Search results for "glycoproteins"
showing 10 items of 496 documents
A New Type of Cytokine Receptor Antagonist Directly Targeting gp130
1998
The interleukin-6-type family of cytokines bind to receptor complexes that share gp130 as a common signal-transducing subunit. So far, receptor antagonists for interleukin-6-type cytokines have been constructed that still bind to the specific ligand binding subunit of the receptor complex, but have lost the ability to stimulate gp130. Such receptor antagonists compete for a specific receptor of a member of the cytokine family. Interleukin-6 only binds to gp130 when complexed with the interleukin-6 receptor that exists as a membrane bound and soluble molecule. Here we have constructed fusion proteins that consist of the soluble form of the human interleukin-6 receptor covalently linked to in…
Soluble interleukin-6 receptor (sIL-6R) makes IL-6R negative T cell line respond to IL-6: it inhibits TNF production
2000
The receptor for interleukin-6 (IL-6) consists of two subunits: a ligand specific IL-6Ralpha and gp130 that is responsible for signal-transduction. A soluble form of the ligand specific chain was described that when complexed to IL-6 is capable of binding to the membrane-bound gp130 subunit and thus can elicit signal-transduction. This soluble receptor can act on cells that express only the gp130 but not the ligand-specific subunit of the IL-6R. This phenomenon, called trans-signaling, introduced a novel aspect of cytokine action. In this study we examined the response of Jurkat cells, that are known not to express IL-6Ralpha, to IL-6, the soluble IL-6 receptor (sIL-6R) and a covalent compl…
Mast cells counteract regulatory T-cell suppression through interleukin-6 and OX40/OX40L axis toward Th17-cell differentiation
2009
Abstract The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell–derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17–producing T cel…
Assignment of the group A rotavirus NSP4 gene into genotypes using a hemi-nested multiplex PCR assay: a rapid and reproducible assay for strain surve…
2009
The rotavirus non-structural protein NSP4 has been implicated in a number of biological functions during the rotavirus cellular cycle and pathogenesis, and has been addressed as a target for vaccine development. The NSP4 gene has been classified into six genotypes (A–F). A semi-nested triplex PCR was developed for genotyping the major human NSP4 genotypes (A–C), which are common in human rotavirus strains but are also shared among most mammalian rotavirus strains. A total of 192 previously characterized human strains representing numerous G and P type specificities (such as G1P[8], G1P[4], G2P[4], G3P[3], G3P[8], G3P[9], G4P[6], G4P[8], G6P[4], G6P[9], G6P[14], G8P[10], G8P[14], G9P[8], G9P…
Rotavirus-Specific Cytotoxic T Lymphocytes Recognize Overlapping Epitopes in the Amino-Terminal Region of the VP7 Glycoprotein
1999
Abstract Rotavirus-specific cytotoxic T lymphocytes (CTL) play an important role in the resolution of rotavirus infection. The outer capsid glycoprotein, VP7, elicits a class I MHC-restricted CTL response. Vaccinia virus recombinants expressing the VP7 genes from simian rotavirus SA11 (serotype G3) and from the RF strain of bovine rotavirus (serotype G6) were used to analyze the CTL activity to this antigen in BALB/c (H-2 d ) and C57BL/6 (H-2 b ) mice neonatally infected with homologous and heterologous rotaviruses. A vaccinia virus recombinant expressing the first amino-terminal 88 amino acids of VP7 was constructed and used to search for cross-reactive CTL against this region of the prote…
Genetic characterization of G3 rotaviruses detected in Italian children in the years 1993–2005
2009
International audience; In recent years an apparent increase in the frequency of detection of G3P[8] rotaviruses has been observed worldwide. Similarly, in Italy G3P[8] strains have been detected sporadically and in a scattered fashion over 20 years, whereas in 2003 and 2005 G3P[8] rotavirus activity increased markedly. By analysis of the VP7, VP4, VP6 and NSP4 genes of a selection of G3P[8] rotaviruses detected between 1993 and 2005, a remarkable sequence conservation was observed in the VP7, VP4 and VP6 genes. By converse, after 2002 the Italian G3P[8] strains were found to possess unique mutations in significant regions of the NSP4 protein.
Rotavirus stimulates release of serotonin (5-HT) from human enterochromaffin cells and activates brain structures involved in nausea and vomiting
2011
Rotavirus (RV) is the major cause of severe gastroenteritis in young children. A virus-encoded enterotoxin, NSP4 is proposed to play a major role in causing RV diarrhoea but how RV can induce emesis, a hallmark of the illness, remains unresolved. In this study we have addressed the hypothesis that RV-induced secretion of serotonin (5-hydroxytryptamine, 5-HT) by enterochromaffin (EC) cells plays a key role in the emetic reflex during RV infection resulting in activation of vagal afferent nerves connected to nucleus of the solitary tract (NTS) and area postrema in the brain stem, structures associated with nausea and vomiting. Our experiments revealed that RV can infect and replicate in human…
Role of nitric oxide during rotavirus infection.
2006
The pathophysiological mechanisms behind rotavirus-induced diarrhoea still remain incomplete. Current views suggest that the non-structural protein 4 (NSP4) of rotavirus and the enteric nervous system (ENS) participate in water secretion and diarrhoea. In the present work the role of nitric oxide (NO) in rotavirus infection and disease has been studied in vitro, mice and humans. Incubation of human intestinal epithelial cells (HT-29) with purified NSP4 but not with infectious virus produced NO2/NO3 accumulation in the incubation media. The NSP4-induced release of NO metabolites occurred within the first minutes after the addition of the toxin. Mice infected with murine rotavirus (strain EDI…
Btn2p is involved in ethanol tolerance and biofilm formation in flor yeast
2008
Flor yeasts are a particular kind of Saccharomyces cerevisiae strains involved in Sherry wine biological ageing. During this process, yeasts form a film on the wine surface and use ethanol as a carbon source, producing acetaldehyde as a by-product. Acetaldehyde induces BTN2 transcription in laboratory strains. Btn2p is involved in the control of the subcellular localization of different proteins. The BTN2 gene shows a complex expression pattern in wine yeast, increasing its expression by acetaldehyde, but repressing it by ethanol. A flor yeast strain transcribes more BTN2 than a first fermentation yeast during growth, but less under different stress conditions. BTN2 deletion decreases flor …
Physiological and genomic characterisation of Saccharomyces cerevisiae hybrids with improved fermentation performance and mannoprotein release capaci…
2015
Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating lactic-acid bacteria growth. The selection of a yeast strain that simultaneously overproduces mannoproteins and presents good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae × S. cerevisiae hybrid bearing the two oenologically relevant features was constructed. According to the genomic characterisation of the hybrids, different copy numbers of some genes probably related with these physiological features were detected. The hybrid shared not only a similar copy number of genes SPR1…