Publications by authors named "Le Bihan T"

Article Synopsis
  • The study focuses on the antibody response to the Moderna Spikevax COVID-19 vaccine, highlighting the importance of understanding this immune response to pathogens.
  • It introduces a new method that combines mass spectrometry and B-cell sequencing to analyze human plasma-derived polyclonal IgG, addressing limitations in traditional B-cell repertoire sequencing.
  • The researchers created 12 recombinant antibodies from their sequencing data, with six showing strong binding affinities and neutralizing capabilities against the target antigen.
View Article and Find Full Text PDF
Article Synopsis
  • The study discusses a new labeling strategy for improving peptide detection in mass spectrometry by modifying peptides at their C-terminal and specific amino acids (Aspartic and Glutamic acid) with arginine methyl ester (R-met).
  • This modification enhances peptide fragmentation and helps distinguish isobaric ambiguities, which can complicate protein sequencing.
  • The approach is tested across various proteins and proteases, demonstrating its effectiveness in producing clearer mass spectrometry results, particularly when focusing on charge states of +2 or higher for better fragmentation.
View Article and Find Full Text PDF

Diel regulation of protein levels and protein modification had been less studied than transcript rhythms. Here, we compare transcriptome data under light-dark cycles with partial proteome and phosphoproteome data, assayed using shotgun MS, from the alga Ostreococcus tauri, the smallest free-living eukaryote. A total of 10% of quantified proteins but two-thirds of phosphoproteins were rhythmic.

View Article and Find Full Text PDF

Next-generation sequencing (NGS) has revolutionized the way we determine the antibody repertoires encoded by B cells in the blood or lymphoid organs and transformed our understanding of adaptive immune responses in many species. Sheep (Ovis aries) have been widely used as a host for therapeutic antibody production since the early 1980s, however, little is known about their immune repertoires or immunological processes affecting the antibody generation. The objective of this study was to employ NGS for a comprehensive analysis of immunoglobulin heavy and light chain repertoires in four healthy sheep.

View Article and Find Full Text PDF

Impaired hepatic glucose and lipid metabolism are hallmarks of type 2 diabetes. Increased sulfide production or sulfide donor compounds may beneficially regulate hepatic metabolism. Disposal of sulfide through the sulfide oxidation pathway (SOP) is critical for maintaining sulfide within a safe physiological range.

View Article and Find Full Text PDF

Twenty-four-hour, circadian rhythms control many eukaryotic mRNA levels, whereas the levels of their more stable proteins are not expected to reflect the RNA rhythms, emphasizing the need to test the circadian regulation of protein abundance and modification. Here we present circadian proteomic and phosphoproteomic time series from Arabidopsis thaliana plants under constant light conditions, estimating that just 0.4% of quantified proteins but a much larger proportion of quantified phospho-sites were rhythmic.

View Article and Find Full Text PDF

Herein we present the preparation of two novel cyclam-based macrocycles ( and ), bearing phosphonate-appended pyridine side arms for the coordination of copper(II) ions in the context of Cu PET imaging. The two ligands have been prepared through conventional protection-alkylation sequences on cyclam, and their coordination properties have been thoroughly investigated. The corresponding copper complexes have been fully characterized in the solid state (X-ray diffraction analysis) and in solution (EPR and UV-vis spectroscopies).

View Article and Find Full Text PDF

An improved glucose-chelator-albumin bioconjugate (GluCAB) derivative, GluCAB-2 , has been synthesized and studied for in vivo Cu-PET/CT imaging in breast cancer mice models together with its first-generation analogue GluCAB-1 . The radioligand works on the principle of tumor targeting through the enhanced permeability and retention (EPR) effect with a supportive role played by glucose metabolism. [ Cu]Cu-GluCAB-2 (99 % RCP) exhibited high serum stability with immediate binding to serum proteins.

View Article and Find Full Text PDF

Marine phytoplankton, comprising cyanobacteria, micro- and pico-algae are key to photosynthesis, oxygen production and carbon assimilation on Earth. The unicellular green picoalga holds a key position at the base of the green lineage of plants, which makes it an interesting model organism. has adapted to survive in low levels of nitrogen and phosphorus in the open ocean and also during rapid changes in the levels of these nutrients in coastal waters.

View Article and Find Full Text PDF
Article Synopsis
  • Oncogenic mutations like KRAS significantly alter protein-protein interaction networks (PPINs), particularly affecting the Epidermal Growth Factor Receptor (EGFR) network in colorectal cancer (CRC) cells.
  • Research shows that over 6000 interactions are modified in cells with KRAS mutations, influenced by factors such as protein expression changes and phosphorylation.
  • These alterations in PPIN structure impact protein complexes, signal flow, and gene regulation, and are linked to poor patient prognosis in CRC due to frequent genetic changes in key network components.
View Article and Find Full Text PDF

Following the successful synthesis of a -functionalized version of the TE1PA ligand, a monopicolinate cyclam, we looked to demonstrate its in vivo properties versus DOTA and NOTA, after conjugation on the 9E7.4 rat antibody, an IgG against CD138 murine, which has relevant properties for multiple myeloma targeting. For each ligand, different conjugation approaches had been considered to select the most appropriate for the comparative study.

