Oligoclonal T cell expansions in patients with Behçet's disease

Behçet's disease (BD) is a multisystem disorder with oral and genital ulcers, mucocutaneous, ocular, joint, vascular and central nervous system involvement. In this study, the peripheral T cell repertoire was analysed in patients with BD with MoAbs against T cell receptor (TCR) Vβ gene products in CD4⁺ and CD8⁺ T cell compartments, and these were compared with rheumatoid arthritis (RA) patients and healthy controls (HC). In the CD4⁺ T cell compartment, oligoclonal TCR Vβ expression was observed in 56% of BD (10/18), 71% of RA (5/7) patients and 21% (3/14) of HC. In the CD8⁺ T cell group 50% of BD (9/18), 57% of RA patients and 28% of HC (4/14) had an oligoclonal TCR repertoire. An increase of TCR Vβ5.1 subset was observed in five BD patients among CD8⁺ T cells. Other elevations of TCR Vβ subsets were heterogeneously distributed with one to three different Vβ subsets. Our results suggest an antigen-driven oligoclonal increase of T cells in BD. There was no overall increase in any Vβ group to suggest a superantigen effect. Analysis of the responsible antigens causing the increase in T cell subsets may give insights into the aetiopathogenesis of BD and immunomodulation of these T cells may lead to new treatments.     

职业铅接触工人外周血T细胞Vβ基因谱系明显缺失

目的:分析职业铅接触工人外周血中T细胞受体Vβ基因(TCR Vβ)谱系分布和克隆性特点,进一步了解铅接触后对T细胞免疫的影响。方法:利用RT-PCR分别检测6例职业铅接触工人和6例健康体检者的外周血中各TCR Vβ亚家族的表达情况;阳性产物经荧光素标记和基因扫描分析其CDR3长度以了解T细胞克隆性。结果:所有健康体检者均可检测到24个Vβ亚家族并呈多克隆,而6例职业铅接触工人外周血TCR Vβ亚家族表现明显的限制性利用,仅能检测到1～7个,并且多数所检测到的Vβ亚家族T细胞呈现为寡克隆或双克隆增殖,发生克隆性改变的亚家族主要集中在Vβ1和Vβ16。结论:职业铅接触可能在不同程度上影响机体TCR Vβ谱系的利用和克隆性改变,可能与铅的免疫毒性有关。     

无症状HBV携带者外周血CD4~+TCR Vβ基因亚家族克隆化特征的研究

分析无症状HBV携带者(AsC)CD4+TCR Vβ基因家族克隆化特征。采用逆转录-聚合酶链反应(RT-PCR)扩增7例AsC外周血CD4+TCR Vβ基因22个亚家族的CDR3区,基因扫描技术对CD4+TCR Vβ亚家族的克隆化进行鉴定。结果基因扫描显示,7例AsC CD4+TCR Vβ基因亚家族均出现一个或一个以上单克隆或寡克隆增生;7例健康者CD4+TCR Vβ基因亚家族均呈正态分布。提示,AsC外周血CD4+TCR Vβ亚家族存在克隆性增生,这可能与AsC免疫耐受的形成有关。     

Characterization of the CDR3 structure of the Vβ21 T cell clone in patients with P210(BCR-ABL)-positive chronic myeloid leukemia and B-cell acute lymphoblastic leukemia

The clonally expanded T cells identified in most cancer patients that respond to tumor-associated antigen such as P210(BCR-ABL) protein have definite, specific antitumor cytotoxicity. T cell receptor (TCR) Vβ CDR3 repertoire diversity was analyzed in patients with chronic myeloid leukemia (CML) and BCR-ABL(+) B-cell acute lymphoblastic leukemia (B-ALL) by GeneScan. A high frequency of oligoclonal expansion of the TCR Vβ21 subfamily was observed in the peripheral blood of CML and B-ALL patients. These clonally expanded Vβ21 T cells were correlated with the pathophysiologic process of CML. A conserved amino acid motif (SLxxV) was observed within the CDR3 region in only 3 patients with CML. Preferential usage of the Jβ segments was also observed in a minority of patients. The 3-dimensional structures of the CDR3 region containing the same motif or using the same Jβ segment displayed low similarity; on the contrary, the conformation of the CDR3 region containing no conserved motif in some T cell clones was highly similar. In conclusion, our findings indicate a high frequency of TCR Vβ21 subfamily expansion in p210(BCR-ABL)-positive CML and B-ALL patients. The characterization of the CDR3 structure was complex. Regrettably, at this time it was not possible to confirm that the Vβ21 T cell clones were derived from the stimulation of p210(BCR-ABL) protein.     

