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91.
Ray S Gao C Wyatt K Fariss RN Bundek A Zelenka P Wistow G 《The Journal of biological chemistry》2005,280(9):8494-8502
Platelet-derived growth factor D (PDGF-D), also known as Iris-expressed growth factor, is a member of the PDGF/vascular endothelial growth factor family. The expression of PDGF-D in the eye is tissue-specific. In the anterior segment, it is localized to iris and ciliary body, whereas in the retina, PDGF-D is restricted to the outer plexiform layer. PDGF-D is present in aqueous humor but is not detectable in mature lens or in mouse lens-derived alphaTN4-1 cells. However, it is expressed in rabbit lens-derived N/N1003A cells. N/N1003A cell-conditioned medium stimulates proliferation in rat lens explants, and this is blocked by immunodepletion of PDGF-D. Immunopurified PDGF-D also stimulates cell proliferation in rat lens explants and in NIH 3T3 cells. In organ culture of rat eye anterior segments, anti-PDGF-D strongly inhibits lens epithelial cell proliferation. This finding suggests a major in vivo role for PDGF-D in the mechanisms of coordinated growth of eye tissues. Intervention in the PDGF-D pathway in the eye, perhaps by antibody or blocking peptide, could be useful in the treatment of certain cataracts, including post-operative secondary cataract. 相似文献
92.
Larrivée B Niessen K Pollet I Corbel SY Long M Rossi FM Olive PL Karsan A 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(5):2890-2899
During embryogenesis, vascular and hemopoietic cells originate from a common precursor, the hemangioblast. Recent evidence suggests the existence of endothelial precursors in adult bone marrow cells, but it is unclear whether those precursors have a role in tumor neovascularization. In this report, we demonstrate that murine bone marrow contains endothelial progenitors, which arise from a cell with self-renewing capacity, and can integrate into tumor microvasculature, albeit at a very low frequency. A transgenic double-reporter strategy allowed us to demonstrate definitively that tumor bone marrow-derived endothelial cells arise by transdifferentiation of marrow progenitors rather than by cell fusion. Single cell transplants showed that a common precursor contributes to both the hemopoietic and endothelial lineages, thus demonstrating the presence of an adult hemangioblast. Furthermore, we demonstrate that increased vascular endothelial growth factor (VEGF)-A secretion by tumor cells, as well as activation of VEGF receptor-2 in bone marrow cells does not alter the mobilization and incorporation of marrow-derived endothelial progenitors into tumor vasculature. Finally, in human umbilical cord blood cells, we show that endothelial precursors make up only approximately 1 in 10(7) mononuclear cells but are highly enriched in the CD133+ cell population. By ruling out cell fusion, we clearly demonstrate the existence of an adult hemangioblast, but the differentiation of marrow stem cells toward the endothelial lineage is an extremely rare event. Furthermore, we show that VEGF-A stimulation of hemopoietic cells does not significantly alter this process. 相似文献
93.
Ho PP Fontoura P Platten M Sobel RA DeVoss JJ Lee LY Kidd BA Tomooka BH Capers J Agrawal A Gupta R Zernik J Yee MK Lee BJ Garren H Robinson WH Steinman L 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(9):6226-6234
Targeting pathogenic T cells with Ag-specific tolerizing DNA vaccines encoding autoantigens is a powerful and feasible therapeutic strategy for Th1-mediated autoimmune diseases. However, plasmid DNA contains abundant unmethylated CpG motifs, which induce a strong Th1 immune response. We describe here a novel approach to counteract this undesired side effect of plasmid DNA used for vaccination in Th1-mediated autoimmune diseases. In chronic relapsing experimental autoimmune encephalomyelitis (EAE), combining a myelin cocktail plus IL-4-tolerizing DNA vaccine with a suppressive GpG oligodeoxynucleotide (GpG-ODN) induced a shift of the autoreactive T cell response toward a protective Th2 cytokine pattern. Myelin microarrays demonstrate that tolerizing DNA vaccination plus GpG-ODN further decreased anti-myelin autoantibody epitope spreading and shifted the autoreactive B cell response to a protective IgG1 isotype. Moreover, the addition of GpG-ODN to tolerizing DNA vaccination therapy effectively reduced overall mean disease severity in both the chronic relapsing EAE and chronic progressive EAE mouse models. In conclusion, suppressive GpG-ODN effectively counteracted the undesired CpG-induced inflammatory effect of a tolerizing DNA vaccine in a Th1-mediated autoimmune disease by skewing both the autoaggressive T cell and B cell responses toward a protective Th2 phenotype. These results demonstrate that suppressive GpG-ODN is a simple and highly effective novel therapeutic adjuvant that will boost the efficacy of Ag-specific tolerizing DNA vaccines used for treating Th1-mediated autoimmune diseases. 相似文献
94.
