Targeting CD33+ Acute Myeloid Leukemia with GLK-33, a Lintuzumab-Auristatin Conjugate with a Wide Therapeutic Window.

CD33 (Siglec-3) is a cell surface receptor expressed in approximately 90% of acute myeloid leukemia (AML) blasts, making it an attractive target for therapy of AML. Although previous CD33-targeting antibody-drug conjugates (ADC) like gemtuzumab ozogamicin (GO, Mylotarg) have shown efficacy in AML treatment, they have suffered from toxicity and narrow therapeutic window. This study aimed to develop a novelADCwith improved tolerability and a wider therapeutic window.

Trastuzumab-MMAU Antibody-Auristatin Conjugates: Valine-Glucoserine Linker with Stabilized Maleimide Conjugation Improves In Vivo Efficacy and Tolerability.

Antibody-drug conjugates (ADC) have shown impressive clinical activity with approval of many agents in hematologic and solid tumors. However, challenges remain with both efficacy and safety of ADCs. This study describes novel trastuzumab-auristatin conjugates with the hydrophilic monomethylauristatin E (MMAE) prodrug MMAU, and optimization of a glycopeptide linker leading to a wider therapeutic window.

Development of an Affordable, Sustainable and Efficacious Plant-Based Immunomodulatory Food Ingredient Based on Bell Pepper or Carrot RG-I Pectic Polysaccharides.

The prevalence of acute respiratory infections and their impact on quality of life underlies the need for efficacious solutions that are safe, sustainable and economically viable. Polysaccharides in several (traditional) plant extracts have been shown to be immunostimulatory, and some studies suggest beneficial effects against respiratory infections. The aim of this study was to (i) identify the active polysaccharide constituents from affordable and renewable crops (bell pepper and carrot) using activity-guided fractionation, (ii) evaluate in vitro effects on innate immune responses (phagocytosis and cytokine secretion), microbiota modulation and production of short chain fatty acids, followed by (iii) the evaluation of effects of a bell pepper extract enriched for the active component in a human proof of concept study.

Structure and Function of Bovine Whey Derived Oligosaccharides Showing Synbiotic Epithelial Barrier Protective Properties.

Commensal gut microbiota and probiotics have numerous effects on the host's metabolic and protective systems, which occur primarily through the intestinal epithelial cell interface. Prebiotics, like galacto-oligosaccharides (GOS) are widely used to modulate their function and abundance. However, important structure-function relations may exist, requiring a detailed structural characterization.

Hydrophilic Auristatin Glycoside Payload Enables Improved Antibody-Drug Conjugate Efficacy and Biocompatibility.

Antibody-drug conjugates (ADCs) offer a combination of antibody therapy and specific delivery of potent small-molecule payloads to target cells. The properties of the ADC molecule are determined by the balance of its components. The efficacy of the payload component increases with higher drug-to-antibody ratio (DAR), while homogeneous DAR = 8 ADCs are easily prepared by conjugation to the four accessible antibody hinge cystines.

Introducing Glycolinkers for the Functionalization of Cytotoxic Drugs and Applications in Antibody-Drug Conjugation Chemistry.

Antibody-drug conjugates (ADCs) are promising alternatives to naked antibodies for selective drug-delivery applications and treatment of diseases such as cancer. Construction of ADCs relies upon site-selective, efficient and mild conjugation technologies. The choice of a chemical linker is especially important, as it affects the overall properties of the ADC.

Diversity in prokaryotic glycosylation: an archaeal-derived N-linked glycan contains legionaminic acid.

VP4, the major structural protein of the haloarchaeal pleomorphic virus, HRPV-1, is glycosylated. To define the glycan structure attached to this protein, oligosaccharides released by β-elimination were analysed by mass spectrometry and nuclear magnetic resonance spectroscopy. Such analyses showed that the major VP4-derived glycan is a pentasaccharide comprising glucose, glucuronic acid, mannose, sulphated glucuronic acid and a terminal 5-N-formyl-legionaminic acid residue.

The N-glycome of human embryonic stem cells.

Background: Complex carbohydrate structures, glycans, are essential components of glycoproteins, glycolipids, and proteoglycans. While individual glycan structures including the SSEA and Tra antigens are already used to define undifferentiated human embryonic stem cells (hESC), the whole spectrum of stem cell glycans has remained unknown. We undertook a global study of the asparagine-linked glycoprotein glycans (N-glycans) of hESC and their differentiated progeny using MALDI-TOF mass spectrometric and NMR spectroscopic profiling.

Glycoforms of human endothelial CD34 that bind L-selectin carry sulfated sialyl Lewis x capped O- and N-glycans.

Endothelial sialomucin CD34 functions as an L-selectin ligand mediating lymphocyte extravasation only when properly glycosylated to express a sulfated carbohydrate epitope, 6-sulfo sialyl Lewis x (6-sulfo SLe(x)). It is thought that multivalent 6-sulfo SLe(x) expression promotes high-affinity binding to L-selectin by enhancing avidity. However, the reported low amount of 6-sulfo SLe(x) in total human CD34 is inconsistent with this model and prompted us to re-evaluate CD34 glycosylation.

Helicobacter pylori binding to new glycans based on N-acetyllactosamine.

Previously we reported binding of Helicobacter pylori to various nonacid and sialylated neolacto carbohydrate structures using a wide range of natural and chemically modified sequences. A novel nonsialylated neolacto-based binding epitope, GlcNAc beta 3Gal beta 4GlcNAc, and analogous structures carrying terminal GalNAc beta 3, GalNAc alpha 3, or Gal alpha 3 showed the binding activity (Miller-Podraza H, Lanne B, Angström J, Teneberg S, Abul-Milh M, Jovall P-A, Karlsson H, Karlsson K-A. 2005.