识别猪SLA的特异性人T细胞系TCR BV基因取用格局和CDR3结构多样性分析

不同T细胞克隆TCR分子的序列不同 ,所识别的抗原特异性也不同。其中第三互补决定区 (CDR3)变异最大 ,是TCR主要的抗原结合部位。本文采用荧光标记半定量PCR技术 ,用DNA测序仪作程序分析 ,了解猪细胞抗原致敏前后的人T细胞群和 5个T细胞系 2 4个TCRBV基因家族取用格局 ,并以TCRα链C区的基因片断作为内参对取用情况作定量估计。发现首次抗原致敏后培养 2周的T细胞除了BV2 4、BV8和BV10未能检测出 ,其它BV基因都有不同程度的取用。然而 ,5个细胞系的TCRBV基因呈现十分有限的取用格局 ,其中两个CD4+ T细胞系都取用BV12和BV14;3个CD8+ T细胞系中都优势取用BV1,有两个还取用BV19。CD4+ T细胞系和CD8+ T细胞系之间TCRBV无交叉取用 ,提示两类细胞识别的抗原表位存在差异。进一步用变性凝胶扫描分析上述T细胞系取用TCRBV中的CDR3的多样性 ,发现未经抗原致敏的T细胞BV的CDR3结构为多峰型且呈正态分布 ,表明涉及多种结构不同的细胞克隆 ;而抗原特异性T细胞系CDR3除了一个CD8+ T细胞系BV1有两个主峰外其它无例外地都显示单峰或者仅一个主峰 ,这从另一个角度证明建系T细胞的单克隆性。     

A possible role of two hydrophobic amino acids in antigen recognition by synovial T cells in rheumatoid arthritis

Synovial T cells play a crucial role in the pathogenesis of rheumatoid arthritis (RA) synovitis. We have quantitatively analyzed the T cell receptor (TcR) variable (V) region gene repertoire of freshly isolated synovial fluid (SF) T cells, comparing it with that of peripheral blood (PB) T cells in RA. The TcR V gene repertoire of PB and SF T cells in RA and osteoarthritis was heterogeneous. In contrast, Vail in SF was expressed to a greater degree in three of five RA patients, and increased levels of Vp6, 1-3 were found in the SF of four of six RA, compared with paired PB. Of note, Vβ6, 1–3 was universally used in four RA patients with a disease duration of less than 10 years, irrespective of their HLA-DR types. This was in contrast to two other RA patients, suffering for more than 20 years, who showed different Vα and Vβ usages. β-chain sequence analysis in RA patients with a preference for Vβ6, 1–3 has shown that a few clones dominated in SF, whereas polyclonality was observed in PB. These findings suggest oligoclonal expansion of T cells in response to specific antigen(s) in the SF of these patients with RA of relatively short duration. Concomitant use of two hydrophobic amino acids, leucine and valine, in the Dβ region was noticeable among the predominant SF clones. These two amino acids might directly contact a peptide specific for the induction of synovitis in RA patients. TcR-directed therapy may, therefore, be useful for the treatment of early RA synovitis.     

Clonal expansion of myelin basic protein-reactive T cells in patients with multiple sclerosis: Restricted T cell receptor V gene rearrangements and CDR3 sequence

Myelin basic protein (MBP)-reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual-dependent properties of MBP-reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP-reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR Vα and Vβ gene rearrangements. The V gene junctional region sequences of identified α and β genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84–102, 110–129 and 143–168, and used various TCR Vα and Vβ rearrangements. The V gene usage of the clones was restricted to certain Vα Vβ combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP-reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP-reactive T cells in their structural and functional charactertistics reflects their clonal expansion in vivo in some patients with MS.     