Vincent P Collette Y Marignier R Vuaillat C Rogemond V Davoust N Malcus C Cavagna S Gessain A Machuca-Gayet I Belin MF Quach T Giraudon P 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(11):7650-7660
The semaphorin-signaling transducer collapsin response mediator protein 2 (CRMP2) has been identified in the nervous system where it mediates Sema3A-induced growth cone navigation. In the present study, we provide first evidence that CRMP2 is present in the immune system and plays a critical role in T lymphocyte function. CRMP2 redistribution at the uropod in polarized T cells, a structural support of lymphocyte motility, suggests that it may regulate T cell migration. This was evidenced in primary T cells by small-interfering RNA-mediated CRMP2 gene silencing and blocking Ab, as well as CRMP2 overexpression in Jurkat T cells tested in a chemokine- and semaphorin-mediated transmigration assay. Expression analysis in PBMC from healthy donors showed that CRMP2 is enhanced in cell subsets bearing the activation markers CD69+ and HLA-DR+. Heightened expression in T lymphocytes of patients suffering from neuroinflammatory disease with enhanced T cell-transmigrating activity points to a role for CRMP2 in pathogenesis. The elucidation of the signals and mechanisms that control this pathway will lead to a better understanding of T cell trafficking in physiological and pathological situations. 相似文献
95.
While typical intracellular protein modules have only one ligand-binding site, there are rare examples of single modules that bind two different ligands at distinct binding sites. Here we present a detailed mutational and energetic analysis of one such domain, the phosphotyrosine binding (PTB) domain of Disabled-1 (Dab1), which binds to both peptide and phosphoinositide (PI) ligands simultaneously at structurally distinct binding sites. Through the techniques of isothermal titration calorimetry (ITC), analysis of Dab1 PTB domain mutants, and nuclear magnetic resonance (NMR), we have evaluated the characteristics of binding of the Dab1 PTB domain to various peptide and PI ligands. These studies reveal that the presence of saturating concentrations of one ligand has little effect on the binding constant for a second ligand at the other site. In addition, proteins with single-point mutations in the peptide-binding site retain native affinity for PI ligands, while proteins with mutations that prevent PI binding retain native affinity for peptide. NMR titrations show that the final structure of the ternary complex is the same independent of the order of addition of the two ligands. Together, these studies show that binding of peptide and PI ligands is energetically independent and noncooperative. 相似文献
96.
An inhibitory Ig superfamily protein expressed by lymphocytes and APCs is also an early marker of thymocyte positive selection 总被引:6,自引:0,他引:6
Han P Goularte OD Rufner K Wilkinson B Kaye J 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(10):5931-5939
Positive selection of developing thymocytes is associated with changes in cell function, at least in part caused by alterations in expression of cell surface proteins. Surprisingly, however, few such proteins have been identified. We have analyzed the pattern of gene expression during the early stages of murine thymocyte differentiation. These studies led to identification of a cell surface protein that is a useful marker of positive selection and is a likely regulator of mature lymphocyte and APC function. The protein is a member of the Ig superfamily and contains conserved tyrosine-based signaling motifs. The gene encoding this protein was independently isolated recently and termed B and T lymphocyte attenuator (Btla). We describe in this study anti-BTLA mAbs that demonstrate that the protein is expressed in the bone marrow and thymus on developing B and T cells, respectively. BTLA is also expressed by all mature lymphocytes, splenic macrophages, and mature, but not immature bone marrow-derived dendritic cells. Although mice deficient in BTLA do not show lymphocyte developmental defects, T cells from these animals are hyperresponsive to anti-CD3 Ab stimulation. Conversely, anti-BTLA Ab can inhibit T cell activation. These results implicate BTLA as a negative regulator of the activation and/or function of various hemopoietic cell types. 相似文献
97.
