Search results for "Humanized mouse"

Gene Therapy With a High-Affinity Single-Chain p53-Specific TCR Mediates Potent Anti-Tumor Response Without Inducing Gvhd In Vivo

2013

Abstract The adoptive transfer of tumor-reactive cells is a promising approach in the treatment of human malignancies, but the challenge of isolating T cells with high-avidity for tumor antigens in each patient has limited its widespread application. Using HLA-A2.1 transgenic mice, we have demonstrated the feasibility of T-cell receptor (TCR) gene transfer into T cells to circumvent self-tolerance to the widely expressed human p53(264-272) tumor-associated antigen and developed approaches to generate high-affinity CD8-independent TCR. However, a safety concern of TCR gene transfer is the risk of pairing between introduced and the naturally expressed endogenous TCR chains, resulting in the g…

Interferon-α Suppresses cAMP to Disarm Human Regulatory T Cells

2013

Abstract IFN-α is an antineoplastic agent in the treatment of several solid and hematologic malignancies that exerts strong immune- and autoimmune-stimulating activity. However, the mechanisms of immune activation by IFN-α remain incompletely understood, particularly with regard to CD4+CD25highFoxp+ regulatory T cells (Treg). Here, we show that IFN-α deactivates the suppressive function of human Treg by downregulating their intracellular cAMP level. IFN-α–mediated Treg inactivation increased CD4+ effector T-cell activation and natural killer cell tumor cytotoxicity. Mechanistically, repression of cAMP in Treg was caused by IFN-α–induced MAP–ERK kinase (MEK)/extracellular signal-regulated ki…

The LDL receptor in the retina: the missing link in aging, the new target in dietary prevention

2012

National audience; Purpose: The discovery of the LDL receptor (LDLR) in 1985 by Brown and Goldstein was awarded by a Nobel Prize. The LDLR has initially been identified for its role in mediating the endocytosis of LDL particles in the vascular endothelium. The deposition of lipids, including cholesterol and cholesteryl esters in Bruch’s Membrane in the one hand, and in the vessel intima in the other hand, is one of the common features of age related macular degeneration (AMD) and cardiovascular disease (CVD). Dietary habits with high intakes of omega 3 long chain fatty acids (LCFA) have been associated with AMD prevention. Similar effects have been demonstrated in CVD prevention. The mechan…

2014

TGF- β is a highly pleiotropic cytokine and a well-known suppressor of inflammatory T cells. Dysregulation in TGF- β function is associated with multiple pathological phenomenons including tumor cell growth, fibrosis and autoimmunity. GARP (glycoprotein A repetitions predominant) is an activation maker on human regulatory T cells (Treg) which is known to modulate the bioavailability of TGF- β . To address the cell-independent regulatory capacity of GARP we generated a soluble GARP protein (sGARP). Interestingly, T cells cultured in presence of sGARP showed SMAD2/3 phosphorylation similar to TGF- β treated T cells. In addition, sGARP function was inhibited by blockade of TGF- β -signaling, s…

2017

Allogeneic hematopoietic stem cell transplantation is the only curative treatment option for several hematological malignancies and immune deficiency syndromes. Nevertheless, the development of a graft-versus-host disease (GvHD) after transplantation is a high risk and a severe complication with high morbidity and mortality causing therapeutic challenges. Current pharmacological therapies of GvHD lead to generalized immunosuppression followed by severe adverse side effects including infections and relapse of leukemia. Several novel cell-based immunomodulatory strategies for treatment or prevention of GvHD have been developed. Herein, thymus-derived regulatory T cells (tTreg), essential for …

Enhanced production of CCL18 by tolerogenic dendritic cells is associated with inhibition of allergic airway reactivity

2012

Background IL-10–treated dendritic cells (DCs) have been shown to inhibit T-cell responses through induction of anergy and regulatory T cells in various model systems, including allergic inflammation, but the factors being involved in this inhibition are still unclear. Objective This study set out to analyze such factors produced or induced by IL-10–treated DCs by using gene expression profiling and to explore their function. Methods CD4 + T cells from allergic donors were stimulated with autologous monocyte-derived allergen-pulsed mature DCs or IL-10–treated DCs. After 24 hours, the transcriptional profile was analyzed by using Affymetrix technology. Results were validated by using quantit…

GARP inhibits allergic airway inflammation in a humanized mouse model

2016

Background Regulatory T cells (Treg) represent a promising target for novel treatment strategies in patients with inflammatory/allergic diseases. A soluble derivate of the Treg surface molecule glycoprotein A repetitions predominant (sGARP) has strong anti-inflammatory and regulatory effects on human cells in vitro as well as in vivo through de novo induction of peripheral Treg. The aim of this study was to investigate the immunomodulatory function of sGARP and its possible role as a new therapeutic option in allergic diseases using a humanized mouse model. Methods To analyze the therapeutic effects of sGARP, adult NOD/Scidγc−/− (NSG) mice received peripheral blood mononuclear cells (PBMC) …

Activated glycoprotein A repetitions predominant (GARP)-expressing regulatory T cells inhibit allergen-induced intestinal inflammation in humanized m…

2015

Background Recently, we developed a humanized mouse model of allergen-induced IgE-dependent gut inflammation in PBMC-engrafted immunodeficient mice. Objective In the present study, we wanted to investigate the role of regulatory T (Treg) cells and their activation status in this model. Methods Nonobese diabetic-severe combined immunodeficiency-γc −/− mice were injected intraperitoneally with human PBMCs from allergic donors together with the respective allergen or NaCl as control in the presence or absence of different concentrations of CD4 + CD25 + Treg cells of the same donor. After an additional allergen boost 1 week later, mice were challenged with the allergen rectally on day 21 and gu…

Reduction Of Pulmonary Inflammation Through HIV-1 Envelope Protein GP120 In A Humanized Mouse Model Of Allergic Asthma Depends On Regulatory T Cells

2011

Depletion of CD56+CD3+ invariant natural killer T cells prevents allergen-induced inflammation in humanized mice

2021

Background CD56-expressing natural killer (NK) cells as well as invariant NK T (iNKT) cells have been shown to either promote or inhibit allergic immune responses. Objective The aim of the present study was to investigate the impact of these cells in a recently developed humanized mouse model of allergen-induced IgE-dependent gut and lung inflammation. Methods Nonobese diabetic–severe combined immunodeficiency γ-chain knockout mice were injected intraperitoneally with human PBMCs or CD56-depleted (CD56neg) PBMCs from highly sensitized donors with birch or grass pollen allergy together with the respective allergen or with NaCl as a control. Three weeks later, the mice were challenged with th…