T cell receptor (TCR) V gene usage in patients with systemic necrotizing vasculitis.

Wegener's granulomatosis (WG) and polyarteritis nodosa (PAN) are systemic necrotizing vasculitides of unknown etiology. These disorders run a fatal course if untreated. T lymphocytes are implicated in the pathogenesis of WG, since they have been found to infiltrate affected organs, and sIL-2R correlates with disease activity. To elucidate further the role of T cells in necrotizing vasculitis, we have used a panel of 12 TCR V-specific MoAbs to investigate the number of cells expressing certain V alpha and V beta gene segments in the CD4+ and CD8+ subsets of altogether 11 patients with WG or PAN. In the group of patients, we found abnormal expansions of T cells using particular TCR V alpha or V beta gene products. These T cell expansions were more numerous, of a dramatically higher magnitude, and frequently more often found in the CD4 subset, compared with T cell expansions identified in healthy individuals. In long-term studies of the T cell expansions for up to 18 months, a heterogeneous pattern was revealed, with no obvious correlation to clinical features such as disease activity or treatment. Studies of TCR V gene usage in this group of patients may help in understanding the pathogenesis of necrotizing vasculitis, and in the identification of unknown antigens, and may open the possibility to a highly selective immunotherapy by targeting disease-mediating T cells.     

T cell repertoire in patients with multiple myeloma and monoclonal gammopathy of undetermined significance: Clonal CD8+ T cell expansions are found preferentially in patients with a low tumor burden

The T cell receptor (TCR) variable (V) gene repertoire was analyzed in patients with monoclonal gammopathy of undetermined significance (MGUS) (n = 17), multiple myeloma (MM) stage I (n = 16), MM stages II/III (n = 31) and agematched controls (n = 27) by immunofluorescence and flow cytometry using a panel of mouse monoclonal antibodies (mAb) (n = 10) against TCR Vα and Vβ gene products. T cell expansion was defined as a value ? thrice the normal median value for each respective TCR V mAb. Fifty-three percent of all patients displayed CD8⁺ expansion(s) as compared to 30% of age-matched controls (p = 0.001). Within the CD4 subset, 18% of the patients displayed T cell expansion(s) in comparison to 11% of the controls (not significant). Interestingly, the CD8⁺ expansion(s) were more frequently noted in patients with a low tumor burden (MGUS/MMI) (73%) as compared to those with advanced disease (MM II/III) (32% and control donors (30%) (p < 0.01). Likewise, multiple CD8⁺ expansions (two or more) were more common in MGUS/MM I patients than in MM II/III and controls (p = 0.01). The T cell expansions were stable over time in patients with a stable disease. A high degree of clonality of the expansions was detected by TCR CDR3 fragment length analysis, determination of Jβ gene usage and nucleotide sequencing. The frequent finding of oligoclonal CD8⁺ T cell expansions in patients with a low tumor mass, but not in patients with advanced disease justifies further work in order to identify the relevance of expanded CD8⁺ T cells. In one patient with T cell reactivity against the autologous myeloma idiotype, two expansions within the CD8 population (Vβ3 and Vβ5.2 respectively) displayed no reactivity against the idiotype. Instead, idiotype recognition was confined to a CD8 non-expanded Vβ22⁺ T cell population, with a highly restricted TCR usage (CDR3 fragment length analysis).     

