CD22 is a cell-surface glycoprotein uniquely located on mature B-cells and B-cell derived tumour cells. Current evidence suggests that binding of endogenous ligands to CD22 leads to modulation of B-cell activation by antigen. Incidentally, however, B-cell activation may derail. and lead to an undesired immune response, for example in cases of allergy, rheumatoid arthritis and Crohn's disease. In this situation, synthetic high-affinity ligands for CD22 may be of therapeutic value as inhibitors of B-cell activation. Recent studies have revealed that natural ligands for CD22 contain the trisaccharide NeuAc alpha-2,6-Lac as the basic binding motif. In addition, it has been demonstrated that binding to CD22 is strongly enhanced by multivalent presentation of the basic binding motif (cluster effect). In this paper. the stepwise development of a novel multivalent high-affinity ligand for CD22 is described. In the first stage, a series of monovalent NeuAc alpha-2,6-Glc(Y)X type binding motifs was prepared, and their affinity for murine CD22 was monitored, to obtain more insight into the effect of separate structure elements on ligand recognition. In the second stage, we prepared a trivalent cluster, based on the monovalent motif that displayed the highest affinity for CD22, NeuAc alpha-2,6-GlcNBzNO2OMe (7). This cluster, TRIS(NeuAc alpha-2,6-GlcNBzNO2)3 (52), displayed a more than 58-fold higher affinity for CD22 than the reference structure NeuAc alpha-2,6-LacOMe (10). To our knowledge, the cluster 52 is one of the most potent antagonists for CD22 yet synthesised.
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http://dx.doi.org/10.1016/s0968-0896(00)00224-8 | DOI Listing |
Cell Immunol
January 2025
Faculty of Health Sciences, Department of Rehabilitation, Health Science University, 7187 Kodachi, Fujikawaguchiko-Machi, Minamitsuru-Gun, Yamanashi, Japan. Electronic address:
Obesity exacerbates susceptibility to infectious diseases. We investigated the effects of a high-fat diet (HFD) on intestinal immunity, particularly immunoglobulin (Ig)A-producing cells, B-cell activating factor (BAFF), and a proliferation-inducing ligand (APRIL) localization. Mice (4- to 20-weeks old) were fed HFD or standard chow diet, and their jejunum and ileum were fixed using the in vivo cryotechnique.
View Article and Find Full Text PDFJ Biol Chem
September 2024
Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan; Department of Pathology, Nihon University School of Dentistry, Tokyo, Japan. Electronic address:
CD22 (also known as Siglec-2) is an inhibitory receptor expressed in B cells. CD22 specifically recognizes α2,6 sialic acid and interacts with α2,6 sialylated membrane proteins expressed on the same cell (cis-ligands) and those derived from outside of the cell (trans-ligands). Previously, CD22 cis-ligands were shown to regulate the activity of CD22, thereby regulating both BCR ligation-induced signaling and low-level "tonic" signaling in the absence of BCR ligation that regulates the survival and differentiation of B cells.
View Article and Find Full Text PDFSci Technol Adv Mater
May 2024
Biologics Engineering, Oncology R&D, AstraZeneca, Gaithersburg, MD, USA.
Targeted nanoparticles offer potential to selectively deliver therapeutics to cells; however, their subcellular fate following endocytosis must be understood to properly design mechanisms of drug release. Here we describe a nanoparticle platform and associated cell-based assay to observe lysosome trafficking of targeted nanoparticles in live cells. The nanoparticle platform utilizes two fluorescent dyes loaded onto PEG-poly(glutamic acid) and PEG-poly(Lysine) block co-polymers that also comprise azide reactive handles on PEG termini to attach antibody-based targeting ligands.
View Article and Find Full Text PDFJ Immunother Cancer
March 2024
Regeneron Pharmaceuticals, Inc, Tarrytown, New York, USA.
Bioconjug Chem
November 2023
Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047, United States.
Pancreatic islet-reactive B lymphocytes promote Type 1 diabetes (T1D) by presenting an antigen to islet-destructive T cells. Teplizumab, an anti-CD3 monoclonal, delays T1D onset in patients at risk, but additional therapies are needed to prevent the disease entirely. Therefore, bifunctional molecules were designed to selectively inhibit T1D-promoting anti-insulin B cells by conjugating a ligand for the B cell inhibitory receptor CD22 (i.
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