排序方式: 共有108条查询结果,搜索用时 31 毫秒
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Aurélie Derré‐Bobillot Naima G. Cortes‐Perez Yuji Yamamoto Pascale Kharrat Elizabeth Couvé Violette Da Cunha Patrice Decker Marie‐Christophe Boissier Frédéric Escartin Bénédicte Cesselin Philippe Langella Luis G. Bermúdez‐Humarán Philippe Gaudu 《Molecular microbiology》2013,89(3):518-531
Most bacteria of the genus Streptococcus are opportunistic pathogens, and some of them produce extracellular DNases, which may be important for virulence. Genome analyses of Streptococcus agalactiae (GBS) neonate isolate NEM316 revealed the presence of seven genes putatively encoding secreted DNases, although their functions, if any, are unknown. In this study, we observed that respiration growth of GBS led to the extracellular accumulation of a putative nuclease, identified as being encoded by the gbs0661 gene. When overproduced in Lactococcus lactis, the protein was found to be a divalent cation‐requiring, pH‐stable and heat‐stable nuclease that we named Nuclease A (NucA). Substitution of the histidine148 by alanine reduced nuclease activity of the GBS wild‐type strain, indicating that NucA is the major nuclease ex vivo. We determined that GBS is able to degrade the DNA matrix comprising the neutrophil extracellular trap (NET). The nucAH148A mutant was impaired for this function, implicating NucA in the virulence of GBS. In vivo infection studies confirmed that NucA is required for full infection, as the mutant strain allowed increased bacterial clearance from lung tissue and decreased mortality in infected mice. These results show that NucA is involved in NET escape and is needed for full virulence. 相似文献
73.
In the cytosol, the sensing of RNA viruses by the RIG-I-like receptors (RLRs) triggers a complex signaling cascade where the mitochondrial antiviral signaling protein (MAVS) plays a crucial role in orchestrating the innate host response through the induction of antiviral and inflammatory responses. Hence, in addition to their known roles in the metabolic processes and the control of programmed cell death, mitochondria are now emerging as a fundamental hub for innate anti-viral immunity. This review summarizes the findings related to the MAVS adapter and mitochondria in the innate immune response to RNA viruses. 相似文献
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Trakatelli M Toungouz M Blocklet D Dodoo Y Gordower L Laporte M Vereecken P Sales F Mortier L Mazouz N Lambermont M Goldman S Coulie P Goldman M Velu T 《Cancer immunology, immunotherapy : CII》2006,55(4):469-474
Dendritic cells derived from monocytes cultured in the presence of type I interferon were found to induce efficient T cell
responses against tumor antigens in vitro. We vaccinated eight stage III or IV melanoma patients with dendritic cells generated
with interferon-β and interleukin-3, activated by poly I: C, and pulsed with the tumor-specific antigen NA17.A2. This dendritic
cell vaccine was well-tolerated with only minor and transient flu-like symptoms and inflammatory reactions at the injection
sites. In most patients, isotopic imaging documented dendritic cells (DC) migration from the intradermal injection site to
the draining lymph nodes. Finally, mixed lymphocyte-peptide culture under limiting dilution conditions followed by tetramer
labeling indicated that three out of eight patients mounted a CD8 T cell response against the NA17.A2 antigenic peptide. We
conclude that DC generated in type I-IFN represent an interesting alternative to DC generated in IL-4 and GM-CSF for cancer
immunotherapy. 相似文献
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Bermúdez-Humarán LG Cortes-Perez NG Ah-Leung S Lefèvre F Yang G Pang Q Wu C Zeng Y Adel-Patient K Langella P 《Journal of molecular microbiology and biotechnology》2008,14(1-3):80-89
The noninvasive and food-grade Gram-positive bacterium Lactococcus lactis is well adapted to deliver medical proteins to the mucosal immune system. In the last decade, the potential of live recombinant lactococci to deliver such proteins to the mucosal immune system has been investigated. This approach offers several advantages over the traditional systemic injection, such as easy administration and the ability to elicit both systemic and mucosal immune responses. This paper reviews the current research and advances made with recombinant L. lactis as live vector for the in situ delivery of biologically active interleukin-12, a potent pleiotropic cytokine with adjuvant properties when co-delivered with vaccinal antigens, at mucosal surfaces. Three well-illustrated examples demonstrate the high potential of interleukin-12-secreting lactococci strains for future prophylactic and therapeutic uses. 相似文献
77.
Bouvrais-Veret C Weiss S Hanoun N Andrieux A Schweitzer A Job D Hamon M Giros B Martres MP 《Journal of neurochemistry》2008,104(3):745-756
The microtubule-associated stable tubule only polypeptide (STOP) protein plays a key-role in neuron architecture and synaptic plasticity. Recent studies suggest that schizophrenia is associated with alterations in the synaptic connectivity. Mice invalidated for the STOP gene display phenotype reminiscent of some schizophrenic-like symptoms, such as behavioral disturbances, dopamine (DA) hyper-reactivity, and possible hypoglutamatergia, partly improved by antipsychotic treatment. In the present work, we examined potential alterations in some DAergic key proteins and behaviors in STOP knockout mice. Whereas the densities of the DA transporter, the vesicular monoamine transporter and the D1 receptor were not modified, the densities of the D2 and D3 receptors were decreased in some DAergic regions in mutant versus wild-type mice. Endogenous DA levels were selectively decreased in DAergic terminals areas, although the in vivo DA synthesis was diminished both in cell bodies and terminal areas. The DA uptake was decreased in accumbic synaptosomes, but not significantly altered in striatal synaptosomes. Finally, STOP knockout mice were hypersensitive to acute and subchronic locomotor effects of cocaine, although the drug equally inhibited DA uptake in mutant and wild-type mice. Altogether, these data showed that deletion of the ubiquitous STOP protein elicited restricted alterations in DAergic neurotransmission, preferentially in the meso-limbic pathway. 相似文献
78.
Lutomski D Imam-Sghiouar N Blondeau K Caron M Joubert-Caron R 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2004,808(1):105-109
The aim of the present work was to develop a highly productive and simplified process for active human galectin-1 (Gal1) production. Gal1 is a beta-galactoside binding lectin that differentially affects biological and cellular functions such as immune surveillance and apoptosis. These effects have attracted the attention of researchers in cell biology, biochemistry and immunology. However, the production of sufficient amounts of recombinant human Gal1 (rhGal1) is needed to study of the effects of Gal1 during cell treatments. To this end, an high-yield expression of rhGal1 was achieved by high-cell density fed-batch cultivation using an exponential glycerol feeding strategy and rhGal1 was purified by a one-step purification scheme using affinity chromatography. 相似文献
79.
New antibacterial peptide derived from bovine hemoglobin 总被引:9,自引:0,他引:9
Daoud R Dubois V Bors-Dodita L Nedjar-Arroume N Krier F Chihib NE Mary P Kouach M Briand G Guillochon D 《Peptides》2005,26(5):713-719
Peptic digestion of bovine hemoglobin at low degree of hydrolysis yields an intermediate peptide fraction exhibiting antibacterial activity against Micrococcus luteus A270, Listeria innocua, Escherichia coli and Salmonella enteritidis after separation by reversed-phase HPLC. From this fraction a pure peptide was isolated and analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). This peptide correspond to the 107-136 fragment of the alpha chain of bovine hemoglobin. The minimum inhibitory concentrations (MIC) towards the four strains and its hemolytic activity towards bovine erythrocytes were determined. A MIC of 38 microM was reported against L. innocua and 76 microM for other various bacterial species. This peptide had no hemolytic activity up to 380 microM concentration. 相似文献