Search results for "Lymphocyte"
showing 10 items of 2280 documents
Cre-mediated cell ablation contests mast cell contribution in models of antibody- and T cell-mediated autoimmunity.
2011
SummaryImmunological functions of mast cells remain poorly understood. Studies in Kit mutant mice suggest key roles for mast cells in certain antibody- and T cell-mediated autoimmune diseases. However, Kit mutations affect multiple cell types of both immune and nonimmune origin. Here, we show that targeted insertion of Cre-recombinase into the mast cell carboxypeptidase A3 locus deleted mast cells in connective and mucosal tissues by a genotoxic Trp53-dependent mechanism. Cre-mediated mast cell eradication (Cre-Master) mice had, with the exception of a lack of mast cells and reduced basophils, a normal immune system. Cre-Master mice were refractory to IgE-mediated anaphylaxis, and this defe…
Regulation of IgG antibody responses by epitope density and CD21-mediated costimulation
2002
Epitope density and organization have been shown to be important factors for B cell activation in many animal model systems. However, it has been difficult to separate the role of antigen organization from the role of local antigen concentrations because highly organized antigens are usually particulate whereas non-organized antigens are more soluble. Hence, highly organized and non-organized antigens may interact with different cell types and in different locations within lymphoid organs. In order to assess the role of antigen organization in regulating B cell responses, we immunized mice with highly repetitive virus-like particles, which exhibit different epitope densities covalently atta…
Physical activity specifically evokes release of cell-free DNA from granulocytes thereby affecting liquid biopsy
2022
Clinical epigenetics 14, 29 (2022). doi:10.1186/s13148-022-01245-3
In Activated Murine Mast Cells, NFATc2 Is Critical for the Production of Autocrine IL-3, Thereby Promoting the Expression of IL-9
2019
Abstract IL-9 has lent its numerical designation to the Th9 subset of CD4+ Th cells, although it is also produced by additional cell types, including mast cells. It is a pleiotropic cytokine involved in allergic reactions, parasitic infections, autoimmune inflammation, and cancer immunity. In this article, we provide evidence that NFATc2 has contradictory functions in the expression of IL-9 in murine Th9 cells and bone marrow–derived mast cells (BMMC). The basis for this is our observation that the production of IL-9 in NFATc2-deficient Th9 cells is increased, whereas it is decreased in BMMC devoid of NFATc2. In addition, NFATc2 deficiency almost completely abrogates the expression of IL-3 …
Notch in T Cell Differentiation: All Things Considered.
2015
Differentiation of naive T cells into effector cells is required for optimal protection against different classes of microbial pathogen and for the development of immune memory. Recent findings have revealed important roles for the Notch signaling pathway in T cell differentiation into all known effector subsets, raising the question of how this pathway controls such diverse differentiation programs. Studies in preclinical models support the therapeutic potential of manipulating the Notch pathway to alleviate immune pathology, highlighting the importance of understanding the mechanisms through which Notch regulates T cell differentiation and function. We review these findings here, and outl…
Mast cells control the expansion and differentiation of IL-10-competent B cells
2014
Abstract The discovery of B cell subsets with regulatory properties, dependent on IL-10 production, has expanded our view on the mechanisms that control inflammation. Regulatory B cells acquire the ability to produce IL-10 in a stepwise process: first, they become IL-10 competent, a poised state in which B cells are sensitive to trigger signals but do not actually express the Il-10 gene; then, when exposed to appropriate stimuli, they start producing IL-10. Even if the existence of IL-10–competent B cells is now well established, it is not yet known how different immune cell types cross talk with B cells and affect IL-10–competent B cell differentiation and expansion. Mast cells (MCs) contr…
Dihydrocucurbitacin B Inhibits Delayed Type Hypersensitivity Reactions by Suppressing Lymphocyte Proliferation
2007
We have studied the effects of dihydrocucurbitacin B, a triterpene isolated from Cayaponia tayuya roots, on different models of delayed type hypersensitivity (DTH) in mice, as well as on T-lymphocyte proliferation and the mediators involved. In experiments with mice, dihydrocucurbitacin B inhibited the inflammatory reactions induced by oxazolone, dinitrofluorobenzene, and sheep red blood cells, reducing both the edema and cell infiltration. Moreover, the analysis of inflamed tissues showed that dihydrocucurbitacin B reduced the presence of the most relevant cytokines implicated in these processes, including interleukin-1 beta, interleukin-4, and tumor necrosis factor-alpha. Dihydrocucurbita…
Spontaneous lymphokine synthesis by human blood mononuclear cells
1975
LYMPHOCYTES, after antigenic stimulation, may synthesise and release biologically active soluble factors other than antibodies. These mediators were termed lymphokines by Dumonde1, and the most extensively studied and best characterised are migration inhibitory factors which can inhibit the migration of macrophages or leukocytes: this is the property used for their in vitro bioassay. Apart from antigens, various other stimuli may trigger lymphokine synthesis by lymphocytes, for example, polyclonal mitogens2, anti-immunoglobulin or membrane Fc or C3-receptor reactions3,4. Furthermore, migration inhibitory activity has been found in the long term culture supernatants of some established lymph…
The transcription factor Interferon Regulatory Factor 4 is required for the generation of protective effector CD8 + T cells
2013
Robust cytotoxic CD8 + T-cell response is important for immunity to intracellular pathogens. Here, we show that the transcription factor IFN Regulatory Factor 4 (IRF4) is crucial for the protective CD8 + T-cell response to the intracellular bacterium Listeria monocytogenes . IRF4-deficient ( Irf4 −/− ) mice could not clear L. monocytogenes infection and generated decreased numbers of L. monocytogenes -specific CD8 + T cells with impaired effector phenotype and function. Transfer of wild-type CD8 + T cells into Irf4 −/− mice improved bacterial clearance, suggesting an intrinsic defect of CD8 + T cells in Irf4 −/− mice. Following transfer into wild-type recipients, Irf4 −/− CD8 + T cells bec…
Th9 cells, new players in adaptive immunity.
2014
Upon antigen-specific stimulation, naive CD4⁺ T cells have the potential to differentiate into various T helper (Th) cell subsets. Earlier models of Th cell differentiation focused on IFN-γ-producing Th1 cells and IL-4-secreting Th2 cells. The discovery of additional CD4⁺ Th cell subsets has extended our understanding of Th cell differentiation beyond this dichotomy. Among these is the recently described Th9 cell subset, which preferentially produces interleukin (IL)-9. Here, we review the latest developments in Th9 cell development and differentiation, focusing on contributing environmental signals, and discuss potential physiological and pathophysiological functions of these cells. We des…