Autoreactive B lymphocytes first encountering self-antigens in peripheral tissues are normally regulated by induction of anergy or apoptosis. According to the “two-signal” model, antigen recognition alone should render cells tolerant unless T cell help inflammatory signals such as lipopolysaccharide provided. However, no seem necessary for responses T-independent type 2 (TI-2) antigens, which multimeric antigens lacking epitopes and Toll-like receptor ligands. How then do mature avoid making...

Selective detection of hydrogen sulfide was achieved with 7-o-2′-(azidomethyl)benzoyl-4-methylcoumarin via analyte mediated reductive removal the 2′-(azidomethyl)benzoyl moiety and concurrent generation fluorescent 7-hydroxy-4-methylcoumarin.

Alteration of lysosome acidity has been implicated in many biological events ranging from apoptosis to cancer metastasis, etc. Mesoporous silica nanoparticles doped with acid activable rhodamine-lactam and fluorescein isothiocyanate (FITC) were developed for ratiometric sensing lysosomal pH changes live cells flow cytometry.

Hypochlorous acid (HOCl) is biosynthesized from hydrogen peroxide via catalysis of myeloperoxidase in lysosomes immunological cells. Despite being harnessed by immune systems against invading pathogens, biogenic HOCl can also damage host tissues and has been associated with a number diseases. In this edge article, Förster resonance energy transfer based ratiometric imaging lysosomal was achieved silica nanoparticles comprising FITC (donor dye) nonfluorescent chemodosimeter which turned into...

Sialoadhesin (Sn, Siglec-1, CD169) is a member of the sialic acid binding Ig-like lectin (siglec) family expressed on macrophages. Its macrophage specific expression makes it an attractive target for delivering antigens to tissue macrophages via Sn-mediated endocytosis. Here we describe novel approach using liposomal nanoparticles displaying high affinity glycan ligands Sn. The Sn-targeted liposomes selectively bind and are internalized by Sn-expressing cells, accumulate intracellularly over...

Abstract CD22 (Siglec-2) is a key regulator of B cell signaling whose function modulated by interaction with extracellular glycan ligands mediated through its N-terminal Ig domain. Its preferred ligand the sequence Siaα2-6Gal that abundantly expressed on N-linked glycans glycoproteins, and binding to in cis causes appear “masked” from synthetic sialoside probes. Yet, despite presence ligands, redistributes sites contact trans neighboring cells. In this study, we demonstrate dynamic...

Three bacterial strains were isolated from sea-water samples taken Amursky Bay of the Gulf Peter Great, East Sea. The isolates, designated KMM 3670, 3673T and 3928, Gram-positive, non-motile, aerobic, non-spore-forming, irregular, rod-shaped actinobacteria. They grew well at mesophilic temperatures neutral pH tolerated up to 10 % NaCl, although salt was not essential for growth. three shared all morphological properties most physiological characteristics tested. Based on subsequent...

The parameters of intracellular acidic compartments are altered in apoptosis, autophagy, cancer metastasis, etc. Low background and selective staining lysosomes autophagosomes was achieved with N-(rhodamine 6G)-lactam-ethylenediamine (R6G-EDA) which fluoresces vesiclesvia pH mediated ring opening the intramolecular lactam. Long retention time R6G-EDA its exceptional stability against photo-bleaching allow full tracking lysosome morphology changes tumor necrosis factor-α (TNF-α) triggered...

A chromogenic and fluorogenic detection of a nerve agent simulant was developed based on diethyl chlorophosphate triggered tandem phosphorylation intramolecular cyclization N-(rhodamine B)-deoxylactam-2-aminoethanol.

A highly sensitive chemodosimeter was identified from a panel of rhodamine derivatives for rapid and visual detection phosgene with limit 50 nM triphosgene. Visual gaseous absorbed paper strips demonstrated.

Agents enabling tumor staging are valuable for cancer surgery. Herein, a targetable sialic acid-armed near-infrared profluorophore (SA-pNIR) is reported fluorescence guided detection. SA-pNIR consists of acid entity effective

The organelle-specific pH is crucial for cell homeostasis. Aberrant of lysosomes has been manifested in myriad diseases. To probe lysosome responses to stress, we herein report the detection lysosomal changes with a dual colored (CM-ROX), featuring coumarin domain "always-on" blue fluorescence and rhodamine–lactam activatable acidity give red fluorescence. With sensitive ratiometric signals upon subtle changes, CM-ROX enables discernment cells undergoing autophagy, death, viral infection.

The siglec family of sialic acid binding proteins participates in diverse cell surface biology that includes regulation immune signaling and the interaction neuronal cells with glial cells. weak intrinsic affinity natural sialoside ligands has hampered development synthetic ligand based probes needed to elucidate their roles function. In this report, we describe a glycan microarray comprising library 9-acyl-substituted acids incorporated into sialosides containing Neu5Acα2−3Gal Neu5Acα2−6Gal...

Glycans arrayed on the exterior of virus particles were used as substrates for glycosyltransferase reactions to build di- and trisaccharides from surface. The resulting exhibited tight specific associations with cognate receptors beads cells, in one example defeating cis cell-surface interactions a manner characteristic polyvalent binding. Combined ability viruses provide structurally well-defined attachment points, methodology provides convenient powerful way prepare complex carbohydrate...

A visual and fluorogenic detection method for a nerve agent simulant was developed based on Lossen rearrangement of rhodamine–hydroxamate, in the presence diethyl chlorophosphate, under alkaline conditions.

Optical probes that could illuminate tumors are promising tools to enable surgical ablation of tumor colonies elusive identify by conventional visual inspection. Polymeric nanoprobes, comprised a biocompatible poly[styrene-alter-(maleic acid)] carrier and pH responsive rhodamine-deoxylactam, preferentially accumulate in mice activated lysosomal acidity into highly fluorescent species. The favorable characteristics passive targeting, e.g. high normal tissue ratio, long retention time low vivo...

Abstract Lipid metabolism disorders in both neurons and glial cells have been found neurodegenerative (ND) patients animal models. However, the pathological connection between lipid droplets NDs remains poorly understood. The recent work has highlighted utility of a neuron‐specific Arf1‐knockout mouse model corresponding for elucidating nexus amyotrophic lateral sclerosis (ALS) multiple (MS). In this study, it is that Arf1 deficiency first induced surplus fatty acid synthesis through...

CD22 is a B cell-specific sialic acid-binding immunoglobulin-like lectin (Siglec) whose function as regulator of cell signaling modulated by its interaction with glycan ligands bearing the sequence NeuAcα2−6Gal. To date, only highly multivalent polymeric (n = 450) have achieved sufficient avidity to bind on native cells. Here we demonstrate that synthetic bifunctional molecule comprising ligand linked an antigen (nitrophenol; NP) can use monoclonal anti-NP IgM decavalent protein scaffold...

A chromogenic and fluorogenic detection of aldehydes was achieved viaanalyte triggered opening the deoxylactam N-(rhodamine B)-deoxylactam-ethylenediamine (dRB-EDA). The utility sensor demonstrated by fluorescent labeling aldehyde-displaying sialoproteins on cell surfaces.

A hetero-organelle partition and lysosome activable sensor was developed for fluorogenic detection of mitochondrial depolarization in autophagy cell death.

Inflammation causes significant morbidity and mortality, necessitating effective in vivo imaging of inflammation. Prior approaches often rely on combination optical agents with entities specific for proteinaceous biomarkers overexpressed inflammatory tissues. We herein report a fundamentally new approach to image inflammation by targeting lysosomes undergoing acidification cells sialic acid (Sia) conjugated near-infrared profluorophore (pNIR). Sia-pNIR contains domain inflamed tissues pNIR...

Determination of nitrite levels is substantial interest in many applications from monitoring drinking water quality to clinical diagnosis, etc. N-(Rhodamine B)-lactam-o-phenylenediamine (RB-PDA) was identified a panel rhodamine-lactams for fluorogenic and visual detection aqueous media via analyte triggered formation highly fluorescent deep colored species.

Activatable molecular systems enabling precise tumor localization are valuable for complete resection. Herein, we report sialic acid-capped polymeric nanovesicles encapsulating the near infrared profluorophore (pNIR@P@SA) lysosome activation based dual modality imaging. The probe features surface-anchored acid targeting and a core of (pNIR) which undergoes lysosomal acidity triggered isomerization to give optical optoacoustic signals upon cell internalization. Imaging studies reveal...

Arginase is a manganese metalloenzyme that catalyzes the hydrolysis of l-arginine to form l-ornithine and urea. The structure stability binuclear cluster are critical for catalytic activity as it activates nucleophile, metal-bridging hydroxide ion, stabilizes tetrahedral intermediate its flanking states. Here, we report X-ray structures series inhibitors bound active site arginase, each inhibitor exploits different mode coordination with Mn2+2 cluster. Specifically, have studied binding...