利用TCR V_β基因分析GVHD患者的克隆性T细胞

应用RT PCR扩增 3例异基因造血干细胞移植术后合并慢性GVHD患者的外周血单个核细胞的TCRVβ 2 4个亚家族的CDR3,了解患者TCRVβT细胞的表达 ,PCR产物进一步经基因扫描分析确定T细胞克隆性。结果显示 ,3例患者均有克隆性T细胞生长 ,它可能与GVHD的发生有关。     

Delineation of the minimal encephalitogenic epitope within the immunodominant region of myelin oligodendrocyte glycoprotein: diverse Vβ gene usage by T cells recognizing the core epitope encephalitogenic for T cell receptor Vβb and T cell receptor Vβa H-2b mice

The nature of the autoimmune T cell response to myelin oligodendrocyte glycoprotein (MOG), recently recognized as a potential target antigen in multiple sclerosis (MS), has not yet been characterized, in contrast to the T cell reactivity to other potential target antigens in MS such as myelin basic protein and proteolipid protein. Here, we show that the encephalitogenicity of the recombinant Ig-like domain of human MOG is associated, in H-2^b mice, with an immunodominant T cell reactivity against a single region of MOG spanning amino acids 35–55, accounting for the previously reported strong encephalitogenic activity of pMOG 35–55. A single injection of pMOG 35–55 with or without administration of pertussis toxin was sufficient to induce severe clinical experimental autoimmune encephalomyelitis (EAE) in H-2^b mice. Encephalitogenic pMOG 35–55-specific T cell lines derived from C3H.SW (Vβ^b) mice were diverse in their TCR Vβ gene usage (Vβ1, Vβ6, Vβ8 and Vβ15), although Vβ8.2 was most predominantly expressed (48%). However, Vβ8⁺ T cells may only be part of the encephalitogenic MOG-specific T cell repertoire in H-2^b mice, as demonstrated by the susceptibility of C57L (Vβ^a) mice to disease induced by pMOG 35–55. Encephalitogenic T cell lines from Vβ^a mice were also diverse in their TCR Vβ gene usage (Vβ1, Vβ2, Vβ6, Vβ14 and Vβ16). Such a heterogeneous TCR Vβ gene expression by pMOG 35–55/I-A^b-reactive T cells from both Vβ^a and Vβ^b H-2^b mice suggested multiple epitopes within pMOG 35–55. Analysis of the pattern of reactivity by pMOG 35–55-reactive T cells to a set of truncated peptides was not commensurate with independent nested epitopes, but revealed a requirement for recognition of a core sequence, YRSPFSRVV (pMOG 40–48). However, optimal stimulation was obtained with longer peptides, with each additional amino acid flanking either the N or the C terminus differentially increasing the stimulatory capacity of pMOG 40–48. Nonetheless, pMOG 40–48 was the minimal encephalitogenic epitope for both Vβ^a and Vβ^b mice. Thus, the T cell reactivity against the immunodominant encephalitogenic region of MOG is characterized by a diverse Vβ gene usage and a requirement for the same core epitope. This pattern of reactivity may favor epitope-directed, rather than TCR-targeted, approaches to immunospecific therapy for MOG-related autoimmune disease.     

T cell receptor diversity in alloreactive responses against HLA-B27 (B*2705) is limited by multiple-level restrictions in both α and β chains

The T cell receptors (TCR) in HLA-B27 (B*2705) alloreactivity were analyzed in cytotoxic T lymphocytes (CTL) from two individuals. Non-random usage was found in Vβ, N+Dβ, Vα, and Jα, but not in Jβ segments or Nα-regions. Vβ segments from homology subgroup 4 were predominant and not associated to a particular donor or fine specificity, suggesting involvement in recognizing the HLA-B27 molecule. In contrast, preferential Vα usage was associated with particular individuals and fine specificities, indicating distinct Vβ and Vα recruitment and contribution to allorecognition. Recurrent N+Dβ motifs and Jα segments, even from different donors, limited junctional diversity, suggesting that CDR3 usage was determined by the alloantigenic epitope independently of individuals. TCR were selected differently at various levels, as indicated by the following findings. Four clonotypes with similar fine specificity had identical β and unrelated α chains. Similar α were associated with unrelated β chains, and vice versa. CTL using Vβ subgroup 4 did not globally show concomitant predominance of other TCR elements. Vα7, one of the preferred Vα segments, was always associated with Vβ subgroups other than 4. Sometimes, a TCR showed homology in elements of one chain to a second TCR or group of TCR, and to another in the other chain. These results are best explained by differential selection of TCR elements by different epitopes, providing a key to the inner structure of allospecific TCR repertoires.     

