Hatching time for monotreme immunology

2009 ◽  
Vol 57 (4) ◽  
pp. 185 ◽  
Author(s):  
Emily S. W. Wong ◽  
Anthony T. Papenfuss ◽  
Robert D. Miller ◽  
Katherine Belov
Keyword(s):  
T Cell ◽  
Gene Families ◽  
Cell Receptor ◽  
Immune Gene ◽  
Gene Repertoire ◽  
Anatomy And Physiology ◽  
Hatching Time ◽  
Platypus Genome ◽  
History Of ◽  
Health And Disease

The sequencing of the platypus genome has spurred investigations into the characterisation of the monotreme immune response. As the most divergent of extant mammals, the characterisation of the monotreme immune repertoire allows us to trace the evolutionary history of immunity in mammals and provide insights into the immune gene complement of ancestral mammals. The immune system of monotremes has remained largely uncharacterised due to the lack of specific immunological reagents and limited access to animals for experimentation. Early immunological studies focussed on the anatomy and physiology of the lymphoid system in the platypus. More recent molecular studies have focussed on characterisation of individual immunoglobulin, T-cell receptor and MHC genes in both the platypus and short-beaked echidna. Here, we review the published literature on the monotreme immune gene repertoire and provide new data generated from genome analysis on cytokines, Fc receptors and immunoglobulins. We present an overview of key gene families responsible for innate and adaptive immunity including the cathelicidins, defensins, T-cell receptors and the major histocompatibility complex (MHC) Class I and Class II antigens. We comment on the usefulness of these sequences for future studies into immunity, health and disease in monotremes.

scholarly journals Expansion, retention and loss in the Acyl-CoA Synthetase “Bubblegum” (Acsbg) gene family in vertebrate history

2018 ◽  
Author(s):  
Mónica Lopes-Marques ◽  
André M. Machado ◽  
Raquel Ruivo ◽  
Elza Fonseca ◽  
Estela Carvalho ◽  
...  
Keyword(s):  
Gene Family ◽  
Metabolic Pathways ◽  
Evolutionary History ◽  
Gene Families ◽  
Gene Repertoire ◽  
Physiological Processes ◽  
Complex Lipid ◽  
History Of ◽  
Enzyme Families ◽  
Rate Limiting

AbstractFatty acids (FAs) constitute a considerable fraction of all lipid molecules with a fundamental role in numerous physiological processes. In animals, the majority of complex lipid molecules are derived from the transformation of FAs through several biochemical pathways. Yet, for FAs to enroll in these pathways they require an activation step. FA activation is catalyzed by the rate limiting action of Acyl-CoA synthases. Several Acyl-CoA enzyme families have been previously described and classified according to the chain length of FA they process. Here, we address the evolutionary history of the ACSBG gene family which activates, FA with more than 16 carbons. Currently, two different ACSBG gene families, ACSBG1 and ACSBG2, are recognized in vertebrates. We provide evidence that a wider and unequal ACSBG gene repertoire is present in vertebrate lineages. We identify a novel ACSBG-like gene lineage which occurs specifically in amphibians, ray finned fish, coelacanths and chondrichthyes named ACSBG3. Also, we show that the ACSBG2 gene lineage duplicated in the Theria ancestor. Our findings, thus offer a far richer understanding on FA activation in vertebrates and provide key insights into the relevance of comparative and functional analysis to perceive physiological differences, namely those related with lipid metabolic pathways.

scholarly journals THER-06. GENOMIC AND IMMUNE CHARACTERIZATION OF TRIPLE NEGATIVE BREAST CANCER BRAIN METASTASES

2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i11-i12
Author(s):  
Benjamin Vincent ◽  
Maria Sambade ◽  
Shengjie Chai ◽  
Marni Siegel ◽  
Luz Cuaboy ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cell ◽  
Brain Metastases ◽  
T Cell Receptor ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Cell Receptor ◽  
Gene Signature ◽  
Specific Response ◽  
Immune Gene

