T-cell receptor (Tcr) γ and δ chains consisting of V, D, in the case of δ, and J regions are generated by somatic rearrangement of these gene segments during the maturation of T-lymphocytes; the mature proteins may then be expressed on the surface of γδ T cells as heterodimeric molecules which function as antigen receptors. T cells bearing γδ Tcr have a number of unusual characteristics which distinguish them from αβ T cells. In sheep, depending on the age of the animal, γδ T cells form from 20% to 60% to 60% of T cells in the blood. On the contrary, in man and mice, Tcr γδ cells comprise a minor subset of the overall lymphocyte pool and usually account for 5% of blood-borne T cells. In order to characterize the Tcr γ genes and their expression during the thymic differentiation in the Gentile di Puglia sheep, two different polymerase chain reaction (PCR) methods were used starting from single or double strand cDNA: the anchored PCR and inverse PCR. Amplification products of 600 and 400 bp were selected and cloned into pBS. The nucleotide and deduced amino acid sequences comprise part of the extracytoplasmic constant region, the transmembrane and the cytoplasmic regions and all the 3' untranslated portion. The comparison of this sequence, identified in the Gentile di Puglia strain, with the published sequences of sheep Cγ1 and Cγ2, revealed that out gene is an allelic form of the Cγ2 gene preferentially expressed in the foetal thymus.
Sequence analysis of a gamma constant T-cell receptor gene expressed in Gentile di Puglia foetal thymus
CICCARESE, Salvatrice Maria
1994-01-01
Abstract
T-cell receptor (Tcr) γ and δ chains consisting of V, D, in the case of δ, and J regions are generated by somatic rearrangement of these gene segments during the maturation of T-lymphocytes; the mature proteins may then be expressed on the surface of γδ T cells as heterodimeric molecules which function as antigen receptors. T cells bearing γδ Tcr have a number of unusual characteristics which distinguish them from αβ T cells. In sheep, depending on the age of the animal, γδ T cells form from 20% to 60% to 60% of T cells in the blood. On the contrary, in man and mice, Tcr γδ cells comprise a minor subset of the overall lymphocyte pool and usually account for 5% of blood-borne T cells. In order to characterize the Tcr γ genes and their expression during the thymic differentiation in the Gentile di Puglia sheep, two different polymerase chain reaction (PCR) methods were used starting from single or double strand cDNA: the anchored PCR and inverse PCR. Amplification products of 600 and 400 bp were selected and cloned into pBS. The nucleotide and deduced amino acid sequences comprise part of the extracytoplasmic constant region, the transmembrane and the cytoplasmic regions and all the 3' untranslated portion. The comparison of this sequence, identified in the Gentile di Puglia strain, with the published sequences of sheep Cγ1 and Cγ2, revealed that out gene is an allelic form of the Cγ2 gene preferentially expressed in the foetal thymus.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