An Uneven Expression of T Cell Receptor V Genes in the Arterial Wall and Peripheral Blood in Giant Cell Arteritis

The aim of the study was to investigate T cell receptor (TCR) usage at the time of diagnosis of giant cell arteritis (GCA) and to estimate the degree of clonality of T-cells infiltrating the lesion. Seven patients with biopsy-proven giant cell arteritis were included in the study. Immunocytochemistry in biopsies from the temporal arteries and flow cytometric analysis of peripheral blood lymphocytes (PBL) was performed using monoclonal antibodies specific for CD3, CD4 and CD8 and 13 TCR Vα and Vβ gene segment products. The CDR3 fragment length polymorphism was assessed by gel electrophoresis of PCR-amplified TCR segments. The T lymphocytes were found to be concentrated to the adventitia rather than the media or intima. Six of the seven patients with GCA had expansions of T lymphocytes, expressing selected TCR V genes in the arterial wall. None of these expansions was found in PBL. The infiltrating T-cells were poly- or oligoclonal. In conclusion, the dominating part of the inflammatory infiltrate in GCA emanates from the adventitial microvessels. There is an uneven expression of TCR V genes by T lymphocytes in the inflammatory infiltrates as compared to peripheral blood T lymphocytes at the time of diagnosis, consistent with an antigen-driven immunological reaction in the arterial wall.     

超抗原SEA和SEB对正常人TCR V_β基因的限制性取用

金黄色葡萄球菌肠毒素 (SE )作为一种超抗原 ,以MHC非限制性及TCRVβ特异性的方式激活T细胞。本文用定量PCR方法 ,分析SEA和SEB刺激的正常人外周血淋巴细胞T细胞抗原受体Vβ的取用格局。揭示在不同HLA遗传背景下 ,SEA刺激的淋巴细胞均选择性地取用Vβ3和Vβ6两种基因片段 ,而SEB刺激的淋巴细胞则优势表达Vβ2、Vβ8和Vβ9。通过比较分析 ,Sigma产的SEB刺激淋巴细胞后则优势表达Vβ3、Vβ4、Vβ16和Vβ2 0 ,提示外周血淋巴细胞在超抗原作用下发生寡克隆扩增。     

肿瘤患者胸/腹水和外周血中TCR Vβ亚家族表达及调节性T细胞亚群的研究

目的:探讨肿瘤患者胸/腹水中肿瘤浸润性淋巴细胞(TIL)和外周血T细胞中T细胞受体(TCR)Vβ亚家族的表达变化情况、CD4/CD8细胞比例变化和Treg细胞的分布情况,分析肿瘤患者的免疫状态。方法:分离11例肿瘤患者胸/腹水和外周血以及4例健康人外周血的T细胞,采用流式方法检测Vβ24个亚家族及CD3、CD4、CD8、CD25、CD127的表达情况,统计分析T细胞中Vβ24个亚家族、Treg细胞的特点。结果:TCR Vβ亚家族的表达在肿瘤患者胸/腹水TIL中与血液淋巴细胞中存在着显著差异,其中肺癌患者(4/5)TIL中TCR Vβ8,结肠癌患者(3/4)TIL中TCR Vβ2等亚家族显著高表达;11例肿瘤患者胸/腹水样本中Treg的比例均比外周血高(P<0.05),其中5例肺癌患者胸腹水中CD8+T细胞比例降低。结论:肿瘤患者胸/腹水中的淋巴细胞TCR Vβ亚家族表达与外周血存在差异,表明肿瘤患者体内淋巴细胞发生了明显的优势取用和定向趋化。此外肿瘤微环境可能影响了TIL中CD4+细胞的分化导致胸腹水中Treg细胞的比例升高,同时伴随着CD8+T比例的下降,并可能因此影响到TIL中TCR Vβ亚家族的优势取用情况,且导致免疫耐受。     

