Search results for "Immunologic"
showing 10 items of 1115 documents
Two new biologically active triterpenoidal saponins acylated with salicylic acid from Albizia adianthifolia
2003
International audience; Two new oleanane-type triterpene saponins, adianthifoliosides A (1) and B (2), were isolated from a 95% ethanolic extract of roots of Albizia adianthifolia. Their structures were elucidated mainly by using a combination of 600 MHz 1D and 2D NMR techniques (COSY, NOESY, TOCSY, HSQC, and HMBC) and by FABMS and HRESIMS. Compounds 1 and 2 were characterized as glycosides of acacic acid acylated by an o-hydroxybenzoyl unit. The crude saponin mixture (CSM), compounds 1 and 2 together with 3 and 4 (prosapogenins obtained from the mild alkaline hydrolysate of the CSM), were evaluated for immunomodulatory activity on the Jurkat T cell line and for hemolytic property against s…
From molecular genetics to phylodynamics: evolutionary relevance of mutation rates across viruses.
2012
Although evolution is a multifactorial process, theory posits that the speed of molecular evolution should be directly determined by the rate at which spontaneous mutations appear. To what extent these two biochemical and population-scale processes are related in nature, however, is largely unknown. Viruses are an ideal system for addressing this question because their evolution is fast enough to be observed in real time, and experimentally-determined mutation rates are abundant. This article provides statistically supported evidence that the mutation rate determines molecular evolution across all types of viruses. Properties of the viral genome such as its size and chemical composition are…
In vitro generated human memory-like T cells are CD95 type II cells and resistant towards CD95-mediated apoptosis
2006
An adaptive immune response implies expansion of activated T cells and subsequent elimination to maintain homeostasis in a process called activation-induced cell death. Some cells, however, differentiate into memory cells and ensure a strong secondary immune response. To analyze the apoptosis phenotype of memory T cells on a cellular and molecular level, we have established an in vitro model of T cell activation and generation of cells phenotypically and functionally similar to memory cells. These long-term cultured T cells show a CD95-resistant phenotype, although they are still sensitive towards TCR/CD3-mediated apoptosis. Biochemical analysis revealed that these cells shift from CD95 typ…
Isolation and differential expression of two isoforms of the ROBO2/Robo2 axon guidance receptor gene in humans and mice.
2006
AbstractExpression of Robo receptor molecules is important for axon guidance across the midline of the mammalian central nervous system. Here we describe novel isoform a of human ROBO2, which is initially strongly expressed in the fetal human brain but thereafter only weakly expressed in adult brain and a few other tissues. The known isoform b of ROBO2 shows a more or less ubiquitous expression pattern, suggesting diverse functional roles. The genomic structure and distinct expression patterns of Robo2a and Robo2b have been conserved in the mouse, but in contrast to human ROBO2a mouse Robo2a is also abundant in adult brain. Exons 1 and 2 of human ROBO2a lie in an inherently unstable DNA seg…
Sea Urchin Granuloma
2005
Sea urchin granuloma is a chronic focal response to the puncture of sea urchin spines, induced by the permanence of prickle remnants in the wound. Until recent years, it was thought to represent a foreign body reaction but, following the description, in 2001, of its several histologic forms, the spectrum of its likely pathogenetic mechanisms has widened to include the immune responses to different non-self antigens. Depending on individual reactivity, in most cases, a limited number of granulomas is observed, however numerous the punctures may be. We report a case with more than 200 lesions and a tuberculoid histologic pattern, indicative of an immune reaction.
Occurrence, mitigation and in vitro cytotoxicity of nivalenol, a type B trichothecene mycotoxin - Updates from the last decade (2010-2020).
2021
Abstract The present review aims to give an overview of the literature of the last decade (2010–2020) concerning the occurrence of the type B trichothecene mycotoxin nivalenol (NIV) and its in vitro toxicity, with the purpose of updating information regarding last researches on this mycotoxin. The most recent studies on the possible methods for preventing Fusarium spp. growth and NIV production are also discussed. Recently, various environmental factors have been shown to influence strongly NIV occurrence. However, Fusarium spp. of the NIV genotype have been found almost worldwide. With regard to NIV cytotoxicity, NIV has been reported to cause a marked decrease in cell proliferation in dif…
The nuclear protein Sge1 of Fusarium oxysporum is required for parasitic growth
2009
Dimorphism or morphogenic conversion is exploited by several pathogenic fungi and is required for tissue invasion and/or survival in the host. We have identified a homolog of a master regulator of this morphological switch in the plant pathogenic fungus Fusarium oxysporum f. sp. lycopersici. This non-dimorphic fungus causes vascular wilt disease in tomato by penetrating the plant roots and colonizing the vascular tissue. Gene knock-out and complementation studies established that the gene for this putative regulator, SGE1 (SIX Gene Expression 1), is essential for pathogenicity. In addition, microscopic analysis using fluorescent proteins revealed that Sge1 is localized in the nucleus, is no…
Identification of sequences in the human peptide transporter subunit TAP1 required for transporter associated with antigen processing (TAP) function
2001
The heterodimeric peptide transporter associated with antigen processing (TAP) consisting of the subunits TAP1 and TAP2 mediates the transport of cytosolic peptides into the lumen of the endoplasmic reticulum (ER). In order to accurately define domains required for peptide transporter function, a molecular approach based on the construction of a panel of human TAP1 mutants and their expression in TAP1(-/-) cells was employed. The characteristics and biological activity of the various TAP1 mutants were determined, and compared to that of wild-type TAP1 and TAP1(-/-) control cells. All mutant TAP1 proteins were localized in the ER and were capable of forming complexes with the TAP2 subunit. H…
Drp1 Controls Effective T Cell Immune-Surveillance by Regulating T Cell Migration, Proliferation, and cMyc-Dependent Metabolic Reprogramming
2018
Summary Mitochondria are key players in the regulation of T cell biology by dynamically responding to cell needs, but how these dynamics integrate in T cells is still poorly understood. We show here that the mitochondrial pro-fission protein Drp1 fosters migration and expansion of developing thymocytes both in vitro and in vivo. In addition, we find that Drp1 sustains in vitro clonal expansion and cMyc-dependent metabolic reprogramming upon activation, also regulating effector T cell numbers in vivo. Migration and extravasation defects are also exhibited in Drp1-deficient mature T cells, unveiling its crucial role in controlling both T cell recirculation in secondary lymphoid organs and acc…
Exposure to N-ethyl-N-nitrosourea in adult mice alters structural and functional integrity of neurogenic sites.
2011
BackgroundPrevious studies have shown that prenatal exposure to the mutagen N-ethyl-N-nitrosourea (ENU), a N-nitroso compound (NOC) found in the environment, disrupts developmental neurogenesis and alters memory formation. Previously, we showed that postnatal ENU treatment induced lasting deficits in proliferation of neural progenitors in the subventricular zone (SVZ), the main neurogenic region in the adult mouse brain. The present study is aimed to examine, in mice exposed to ENU, both the structural features of adult neurogenic sites, incorporating the dentate gyrus (DG), and the behavioral performance in tasks sensitive to manipulations of adult neurogenesis.Methodology/principal findin…