Novel mimics of sialyl Lewis X: design, synthesis and biological activity of a series of 2- and 3-malonate substituted galactoconjugates

Synthesis of the tetrasaccharide repeating unit of the cryoprotectant capsular polysaccharide from Colwellia psychrerythraea 34H

Synthesis of the threonine-decorated tetrasaccharide repeating unit of a cryoprotectant polysaccharide with a glycosaminoglycan-like structure.

IQCA-TASS: a nano-scaled P-selectin inhibitor capable of targeting thrombus and releasing IQCA/TARGD(S)S in vivo

Thrombosis is a serious threat to human health worldwide. Tetrahydroisoquinoline-3-carboxylic acid (IQCA) is an antithrombotic agent, while Thr-Ala-Arg-Gly-Asp(Ser)-Ser (TASS) can target thrombus.

Synthesis of conjugation-ready zwitterionic oligosaccharides by chemoselective thioglycoside activation

A method to chemoselectively activate thioglycosides in the presence of thioethers is developed and applied in the total synthesis of repeating units of S. pneumoniae Sp1 and B. fragilis PS A1. Biochemical evaluation of these glycans is performed after conjugation to reporter moieties.

Lymphocyte trafficking to inflamed skin--molecular mechanisms and implications for therapeutic target molecules

Tissue-selective recruitment of lymphocytes to peripheral organs, such as the skin, is crucial for spatial compartmentalisation within the immune system as well as immune surveillance under normal conditions. In addition, this process plays a key role for the pathogenesis of various diseases including common inflammatory disorders such as atopic dermatitis or psoriasis, but also malignancies such as cutaneous T cell lymphomas. Recruitment of lymphocytes to the skin is a highly complex process that involves adhesion to the endothelial lining, extravasation, migration through the connective tissue, and, finally, localisation of a subpopulation of lymphocytes to the epithelial compartment, the epidermis. An intertwined network of constitutively expressed and inducible cytokines, chemokines and other mediators provides guidance for lymphocyte migration, and a large number of adhesion receptors mediate sequential steps of cell-cell- and cell-substrate-interactions resulting in tissue-specific localisation of immune cells. Selectively targeting the functions of one or several key molecules involved in this complex cascade promises exciting new therapeutic options for treating inflammatory disorders, but at the same time, bears considerable imponderables which will be discussed in this article.

The molecular basis of lymphocyte recruitment to the skin: clues for pathogenesis and selective therapies of inflammatory disorders

Spatial compartmentalization and tissue-selective localization of T lymphocytes to the skin are crucial for immune surveillance and the pathogenesis of various disorders including common inflammatory diseases such as atopic dermatitis or psoriasis, but also malignancies such as cutaneous T cell lymphomas. Cutaneous recruitment of lymphocytes is a highly complex process that involves extravasation, migration through the dermal connective tissue, and eventually, localization to the epidermis. An intertwined network of cytokines and chemokines provides the road signs for leukocyte migration, while various adhesion receptors orchestrate the dynamic events of cell-cell and cell-substrate interactions resulting in cutaneous localization of T cells. Selectively targeting the functions of molecules involved in this interplay promises exciting new therapeutic options for treating inflammatory skin disorders.

Discovery of a potent nanoparticle P-selectin antagonist with anti-inflammatory effects in allergic airway disease

The severity of allergic asthma is dependent, in part, on the intensity of peribronchial inflammation. P-selectin is known to play a role in the development of allergen-induced peribronchial inflammation and airway hyperreactivity. Selective inhibitors of P-selectin-mediated leukocyte endothelial-cell interactions may therefore attenuate the inflammatory processes associated with allergic airway disease. Novel P-selectin inhibitors were created using a polyvalent polymer nanoparticle capable of displaying multiple synthetic, low molecular weight ligands. By assembling a particle that presents an array of groups, which as monomers interact with only low affinity, we created a construct that binds extremely efficiently to P-selectin. The ligands acted as mimetics of the key binding elements responsible for the high-avidity adhesion of P-selectin to the physiologic ligand, PSGL-1. The inhibitors were initially evaluated using an in vitro shear assay system in which interactions between circulating cells and P-selectin-coated capillary tubes were measured. The nanoparticles were shown to preferentially bind to selectins expressed on activated endothelial cells. We subsequently demonstrated that nanoparticles displaying P-selectin blocking arrays were functionally active in vivo, significantly reducing allergen-induced airway hyperreactivity and peribronchial eosinophilic inflammation in a murine model of asthma.

Design and synthesis of sialyl Lewis(x) mimics as E- and P-selectin inhibitors

The selectins are a family of cell-adhesion proteins that mediate the rolling of leukocytes on activated endothelial cells through the recognition of the carbohydrate epitope sialyl Lewis(x) (sLe(x)). Control of the leukocyte-endothelial cell adhesion process may prove useful in cases where excess recruitment of leukocytes can contribute to acute diseases such as stroke and reperfusion injury and chronic diseases such as psoriasis and rheumatoid arthritis. The development of molecules that block the interactions between sLe(x) and the selectins has become an active area of research. In this review, we will highlight the various approaches taken toward the development of sLe(x) mimetics as antagonists of E- and P-selectin, including the use of structural information about the selectins and their interactions with sLe(x) that have been revealed through the use of NMR, protein crystallography and molecular modeling.