Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Gabrielle Zeder-Lutz is active.

Publication


Featured researches published by Gabrielle Zeder-Lutz.


Journal of Experimental Medicine | 2002

Arthritogenic Monoclonal Antibodies from K/BxN Mice

Mariana Maccioni; Gabrielle Zeder-Lutz; Haochu Huang; Claudine Ebel; Philippe Gerber; Josiane Hergueux; Patricia Marchal; Véronique Duchatelle; Claude Degott; Marc H.V. Van Regenmortel; Christophe Benoist; Diane Mathis

Arthritis in the K/BxN mouse model is provoked by pathogenic antibodies (Abs) directed against a ubiquitously expressed protein, glucose-6-phosphate isomerase (GPI). To begin dissecting the repertoire of arthritogenic immunoglobulins (Igs) in the K/BxN model, and to provide a basis for comparison with RA patientswe have generated anti-GPI monoclonal Abs (mAbs) from spontaneously activated B cells in the lymphoid organs of arthritic mice. B cell clones with anti-GPI specificities were present at extraordinarily high frequencies in the spleen, and less frequently in other lymphoid organs and in the synovial fluid. None of the anti-GPI mAbs induced arthritis when injected individually into healthy recipients, but most were effective when combined in pairs or larger pools. Arthritogenic combinations depended on mAbs of the IgG1 isotype, which bound to GPI with Kd in the 10−9 M range, with no indication of cooperative binding between complementing pairs. Pathogenicity was not associated with recognition of a particular epitope, but the ability to form mAb/GPI multimers by simultaneous recognition of different epitopes was clearly required, consistent with the known role of complement and FcRs in this model. Sequence analysis revealed structural similarities amongst the mAbs, indicating that a particular subset of B cells may evade tolerance in K/BxN mice, and that affinity maturation by somatic mutation likely takes place. These results confirm that GPI itself, rather than a cross-reactive molecule, is the target of pathogenic Igs.


Journal of Structural and Functional Genomics | 2007

Structural genomics on membrane proteins: comparison of more than 100 GPCRs in 3 expression systems.

Kenneth Lundstrom; Renaud Wagner; Christoph Reinhart; Aline Desmyter; Nadia Cherouati; Thierry Magnin; Gabrielle Zeder-Lutz; Melanie Courtot; Cécile Prual; Nicolas André; Ghérici Hassaïne; Hartmut Michel; Christian Cambillau; Franc Pattus

Production of recombinant receptors has been one of the major bottlenecks in structural biology on G protein-coupled receptors (GPCRs). The MePNet (Membrane Protein Network) was established to overexpress a large number of GPCRs in three major expression systems, based on Escherichia coli, Pichia pastoris and Semliki Forest virus (SFV) vectors. Evaluation by immunodetection demonstrated that 50% of a total of 103 GPCRs were expressed in bacterial inclusion bodies, 94% in yeast cell membranes and 95% in SFV-infected mammalian cells. The expression levels varied from low to high and the various GPCR families and subtypes were analyzed for their expressability in each expression system. More than 60% of the GPCRs were expressed at milligram levels or higher in one or several systems, compatible to structural biology applications. Functional activity was determined by binding assays in yeast and mammalian cells and the correlation between immunodetection and binding activity was analyzed.


Journal of Immunology | 2006

Cutting Edge: Monovalency of CD28 Maintains the Antigen Dependence of T Cell Costimulatory Responses

Kevin M. Dennehy; Fernando Elias; Gabrielle Zeder-Lutz; Xin Ding; Danièle Altschuh; Fred Lühder; Thomas Hünig

CD28 and CTLA-4 are the major costimulatory receptors on naive T cells. But it is not clear why CD28 is monovalent whereas CTLA-4 is bivalent for their shared ligands CD80/86. We generated bivalent CD28 constructs by fusing the extracellular domains of CTLA-4 or CD80 with the intracellular domains of CD28. Bivalent or monovalent CD28 constructs were ligated with recombinant ligands with or without TCR coligation. Monovalent CD28 ligation did not induce responses unless the TCR was coligated. By contrast, bivalent CD28 ligation induced responses in the absence of TCR engagement. To extend these findings to primary cells, we used novel superagonistic and conventional CD28 Abs. Superagonistic Ab D665, but not conventional Ab E18, predominantly ligates CD28 bivalently at low CD28/Ab ratios and induces Ag-independent T cell proliferation. Monovalency of CD28 for its natural ligands is thus essential to provide costimulation without inducing responses in the absence of TCR engagement.