Abstract INTRODUCTION: Approximately 50% of patients with metastatic triple negative breast cancer (TNBC) will develop brain metastases (BM). Routinely treated with radiotherapy and/or surgery, survival is generally less than one year. There are no approved systemic therapies to treat TNBC BM. We characterized the genomic and immune landscape of TNBC BM to foster the development of effective brain permeable anti-cancer agents, including immunotherapy. EXPERIMENTAL PROCEDURES: A clinically-annotated BCBM biobank of archival tissues was created under IRB approval. DNA (tumor/normal) and RNA (tumor) were extracted from TNBC primaries and BM; whole exome (WES) and RNA sequencing (RNASeq) was performed. Mutations were determined from WES as those co-identified by two variant callers (Strelka|Cadabra). Immune gene signature expression, molecular subtype identification, and T cell receptor repertoires were inferred from RNAseq. RESULTS: 32 TNBC patient tissues (14 primaries, 18 BCBM, 6 primary-BCBM matched), characterized as basal-like by PAM50, were analyzed. Top exome mutation calls included ten genes in ≥19% of BCBMs including TP53, ATM, and PIK3R1, and four genes in ≥18% of primaries including TP53 and PIK3R1. Many immune gene signatures were lower in BM compared to primaries including B cell, dendritic cell, regulatory T cell, and IgG cluster (p< 0.05). A signature of PD-1 inhibition responsiveness was higher in BM compared with primaries (p< 0.05). BCBM T cell receptor repertoires showed higher evenness and lower read count (both p < 0.01) compared to primaries. CONCLUSIONS: TNBC BM compared to primaries that metastasize to the brain show lower immune gene signature expression, higher PD-1 inhibition response signature expression, and T cell receptor repertoire features less characteristic of an active antigen-specific response. Mutations common to TNBC BM and primaries include TP53 and PIK3R1. Given that non-BCBM (i.e. lung and melanoma) show response to checkpoint inhibitors, these findings collectively support further study of immunotherapy for TNBC BM.

Correction of Abnormal T-Cell Receptor Repertoire During Interferon-α Therapy in Patients With Hairy Cell Leukemia

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4224-4231 ◽  
Author(s):  
Hanneke C. Kluin-Nelemans ◽  
Michel G.D. Kester ◽  
Lisette van deCorput ◽  
Patrick P.C. Boor ◽  
Jim E. Landegent ◽  
...  
Keyword(s):  
T Cell ◽  
T Lymphocytes ◽  
Gene Families ◽  
Cell Receptor ◽  
Interferon Α ◽  
T Cell Repertoire ◽  
Hairy Cell ◽  
Cell Leukemia ◽  
Rt Pcr ◽  
Cell Repertoire

Abstract Patients with the B-cell malignancy hairy cell leukemia (HCL) exhibit a skewed T-cell repertoire with oligoclonal expression or absence of many members of the T-cell receptor (TCR) BV gene families. To evaluate whether interferon-α (IFN-α) therapy would not only restore normal hematopoiesis, but also the abnormal T-cell repertoire, we studied T lymphocytes from a cohort of HCL patients treated by IFN-α in the past, at initiation, and at several intervals up to 6 years of IFN-α treatment. The junctional regions from 22 TCRBV gene families were analyzed after polymerase chain reaction amplification of cDNA (RT-PCR) using family specific primers. In all seven patients improvement of the skewed T-cell repertoire was not seen until 2 years of treatment. It consisted of disappearance of oligoclonal subpopulations and (polyclonal) reappearance of absent TCRBV gene families. The RT-PCR results were correlated with the TCRBV protein expression using TCRBV-specific monoclonal antibodies. T lymphocytes from four patients with active HCL contained large expansions of particular TCRBV-expressing cells (up to 25% of the CD3+cells; 600 to 700/μL whole blood), which decreased during IFN-α therapy in both patients tested. Finally, restoration of the TCR repertoire matched normalization of the functional immune repertoire as measured by proliferative, helper, and cytotoxic T-lymphocyte precursor frequencies against major histocompatibility complex–unrelated individuals. In conclusion, oligoclonal bands of TCRBV gene families found by RT-PCR correspond with a dramatic increase in circulating T lymphocytes expressing the same TCRBV family. Moreover, IFN-α can restore the skewed T-cell repertoire and suppress persistent T-cell clones upon treatment of the accompanying malignancy.

