Search results for "MHC"
showing 10 items of 233 documents
Large scale preparation of human MHC class II+ integrin beta(1)+ Tregs.
2010
Abstract The human CD4 + CD25 + FoxP3 + regulatory T cell population (Tregs) contains both MHC class II + and MHC class II − cells. MHC class II + Tregs belong to the integrin α 4 β 1 + subpopulation and exclusively execute contact-dependent suppressive activity. Here we present a method optimized for isolation of these MHC class II expressing Tregs from large leukaphereses products using magnetic microbeads that achieves a reproducible purity of more than 90% and enables the use of this small-sized Treg population in pre-clinical application and basic research.
Butyrophilin 3A1 presents phosphoantigens to human γδ T cells: the fourth model of antigen presentation in the immune system.
2013
Butyrophilin 3A1 presents phosphoantigens to human γδ T cells: the fourth model of antigen presentation in the immune system
An MHC class II-expressing T cell clone presenting conventional antigen lacks the ability to present bacterial superantigen.
1995
We have analyzed the response of rat T cells to myelin basic protein (MBP) and the bacterial superantigen, staphylococcal enterotoxin E (SEE). Rat T cells reactive with MBP can respond to SEE presented by spleen cells but not to SEE presented by LOA, a rat T cell clone that expresses both I-A and I-E MHC class II molecules, even though LOA is much more efficient than splenic APC in the presentation of MBP. The inability of LOA to present superantigen is not due to a structural difference in MHC II molecules between LOA and the splenic APC or to differential expression of major accessory/adhesion molecules, including CD2, CD5, CD4 and CD44, on LOA. The non-responsiveness of SEE/LOA-induced T…
Structure Learning in Nested Effects Models
2007
Nested Effects Models (NEMs) are a class of graphical models introduced to analyze the results of gene perturbation screens. NEMs explore noisy subset relations between the high-dimensional outputs of phenotyping studies, e.g., the effects showing in gene expression profiles or as morphological features of the perturbed cell. In this paper we expand the statistical basis of NEMs in four directions. First, we derive a new formula for the likelihood function of a NEM, which generalizes previous results for binary data. Second, we prove model identifiability under mild assumptions. Third, we show that the new formulation of the likelihood allows efficiency in traversing model space. Fourth, we…
Neuronal nitric oxide synthase modulates maturation of human dendritic cells.
2010
AbstractDendritic cells (DCs) are the most potent APCs of the immune system. Understanding the intercellular and intracellular signaling processes that lead to DC maturation is critical for determining how these cells initiate T cell-mediated immune processes. NO synthesized by the inducible NO synthase (iNOS) is important for the function of murine DCs. In our study, we investigated the regulation of the arginine/NO-system in human monocyte-derived DCs. Maturation of DCs induced by inflammatory cytokines (IL-1β, TNF, IL-6, and PGE2) resulted in a pronounced expression of neuronal NOS (nNOS) but only minimal levels of iNOS and endothelial NOS were detected in human mature DCs. In addition, …
Mycoplasma fermentans-derived lipid inhibits class II major histocompatibility complex expression without mediation by interleukin-6, interleukin-10,…
1996
Mycoplasma cause several diseases in man and animals. Some strains can chronically infect humans, leading to fever or inflammatory syndromes such as arthritis, particularly in immunosuppressed patients. A set of pathogenicity factors shared by many mollicutes may be membrane components that activate macrophages to secrete cytokines and other inflammatory mediators. Mycoplasma-derived high molecular weight material (MDHM) is a macrophage-activating amphiphilic lipid which was purified from Mycoplasma fermentans. We studied the influence of MDHM on the expression of major histocompatibility complex (MHC) class II molecules by mouse resident peritoneal macrophages with an ELISA. Highly purifie…
Beta-Catenin mediates tumor-induced immunosuppression by inhibiting cross-priming of CD8(+) T cells
2014
Tumors activate -catenin in DCs to suppress CD8 immunity by inhibiting cross-priming; -catenin-suppressed CD8 immunity could be rescued by enhancing cross-priming. Whereas CD8(+) T cells are essential for anti-tumor immunity, tumors often evade CD8(+) T cell surveillance by immunosuppression. As the initiators of antigen-specific immune responses, DCs are likely to play a central role in regulating the balance between immunity and tolerance to tumor antigens and are specialized in their ability to cross-present exogenous tumor antigens on MHC class I molecules to initiate CD8(+) T cell immunity. However, it remains unclear whether and how tumors modulate DC functions to suppress CD8(+) T ce…
Cortical neurons selectively inhibit MHC class II induction in astrocytes but not in microglial cells.
1993
Astrocytes have been shown to act as potent accessory cells for MHC class II-restricted T cell responses in vitro after treatment with interferon-gamma. In contrast, even under conditions of severe central nervous system (CNS) inflammation, they seem to express little, if any, class II molecules in vivo. Thus the role of astroglial cells as accessory cells in immune responses in the CNS remains to be determined. We have studied neuron--glia interactions with respect to induction of MHC class II molecules. Surprisingly, in a co-culture system, viable neurons inhibited the induction of class II restriction elements on astrocytes. This effect was only observed when neurons had contact to astro…
Macrophages are dispensable for superantigen-mediated stimulation and anergy induction of peripheral T cells in vivo.
1994
Bacterial superantigens provoke T lymphocyte activation by cross-linking the variable part of the T cell receptor (TCR) beta-chain with MHC class II molecules on antigen-presenting cells. Although the molecular mechanisms of this interaction are well characterized, the in vivo accessory cell requirements for this stimulation of T lymphocytes by bacterial superantigens remain unknown. In the present study we have addressed the role of splenic macrophages in the activation of V beta 8+ peripheral T cells by staphylococcal enterotoxin B (SEB) in BALB/c mice. SEB-triggered clonal expansion and subsequent induction of unresponsiveness of both CD4+ and CD8+ T cells were investigated in naive anim…
The Role of the Major Histocompatibility Gene Complex in Murine Cytotoxic T Cell Responses
1980
Publisher Summary An interpretation of the function of major histocompatibility complex (MHC) in cytotoxic T cell responses requires making certain assumptions, which, because of the lack of experimental data, are often based on intuition. This chapter discusses some specific aspects of the role of MHC in cytotoxic T cell responses. It also summarizes the expression of T cell-mediated responses to alloantigens. It also focuses on H-2-restricted cytotoxic T lymphocytes (CTL) responses and discusses the influence of the MHC on cytotoxic T cell specificity and CTL responsiveness against foreign antigens. T cell responses to alloantigens mirror all the functional activities seen in H-2-restrict…