Dendritic cells (DC) are potent initiators of immune responses, compared to other professional antigen-presenting cells, based on their ability to capture antigen, express high amounts of MHC and co-stimulatory molecules, and to secrete immunostimulatory cytokines. Altered functions of DC in atopic individuals have been observed, though it is not clear if this is a cause or a result of the development of allergic disease. In this report we demonstrate altered cytokine production by DC isolated from infants with atopic dermatitis but without a diagnosis of asthma, compared to infants with non-atopic dermatitis. Increased production of IL-6, IL-10 and IFNα from DC isolated from atopic infants is less apparent when DC from infants were examined one year later. An increase in the same cytokines was observed in neonatal mice that are genetically predisposed towards allergic inflammation. These results suggest that an atopic environment promotes altered cytokine production by DC from infants.
Helicobacter pylori colonizes the human stomach and can cause gastroduodenal disease. Flagellar motility is regarded as a major factor in the colonizing ability of H. pylori. The functional roles of flagellar structural proteins other than FlaA, FlaB, and FlgE are not well understood. The fliD operon ofH. pylori consists of flaG, fliD, and fliS genes, in the order stated, under the control of a ς28-dependent promoter. In an effort to elucidate the function of the FliD protein, a hook-associated protein 2 homologue, in flagellar morphogenesis and motility, the fliD gene (2,058 bp) was cloned and isogenic mutants were constructed by disruption of the fliD gene with a kanamycin resistance cassette and electroporation-mediated allelic-exchange mutagenesis. In thefliD mutant, morphologically abnormal flagellar appendages in which very little filament elongation was apparent were observed. The fliD mutant strain was completely nonmotile, indicating that these abnormal flagella were functionally defective. Furthermore, the isogenic fliD mutant of H. pylori SS1, a mouse-adapted strain, was not able to colonize the gastric mucosae of host mice. These results suggest that H. pyloriFliD is an essential element in the assembly of the functional flagella that are required for colonization of the gastric mucosa.
Escherichia coli heat-labile enterotoxin (LT), which causes a characteristic diarrhea in humans and animals, is a strong mucosal immunogen and has powerful mucosal adjuvant activity towards coadministered unrelated antigens. Here we report the different mucosal adjuvanticity of nontoxic LT derivatives, LTS63Y and LT∆110/112, generated by immunizing through two different mucosal routes. Intragastric (
Abbreviations: ETEC, enterotoxigenic Escherichia coli; LT, Escherichia c o l i h e a t -l a b i l e enterotoxin; CT, cholera toxin; GM 1, monosialoganglioside; ELISA, enzyme-linked immunosorbent assay AbstractEscherichia coli heat-labile enterotoxin (LT) is composed of catalytic A and non-catalytic homo-pentameric B subunits and causes diarrheal disease in human and animals. In order to produce a nontoxic LT for vaccine and adjuvant development, two novel derivatives of LT were constructed by a site-directed mutagenesis of A subunit; Ser 6 3 to Ty r 6 3 in LTS63Y and Glu 11 0 , G l u 11 2 were deleted in LT 11 0 / 112. The purified mutant LTs (mLTs) showed a similar molecular structural complex as AB 5 to that of wild LT. In contrast to wild-type LT, mLTs failed to induce either elongation activity, ADP-ribosyltransferase activity, cAMP synthesis in CHO cells or fluid accumulation in mouse small intestine in vivo. Mice immunized with m LTs either intragastrically or intranasally elicited high titers of LT-specific serum and mucosal antibodies comparable to those induced by wild-type LT. These results indicate that substitution of Ser 63 to Ty r 6 3 or deletion of Glu 11 0 and Glu 11 2 eliminate the toxicity of LT without a change of AB 5 conformation, and both mutants are immunogenic to LT itself. Therefore, both mLTs may be used to develop novel anti-diarrheal vaccines against enterotoxigenic E. coli.
An amphiphilic diacetylene compound was deposited on the surface of nano sized magnetite particles (Fe 3 O 4 ) using a self-assembly method. The diacetylene molecular assembly formed on the surface of nanoparticle was subjected to photopolymerization. This resulted in the formation of a polymeric assembly on the surface of the nanoparticles in which the adjacent diacetylene molecules were connected through conjugated covalent networks. The presence of immobilized polymer species on the surface of nanoparticles is expected to protect them from agglomeration and ripening, thereby stabilizing their physical properties. In this work, Fe 3 O 4 nanoparticles were prepared by chemical coprecipitation method and the diacetylene molecule 10,12-pentacosadiynoic acid (PCDA) was anchored to the surface of Fe 3 O 4 nanoparticles through its carboxylate head group. Irradiation of UV light on the nanoparticles containing immobilized diacetylenes resulted in the formation of a polymeric assembly. Presence of diacetylene molecules on the surface of nanoparticles was confirmed by X-ray photoelectron spectroscopy and FT-IR measurements. Photopolymerization of the diacetylene assembly was detected by UV-Visible spectroscopy. Magnetic properties of the nanoparticles coated with polymeric assembly were investigated with SQUID and magnetic hysteresis showed superparamagnetic behaviors. The results put forward a simple and effective method for achieving polymer coating on the surface of magnetic nanoparticle.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.