PKCθ-regulated signalling in health and disease

2014 ◽  
Vol 42 (6) ◽  
pp. 1484-1489 ◽  
Author(s):  
Pulak R. Nath ◽  
Noah Isakov
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Immunological Synapse ◽  
Cell Types ◽  
Cell Receptor ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Health And Disease

Protein kinase Cθ (PKCθ) is a key enzyme in T-lymphocytes where it plays an important role in signal transduction downstream of the activated T-cell receptor (TCR) and the CD28 co-stimulatory receptor. Antigenic stimulation of T-cells triggers PKCθ translocation to the centre of the immunological synapse (IS) at the contact site between antigen-specific T-cells and antigen-presenting cells (APCs). The IS-residing PKCθ phosphorylates and activates effector molecules that transduce signals into distinct subcellular compartments and activate the transcription factors, nuclear factor κB (NF-κB), nuclear factor of activated T-cells (NFAT) and activating protein 1 (AP-1), which are essential for the induction of T-cell-mediated responses. Besides its major biological role in T-cells, PKCθ is expressed in several additional cell types and is involved in a variety of distinct physiological and pathological phenomena. For example, PKCθ is expressed at high levels in platelets where it regulates signal transduction from distinct surface receptors, and is required for optimal platelet activation and aggregation, as well as haemostasis. In addition, PKCθ is involved in physiological processes regulating insulin resistance and susceptibility to obesity, and is expressed at high levels in gastrointestinal stromal tumours (GISTs), although the functional importance of PKCθ in these processes and cell types is not fully clear. The present article briefly reviews selected topics relevant to the biological roles of PKCθ in health and disease.

scholarly journals Evolution of the T-Cell Receptor (TR) Loci in the Adaptive Immune Response: The Tale of the TRG Locus in Mammals

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 624 ◽  
Author(s):  
Rachele Antonacci ◽  
Serafina Massari ◽  
Giovanna Linguiti ◽  
Anna Caputi Jambrenghi ◽  
Francesco Giannico ◽  
...  
Keyword(s):  
Immune Response ◽  
Genomic Organization ◽  
Mammalian Species ◽  
Adaptive Immune Response ◽  
Gene Families ◽  
Cell Receptor ◽  
Gene Organization ◽  
Cell Mediated Immunity ◽  
Gene Repertoire ◽  
Trg Locus

T lymphocytes are the principal actors of vertebrates’ cell-mediated immunity. Like B cells, they can recognize an unlimited number of foreign molecules through their antigen-specific heterodimer receptors (TRs), which consist of αβ or γδ chains. The diversity of the TRs is mainly due to the unique organization of the genes encoding the α, β, γ, and δ chains. For each chain, multi-gene families are arranged in a TR locus, and their expression is guaranteed by the somatic recombination process. A great plasticity of the gene organization within the TR loci exists among species. Marked structural differences affect the TR γ (TRG) locus. The recent sequencing of multiple whole genome provides an opportunity to examine the TR gene repertoire in a systematic and consistent fashion. In this review, we report the most recent findings on the genomic organization of TRG loci in mammalian species in order to show differences and similarities. The comparison revealed remarkable diversification of both the genomic organization and gene repertoire across species, but also unexpected evolutionary conservation, which highlights the important role of the T cells in the immune response.

High-Throughput Profiling of the T-Cell Receptor Gene Repertoire Supports Antigen Drive in the Pathogenesis of Chronic Idiopathic Neutropenia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2731-2731 ◽  
Author(s):  
Evangelia Stalika ◽  
Anastasia Hadzidimitriou ◽  
Athanasios Gkoufas ◽  
Maria Karypidou ◽  
Semeli Mastrodemou ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Sanger Sequencing ◽  
Conflicts Of Interest ◽  
Receptor Gene ◽  
Cell Receptor ◽  
Local Alignment ◽  
Gene Rearrangements ◽  
Gene Repertoire ◽  
Chronic Idiopathic Neutropenia

