Interactions immunoglobulines-lipides

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Destabilization and fusion of oleic acid-containing vesicles is strikingly accelerated by a specific protein – fc-gamma of igg

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Cationic liposomal lipids: from gene carriers to cell signaling

Cationic lipids are positively charged amphiphilic molecules which, for most of them, form positively charged liposomes, sometimes in combination with a neutral helper lipid. Such liposomes are mainly used as efficient DNA, RNA or protein carriers for gene therapy or immunization trials. Over the past decade, significant progress has been made in the understanding of the cellular pathways and mechanisms involved in lipoplex-mediated gene transfection but the interaction of cationic lipids with cell components and the consequences of such an interaction on cell physiology remains poorly described. The data reported in the present review provide evidence that cationic lipids are not just carriers for molecular delivery into cells but do modify cellular pathways and stimulate immune or anti-inflammatory responses. Considering the wide number of cationic lipids currently available and the variety of cellular components that could be involved, it is likely that only a few cationic lipid-dependent functions have been identified so far. © 2008 Elsevier Ltd. All rights reserved.Journal ArticleResearch Support, Non-U.S. Gov'tReviewinfo:eu-repo/semantics/publishe

Tobacco mosaic virus protein induces fusion of liposome membranes.

The fusogenic properties of tobacco mosaic virus (TMV) coat protein were investigated. Tobacco mosaic virus protein induces membrane fusion of a population of L-alpha-dimyristoylphosphatidylcholine (DMPC) and DL-alpha-dipalmitoylphosphatidylcholine (DPPC) vesicles giving rise to larger particles as seen by a drastic absorbance increase of the liposomal solution. Differential scanning calorimetry spectra demonstrate complete mixing of the acyl chains of the lipids during fusion. Electron micrographs indicate that the fused entities are multilamellar.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Cationic lipids activate intracellular signaling pathways.

Cationic liposomes are commonly used as a transfection reagent for DNA, RNA or proteins and as a co-adjuvant of antigens for vaccination trials. A high density of positive charges close to cell surface is likely to be recognized as a signal of danger by cells or contribute to trigger cascades that are classically activated by endogenous cationic compounds. The present review provides evidence that cationic liposomes activate several cellular pathways like pro-apoptotic and pro-inflammatory cascades. An improved knowledge of the relationship between the cationic lipid properties (nature of the lipid hydrophilic moieties, hydrocarbon tail, mode of organization) and the activation of these pathways opens the way to the use and design of cationic tailored for a specific application (e.g. for gene transport or as adjuvants).JOURNAL ARTICLESCOPUS: re.jinfo:eu-repo/semantics/publishe

Fc gamma of IgG: a specific agent of destabilization of lipid bilayers containing oleic acid.

gamma-Immunoglobulins induce the fusion of oleic acid-containing liposomes into tubular structures. An F(ab')2 preparation does not exert the same influence unless it is several orders of magnitude more concentrated. The same is true for several proteins with an isoelectric point higher or lower than the IgG isoelectric point. The Fc of IgG seems thus to exert a specific destabilizing and fusogenic action on artificial lipid membranes. An hypothesis is presented concerning the mode of action of Fc gamma on lymphocyte membrane which is based on the facts mentioned above and on the existence of a phospholipasic activity of Fc gamma membrane receptor.Journal Articleinfo:eu-repo/semantics/publishe

Thermotropic properties of dipalmitoyl phosphatidyl choline stearylamine liposomes

Fluorescence polarization and differential scanning calorimetry measurements made on dipalmitoyl phosphatidyl choline-stearylamine mixed liposomes show striking changes in the biophysical properties of these vesicles. The liposomes formed have transition temperature largely shifted to higher temperature and evolve to larger structure. These results strongly suggest that the alteration of liposomal structures due to the incorporation of lipid soluble compound like drugs requires physico-chemical studies before any screening with liposomes as pharmacological capsules. © 1982 The Italian Pharmacological Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Mistargeted MRPdeltaF728 mutant is rescued by intracellular GSH.

The most common cystic fibrosis-causing mutation is the deletion of the widely conserved phenylalanine 508 (DeltaF508) of CFTR. The mutant is unable to fold correctly and to transit to the plasma membrane. MRP1 belongs to the same subfamily of ABC proteins as CFTR and confers resistance to a wide range of chemotherapeutic drugs. By analogy, phenylalanine 728 was deleted in MRP1. Our results shown that MRPDeltaF728 is correctly targeted to the plasma membrane, actively transports doxorubicin (DOX) and vincristine (VCR) and shares a structure identical to MRP1. Intracellular GSH depletion however results in a mistargeted mutant that is retained into the cytoplasm, while in the same conditions wild-type MRP1 is correctly routed to the plasma membrane. The GSH-protein complex could adopt a stable conformation protected against proteolytic degradation and correctly targeted to the plasma membrane.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Reconstitution of HIV envelopes

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