Thymus最新文献_第6页

Unravelling human T-cell receptor junctional region sequences. 解开人类t细胞受体连接区序列。

Thymus Pub Date : 1994-01-01

T M Breit, J J Van Dongen

{"title":"Unravelling human T-cell receptor junctional region sequences.","authors":"T M Breit, J J Van Dongen","doi":"","DOIUrl":"","url":null,"abstract":"Careful analysis of functional V delta 2-J delta 1 and V gamma 9-J gamma 1.2 rearrangements of peripheral T-lymphocytes showed high frequencies of leucine and valine at a fixed position in the V delta 2-J delta 1 junctional regions. This phenomenon remained unnoticed in the numerous published junctional regions for over several years. Because comparable preferential motifs might also occur in junctional regions of other T-cell populations in health and disease, more precise analysis of junctional region diversity is needed. For this reason we describe general guidelines for identification of the various elements in TcR junctional regions: D-gene-derived nucleotides (in case of TcR-beta and TcR-delta genes), P-region nucleotides, N-region nucleotides, and deletion of nucleotides by trimming of the rearranged gene segments. In addition, we summarized the known genomic germline sequences of rearranging TcR gene segments, which are necessary for proper application of the general guidelines. Subsequent analysis of the majority of published TcR junctional regions, allowed us to determine the composition and average insertion and deletion of nucleotides in genomic junctional regions. Because the protein junctional region instead of the genomic junctional region determines the actual specificity of TcR chains, the amino acid composition of the protein junctional regions of different types of TcR gene rearrangements was determined. This revealed some unexpected characteristics, such as the virtual absence of cysteine in all functional TcR junctional regions and increased or decreased frequencies of particular amino acid residues in specific TcR junctional regions. Application of the guidelines in combination with the summarized TcR germline sequences may contribute to uniformity in the analysis of junctional regions and may lead to important information concerning TcR specificity.","PeriodicalId":76738,"journal":{"name":"Thymus","volume":"22 3","pages":"177-99"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18937002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Role of thymic stromal cells in thymocyte education: a comparitive analysis of different models. 胸腺基质细胞在胸腺细胞教育中的作用:不同模型的比较分析。

Thymus Pub Date : 1994-01-01

A Martín-Fontecha, H J Schuurman, A Zapata

引用次数: 0

Programming for recognition and programming for response. Separate developmental subroutines in the murine thymus. 识别编程和响应编程。小鼠胸腺的独立发育子程序。

Thymus Pub Date : 1994-01-01

E V Rothenberg, R A Diamond, D Chen

{"title":"Programming for recognition and programming for response. Separate developmental subroutines in the murine thymus.","authors":"E V Rothenberg, R A Diamond, D Chen","doi":"","DOIUrl":"","url":null,"abstract":"Pre-T cells become programmed with the capacity to make functional responses to activating stimuli in a process that occurs prior to, and independently of, T-cell receptor gene rearrangement and T-cell receptor-dependent positive selection. In spite of this early programming, as differentiation proceeds further the cells enter a stage in which they appear to be unable to make any functional responses. This 'eclipse' phase begins when the cells undergo successful T-cell receptor beta-chain rearrangement and ends, with the return of their functional competence, only when they successfully traverse positive selection. These results suggest that pre-T cells are subject to two distinct subroutines of differentiation, which cannot operate at the same time: one which confers function and one which confers and selects recognition specificity. To provide a possible molecular basis for the relationship between these two processes, we consider specific alterations in response-associated transcription factors that may cause the changes in responsiveness observed during programming for recognition. The interplay of the two differentiation subroutines is proposed to be a consequence of the use of common transcription factors in different combinatorial contexts for functional responses, assembly of T-cell receptor complexes, and selection.","PeriodicalId":76738,"journal":{"name":"Thymus","volume":"22 4","pages":"215-44"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18984209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Differential effects of T cell receptor ligation of TCR gamma delta thymocyte development in fetal thymic organ culture. 胎儿胸腺器官培养中T细胞受体结扎对TCR γ δ胸腺细胞发育的差异影响。