Immunity to the extracellular domain of Nogo-A modulates experimental autoimmune encephalomyelitis 总被引:3,自引:0,他引:3
Fontoura P Ho PP DeVoss J Zheng B Lee BJ Kidd BA Garren H Sobel RA Robinson WH Tessier-Lavigne M Steinman L 《Journal of immunology (Baltimore, Md. : 1950)》2004,173(11):6981-6992
Nogo-66, the extracellular 66 aa loop of the Nogo-A protein found in CNS myelin, interacts with the Nogo receptor and has been proposed to mediate inhibition of axonal regrowth. It has been shown that immunization with Nogo-A promotes recovery in animal models of spinal cord injury through induction of Ab production. In this report, studies were performed to characterize the immune response to Nogo-66 and to determine the role of Nogo in experimental autoimmune encephalomyelitis (EAE). Immunization of EAE-susceptible mouse strains with peptides derived from Nogo-66 induced a CNS immune response with clinical and pathological similarities to EAE. The Nogo-66 peptides elicited strong T cell responses that were not cross-reactive to other encephalitogenic myelin Ags. Using a large scale spotted microarray containing proteins and peptides derived from a wide spectrum of myelin components, we demonstrated that Nogo-66 peptides also generated a specific Ab response that spreads to several other encephalitogenic myelin Ags following immunization. Nogo-66-specific T cell lines ameliorated established EAE, via Nogo-66-specific Th2 cells that entered the CNS. These results indicate that some T cell and B cell immune responses to Nogo-66 are associated with suppression of ongoing EAE, whereas other Nogo-66 epitopes can be encephalitogenic. 相似文献
98.
99.
Ellenberger EA Lucas HL Mueller JL Barrington PL Chung E Ohgami Y Quock RM 《Life sciences》2004,76(5):499-507
This study was conducted to demonstrate the involvement of nitric oxide synthase (NOS) in the early-phase isoflurane-induced hypotension and to ascertain whether this NOS is neuronal NOS (nNOS) or endothelial NOS (eNOS). Mean arterial pressures (MAPs) were directly measured from the femoral arteries of urethane-anesthetized rats. Isoflurane-induced changes in MAP were monitored in rats following pretreatment with vehicle or one of the following NOS inhibitors: L-NG-monomethyl-L-arginine (L-NMMA), which is non-selective; L-NG-nitro arginine (L-NOARG), which is more selective for nNOS and eNOS; and 7-nitroindazole (7-NI), which is selective for nNOS. Exposure to 2% isoflurane in oxygen produced a triphasic reduction in MAP, including an early phase in which mean arterial pressure (MAP) fell by 25-30% during the initial 2½ min. This early hypotensive response, but not subsequent phases, was abolished by i.v. pretreatment with either L-NMMA or L-NOARG. The early-phase hypotension was also significantly attenuated by i.p. pretreatment with 7-NI; however, the blockade was not as complete as with L-NMMA or L-NOARG. Cerebella and aorta were removed from vehicle- and 7-NI pretreated rats and assayed for NOS activity by determining the conversion of [14C]L-arginine to [14C]L-citrulline. The 7-NI pretreatment significantly reduced NOS activity in the cerebellum but not the aorta. These findings indicate that the early-phase isoflurane-induced hypotension may involve nNOS as well as eNOS. The nNOS may participate in regulation of isoflurane-induced neuronal release of endogenous opioid peptide, which produces a vasodilation that is dependent on NO derived from an action of eNOS. 相似文献
100.
Sebalda C Leshabari Peggy Koniz-Booher Anne N Åstrøm Marina M de Paoli Karen M Moland 《Implementation science : IS》2006,1(1):1-14