patients with ataxia telangiectasia (AT). We have used an optimized reverse transcriptase polymerase chain reaction (RT‐PCR) approach to investigate the occurrence of TCRVγ–JβCβ transrearrangements involving the dominantly used Vγ element in peripheral blood γδ T cells, i.e. Vγ9. We detected in frame transcripts of Vγ9‐JβCβ transrearrangements in 4/16 AT patients and in 3/13 healthy control donors. A panel of monoclonal antibodies (mAb) against all expressed TCRVγ elements was used to monitor cell‐surface expression of transrearranged TCR. A very low proportion (< 1%) of peripheral blood TCRαβ cells expressed Vγ instead of Vβ elements. For the first time, we have isolated and molecularly characterized αβ T cells with a Vγ9‐JβCβ transrearrangement from two AT patients and we have shown that such TCR are functional. We conclude that functional TCR transrearrangements can also involve Vγ9, the dominant Vγ element in peripheral blood γδ T cells.</jats:p>