多发性骨髓瘤患者外周血中TCR Vβ亚家族nave T细胞水平变化

目的： 检测多发性骨髓瘤（MM）患者外周血中23个TCR Vβ亚家族的T细胞受体删除DNA环（sjTRECs）的存在特点，从而了解MM患者相应Vβ亚家族nave T细胞的近期胸腺输出情况。方法: 利用半巢式PCR分别扩增12例MM患者每5×104个外周血单个核细胞（PBMCs）中的23个Vβ亚家族sjTRECs，10例正常人外周血作为对照。结果: 在5×104个PBMCs中，检测到MM患者sjTRECs的Vβ亚家族数量约为（5.00±2.45）个，与正常人的（9.60±5.48）个相比，检出的亚家族数量明显减少（P<0.05）；23个Vβ亚家族sjTRECs在正常人中均可以检测到，而在MM患者仅检测到部分；并且Vβ2、Vβ10、Vβ16、Vβ17和Vβ21等5个亚家族sjTRECs的检出率明显低于正常水平。12例MM患者检出的亚家族数量（2-9个）不等，患者的年龄与检出的亚家族数量存在负相关（r=-0.892；P<0.01）。结论: MM患者胸腺近期输出的23个Vβ亚家族nave T细胞存在不同程度的缺失或水平降低，表明患者存在不同程度的细胞免疫功能缺陷以及T细胞谱系重建的能力和潜能受损。     

Abnormal T cell receptor V gene usage in myasthenia gravis: prevalence and characterization of expanded T cell populations

The usage of T cell receptor (TCR) Vα/Vβ chains on cells from 38 patients with myasthenia gravis (MG) was determined by flow cytometry. There was a decreased number of cells expressing Vβ2 in CD8⁺ and Vβ3 in CD4⁺ cells in patients compared with healthy individuals. Abnormal expansions of T cells using particular TCR Vα/Vβ gene products were found in 18/38 patients. A significantly higher usage of Vβ13 was observed but there was no restriction with regard to other TCR Vα/Vβ. Expanded cells belonging to both CD4⁺ and CD8⁺ were present in MG patients while restricted to the CD8⁺ population in healthy individuals. To elucidate the role of the expanded populations, we studied characteristics of the expanded and non-expanded T cells from MG patients who had persistent T cell expansions over more than 2 years. The cells were analysed with regard to phenotype, cytokine secretion, cytokine mRNA expression and reactivity with the autoantigen, the acetylcholine receptor. The characteristics of the expanded populations in MG clearly differed from those found in healthy individuals. More cells in the CD4⁺ expanded populations expressed HLA-DR and there was also a tendency for higher expression of CD25, CD28 and CD57. The number of cells spontaneously secreting cytokines was higher in the expanded populations. A dominant Th1-type cytokine secretion and mRNA expression was noted. Autoantigen-reactive CD4⁺ T cells were largely restricted to the expanded populations.     

Peripheral blood T cell expansions in patients with Behc¸et's disease

Behc¸et's disease (BD) is a chronic multisystemic inflammatory disorder characterized mainly by recurrent oral and genital aphthous ulcerations and uveitis. Etiology and pathogenesis of BD remain unknown. T cell receptor (TCR) Vα/Vβ gene product expression as well as Jβ gene segment expression in peripheral blood of BD patients were analysed to investigate the possible role of T lymphocytes in the etiopathogenesis of BD. Flow cytometry with 12 TCR V-specific MoAbs was used for TCRV analyses. Jβ gene segment usage by T cell populations expressing certain Vβs was determined by polymerase chain reaction (PCR) technique with Vβ- and Cβ-specific primers, Southern blotting of PCR products, and subsequent hybridization with radiolabelled Jβ gene segment-specific probes. Although 13 of the 23 BD patients exhibited increases in expression of one or more TCR V-gene products, only expansions among the CD4⁺ T cell subset were significantly more frequent in BD patients (7/23) compared with healthy controls (0/15) (P = 0.019). Six out of eight cases followed for up to 20 months had at least one expansion correlated with disease activity. A strict preference for particular Jβ gene segments implicating clonality was apparent in all analysed T cell expansions and correlated well with disease activity. These results suggest a possible involvement of antigen-specific T lymphocytes in the pathogenesis of BD.