Abstract Chronic idiopathic neutropenia (CIN) is an acquired disorder of granulopoiesis characterized by prolonged neutropenia, mainly affecting middle-age females of the HLA-DRB1*1302 type. The defective hematopoiesis in CIN can be mainly attributed to accelerated Fas-mediated death of the CD34+/CD33+ granulocytic progenitors, secondary to an inflammatory bone marrow (BM) microenvironment. Crucial to CIN pathogenesis are the increased numbers of activated T cells identified in both peripheral blood (PB) and BM of CIN patients, supporting an immune pathogenesis. Using Sanger sequencing, we previously reported that the T-cell receptor (TR) gene repertoire in CIN is skewed, indicating antigen selection in CIN ontogeny. However, the analytical depth afforded by Sanger sequencing is limited, hindering definitive conclusions. In order to obtain a truly comprehensive view into the role of antigen drive in CIN, using next generation sequencing (NGS) we interrogated the TR repertoire of 13 patients (8 females, 5 males) included in our previous study as well as a healthy female. TRBV-TRBD-TRBJ gene rearrangements were amplified according to the BIOMED2 protocol on either genomic DNA or cDNA isolated from CD8+ cells of PB (n=4) or BM (n=10) samples. PCR products were used as a substrate for paired-end sample preparation (Illumina) and subjected to NGS on the MiSeq Illumina Platform. The raw NGS data were preprocessed with a dedicated pipeline for this purpose, including: (i) quality filtering of each read; (ii) merging of paired-end reads via local alignment; (iii) preparation of fasta files for submission to the IMGT/High V-QUEST tool; and, (iv) IMGT/High V-QUEST metadata analysis, interpretation and visualization. Overall, 6,196,980 TRBV-TRBD-TRBJ gene rearrangements were analyzed (130,020-1,037,680 /case) of which 5,317,609 were productive since they used functional TRBV genes and also carried in-frame CDR3. Rearrangements with identical TRBV gene usage and CDR3 sequence were defined as clonotypes. For repertoire analyses, clonotypes rather than single rearrangement sequences were considered. Overall, 553,145 unique clonotypes were identified (median 39,510; range 7,732-172,253/case), of which 408,744 represented singletons. All clonotypes from the Sanger analysis were detected by NGS as well. Among the 46 functional TRBV genes identified, the most frequent were: TRBV29-1 (13.9%), TRBV19 (6.7%), TRBV12-3 (5.6%), TRBV6-5 (5.4%), TRBV27 (4.9%) and TRBV6-1 (4.0%), collectively accounting for 40,5% of the TRBV repertoire; the TRBV29-1 gene predominated in 9/13 CIN cases. All CIN cases were found to carry distinct expanded clonotypes (median 10,314; range 2,279-40,245/case). The predominant clonotype ranged in frequency from 5.25 to 20.2% of the total clonotypes observed in each case. This contrasts significantly (p<0.001) with a 0.47% frequency of the dominant clonotype in the healthy control. Cluster analysis of the sequences of all CIN cases identified 9034 different clonotypes shared by different patients and, thus, deemed as public. Notably, public clonotypes of a given CDR3 length could show high sequence similarity, further underscoring the restricted nature of the repertoire. As an example, 1632/2665 (61.2%) public clonotypes with 12 aminoacid-long CDR3 were grouped into 168 distinct communities, populated with 2-280 highly similar sequences, each linked with 1 aminoacid distance with at least another member of the community. Overall, the present study offers conclusive evidence that the TR repertoire in CIN is remarkably skewed. The finding of oligoclonal T-cell expansions and public clonotypes strongly indicates that antigen-driven immune responses are very likely implicated in the pathogenesis of CIN. Disclosures No relevant conflicts of interest to declare.

scholarly journals Specific T Cell Receptor Gene Repertoire Profiles in Subgroups of CLL Patients with Distinct Genomic Aberrations

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3749-3749
Author(s):  
Elisavet Vlachonikola ◽  
Electra Sofou ◽  
Glykeria Gkoliou ◽  
Nikos Pechlivanis ◽  
Georgios Karakatsoulis ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Research Funding ◽  
Cell Receptor ◽  
Gene Repertoire ◽  
Genomic Aberration ◽  
Genomic Aberrations ◽  
Trbv Gene