Molecular Immunology | 1993

Monoclonal antipeptide antibodies: Affinity and kinetic rate constants measured for the peptide and the cognate protein using a biosensor technology

Gabrielle Zeder-Lutz; Danièle Altschuh; H. Mario Geysen; Elisabeth Trifilieff; G. Sommermeyer; Marc H.V. Van Regenmortel

The interaction of antipeptide antibodies with the corresponding peptide and the cognate protein has been compared using a novel biosensor technology (BIAcore, Pharmacia). The peptide corresponds to residues 110-135 of the coat protein of tobacco mosaic virus, known to encompass an alpha-helical region reactive with antiprotein antibodies. A panel of 33 monoclonal antibodies raised against the peptide was studied and the epitope recognized by these antibodies was determined by the pepscan method. Further discrimination between the antibodies was performed by measurements of association and dissociation kinetic constants. Several antibodies showed an heterogeneous binding profile when reacting with the 25 residue long peptide but not with a shorter 10 residue peptide suggesting that they recognized different conformational states in the longer peptide. Equilibrium affinity constants were calculated for five of the antibodies and were found to be 10-50 times higher for the peptide than for the protein, the difference being caused mainly by a lower association rate constant.


Journal of Bacteriology | 2008

The Metal Dependence of Pyoverdine Interactions with Its Outer Membrane Receptor FpvA

Jason Greenwald; Gabrielle Zeder-Lutz; Agnès Hagege; Hervé Celia; Franc Pattus

To acquire iron, Pseudomonas aeruginosa secretes the fluorescent siderophore pyoverdine (Pvd), which chelates iron and shuttles it into the cells via the specific outer membrane transporter FpvA. We studied the role of iron and other metals in the binding and transport of Pvd by FpvA and conclude that there is no significant affinity between FpvA and metal-free Pvd. We found that the fluorescent in vivo complex of iron-free FpvA-Pvd is in fact a complex with aluminum (FpvA-Pvd-Al) formed from trace aluminum in the growth medium. When Pseudomonas aeruginosa was cultured in a medium that had been treated with a metal affinity resin, the in vivo formation of the FpvA-Pvd complex and the recycling of Pvd on FpvA were nearly abolished. The accumulation of Pvd in the periplasm of Pseudomonas aeruginosa was also reduced in the treated growth medium, while the addition of 1 microM AlCl(3) to the treated medium restored the effects of trace metals observed in standard growth medium. Using fluorescent resonance energy transfer and surface plasmon resonance techniques, the in vitro interactions between Pvd and detergent-solubilized FpvA were also shown to be metal dependent. We demonstrated that FpvA binds Pvd-Fe but not Pvd and that Pvd did not compete with Pvd-Fe for FpvA binding. In light of our finding that the Pvd-Al complex is transported across the outer membrane of Pseudomonas aeruginosa, a model for siderophore recognition based on a metal-induced conformation followed by redox selectivity for iron is discussed.


Molecular Cancer Therapeutics | 2007

Suppression of cervical carcinoma cell growth by intracytoplasmic codelivery of anti-oncoprotein E6 antibody and small interfering RNA.

Jérôme Courtête; Annie-Paule Sibler; Gabrielle Zeder-Lutz; Deniz Dalkara; Mustapha Oulad-Abdelghani; Guy Zuber; Etienne Weiss

Cervical cancer is caused by high-risk types of human papillomaviruses (HPV) that encode the E6 and E7 oncogenes. Silencing of E6 gene expression in HPV-positive cell lines by transfection of small interfering RNA (siRNA) with cationic lipids restores the dormant p53 tumor suppressor pathway. Because cationic lipids can also be used for intracytoplasmic delivery of proteins, we tested whether the delivery of monoclonal antibodies that bind to HPV16 E6 and neutralize its biological activity in vitro could restore p53 function in tumor cells. Here, we show that the 4C6 antibody is efficiently delivered into the cell cytoplasm using a lipidic reagent used for siRNA transfection. The delivery of 4C6 resulted in the nuclear accumulation of p53 protein in CaSki and SiHa cells but not in HeLa cells. Furthermore, the antibody-mediated p53 response was dramatically increased when a peptide corresponding to the 4C6 epitope and bearing a COOH-terminal cysteine residue was added to the transduction mixture. We found that a fraction of the added peptides were dimers that allowed the formation of antibody polymers adsorbed onto the lipidic matrix. With this system, the proliferation of CaSki and SiHa cells was strongly diminished, but no apoptosis was detectable. Remarkably, cell growth was almost totally suppressed by the addition of E6-specific siRNA to the transduction complex. The results indicate that the activity of E6 oncoprotein can be down-regulated in vivo by lipid-mediated antibody delivery and that antibodies and siRNA act synergistically when codelivered. This novel targeting strategy is simple to implement and may find therapeutic applications. [Mol Cancer Ther 2007;16(5):1728–35]


Journal of Molecular Recognition | 1999

Active concentration measurements of recombinant biomolecules using biosensor technology