Mass spectrometric detection of tyrosine sulfation in human pancreatic trypsinogens, but not in tumor-associated trypsinogen.

Trypsinogen-1 and -2 are well-characterized enzymes that are expressed in the pancreas and also in several other tissues. Many cancers produce trypsinogen isoenzymes that differ from the pancreatic ones with respect to substrate specificity and isoelectric point. These tumor-associated trypsinogens play a pivotal role in cancer progression and metastasis.

Conjugation of oligosaccharides by reductive amination to amine modified chondroitin oligomer and gamma-cyclodextrin.

Carbohydrates present on cell surfaces participate in numerous biological recognition phenomena including cell-cell interactions, cancer metastasis and pathogen invasion. Therefore, synthetic carbohydrates have a potential to act as pharmaceutical substances for treatment of various pathological phenomena by inhibiting specifically the interaction between cell surface carbohydrates and their protein receptors (lectins). However, the inherently low affinity of carbohydrate-protein interactions has often been an obstacle for successful generation of carbohydrate based pharmaceuticals.

Cysteine cathepsins are central contributors of invasion by cultured adenosylmethionine decarboxylase-transformed rodent fibroblasts.

Adenosylmethionine decarboxylase (AdoMetDC), a key enzyme in the biosynthesis of polyamines, is often up-regulated in cancers. We have demonstrated previously that overexpression of AdoMetDC alone is sufficient to transform NIH 3T3 cells and induce highly invasive tumors in nude mice. Here, we studied the transformation-specific alterations in gene expression induced by AdoMetDC by using cDNA microarray and two-dimensional electrophoresis technologies.

Purification and cDNA cloning of UDP-GlcNAc:GlcNAcbeta1-3Galbeta1-4Glc(NAc)-R [GlcNAc to Gal]beta1,6N-acetylglucosaminyltransferase from rat small intestine: a major carrier of dIGnT activity in rat small intestine.

A rat intestinal beta1,6N-acetylglucosaminyltransferase (beta1-6GnT) responsible for the formation of the beta1,6-branched poly-N-acetyllactosamine structure has been purified to apparent homogeneity by successive column chromatographic procedures using an assay wherein pyridylaminated lacto- N-triose II (GlcNAcbeta1-3Galbeta1-4Glc-PA) was used as an acceptor substrate and the reaction product was GlcNAcbeta1-3(GlcNAcbeta1-6)Galbeta1-4Glc-PA. The purified enzyme catalyzed the conversion of the polylactosamine acceptor GlcNAcbeta1-3'LacNAc into GlcNAcbeta1-3'(GlcNAcbeta1-6') LacNAc (dIGnT activity), but it could not transfer GlcNAc to LacNAcbeta1-3'LacNAc (cIGnT activity). This enzyme could also convert mucin core 1 and core 3 analogs, Galbeta1-3GalNAcalpha1-O-paranitrophenyl (pNP) and GlcNAcbeta1-3GalNAcalpha1-O-pNP, into Galbeta1-3(GlcNAcbeta1-6) GalNAcalpha1-O-pNP (C2GnT activity) and GlcNAcbeta1-3(GlcNAcbeta1-6)GalNAcalpha1-O-pNP (C4GnT activity), respectively.

NisB is required for the dehydration and NisC for the lanthionine formation in the post-translational modification of nisin.

Nisin produced by Lactococcus lactis subsp. lactis is a 34-residue antibacterial polypeptide and belongs to a group of post-translationally modified peptides, lantibiotics, with dehydrated residues and cyclic amino acids, lanthionines. These modifications are supposed to be made by enzymes encoded by lanB and lanC genes, found only in biosynthetic operons encoding lantibiotics.

Enhanced activation of bound plasminogen on Staphylococcus aureus by staphylokinase.

Activation of plasminogen (plg) to plasmin by the staphylococcal activator, staphylokinase (SAK), is effectively regulated by the circulating inhibitor, alpha2-antiplasmin (alpha2AP). Here it is demonstrated that intact Staphylococcus aureus cells and solubilized staphylococcal cell wall proteins not only protected SAK-promoted plg activation against the inhibitory effect of alpha2AP but also enhanced the activation. The findings suggest that the surface-associated plg activation by SAK may have an important physiological function in helping staphylococci in tissue dissemination.

Purification and characterization of novel kininogens from spotted wolffish and Atlantic cod.

Kininogens are multifunctional proteins found so far mainly in mammals. They carry vasoactive kinins as well as participate in defense, blood coagulation and the acute phase response. In this study, novel kininogens were isolated from Atlantic cod (Gadus morhua L.

The major conformational IgE-binding epitopes of hevein (Hev b6.02) are identified by a novel chimera-based allergen epitope mapping strategy.

A novel approach to localize and reconstruct conformational IgE-binding epitope regions of hevein (Hev b6.02), a major natural rubber latex allergen, is described. An antimicrobial protein (AMP) from the amaranth Amaranthus caudatus was used as an immunologically non-IgE-binding adaptor molecule to which terminal or central parts of hevein were fused.

O-glycans on human high endothelial CD34 putatively participating in L-selectin recognition.

Leukocyte traffic into lymph nodes and sites of inflammation is guided by L-selectin. Experiments performed in vitro and with gene-deleted mice suggest that CD34 recognizes L-selectin if decorated by 6-sulfo sialyl Lewis x (sLex) saccharides and the MECA-79 epitope. However, very little is known about glycosylation of human L-selectin ligands.