Abstract Chronic lymphocytic leukemia (CLL) B cells engage in multifaceted bi-directional interactions with bystander cells, including T cells. Immunogenetic studies in CLL revealed clonal expansions of T cells and shared T cell clonotypes between different patients, strongly implying clonal selection by antigens. Although the exact nature of these antigens remains largely elusive, evidence exists that the clonotypic B cell receptor immunoglobulin (BcR IG) may serve as a source of antigenic epitopes for T cells. That said, recurrent genomic aberrations associated with distinct abnormal expression profiles could represent an alternative, non mutually exclusive, source of potent immunogenic onco-antigens that might shape the T cell repertoire in CLL. On these grounds, here we interrogated the T cell receptor (TR) gene repertoire of CLL patients with different genomic aberration profiles with the aim to identify unique signatures that would allude to distinct antigen selection pressures. The study group included 46 patients with CLL, sampled before treatment initiation, who were categorized in 5 subgroups defined by a unique genomic aberration, as follows: +12, n=18; del(11q), n=10; del(13q), n=7; del(17p)/TP53mut, n=6; NOTCH1mut, n=5. Confounding effects of multiple aberrations have been minimized, as we previously established through comprehensive characterization (including FISH, SNP arrays and gene panels) that the analyzed patients carried only one of the above aberrations. Starting material was RNA extracted from blood mononuclear cells. TRBV-TRBD-TRBJ gene rearrangements were RT-PCR amplified and subjected to paired-end next generation sequencing (NGS). Raw NGS reads (n=13,213,563| median: 294,757/sample) were processed through a purpose-built bioinformatics pipeline. Only productive rearrangements (n=9,249,546 | median=199,184/sample) were taken into consideration for the computation of clonotypes i.e. TRB rearrangements with identical TRBV gene usage and amino acid complementarity-determining region 3 (CDR3) sequence. Overall, 513,984 distinct clonotypes (median=10,304 clonotypes/sample) were assessed. The main measure of clonality employed in this study was the median cumulative frequency of the 10 most expanded T cell clonotypes/sample (MCF-10). For comparisons of the clonality profiles, a group of 17 aged-matched healthy individuals were used as controls. All patients displayed oligoclonal T cell expansions with the following MCF-10 values: del(11q): 21.6%, +12: 25%, del(13q): 20.6%, NOTCH1mut: 9.1%, del(17p)/TP53mut: 12.9%; the difference between the del(11q) and +12 groups versus the NOTCH1mut group was statistically significant (p&lt;0.05). The MCF-10 value of the control group was estimated at 17.5%, supporting the notion of age-related decrease in TR repertoire diversity. However, the del(11q), +12 and del(13q) CLL groups displayed elevated clonality, reaching statistical significance (p&lt;0.002) in the case of +12. TRBV gene repertoire analysis revealed that the TRBV12-3 gene predominated in most groups, except for the del(17p)/TP53mut, where the predominant gene was TRBV10-3. Clonotype comparisons disclosed the presence of shared TR clonotypes both within a particular group but also between groups. Overall, 446/513,984 clonotypes were found to be shared by at least two patients across all groups; the vast majority (392/446, 88%) of shared clonotypes appeared to be CLL-biased since they did not match entries in public databases of TR clonotypes from various contexts. Subgroup-specific clonotypes were identified for all aberrations examined; these emerged as unique to the particular subgroups, as revealed by extensive comparisons against both public databases but also a large TR clonotype database from CLL available to us from our previous studies. In conclusion, recurrent genomic aberrations, especially large chromosomal abnormalities, display an oligoclonal TR gene repertoire. The distinct immunogenetic profile of each group examined here and, most importantly, the existence of subgroup-specific clonotypes, suggest that abnormal protein expression and gene dosage effects likely represent a relevant source of CLL-specific selecting antigens. Disclosures Scarfo: Janssen: Honoraria, Other: Travel grants; Astra Zeneca: Honoraria; Abbvie: Honoraria. Anagnostopoulos: Abbvie: Other: clinical trials; Sanofi: Other: clinical trials ; Ocopeptides: Other: clinical trials ; GSK: Other: clinical trials; Incyte: Other: clinical trials ; Takeda: Other: clinical trials ; Amgen: Other: clinical trials ; Janssen: Other: clinical trials; novartis: Other: clinical trials; Celgene: Other: clinical trials; Roche: Other: clinical trials; Astellas: Other: clinical trials . Ghia: AbbVie: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; ArQule/MSD: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Celgene/Juno/BMS: Consultancy, Honoraria; Gilead: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Sunesis: Research Funding. Haferlach: MLL Munich Leukemia Laboratory: Other: Part ownership. Rosenquist: Roche: Honoraria; Janssen: Honoraria; Illumina: Honoraria; AstraZeneca: Honoraria; Abbvie: Honoraria. Stamatopoulos: Gilead: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Baliakas: Janssen: Honoraria; Gilead: Honoraria, Research Funding; Abbvie: Honoraria. Chatzidimitriou: Abbvie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding.

scholarly journals Overexpression of Select T Cell Receptor Vβ Gene Families within CD4+ and CD8+ T Cell Subsets of Myasthenia Gravis Patients: A Role for Superantigen(s)?