Thymus Pub Date : 1994-01-01

Y Tatsumi, D Deluca, R Q Cron, J A Bluestone

{"title":"Differential effects of T cell receptor ligation of TCR gamma delta thymocyte development in fetal thymic organ culture.","authors":"Y Tatsumi, D Deluca, R Q Cron, J A Bluestone","doi":"","DOIUrl":"","url":null,"abstract":"Fetal thymus organ culture system (FTOC), a well-known model used for the study of TCR alpha beta development, was employed to study TCR gamma delta cell development. It was found that different waves of TCR gamma delta cells develop from precursors within the fetal thymi at the time in vitro culture. Subsets of fetal thymocytes were analyzed by flow cytometry and 2-D gel biochemical analysis was performed. After 5 days in FTOC, V gamma 3+ and V gamma 2+ cells were dominant. By day 12 FTOC, the absolute number of V gamma 3+ cells decreased while V gamma 2+ and V gamma 4+ cells became dominant. These observations suggest that the thymic micro-environment affects the thymic waves of TCR gamma delta subsets. Furthermore, the effect of TCR/antigen interaction in the development of TCR gamma delta cells was examined with anti-TCR mAbs added into the FTOC. Anti-CD3 mAb added to day 5 and day 12 FTOC inhibited TCR gamma delta development, especially V gamma 4+ cells. On the other hand, V gamma 2+ cells were relatively resistant to the addition of anti-TCR mAb. The reduction of TCR gamma delta+ thymocytes was not due to the modulation of TCR molecules and could be reversed by Cyclosporin A (CsA). These results suggest that TCR ligation negatively regulates the development of TCR gamma delta cells in a V gamma-specific manner.","PeriodicalId":76738,"journal":{"name":"Thymus","volume":"23 3-4","pages":"131-53"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19505908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Developmental regulation of cAMP signaling pathways in thymocyte development. 胸腺细胞发育过程中cAMP信号通路的发育调控。

Thymus Pub Date : 1994-01-01

L J Scherer, R A Diamond, E V Rothenberg

{"title":"Developmental regulation of cAMP signaling pathways in thymocyte development.","authors":"L J Scherer, R A Diamond, E V Rothenberg","doi":"","DOIUrl":"","url":null,"abstract":"Major developmental transitions in thymocyte differentiation are accompanied by sharp alterations in cAMP metabolism. We have analyzed the cAMP accumulation responses of cell populations representing successive stages of T-cell development, namely: immature TcR- thymocytes from SCID mice, proliferating cortical blasts, small cortical thymocytes, medullary thymocytes and peripheral T cells. We find that all classes of thymocytes exhibit higher cAMP synthesis in response to forskolin than peripheral T cells. In immature TcR- thymocytes, this high capacity is buffered by efficient phosphodiesterase activity, but in CD4+CD8+TcRlow thymocytes, phosphodiesterase activity becomes much less effective. Phosphodiesterase activity then rises again after positive selection. The ability of thymocytes to respond to prostaglandin E is regulated distinctly from their ability to respond to forskolin. Unlike forskolin, PGE1 induces cAMP synthesis to similar levels in all classes of thymocytes, possibly due to partial activation of phosphodiesterase in cortical thymocytes by PGE1. Finally, we report a novel effect of Ca2+/protein kinase C signaling on cAMP accumulation, which occurs selectively in the proliferating cortical blasts.","PeriodicalId":76738,"journal":{"name":"Thymus","volume":"23 3-4","pages":"231-57"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19506498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Corticosteroid treatment and X-ray irradiation in adult rats induce the reexpression of fetal markers in cortical thymic epithelial cells. 皮质类固醇治疗和x射线照射诱导成年大鼠胸腺皮质上皮细胞中胎儿标记物的重新表达。

Thymus Pub Date : 1994-01-01

S Stojanović, V Dragojević-Simić, M Colić

引用次数: 0

Signal transduction defect in the acquired immunodeficiency syndrome and AIDS-related complex. 获得性免疫缺陷综合征和艾滋病相关复合体的信号转导缺陷。

Thymus Pub Date : 1993-09-01

S Gupta

引用次数: 0

NADPH-diaphorase positive cells in the chick and rat thymus. 鸡和大鼠胸腺nadph - diaphase阳性细胞。

Thymus Pub Date : 1993-09-01

P Gulati, A S Chan, S K Leong