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1.
Infection and replication of HIV-1 in purified progenitor cells of normal human bone marrow 总被引：40，自引：0，他引：40
T M Folks S W Kessler J M Orenstein J S Justement E S Jaffe A S Fauci 《Science (New York, N.Y.)》1988,242(4880):919-922
2.
将昆明鼠随机分为A,B,C,D4组,各组分别采用含有猪轮状病毒(RV)JL94株VP7基因的重组真核表达质粒pcDNA-VP7,含有猪传染性胃肠炎病毒(TGEV)TH98株N基因的重组真核表达质粒pcDNA-N,pcD-NA-VP7和pcDNA-N、真核表达载体pcDNA3.1(+),肌肉注射3次,每次间隔2周。首次注射前后定期采血,检测血清抗体和外周血淋巴细胞中CD4+,CD8+T细胞数量的变化。A,C组小鼠血清在首免后第14天即可检出针对RVVP7的阳性抗体(P/N≥2.0)。B组小鼠血清在首免后第39天检出针对TGEVN蛋白的阳性抗体(P/N≥2.0)。A,B,C组小鼠在首免后外周血CD4+、CD8+T细胞数量与D组小鼠相比,在不同时间有显著差异(P<0.05),并明显高于D组小鼠。说明猪轮状病毒与传染性胃肠炎病毒核酸免疫后能诱发机体免疫反应。 相似文献
3.
Thymic origin of intestinal alphabeta T cells revealed by fate mapping of RORgammat+ cells 总被引：1，自引：0，他引：1
Intestinal intraepithelial T lymphocytes (IELs) are likely to play a key role in host mucosal immunity and, unlike other T cells, have been proposed to differentiate from local precursors rather than from thymocytes. We show here that IELs expressing the alphabeta T cell receptor are derived from precursors that express RORgammat, an orphan nuclear hormone receptor detected only in immature CD4+CD8+ thymocytes, fetal lymphoid tissue-inducer (LTi) cells, and LTi-like cells in cryptopatches within the adult intestinal lamina propria. Using cell fate mapping, we found that all intestinal alphabeta T cells are progeny of CD4+CD8+ thymocytes, indicating that the adult intestine is not a significant site for alphabeta T cell development. Our results suggest that intestinal RORgammat+ cells are local organizers of mucosal lymphoid tissue. 相似文献
4.
In order to examine the mechanisms by which clonal deletion of autoreactive T cells occurs, a peptide antigen was used to induce deletion of antigen-reactive thymocytes in vivo. Mice transgenic for a T cell receptor (TCR) that reacts to this peptide contain thymocytes that progress from the immature to the mature phenotype. Intraperitoneal administration of the peptide antigen to transgenic mice results in a rapid deletion of the immature CD4+ CD8+ TCRlo thymocytes. Apoptosis of cortical thymocytes can be seen within 20 hours of treatment. These results provide direct evidence for the in vivo role of apoptosis in the development of antigen-induced tolerance. 相似文献
5.
Sun Z Unutmaz D Zou YR Sunshine MJ Pierani A Brenner-Morton S Mebius RE Littman DR 《Science (New York, N.Y.)》2000,288(5475):2369-2373
Most developing thymocytes undergo apoptosis because they cannot interact productively with molecules encoded by the major histocompatibility complex. Here, we show that mice lacking the orphan nuclear hormone receptor RORgamma lose thymic expression of the anti-apoptotic factor Bcl-xL. RORgamma thus regulates the survival of CD4+8+ thymocytes and may control the temporal window during which thymocytes can undergo positive selection. RORgamma was also required for development of lymph nodes and Peyer's patches, but not splenic follicles. In its absence, there was loss of a population of CD3-CD4+CD45+ cells that normally express RORgamma and that are likely early progenitors of lymphoid organs. Hence, RORgamma has critical functions in T cell repertoire selection and lymphoid organogenesis. 相似文献
6.
The SCID-hu mouse: murine model for the analysis of human hematolymphoid differentiation and function 总被引：143，自引：0，他引：143
J M McCune R Namikawa H Kaneshima L D Shultz M Lieberman I L Weissman 《Science (New York, N.Y.)》1988,241(4873):1632-1639
The study of human hematopoietic cells and the human immune system is hampered by the lack of a suitable experimental model. Experimental data are presented showing that human fetal liver hematopoietic cells, human fetal thymus, and human fetal lymph node support the differentiation of mature human T cells and B cells after engraftment into mice with genetically determined severe combined immunodeficiency. The resultant SCID-hu mice are found to have a transient wave of human CD4+ and CD8+ T cells and human IgG (immunoglobulin G) in the peripheral circulation. The functional status of the human immune system within this mouse model is not yet known. 相似文献
7.