Gabrielle Zeder-Lutz; Antoni Benito; M.H.V. Van Regenmortel

Whereas the concentration of a biomolecule simply refers to the amount of chemical substance per unit of volume, its active concentration refers to a relational parameter that has meaning only with respect to the molecules ability to interact specifically with one particular ligand. When proteins are studied in a biological context, it is the biologically active concentration that is relevant, and not the total concentration of correctly and incorrectly folded molecules. Using a biosensor instrument the concentration of active biomolecules in a preparation can be measured by injecting the preparation at different flow rates onto a sensor chip surface presenting a high concentration of a specific ligand. The method can be used under conditions of partial mass transport limitation and does not require a pre‐established standard curve. When the method was used to measure the active concentration of several recombinant proteins it was found that the active concentration was much lower than the nominal concentration determined by conventional methods. The active concentration also depended on the ligand used in the binding assay, reflecting the fact that active concentration can only be defined with respect to one specific probe. Such discrepancies in concentration values, if undetected, may lead to erroneous conclusions regarding the properties and behaviour of recombinant proteins tested in different assays. Copyright


Journal of Bacteriology | 2006

Interaction of TonB with the Outer Membrane Receptor FpvA of Pseudomonas aeruginosa

Hendrik Adams; Gabrielle Zeder-Lutz; Isabelle J. Schalk; Franc Pattus; Hervé Celia

Pyoverdine-mediated iron uptake by the FpvA receptor in the outer membrane of Pseudomonas aeruginosa is dependent on the inner membrane protein TonB1. This energy transducer couples the proton-electrochemical potential of the inner membrane to the transport event. To shed more light upon this process, a recombinant TonB1 protein lacking the N-terminal inner membrane anchor (TonB(pp)) was constructed. This protein was, after expression in Escherichia coli, purified from the soluble fraction of lysed cells by means of an N-terminal hexahistidine or glutathione S-transferase (GST) tag. Purified GST-TonB(pp) was able to capture detergent-solubilized FpvA, regardless of the presence of pyoverdine or pyoverdine-Fe. Targeting of the TonB1 fragment to the periplasm of P. aeruginosa inhibited the transport of ferric pyoverdine by FpvA in vivo, indicating an interference with endogenous TonB1, presumably caused by competition for binding sites at the transporter or by formation of nonfunctional TonB heterodimers. Surface plasmon resonance experiments demonstrated that the FpvA-TonB(pp) interactions have apparent affinities in the micromolar range. The binding of pyoverdine or ferric pyoverdine to FpvA did not modulate this affinity. Apparently, the presence of either iron or pyoverdine is not essential for the formation of the FpvA-TonB complex in vitro.


Journal of Immunological Methods | 1994

Cross-reactivity of monoclonal antibodies to a chimeric V3 peptide of HIV-1 with peptide analogues studied by biosensor technology and ELISA.

Pascale M. Richalet-Sécordel; Gabrielle Zeder-Lutz; Serge Plaue; Ghislaine Sommermeyer-Leroux; Marc H.V. Van Regenmortel

The reactivity of monoclonal antibodies (Mabs) raised against a cyclic peptide representing a chimeric V3 loop of HIV-1 gp120 with different peptide analogues was studied with a biosensor system (BIAcore) and by ELISA. In both assays, the Mabs cross-reacted extensively with the V3 regions of different HIV-1 strains and recognized the cyclic form of the peptide immunogen better than its linear form. The highest degree of cross-reactivity was observed with peptides that shared a Lys312 with the chimeric sequence. Dissociation rate constants of ten Mabs measured with the BIAcore with respect to different peptides increased with increasing numbers of substitutions in the flanking regions of the V3 tip sequence Gly Pro Gly Arg. Immobilization of the cyclic peptide on the sensor chip via a thiol group added near the end of the loop structure preserved the conformation of the peptide. In view of the good correlation between the BIAcore and ELISA results, biosensor data should be useful for selecting peptides to be used in diagnostic solid phase assays.


FEBS Letters | 1993

Interaction of cyclosporin A with an Fab fragment or cyclophilin. Affinity measurements and time-dependent changes in binding.

Gabrielle Zeder-Lutz; Roland H. Wenger; Marc H.V. Van Regenmortel; Danièle Altschuh

Different conformers of the immunosuppressant cyclosporin A have been observed in structural studies of the isolated molecule and of its complex with cyclophilin or with an Fab fragment. The factors that control this conformational change are not well understood. Variations in the amount of complex formed with cyclophilin or with the antibody were measured as a function of time after adding cyclosporin to the proteins, using the Pharmacia BIAcore biosensor instrument. Up to 1 hour was needed to reach maximum complex formation in solution, which is likely to reflect the time needed for a conformational transition of cyclosporin. The equilibrium affinity constant of both proteins for cyclosporin has been measured.

Collaboration


Dive into the Gabrielle Zeder-Lutz's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Marc H.V. Van Regenmortel

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

Franc Pattus

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

M.H.V. Van Regenmortel

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

Hervé Celia

École Normale Supérieure

View shared research outputs
Top Co-Authors

Avatar

Laurence Choulier

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

Nadia Cherouati

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

Pascale M. Richalet-Sécordel

Centre national de la recherche scientifique

View shared research outputs
Top Co-Authors

Avatar

Etienne Weiss

University of Strasbourg

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge