Exposure of Keratinocytes to in the Context of Atopic Induces Changes in the Surface Glycosylation Pattern of Small Extracellular Vesicles to Enhance Their Propensity to Interact With Inhibitory Siglec Receptors.

infection is a potential complication in the individuals with atopic dermatitis (AD) and can affect clinical course of the disease. Here, using primary keratinocytes we determined that atopic promotes changes in the interaction of small extracellular vesicles (sEVs) with dendritic cells and that this is further enhanced by the presence of . sEV uptake is largely dependent on the expression of glycans on their surface; modelling of the protein interactions indicated that recognition of this pathogen through -relevant pattern recognition receptors (PRRs) is linked to several glycosylation enzymes which may in turn affect the expression of sEV glycans.

Colonic epithelial cell diversity in health and inflammatory bowel disease.

The colonic epithelium facilitates host-microorganism interactions to control mucosal immunity, coordinate nutrient recycling and form a mucus barrier. Breakdown of the epithelial barrier underpins inflammatory bowel disease (IBD). However, the specific contributions of each epithelial-cell subtype to this process are unknown.

Acyloxymethyl esterification of nodularin-R and microcystin-LA produces inactive protoxins that become reactivated and produce apoptosis inside intact cells.

We report the esterification of the carboxyl groups of the cyclic peptide toxins nodularin-R and microcystin-LA to produce stable diacetoxymethyl and dipropionyloxymethyl ester derivatives. The derivatives had no activity but were reactivated upon esterase treatment. When injected into cells, the acyloxymethyl moieties were cleaved off and apoptosis induced.

Depolarized light scattering from silver nanoparticles.

We present an observation of depolarized scattering by silver colloids. The profile of the wavelength-dependent anisotropy of the colloidal solution of silver nanoparticles traces the plasmonic extinction spectrum. The scattering component of the colloid extinction spectrum is responsible for the depolarization effect.

One- and two-photon induced fluorescence of Pacific Blue-labeled human serum albumin deposited on different core size silver colloids.

We studied one- and two-photon induced fluorescence of Pacific Blue (PB)-labeled human serum albumin (HSA) in the presence of different size silver colloids. The PB fluorescence emission intensity was observed with small (30-40 nm) and large (about 120 nm) colloids and compared with PB emission in absence of colloids. For the system with a small core size colloids we did not detect any fluorescence enhancement with one-photon excitation and the enhancement observed with two-photon excitation was about 2.

Directional surface plasmon-coupled emission: application for an immunoassay in whole blood.

We present a new approach for performing fluorescence immunoassay in whole blood using fluorescently labeled anti-rabbit immunoglobulin G (IgG) on a silver surface. This approach, which is based on surface plasmon-coupled emission (SPCE), provides increased sensitivity and substantial background reduction due to exclusive selection of the signal from the fluorophores located near a bioaffinity surface. This article describes the effect of an optically dense sample matrix, namely human whole blood and serum, on the intensity of the SPCE.

Spectroscopic characterization of the EF-hand domain of phospholipase C delta1: identification of a lipid interacting domain.

The interaction of the isolated EF-hand domain of phospholipase C delta1 with arachidonic acid (AA) was characterized using circular dichroism (CD) and fluorescence spectroscopy. The far-UV CD spectral changes indicate that AA binds to the EF domain. The near-UV CD spectra suggest that the orientations of aromatic residues in the peptide are affected when AA binds to the protein.

Two-photon induced fluorescence of Cy5-DNA in buffer solution and on silver island films.

We report the observation of a strong two-photon induced fluorescence emission of Cy5-DNA within the tunable range of a Ti:Sapphire laser. The estimated two-photon cross-section for Cy5-DNA of 400GM is about 3.5-fold higher than it was reported for rhodamine B.

Surface plasmon-coupled polarized emission of N-acetyl-l-tryptophanamide.

We report an observation of ultraviolet (UV) surface plasmon-coupled emission (SPCE) of N-acetyl-l-tryptophanamide (NATA). The sample was spin coated from poly(vinyl alcohol) (PVA) solution on 20 nm aluminum film deposited on a quartz substrate. The directional UV SPCE occurs within a well-defined narrow angle at 52 degrees from the normal to the coupling hemicylinder quartz prism.

Advances in surface-enhanced fluorescence.

We report recent achievements in metal-enhanced fluorescence from our laboratory. Several fluorophore systems have been studied on metal particle-coated surfaces and in colloid suspensions. In particular, we describe a distance dependent enhancement on silver island films (SIFs), release of self-quenching of fluorescence near silver particles, and the applications of fluorescence enhancement near metalized surfaces to bioassays.

Fluorescence enhancements on silver colloid coated surfaces.

We observed a strong, more than 16-fold, enhancement of Texas Red-labeled BSA fluorescence emission when deposited on silver colloid coated surfaces (SCCS). The same labeled protein deposited on silver island films (SIFs) showed an approximate 8-fold fluorescence enhancement. The lifetimes of Texas Red-BSA fluorescence are significantly shorter on silvered surfaces than on uncoated quartz substrate indicating a strong change in radiative decay rate of the dyes.

Fluorescence enhancement of fluorophores tethered to different sized silver colloids deposited on glass substrate.

We studied fluorescence enhancements of fluorescein tethered to silver colloids of different size. Thiolated 23-mer oligonucleotide (ss DNA-SH) was bound selectively to silver colloids deposited on 3-aminopropyltriethoxysilane (APS)-treated quartz slides. Fluorescein-labeled complementary oligonucleotide (ss Fl-DNA) was added in an amount significantly lower than the amount of unlabeled DNA tethered to the colloids.