T cell receptor rearrangement excision circles

TRECs are extrachromosomal DNA byproducts of T-cell receptor TCR rearrangement which are nonreplicative. During each of the rearrangement steps DNA fragments between rearranging V D and J gene segments are deleted as circular excision products the so-called TRECs T cell receptor excision circles.

T cell receptor excision circles as markers for recent thymic emigrants.

T cell receptor rearrangement excision circles. The introduction of T-cell receptor excision circle TREC PCR-assay seemed to enable direct detection of recent thymic emigrants in peripheral blood and therefore the quantification of thymic output. High TREC levels were detected during childhood and were decreasing with age but TREC-expressing cells are not completely lost in the elderly. T-Cell Receptor Excision Circles.

TCR excision circles TREC are generated during TCR gene rearrangement of thymocytes and may persist for long periods in T-lineage cells that do not proliferate. Clinical Immunology Fourth Edition 2013. Hematopoietic Stem Cell Transplantation.

T-Cell Receptor Excision Circles. TCR excision circles TREC are generated during TCR gene rearrangement of thymocytes and may persist for long periods in T-lineage cells that do not proliferate. Clinical Immunology Third Edition 2008.

Thymic function can be determined by T-cell receptor excision circle TREC analysis. TRECs are extrachromosomal DNA byproducts of T-cell receptor TCR rearrangement which are nonreplicative. TRECs are expressed only in T cells of thymic origin and each cell is thought to contain a single copy of TREC.

Hence TREC analysis provides a very specific assessment of T-cell recovery eg after. The introduction of T-cell receptor excision circle TREC PCR-assay seemed to enable direct detection of recent thymic emigrants in peripheral blood and therefore the quantification of thymic output. High TREC levels were detected during childhood and were decreasing with age but TREC-expressing cells are not completely lost in the elderly.

At the first stage of our investigation we. These receptors respond to nonself-antigens and are tolerant to self-antigens. During TCR rearrangement processes unused excised DNA fragments create byproducts termed TCR excision circles TRECs.

Although these byproducts have no function their detection in the peripheral blood stream is a clear indication that a rearrangement process has occurred. Their enumeration in the latest circle created during TCR delta deletion and the final TCR alpha rearrangement. This study investigated levels of T cell receptor gene rearrangement excision circles TRECs as a measure of recent thymic emigrant cells in peripheral blood lymphocytes of 50 HIV-infected infants and children who were followed-up for 40 months after the start or change of antiretroviral therapy.

At baseline patients exhibited fewer TRECs than did uninfected control. T cell receptor gene rearrangement excision circles TRECs in peripheral blood mononuclear cells PBMC before and after 612 months of antiretroviral therapy in infants A and older children B. Human immunodeficiency virus HIVinfected children were evaluated at baseline and after starting or changing therapy and were grouped as responders R discordant D.

The generation of T cell receptor TCR diversity occurs in the thymus through recombination of gene segments encoding the variable parts of the TCR alpha and beta chains. Tcell receptor rearrangement excision circles TREC are circular DNA molecules generated during Tcell maturation in the thymus. Recent studies suggested that a decreased TREC concentration in peripheral blood may be a general feature of autoimmunity.

Our purpose was to assess the TREC concentration in Graves disease GD. Rearrangements are generated in the form of TCR excision circles TRECs. As these molecules are lost upon further cell division their quantification is actually considered as a.

T cell differentiation in the thymus is characterized by a hierarchical order of rearrangement steps in the T cell receptor TCR genes resulting in the joining of V D and J gene segments. During each of the rearrangement steps DNA fragments between rearranging V D and J gene segments are deleted as circular excision products the so-called TRECs T cell receptor excision circles. Thymic Emigrants and T-Cell Receptor Excision Circles in Infants Eugene Ravkov1 Patricia Slev12 and Nahla Heikal12 1ARUP Institute for Clinical and Experimental Pathology Salt Lake City Utah 2Department of Pathology University of Utah School of Medicine Salt Lake City Utah Background.

CD41 recent thymic emigrants CD41 RTEs constitute a subset of T cells recently generated in the. Tribution or decreased T cell destruction. This study investigated levels of T cell receptor gene rearrangement excision circles TRECs as a measure of recent thymic emigrant cells in pe-ripheral blood lymphocytes of 50 HIV-infected infants and children who were followed-up for 40 months after the start or change of antiretroviral therapy.

At baseline patients exhibited. Recently the concentration of T cell receptor excision circles TREC has been suggested as a measure for quantifying thymic output in humans 9 10. During TCR gene rearrangement ex-cised DNA fragments are maintained in cells episomally as TREC.

Two TREC species signal-joint TREC sjTREC and coding-joint TREC cj TREC which are products of the deletion of the TCR locus from. Has been implicated as a mechanism for CD4-T cell loss in other conditions such as AIDS by assays of T cell receptor excision circles TRECs a marker of naıve T cells that have recently emigrated from the thymus. To evaluate alteration of thymic function as a mechanism for benzenes effects on CD4-T cell counts we measured total TREC levels in 45 benzene-exposed workers and 45.

Circular DNA formed as a byproduct of successful T-cell receptor rearrangement TCR alpha chain rearrangement deleting the delta locus Present only in T-cells both CD4 and CD8 Rec TREC concentrations correlate with number of newly formed rearranged T-cells emigrating from the thymus and are a general marker for T-cell numbers. T cell receptor excision circles as markers for recent thymic emigrants. Basic aspects technical approach and guidelines for interpretation Received.

21 March 2001 Accepted. 20 July 2001.