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1.
Mona El Agoze Marylène Poirié Georges Périquet 《Entomologia Experimentalis et Applicata》1995,75(3):251-255
In most insect species where double matings occur, sperm from the second male preferentially fertilize subsequent eggs. However,
we demonstrate here that, as already shown for some other hymenopteran species, this is not the case in the ichneumonid waspDiadromus pulchellus (Wesmeal): sperm from the first male usually father all the female progeny. This precedence of the first male sperm is also
observed in double matings involving an haploid male and a diploid sterile male, whichever is the first mating male. We discuss
the consequences of this phenomenon from an evolutionary point of view. 相似文献
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Lengagne R Pommier A Caron J Douguet L Garcette M Kato M Avril MF Abastado JP Bercovici N Lucas B Prévost-Blondel A 《PloS one》2011,6(5):e20235
Tumors affect myelopoeisis and induce the expansion of myeloid cells with immunosuppressive activity. In the MT/ret model of spontaneous metastatic melanoma, myeloid cells are the most abundant tumor infiltrating hematopoietic population and their proportion is highest in the most aggressive cutaneous metastasis. Our data suggest that the tumor microenvironment favors polarization of myeloid cells into type 2 cells characterized by F4/80 expression, a weak capacity to secrete IL-12 and a high production of arginase. Myeloid cells from tumor and spleen of MT/ret mice inhibit T cell proliferation and IFNγ secretion. Interestingly, T cells play a role in type 2 polarization of myeloid cells. Indeed, intra-tumoral myeloid cells from MT/ret mice lacking T cells are not only less suppressive towards T cells than corresponding cells from wild-type MT/ret mice, but they also inhibit more efficiently melanoma cell proliferation. Thus, our data support the existence of a vicious circle, in which T cells may favor cancer development by establishing an environment that is likely to skew myeloid cell immunity toward a tumor promoting response that, in turn, suppresses immune effector cell functions. 相似文献
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Chappert P Leboeuf M Rameau P Stockholm D Liblau R Danos O Davoust JM Gross DA 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(1):327-334
Foxp3+ regulatory T cells (Tregs) play a pivotal role in the maintenance of peripheral T cell tolerance and are thought to interact with dendritic cells (DC) in secondary lymphoid organs. We analyzed here the in vivo requirements for selective expansion of Ag-specific Treg vs CD4+CD25- effector T cells and engagement of Ag-specific Treg-DC interactions in secondary lymphoid organs. Using i.v. Ag delivery in the absence of inflammation, we found that CD4+CD25+Foxp3+ Tregs undergo vigorous expansion and accumulate whereas naive CD4+CD25-Foxp3- T cells undergo abortive activation. Quantifying directly the interactions between Tregs and CD11c+ DC, we found that Tregs establish cognate contacts with endogenous CD11c+ DC in spleen and lymph nodes at an early time point preceding their expansion. Importantly, we observed that as few as 10(3) Tregs selectively expanded by i.v. Ag injection are able to suppress B and T cell immune responses in mouse recipients challenged with the Ag. Our results demonstrate that Tregs are selectively mobilized by Ag recognition in the absence of inflammatory signals, and can induce thereafter potent tolerance to defined Ag targets. 相似文献
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Lengagne R Graff-Dubois S Garcette M Renia L Kato M Guillet JG Engelhard VH Avril MF Abastado JP Prévost-Blondel A 《Journal of immunology (Baltimore, Md. : 1950)》2008,180(1):130-137
The growth of immunogenic tumors in immunocompetent individuals is one of the oldest conundrums in tumor immunology. Although the ability of mouse CD8+ T cells to control transplanted tumors is well documented, little is known about their impact on autochthonous tumors. To gain insight into the role of CD8+ T cells during the course of cancer development, we produced a novel model of spontaneous melanoma. The metallothionein (MT)-ret/AAD mouse is transgenic for the RET oncogene and the chimeric MHC molecule AAD (alpha1-alpha2 domains of HLA-A2 linked to alpha3 domain of H2-Dd). This model recapitulates the natural history of human melanoma, and expression of the AAD molecule makes it suitable for analyzing CD8+ T cell responses directed against peptide Ags that have been previously identified in HLA-A2+ melanoma patients. We found that, as tumors grow, mice develop a broad melanoma-specific CD8+ T cell response. Occurrence of cutaneous nodules is not affected by CD8+ T cell depletion, showing that although CD8+ T cells are functional, they have no effect on established cutaneous tumors. However, depleted mice die from visceral disease much earlier than controls, showing that CD8+ T cells control metastasis spreading and disease progression. Antigenic modulation is observed in visceral metastases, suggesting that visceral nodules may be subject to immunoediting. Our data demonstrate that growth of melanoma in the MT-ret/AAD model involves several tolerance mechanisms sequentially. They also reveal a different role for CD8+ T cells toward early stage of cutaneous tumors and late visceral metastatic stage of the disease. 相似文献