1996 ◽  
Vol 2 (4) ◽  
pp. 452-459 ◽  
Author(s):  
Dulceaydee Gigliotti ◽  
Ann-Kari Lefvert ◽  
Mahmood Jeddi-Tehrani ◽  
Semih Esin ◽  
Vida Hodara ◽  
...  
Keyword(s):  
T Cell ◽  
Myasthenia Gravis ◽  
T Cell Receptor ◽  
Gene Families ◽  
Cd8 T Cell ◽  
Cell Receptor ◽  
T Cell Subsets ◽  
T Cell Receptor Vβ

Clonality Analysis as a Tool To Study the Immunologic Reconstitution with Leukemia Patients Following Allogeneic Hematopoietic Stem Cell Transplantation.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 5020-5020
Author(s):  
Xin Du ◽  
Yangqiu Li ◽  
Jianyu Weng ◽  
Zesheng Lu ◽  
Rong Xie ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Gene Repertoire ◽  
Hematopoietic Stem ◽  
Receptor Repertoire

Abstract Introduction The extensive diversity of the mature T-cell receptor(TCR) is determined primarily by the complementarity-determining regions (CDR3) of the TCR. The CDR3 of both TCRα and TCRβ genes is generated by extensive rearrangement and fusion between the V,D,and J segments and by random insertion and deletion of junctional nucleotides, which yields final products that are quite heterogeneous in size. As a result of these gene rearrangements, each T cell has a unique TCR and the diversity of the T-cell repertoire at any specific time can be characterized by the examination of CDR3 within that population. Using CDR3 spectratying technique, normal individuals demonstrate a highly diverse and polyclonal The aim of our study was to evaluate to investigate restricted expansion of TCR Vβ gene repertoire and the reconstitution of T cell receptor repertoire following allogeneic hematopoietic stem cell transplantation. Methods Patients Ten patients(9 males, 1 females; median age 31 years,range18–45) with 6 chronic myeloid leukemia-chronic phase and 4 cases of acute myelogenous lenkemia(CR1) who underwent HLA-matching sibling or unrelated BMT and/or peripheral blood stem cell transplantation (PBSCT) at our department between July 1999 and May 2000 were considered evaluable restricted expansion of TCR Vβ gene repertoire, the reconstitution of T cell receptor repertoire and oligoclonal T Cell Expansion in Chronic Graft-Versus-Host Disease. RT-PCR and Genes scan analysis (CDR 3 length analysis). Results Only 2-18Vβ genes were found in samples from these ten patients within one year, and there are different distribution in different patients. TCR repertoire complexity was abnormal in all patients, parts of the genes were expansion and part of them were suppressed. Samples from 9 patients with GVHD show V β3 in 7 cases, V β 8 and V β 23 in 6 patients. The results of genescan show that the PCR production of peripheral blood samples from these patients disply oligoclonal. Only 5–22Vβ subfamily T cells were found in samples from these patients whose transplantation more than one year. TCR repertoire complexity was abnormal in all patients. Discussion Following allogeneic BMT, regeneration of T-cell populations with a diverse repertoire can occure by at least two mechanisms: One mechanism is a thymic-dependent pathway, which presumably involves both negative and positive selection and recapitulates fetal ontogeny. Alternatively, regeneration of peripheral T cells may occur through thymic-independent mechanisms. All patients had marked abnormalities in their spectratypes, only 5-22Vβ subfamily T cells were found in samples from these patients, most of it was influenced after transplant, although the number of circulating CD3+ T lymphocytes in these patients have restored at normal lever by flow cytometic analysis, but the CD4+ T cell subset returned slowly in these patients resulting in an inversion of the normal CD4/CD8 ratio for more than 1 year after tuansplantation. Therefore, the analysis of TCRVβ subfamily is a usuaful methods and techniques for monitoring immune reconstitution after transplant.

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