View Article and Find Full Text PDF

SUMOylation, the covalent attachment of the small ubiquitin-like modifier (SUMO) to target proteins, is emerging as a key modulator of eukaryotic immune function. In plants, a SUMO1/2-dependent process has been proposed to control the deployment of host defense responses. The molecular mechanism underpinning this activity remains to be determined, however.

View Article and Find Full Text PDF

Platinum and palladium are much sought-after metals of critical global importance in terms of abundance and availability. At the nano-scale these metals are of even higher value due to their catalytic abilities for industrial applications. is able to capture ionic forms of both of these metals, reduce them and synthesize elemental nanoparticles.

View Article and Find Full Text PDF

The malaria mosquito, Anopheles stephensi, and other mosquitoes modulate their biology to match the time-of-day. In the present work, we used a non-hypothesis driven approach (untargeted proteomics) to identify proteins in mosquito tissue, and then quantified the relative abundance of the identified proteins from An. stephensi bodies.

View Article and Find Full Text PDF

Phosphorylation events are important during cellular function. Analysis of phosphorylation in complex samples has been extensively studied using large-scale phosphopeptide enrichment methods. Quantitative analysis of the enriched phosphopeptides is subsequently performed using label-based methodologies (e.

View Article and Find Full Text PDF

The plant-specific protein GIGANTEA (GI) controls many developmental and physiological processes, mediating rhythmic post-translational regulation. GI physically binds several proteins implicated in the circadian clock, photoperiodic flowering, and abiotic stress responses. To understand GI's multifaceted function, we aimed to comprehensively and quantitatively identify potential interactors of GI in a time-specific manner, using proteomics on Arabidopsis plants expressing epitope-tagged GI.

View Article and Find Full Text PDF

We show here that the M2 isoform of human pyruvate kinase (M2PYK) is susceptible to nitrosation and oxidation, and that these modifications regulate enzyme activity by preventing the formation of the active tetrameric form. The biotin-switch assay carried out on M1 and M2 isoforms showed that M2PYK is sensitive to nitrosation and that Cys326 is highly susceptible to redox modification. Structural and enzymatic studies have been carried out on point mutants for three cysteine residues (Cys424, Cys358, and Cys326) to characterise their potential roles in redox regulation.

View Article and Find Full Text PDF

In view of the excellent copper(ii) and 64-copper(ii) complexation of a TE1PA ligand, a monopicolinate cyclam, in both aqueous medium and in vivo, we looked for a way to make it bifunctional, while maintaining its chelating properties. Overcoming the already known drawback of grafting via its carboxyl group, which is essential to the overall properties of the ligand, a TE1PA bifunctional derivative bearing an additional isothiocyanate coupling function on a carbon atom of the macrocyclic ring was synthesized. This led to an architecture that is comparable to that of other commercially available bifunctional copper(ii) chelators such as p-SCN-Bn-DOTA already used in clinical trials for 64Cu-immuno-PET imaging.

View Article and Find Full Text PDF

In plants, the circadian clock regulates the expression of one-third of all transcripts and is crucial to virtually every aspect of metabolism and growth. We now establish sumoylation, a posttranslational protein modification, as a novel regulator of the key clock protein CCA1 in the model plant Arabidopsis. Dynamic sumoylation of CCA1 is observed in planta and confirmed in a heterologous expression system.

View Article and Find Full Text PDF

Helminth parasites defy immune exclusion through sophisticated evasion mechanisms, including activation of host immunosuppressive regulatory T (Treg) cells. The mouse parasite Heligmosomoides polygyrus can expand the host Treg population by secreting products that activate TGF-β signalling, but the identity of the active molecule is unknown. Here we identify an H.

View Article and Find Full Text PDF

The decision between T cell activation and tolerance is governed by the spatial and temporal integration of diverse molecular signals and events occurring downstream of TCR and costimulatory or coinhibitory receptor engagement. The PI3K-protein kinase B (PKB; also known as Akt) signaling pathway is a central axis in mediating proximal signaling events of TCR and CD28 engagement in T cells. Perturbation of the PI3K-PKB pathway, or the loss of negative regulators of T cell activation, such as the E3 ubiquitin ligase Cbl-b, have been reported to lead to increased susceptibility to autoimmunity.

View Article and Find Full Text PDF

Infection by helminth parasites is associated with amelioration of allergic reactivity, but mechanistic insights into this association are lacking. Products secreted by the mouse parasite Heligmosomoides polygyrus suppress type 2 (allergic) immune responses through interference in the interleukin-33 (IL-33) pathway. Here, we identified H.

View Article and Find Full Text PDF

Cellular accumulation of reactive oxygen species (ROS) is associated with a wide range of developmental and stress responses. Although cells have evolved to use ROS as signaling molecules, their chemically reactive nature also poses a threat. Antioxidant systems are required to detoxify ROS and prevent cellular damage, but little is known about how these systems manage to function in hostile, ROS-rich environments.

View Article and Find Full Text PDF

Although correlation network studies from co-expression analysis are increasingly popular, they are rarely applied to proteomics datasets. Protein co-expression analysis provides a complementary view of underlying trends, which can be overlooked by conventional data analysis. The core of the present study is based on Weighted Gene Co-expression Network Analysis applied to a glioblastoma multiforme proteomic dataset.

View Article and Find Full Text PDF