Demethylated CD8 gene in CD4+ T cells suggests that CD4+ cells develop from CD8+ precursors 总被引：2，自引：0，他引：2
Mature T cells and medullary thymocytes bear either the CD4 or CD8 differentiation antigen. Precursor cells in the thymus express neither CD4 nor CD8 (CD4-8-), but most cortical thymocytes are CD4+8+. Whether CD4+ and CD8+ mature T cells arise directly from CD4-8- precursors or from a CD4+8+ intermediate remains unresolved. In this study, methylation of the CD8 gene in murine T cells and thymocytes was examined. There was progressive demethylation of the CD8 gene in the thymus during the transition from CD4-8- to CD4+8+. A similar pattern of demethylation of the CD8 gene was seen in CD4+ mature T cells, suggesting previous expression of CD8 in the CD4+ lineage. 相似文献
8.
Expanded HIV-1 cellular tropism by phenotypic mixing with murine endogenous retroviruses 总被引：26，自引：0，他引：26
P Lusso F di Marzo Veronese B Ensoli G Franchini C Jemma S E DeRocco V S Kalyanaraman R C Gallo 《Science (New York, N.Y.)》1990,247(4944):848-852
In view of the current interest in in vivo murine models for acquired immunodeficiency syndrome (AIDS), the interaction between human immunodeficiency virus type 1 (HIV-1) and endogenous murine leukemia virus (MuLV)-related retroviruses was investigated with a human leukemic T cell line (PF-382x) that acquired xenotropic MuLV (X-MuLV) after in vivo passage in immunosuppressed mice. Despite similar levels of membrane CD4 expression and HIV-1 125I-labeled gp 120 binding, a dramatic acceleration in the time course of HIV-1 infection was observed in PF-382x compared to its X-MuLV-negative counterpart (PF-382). Moreover, PF-382 cells coinfected by X-MuLV and HIV-1 generated a progeny of phenotypically mixed viral particles, enabling HIV-1 to productively infect a panel of CD4- human cells, including B lymphoid cells and purified normal peripheral blood CD4-/CD8+ T lymphocytes. Mixed viral phenotypes were also produced by human CD4+ T cells coinfected with an amphotropic MuLV-related retrovirus (A-MuLV) and HIV-1. These data show that endogenous MuLV acquired by human cells transplanted into mice can significantly interact with HIV-1, thereby inducing important alterations of HIV-1 biological properties. 相似文献
9.
Inhibition of T cell receptor expression and function in immature CD4+CD8+ cells by CD4 总被引：14，自引：0，他引：14
T Nakayama C H June T I Munitz M Sheard S A McCarthy S O Sharrow L E Samelson A Singer 《Science (New York, N.Y.)》1990,249(4976):1558-1561
Most immature CD4+CD8+ thymocytes express only a small number of T cell receptor (TCR) molecules on their surface, and the TCR molecules they do express are only marginally capable of transducing intracellular signals. TCR expression and function was not intrinsically low in immature CD4+CD8+ thymocytes, but was found to be actively inhibited by CD4-mediated signals. Indeed, release of CD4+CD8+ thymocytes from CD4-mediated signals resulted in significant increases in both TCR expression and signaling function. These results suggest that, in CD4+CD8+ cells developing in the thymus, increased TCR expression and function requires release from CD4-mediated inhibition. 相似文献
10.
Effects of cyclosporine A on T cell development and clonal deletion 总被引：29，自引：0，他引：29
Cyclosporine A (CsA) is an important immunosuppressive drug that is widely used in transplantation medicine. Many of its suppressive effects on T cells appear to be related to the inhibition of T cell receptor (TCR)-mediated activation events. Paradoxically, in certain situations CsA is responsible for the induction of a T cell-mediated autoimmunity. The effects of CsA on T cell development in the thymus were investigated to elucidate the physiologic events underlying this phenomenon. Two major effects were revealed: (i) CsA inhibits the development of mature single positive (CD4+8- or CD4-8+) TCR-alpha beta+ thymocytes without discernibly affecting CD4-8- TCR-gamma delta+ thymocytes and (ii) CsA interferes with the deletion of cells bearing self-reactive TCRs in the population of single positive thymocytes that do develop. This suggests a direct mechanism for CsA-induced autoimmunity and may have implications for the relative contribution of TCR-mediated signaling events in the development of the various T cell lineages. 相似文献
11.
12.
K R Schultz J P Klarnet R S Gieni K T HayGlass P D Greenberg 《Science (New York, N.Y.)》1990,249(4971):921-923
B cells can function as antigen-presenting cells and accessory cells for T cell responses. This study evaluated the role of B cells in the induction of protective T cell immunity to a Friend murine leukemia virus (F-MuLV)-induced leukemia (FBL). B cell-deficient mice exhibited significantly reduced tumor-specific CD4+ helper and CD8+ cytotoxic T cell responses after priming with FBL or a recombinant vaccinia virus containing F-MuLV antigens. Moreover, these mice had diminished T cell responses to the vaccinia viral antigens. Tumor-primed T cells transferred into B cell-deficient mice effectively eradicated disseminated FBL. Thus, B cells appear necessary for efficient priming but not expression of tumor and viral T cell immunity. 相似文献
13.
旨在建立C57BL/6小鼠骨髓源CD103+树突状细胞(CD103+ dendritic cell,CD103+DC)分离培养方法,阐述LPS对其形态与功能特征的影响。在无菌条件下分离C57BL/6小鼠骨髓细胞,并用重组GM-CSF和FLT3L对其进行体外联合诱导培养;利用光镜、扫描电镜、荧光显微镜和流式细胞术,分别对LPS作用前后细胞形态、表型及功能进行了分析。结果表明,细胞培养至第3天有零星集落出现,第13天后集落开始分散,可见典型的树突状突起,第15天后可得到大量的CD103+DC,加LPS刺激培养24 h后细胞表面树突样结构更加明显;分离培养的骨髓细胞能够表达表面分子CD103,其表达率达90%以上。RPMI-1640组(LPS未刺激组)可吞噬VOA的CD103+DC比例为25.70%,能够表达MHC-Ⅱ和CD83阳性细胞分别为41.31%和13.79%;LPS刺激组可吞噬VOA的CD103+DC比例为10.33%,能够表达MHC-Ⅱ和CD83的阳性细胞分别为68.10%和24.71%。MTT法检测结果显示,经LPS处理的CD103+DC刺激T细胞增殖的能力明显增强。综上所述,分离于C57BL/6小鼠的骨髓细胞,可在体外经FLT3L和GM-CSF共同诱导培养出CD103+DC,LPS可促进CD103+DC的成熟。 相似文献
14.
J H Kersey A Sabad K Gajl-Peczalska H M Hallgren E J Yunis M E Nesbit 《Science (New York, N.Y.)》1973,182(119):1355-1356
Five of nine children with acute lymphoblastic leukemia had lymphoblasts that bound sheep erythrocytes or reacted with antiserum to thymocytes, suggesting involvement of T (thymus-derived) cells. When lymphoblasts from all patients were examined by immunofluorescence they were found to lack a marker for B (bone marrow or bursa-equivalent) cells, that is, the presence of surface immunoglobulins. 相似文献
15.
Acceleration of diabetes in young NOD mice with a CD4+ islet-specific T cell clone 总被引：25，自引：0，他引：25
Nonobese diabetic (NOD) mice develop an autoimmune form of diabetes, becoming hyperglycemic after 3 months of age. This process was accelerated by injecting young NOD mice with CD4+ islet-specific T cell clones derived from NOD mice. Overt diabetes developed in 10 of 19 experimental animals by 7 weeks of age, with the remaining mice showing marked signs of the disease in progress. Control mice did not become diabetic and had no significant pancreatic infiltration. This work demonstrates that a CD4 T cell clone is sufficient to initiate the disease process in the diabetes-prone NOD mouse. 相似文献
16.
Pagès G Guérin S Grall D Bonino F Smith A Anjuere F Auberger P Pouysségur J 《Science (New York, N.Y.)》1999,286(5443):1374-1377
The p42 and p44 mitogen-activated protein kinases (MAPKs), also called Erk2 and Erk1, respectively, have been implicated in proliferation as well as in differentiation programs. The specific role of the p44 MAPK isoform in the whole animal was evaluated by generation of p44 MAPK-deficient mice by homologous recombination in embryonic stem cells. The p44 MAPK-/- mice were viable, fertile, and of normal size. Thus, p44 MAPK is apparently dispensable and p42 MAPK (Erk2) may compensate for its loss. However, in p44 MAPK-/- mice, thymocyte maturation beyond the CD4+CD8+ stage was reduced by half, with a similar diminution in the thymocyte subpopulation expressing high levels of T cell receptor (CD3high). In p44 MAPK-/- thymocytes, proliferation in response to activation with a monoclonal antibody to the T cell receptor in the presence of phorbol myristate acetate was severely reduced even though activation of p42 MAPK was more sustained in these cells. The p44 MAPK apparently has a specific role in thymocyte development. 相似文献
17.
Identification of a T3-associated gamma delta T cell receptor on Thy-1+ dendritic epidermal Cell lines 总被引：27，自引：0，他引：27
F Koning G Stingl W M Yokoyama H Yamada W L Maloy E Tschachler E M Shevach J E Coligan 《Science (New York, N.Y.)》1987,236(4803):834-837
The murine epidermis contains a subpopulation of bone marrow-derived lymphocytes that have a dendritic morphology and that express Thy-1 and T3 cell-surface antigens but not other markers (L3T4 or Lyt-2) characteristic of mature peripheral T lymphocytes. An alternative type of T cell receptor was earlier identified on a subpopulation of murine thymocytes with a similar phenotype (T3+, L3T4-, Lyt-2-), but not on peripheral murine T lymphocytes. Two independently derived Thy-1+, L3T4-, and Lyt-2- dendritic cell lines of epidermal origin that express a T3-associated disulfide-linked heterodimer composed of a 34-kilodalton gamma-chain and 46-kilodalton partner (the delta chain) have now been identified. Analysis of N-linked glycosylation revealed that this receptor is similar to that detected on thymocytes. These results demonstrate that Thy-1+ dendritic epidermal cell lines can express gamma delta T cell receptors in vitro and suggest that Thy-1+ dendritic epidermal cells express such receptors in vivo. The localization of these gamma delta T cell receptor-expressing cells in the epidermis may be of importance for understanding the function of these receptors. 相似文献
18.
Human immunodeficiency virus infection of human-PBL-SCID mice 总被引：32，自引：0，他引：32
D E Mosier R J Gulizia S M Baird D B Wilson D H Spector S A Spector 《Science (New York, N.Y.)》1991,251(4995):791-794
Severe combined immunodeficient (SCID) mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID mice) have inducible human immune function and may be useful as a small animal model for acquired immunodeficiency syndrome (AIDS) research. Hu-PBL-SCID mice infected with human immunodeficiency virus-1 (HIV-1) contained virus that was recoverable by culture from the peritoneal cavity, spleen, peripheral blood, and lymph nodes for up to 16 weeks after infection; viral sequences were also detected by in situ hybridization and by amplification with the polymerase chain reaction (PCR). Mice could be infected with multiple strains of HIV-1, including LAV-1/Bru, IIIB, MN, SF2, and SF13. HIV-1 infection affected the concentration of human immunoglobulin and the number of CD4+ T cells in the mice. These results support the use of the hu-PBL-SCID mouse for studies of the pathogenesis and treatment of AIDS. 相似文献
19.
龚勋 《黑龙江八一农垦大学学报》2016,(4):143-146,154
探讨不同运动强度对大学生免疫球蛋白、T淋巴细胞亚群水平的影响。随机选取我校体育专业二年级学生38人为研究对象,随机分为A组(13人)、B组(13人)和C组(12人)。A组学生给予中等强度的运动,B组学生给予小强度的运动,C组学生不进行运动锻炼,进行运动锻炼时每次40 min,3次/周,时间为3个月。三组学生均在相应运动强度干预前及干预后第二天,在同一时间抽取空腹肘静脉血液进行相关指标的检测。观察并记录三组学生在干预前后的免疫球蛋白、T淋巴细胞亚群水平的变化。运动干预前,三组学生的相关检查指标组间比较,差异无统计学意义(P0.05);在3个月的不同运动强度干预后,A组研究对象的免疫球蛋白Ig G明显升高(P0.05),Ig A、Ig M变化不大;B组、C组研究对象的Ig G、Ig A、Ig M均无明显变化。三组研究对象的CD4+升高、CD8+降低、CD4+/CD8+升高,但只有A组研究对象的变化差异有统计学意义(P0.05)。中等强度的运动可以提高学生的免疫功能,值得在大学中推广。 相似文献
20.
Thymocyte expression of RAG-1 and RAG-2: termination by T cell receptor cross-linking. 总被引：30，自引：0，他引：30
L A Turka D G Schatz M A Oettinger J J Chun C Gorka K Lee W T McCormack C B Thompson 《Science (New York, N.Y.)》1991,253(5021):778-781
The expression of the V(D)J [variable (diversity) joining elements] recombination activating genes, RAG-1 and RAG-2, has been examined during T cell development in the thymus. In situ hybridization to intact thymus and RNA blot analysis of isolated thymic subpopulations separated on the basis of T cell receptor (TCR) expression demonstrated that both TCR- and TCR+ cortical thymocytes express RAG-1 and RAG-2 messenger RNA's. Within the TCR+ population, RAG expression was observed in immature CD4+CD8+ (double positive) cells, but not in the more mature CD4+CD8- or CD4-CD8+ (single positive) subpopulations. Thus, although cortical thymocytes that bear TCR on their surface continue to express RAG-1 and RAG-2, it appears that the expression of both genes is normally terminated during subsequent thymic maturation. Since thymocyte maturation in vivo is thought to be regulated through the interaction of the TCR complex with self major histocompatibility complex (MHC) antigens, these data suggest that signals transduced by the TCR complex might result in the termination of RAG expression. Consistent with this hypothesis, thymocyte TCR cross-linking in vitro led to rapid termination of RAG-1 and RAG-2 expression, whereas cross-linking of other T cell surface antigens such as CD4, CD8, or HLA class I had no effect. 相似文献