Search results for "t cells"

Inhibition of Delayed-Type Hypersensitivity by Cucurbitacin R through the Curbing of Lymphocyte Proliferation and Cytokine Expression by Means of Nuc…

2009

Cucurbitacin R is known to exhibit an anti-inflammatory effect in different experimental models of inflammation. In this article, we outline the effect of cucurbitacin R on T lymphocyte proliferation, cytokine production, and nuclear factor activation, as well as its influence on various experimental models of delayed-type hypersensitivity (DTH) in mice. Cucurbitacin R reduced the proliferation of phytohemagglutinin A-stimulated human T lymphocytes (IC(50), 18 microM), modifying the cell cycle, as well as the production of cytokines [interleukin (IL)-2, IL-4, IL-10, and especially interferon-gamma] and the induction of the principal cyclins implicated in the cell cycle (A(1), B(1), D(2), an…

Dinitrosyl-iron triggers apoptosis in Jurkat cells despite overexpression of Bcl-2

2004

Cells expressing the cytokine-inducible NO synthase are known to trigger apoptosis in neighboring cells. Paramagnetic dinitrosyl nonheme iron complexes (DNIC) were found in tumor tissue about 40 years ago; however, the role of these NO(+)-bearing species is not completely understood. In the human Jurkat leukemia cell line, the application of the model complex DNIC-thiosulfate (50-200 microM) induced apoptosis (defined by phosphatidylserine externalization) in a concentration- and time-dependent manner. In Jurkat cells, the pan-caspase inhibitor, zVADfmk (50 microM), and/or stable transfection of antiapoptotic protein, Bcl-2, was unable to afford protection against DNIC-induced apoptosis. Th…

Revisiting CD8 T-cell ‘Memory Inflation’: New Insights with Implications for Cytomegaloviruses as Vaccine Vectors

2020

Murine models of cytomegalovirus (CMV) infection have revealed an exceptional kinetics of the immune response. After resolution of productive infection, transient contraction of the viral epitope-specific CD8 T-cell pool was found to be followed by a pool expansion specific for certain viral epitopes during non-productive &lsquo

Kalanchoe pinnata inhibits mast cell activation and prevents allergic airway disease

2011

Aqueous extract of Kalanchoe pinnata (Kp) have been found effective in models to reduce acute anaphylactic reactions. In the present study, we investigate the effect of Kp and the flavonoid quercetin (QE) and quercitrin (QI) on mast cell activation in vitro and in a model of allergic airway disease in vivo. Treatment with Kp and QE in vitro inhibited degranulation and cytokine production of bone marrow-derived mast cells following IgE/FcɛRI crosslinking, whereas treatment with QI had no effect. Similarly, in vivo treatment with Kp and QE decreased development of airway hyperresponsiveness, airway inflammation, goblet cell metaplasia and production of IL-5, IL-13 and TNF. In contrast, treatm…

Langerhans Cells Prevent Autoimmunity via Expansion of Keratinocyte Antigen-Specific Regulatory T Cells

2017

Langerhans cells (LCs) are antigen-presenting cells in the epidermis whose roles in antigen-specific immune regulation remain incompletely understood. Desmoglein 3 (Dsg3) is a keratinocyte cell-cell adhesion molecule critical for epidermal integrity and an autoantigen in the autoimmune blistering disease pemphigus. Although antibody-mediated disease mechanisms in pemphigus are extensively characterized, the T cell aspect of this autoimmune disease still remains poorly understood. Herein, we utilized a mouse model of CD4+ T cell-mediated autoimmunity against Dsg3 to show that acquisition of Dsg3 and subsequent presentation to T cells by LCs depended on the C-type lectin langerin. The lack of…

Genetic ablation of mast cells redefines the role of mast cells in skin wound healing and bleomycin-induced fibrosis.

2014

Conclusive evidence for the impact of mast cells (MCs) in skin repair is still lacking. Studies in mice examining the role of MC function in the physiology and pathology of skin regenerative processes have obtained contradictory results. To clarify the specific role of MCs in regenerative conditions, here we used a recently developed genetic mouse model that allows conditional MC ablation to examine MC-specific functions in skin. This mouse model is based on the cell type–specific expression of Cre recombinase in connective tissue–type MCs under control of the Mcpt5 promoter and the Cre-inducible diphtheria toxin receptor–mediated cell lineage ablation by diphtheria toxin. In response to ex…

Optimizing tumor-reactive γδ T cells for antibody-based cancer immunotherapy.

2010

Monoclonal antibodies (mAbs) constitute the most rapidly growing class of human therapeutics and the second largest class of drugs after vaccines. The treatment of B-cell malignancies and HER2/Neu(+) breast cancer has benefited considerably from the use of therapeutic mAbs, either alone or in combination with standard chemotherapy. Frequent relapses, however, demonstrate that the bioactivity of these mAbs is still suboptimal. The concept of improving the anti-tumor activity of mAbs is well established and potentiating the cytotoxicity induced by anticancer mAbs can be achieved by strategies that target the downstream cytolytic effector cells. The recruitment of Fcγ receptor-dependent functi…

Mast cells partly contribute to allergic enteritis development: Findings in two different mast cell-deficient mice

2021

Allergic enteritis (AE) is a gastrointestinal form of food allergy. The presence of mast cells and granulocytes has been detected in the inflamed tissues in AE. In this study, we aimed to elucidate the role of mast cells in AE development using two mast cell-deficient mouse strains: KIT(W-sh/W-sh) bearing the W-sash (W(sh)) inversion mutation and Cpa3Cre/+, which lack mast cells due to Cre-mediated mast cell eradication, were used in an AE experimental model. The development of clinical symptoms (e.g. drop in body temperature and weight loss) were abolished in both strains, whereas inflammatory levels of AE (e.g. villous atrophy, edema, and granulocyte accumulation) were reduced mainly in K…

Mast Cell Deficiency Protects Susceptible BALB/c Mice from Progressive Murine Cutaneous Leishmaniasis.

2020

Role of adipokines signaling in the modulation of T cells function

2013

The field that links immunity and metabolism is rapidly expanding. Apparently non-immunological disorders such as obesity and type 2 diabetes have been linked to immune dysregulation, suggesting that metabolic alterations can be induced by or be consequence of an altered self-immune tolerance. In this context, adipose tissue produces and releases a variety of pro-inflammatory and anti-inflammatory factors, termed "adipokines," which can be considered as the bridge between obesity-related exogenous factors, such as nutrition and lifestyle, and the molecular events leading to metabolic syndrome, inflammatory, and/or autoimmune conditions. In obesity, increased production of most adipokines im…