Search results for "tolerance"

Regulatory T-Cells in Antitumor Therapy: Isolation and Functional Testing of CD4<SUP>+</SUP>CD25<SUP>+</SUP> Regulatory T-Cel…

2004

Naturally occurring CD4+CD25+ T regulatory cells originate from the thymus and play a central role regarding the maintenance of peripheral tolerance by suppression of autoreactive T-cell populations. However, T regulatory cells can have beneficial as well as harmful effects. On the one hand, they prevent a variety of autoimmune and inflammatory diseases; but on the other hand, they concomitantly inhibit antitumor immune reactions by suppressing tumor-specific T-cell responses. Therefore, these ambivalent properties of T regulatory cells require detailed investigation especially with respect to a potential therapeutic exploitation of these cells. A prerequisite for such analyses is the isola…

Interleukin-10-treated dendritic cells do not inhibit Th2 immune responses in ovalbumin/alum-sensitized mice.

2005

<i>Background:</i> It is well known that the immunoregulatory cytokine interleukin (IL)-10 inhibits the accessory function of human dendritic cells (DC) in vitro. Recently, we have shown that these IL-10 DC inhibit the production of T helper cell 1 (Th1) and T helper cell 2 (Th2) cytokines by T cells from atopic individuals in vitro. The current study was set out to analyze whether IL-10 DC also exert inhibitory effects in vivo in a murine model of allergy to ovalbumin adsorbed to the adjuvant aluminium hydroxide (OVA/alum). <i>Methods:</i> OVA-pulsed or unpulsed bone marrow-derived DC, treated with IL-10 or left untreated during generation, were injected intravenous…

A specific CD4 epitope bound by tregalizumab mediates activation of regulatory T cells by a unique signaling pathway

2014

CD4(+)CD25(+) regulatory T cells (Tregs) represent a specialized subpopulation of T cells, which are essential for maintaining peripheral tolerance and preventing autoimmunity. The immunomodulatory effects of Tregs depend on their activation status. Here we show that, in contrast to conventional anti-CD4 monoclonal antibodies (mAbs), the humanized CD4-specific monoclonal antibody tregalizumab (BT-061) is able to selectively activate the suppressive properties of Tregs in vitro. BT-061 activates Tregs by binding to CD4 and activation of signaling downstream pathways. The specific functionality of BT-061 may be explained by the recognition of a unique, conformational epitope on domain 2 of th…

Interplay of oxidants and antioxidants during exercise: Implications for muscle health

2010

Muscle contraction results in generation of reactive oxygen and nitrogen species (RONS) at a rate determined by the intensity, frequency, and duration of the exercise protocols. Strenuous exercise causes oxidation of protein, lipid, and DNA, release of cytosolic enzymes, and other signs of cell damage; however, only exhaustive exercise is detrimental. Indeed, the regulation of vascular tone, the excitation-contraction coupling, growth, and differentiation in skeletal muscle, are governed in part by RONS. This is accomplished by RONS interaction with redox-sensitive transcription factors, leading to increased gene expression of antioxidant enzymes, cytoprotective proteins, and other enzymes …

Remission of experimental autoimmune hepatitis is associated with antigen-specific and non-specific immunosuppression.

1993

SUMMARY Experimental autoimmune hepatitis (EAH) is an animal model for autoimmune hepatitis. The disease is T cell-mediated and runs a subacute course, with maximal disease activity around week four after disease induction and a slow ensuing recovery. The aim of the present study was to investigate the immunoregulatory mechanisms that may account for recovery in EAH. It was found that T cell reactivity to liver antigens preceded histological disease, but at the peak of disease activity this T cell response was already suppressed. Active and antigen-specific suppression could be demonstrated, as irradiated splenocytes from animals at the beginning of recovery from EAH were able to suppress i…

Nanoparticles and the immune system: challenges and opportunities

2016

How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

2015

This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1). For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace chang…

Detecting Cd adaptation footprint in C. riparius with a multi-genomic approach

2021

AbstractEvolutionary processes and acquired tolerance to toxicants are important factors governing how animals respond to chemical exposure. Evidence for increased tolerance to cadmium (Cd), a widely distributed toxic metal in aquatic environments, in Chironomus riparius is conflicting and still questioned if it happens through phenotypic plasticity or genetic adaptation. The present study considered the relevance of directional environmental changes by increasing contaminant concentration in a multigenerational selection experiment. Evaluation of measurable life-cycle traits, transcriptomic responses and quantitative genetics from an evolve and resequencing (E&R) experiment were integr…

Hubungan Aktivitas Nitrat Reduktase dan Kadar Klorofil Kultivar Kedelai Tahan Kekeringan

2018

<em>Plants suffering from drought stress can be indicated by the changing of character on the morphology, anatomy and physiology, characterized by inhibition of leaf growth, accelerated root growth, stomata closure and leaf curly. Cultivars that are tolerance to drought can physiologically adapted by increasing prolin level reduce the osmotic potential in order to maintain turgor in the condition of low tissue water potential. The research was aimed to study the physiological characters of drought tolerant soybean cultivar of determine the relationship of nitrate reductase activity and chlorophyll content of drought-tolerance cultivars and susceptible to drought stress conditions. The…

Cholera-Like Enterotoxins and Regulatory T cells

2010

Cholera toxin (CT) and the heat-labile enterotoxin of E. coli (LT), as well as their non toxic mutants, are potent mucosal adjuvants of immunization eliciting mucosal and systemic responses against unrelated co-administered antigens in experimental models and in humans (non toxic mutants). These enterotoxins are composed of two subunits, the A subunit, responsible for an ADP-ribosyl transferase activity and the B subunit, responsible for cell binding. Paradoxically, whereas the whole toxins have adjuvant properties, the B subunits of CT (CTB) and of LT (LTB) have been shown to induce antigen specific tolerance when administered mucosally with antigens in experimental models as well as, rece…