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Nucleocapsid mutations turn HIV-1 into a DNA-containing virus 总被引:2,自引:1,他引:1
Houzet L Morichaud Z Didierlaurent L Muriaux D Darlix JL Mougel M 《Nucleic acids research》2008,36(7):2311-2319
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Marylène Fortin Hélène D'Anjou Marie-ève Higgins Jasmine Gougeon Paméla Aubé Kamel Moktefi Sonia Mouissi Serge Séguin Rosanne Séguin Paolo M Renzi Luc Paquet Nicolay Ferrari 《Respiratory research》2009,10(1):39
Background
Recent development in the field of COPD has focused on strategies aimed at reducing the underlying inflammation through selective inhibition of the phosphodiesterase type IV (PDE4) isoform. Although the anti-inflammatory and bronchodilator activity of selective PDE4 inhibitors has been well documented, their low therapeutic ratio and dose-dependent systemic side effects have limited their clinical utility. This study examined the effect of 2''-deoxy-2''-Fluoro-β-D-Arabinonucleic Acid (FANA)-containing antisense oligonucleotides (AON) targeting the mRNA for the PDE4B/4D and 7A subtypes on lung inflammatory markers, both in vitro and in vivo.Methods
Normal human bronchial epithelial (NHBE) cells were transfected with FANA AON against PDE4B/4D and 7A alone or in combination. mRNA levels for target PDE subtypes, as well as secretion of pro-inflammatory chemokines were then measured following cell stimulation. Mice were treated with combined PDE4B/4D and 7A AON via endo-tracheal delivery, or with roflumilast via oral delivery, and exposed to cigarette smoke for one week. Target mRNA inhibition, as well as influx of inflammatory cells and mediators were measured in lung lavages. A two-week smoke exposure protocol was also used to test the longer term potency of PDE4B/4D and 7A AONs.Results
In NHBE cells, PDE4B/4D and 7A AONs dose-dependently and specifically inhibited expression of their respective target mRNA. When used in combination, PDE4B/4D and 7A AONs significantly abrogated the cytokine-induced secretion of IL-8 and MCP-1 to near baseline levels. In mice treated with combined PDE4B/4D and 7A AONs and exposed to cigarette smoke, significant protection against the smoke-induced recruitment of neutrophils and production of KC and pro-MMP-9 was obtained, which was correlated with inhibition of target mRNA in cells from lung lavages. In this model, PDE AONs exerted more potent and broader anti-inflammatory effects against smoke-induced lung inflammation than roflumilast. Moreover, the protective effect of PDE4B/4D and 7A AON was maintained when a once-weekly treatment schedule was used.Conclusion
These results indicate that inhaled AON against PDE4B/4D and 7A have unique effects on biomarkers that are believed to be important in the pathophysiology of COPD, which supports further development as a potential therapy in this disease. 相似文献9.
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Emilie Chevalier Marylène Viana Aymeric Artaud Lisette Chomette Samir Haddouchi Gille Devidts Dominique Chulia 《AAPS PharmSciTech》2009,10(2):597-605
Porous calcium phosphate pellets were produced according to two granulation processes (low and high shear wet granulations)
and drug loaded with five ibuprofen contents (1.75%, 7%, 12.5%, 22%, and 36%) in order to ensure both bone defect filling
and local drug delivery. The drug-release kinetics from the two types of pellets was studied using three dissolution apparatuses:
paddle apparatus, reciprocating cylinder, and flow-through cell. The paper compared the three dissolution methods and considered
the effect of the granulation process on the ibuprofen-release kinetics. Dissolution data were analyzed using the Weibull
function as well as the difference (f1) and similarity (f2) factors. Dissolution kinetics was not influenced by the granulation
process, regardless of the dissolution apparatus and of the drug content. The comparison of the three dissolution devices
indicated that ibuprofen was released faster from granules loaded with 36% of drug content with the reciprocating apparatus,
due to the disintegration of the granules occurring during the dissolution test. For the other drug contents, dissolution
profiles were not significantly different from one apparatus to another. However, the flow-through cell seemed to be more
suitable for the drug-release study of implantable materials. 相似文献