Chitinase-like proteins promote IL-17-mediated neutrophilia in a tradeoff between nematode killing and host damage

Enzymatically inactive chitinase-like proteins (CLPs) such as BRP-39, Ym1 and Ym2 are established markers of immune activation and pathology, yet their functions are essentially unknown. We found that Ym1 and Ym2 induced the accumulation of neutrophils through the expansion of γδ T cell populations that produced interleukin 17 (IL-17). While BRP-39 did not influence neutrophilia, it was required for IL-17 production in γδ T cells, which suggested that regulation of IL-17 is an inherent feature of mouse CLPs. Analysis of a nematode infection model, in which the parasite migrates through the lungs, revealed that the IL-17 and neutrophilic inflammation induced by Ym1 limited parasite survival but at the cost of enhanced lung injury. Our studies describe effector functions of CLPs consistent with innate host defense traits of the chitinase family

Influence of DNA condensation state on transfection efficiency in DNA/polymer complexes: An AFM and DLS comparative study

peer reviewedaudience: professionalAtomic force microscopy (AFM) is used to describe the formation process of polymer/DNA complexes. Two main objectives of this research are presented. The first one is to apply AFM as an effective tool to analyse DNA molecules and different polycation/DNA complexes in order to evaluate their degree of condensation (size and shape). The other one is to search for a relationship between the condensation state of DNA and its transfection efficiency. In this study, linear methacrylate based polymers and globular SuperFect polymers are used in order to induce DNA condensation. Ternary complexes, composed of methacrylate based polymers and polyethylene glycol (PEG)-based copolymers, are also investigated. AFM allows us to confirm good condensation conditions and relate them (or not) to transfection efficiencies. These AFM results (obtained after drying in air) are compared with measurements deduced from Dynamic Light Scattering (DLS) experiments performed in water. This comparison allowed us to identify the structural modifications resulting from deposition on the mica surface. (c) 2006 Elsevier B.V. All rights reserved.Nouveaux polycations et vectorisation d’ADN dans les cellules de parois vasculaires” Convention Région Wallonne n° 14612, année 2001-2004 dans le cadre du concours Initiative 200

Nanoparticles Based on Hydrophobic Polysaccharide Derivatives—Formation Principles, Characterization Techniques, and Biomedical Applications

Polysaccharide (PS) nanoparticles (NP) are fascinating materials that combine huge application potential with the unique beneficial features of natural biopolymers. Different types of PS‐NP can be distinguished depending on the basic preparation principles (top‐down vs bottom‐up vs coating of nanomaterials) and the material from which they are obtained (native PS vs chemically modified PS derivatives vs nanocomposites). This review provides a comprehensive overview of an approach towards PS‐NP that has gained rapidly increasing interest within the last decade; the nanoself‐assembling of hydrophobic PS derivatives. This facile process is easy to perform and offers a broad structural diversity in terms of the PS backbone and the additional functionalities that can be introduced. Fundamental principles of different NP preparation techniques along with useful characterization methods are presented in this work. A comprehensive summary of PS‐NP prepared by different techniques and with various PS backbones and types/amounts of hydrophobic substituents is given. The intention is to demonstrate how different parameters determine the size, size distribution, and zeta‐potential of the particles. Moreover, application trends in biomedical areas are highlighted in which tailored functional PS‐NP are evaluated and constantly developed further

Synthesis of graft copolymers by the combination of ATRP and Enzymatic ROP in scC02

A simple strategy is reported for the synthesis of well-defined graft copolymers of poly(methyl methacrylate-co-2-hydroxyethyl methacrylate) P(MMA-co-HEMA) with poly(ε-caprolactone) (PCL) grafted chains. Using scCO2 as the only solvent, a one-step synthetic approach is adopted to prepare copolymer backbones via atom transfer radical polymerization (ATRP), and grafted chains are added via enzymatic ring-opening polymerization (eROP). Exhaustive study of the enzymatic grafting efficiency showed that only the hydroxyl groups in the backbone initiated the polymerization of ε-CL, resulting in an exceptional polymer architecture which is not accessible by conventional chemical polymerization methodology. The lower grafting density obtained (ca. 30−40%) with the enzymatic polymerization of ε-CL indicates that the system is likely limited by steric hindrance