Search results for "tolerance"

Protection from graft-versus-host disease by HIV-1 envelope protein gp120-mediated activation of human CD4+CD25+ regulatory T cells.

2009

AbstractNaturally occurring CD4+CD25+ regulatory T cells (Tregs) represent a unique T-cell lineage that is endowed with the ability to actively suppress immune responses. Therefore, approaches to modulate Treg function in vivo could provide ways to enhance or reduce immune responses and lead to novel therapies. Here we show that the CD4 binding human immunodeficiency virus-1 envelope glycoprotein gp120 is a useful and potent tool for functional activation of human Tregs in vitro and in vivo. Gp120 activates human Tregs by binding and signaling through CD4. Upon stimulation with gp120, human Tregs accumulate cyclic adenosine monophosphate (cAMP) in their cytosol. Inhibition of endogeneous cA…

ROTATIONAL TOLERANCES IN ABUTMENT-IMPLANT CONNECTION FOR ORIGINAL AND COMPATIBLE ABUTMENTS

2022

Exploring a regulatory role for mast cells: 'MCregs'?

2010

Regulatory cells can mould the fate of the immune response by direct suppression of specific subsets of effector cells, or by redirecting effectors against invading pathogens and infected or neoplastic cells. These functions have been classically, although not exclusively, ascribed to different subsets of T cells. Recently, mast cells have been shown to regulate physiological and pathological immune responses, and thus to act at the interface between innate and adaptive immunity assuming different functions and behaviors at discrete stages of the immune response. Here, we focus on these poorly defined, and sometimes apparently conflicting, functions of mast cells.

An advanced and distributed control architecture based on intelligent agents and neural networks

2004

A new layered architecture for the implementation of intelligent distributed control systems is proposed. The proposed architecture distinguishes four layers in a distributed control system. Upper layer consists of a digital control layer, where high level decisions are taken. This level is implemented by means of intelligent agents that carry out the discrete control functions, system supervision as well as diagnosis and fault tolerance. Third layer deals with numeric values, performs analog operations and implement analog control loops. It is also in carry of the conversion from numerical variables values to evaluated expressions. This layer has been implemented by means of neural network…

Abnormalities in serum concentrations of interleukin-2, interferon-alpha and interferon-gamma in schizophrenia not detected.

1992

The hypothesis of an immunological defect in schizophrenia has been supported by reports on abnormal production of interleukin-2 (IL-2) and interferons (IFNs) in schizophrenic patients. In the present study we determined the serum concentrations of IL-2, IFN-alpha and IFN-gamma in 10 first onset, neuroleptic-naive schizophrenics, in 6 pretreated patients who were drug free (1 week to 2 years) at the time of the investigation and in 15 matched healthy controls. No IFN-alpha was detected in schizophrenics' and in control sera. No differences were found in IL-2 and IFN-gamma levels between schizophrenics and controls. Thus the present study failed to support the hypothesis of an immunological …

Uremic serum inhibits monocyte-dependent, but not interleukin-2-dependent steps of T cell proliferation.

1990

We examined the influence of uremic serum on antigen receptor triggered T cell proliferation in dialysis patients with impaired immune function, i.e., 12 nonresponders to hepatitis B vaccination. The dialysis patients showed a monocyte dysfunction and an increased responsiveness to interleukin 2 (IL-2) according to our previous findings. In vitro the addition of IL-2 completely reconstituted the defect. Uremic serum inhibited monocyte-dependent T cell proliferation of patients and of healthy controls. Contrary, monocyte-independent steps of T cell proliferation were not impaired by uremic serum. When IL-2 was added to cultures, the T cell proliferation in the presence of uremic serum was ev…

Human interleukin 2: molecular biology, physiology and clinical possibilities.

1986

Cyclic adenosine monophosphate is a key component of regulatory T cell–mediated suppression

2007

Naturally occurring regulatory T cells (T reg cells) are a thymus-derived subset of T cells, which are crucial for the maintenance of peripheral tolerance by controlling potentially autoreactive T cells. However, the underlying molecular mechanisms of this strictly cell contact–dependent process are still elusive. Here we show that naturally occurring T reg cells harbor high levels of cyclic adenosine monophosphate (cAMP). This second messenger is known to be a potent inhibitor of proliferation and interleukin 2 synthesis in T cells. Upon coactivation with naturally occurring T reg cells the cAMP content of responder T cells is also strongly increased. Furthermore, we demonstrate that natur…

Prevention and reversal of superantigen-induced anergy by contact allergen exposure

1995

The superantigen Staphylococcal enterotoxin B (SEB) and the contact allergen 2,4-dinitrofluorbenzene (DNFB) both react with V beta 8+ T-cells delivering distinct signals. Pre-treatment with DNFB painted onto the same skin site where SEB was to be injected, prevented the induction of anergy in V beta + T-cells that was otherwise induced after SEB had been injected intradermally over a period of 2 weeks. Application of the irritant sodium dodecyl sulfate (SDS) instead of DNFB did not exert this effect. Application of DNFB at a site distant from the site where SEB was injected resulted in a much weaker inhibitory influence on the induction of anergy by SEB. Established anergy of V beta 8+ T-ce…

The role of emotion regulation and intolerance to uncertainty on the relationship between fear of COVID-19 and distress

2022

AbstractThe COVID-19 pandemic is increasing negative consequences on mental health around the globe. To date, research on what psychological factors could influence individuals’ distress is still scarce. The current study aims to test a multiple mediation model to examine the role of Intolerance of Uncertainty (IU) and emotional regulation (i.e., expressive suppression and cognitive reappraisal) as joint factors, which can increase understanding of psychological distress due to the COVID-19 outbreak. An online survey measuring fear of COVID-19, IU, emotional regulation, and psychological distress was administered to 3863 Italian adults (females 73.3%; Mage = 36.44; SD = 14.74) during lockdo…