Search results for "Histocompatibility"
showing 10 items of 473 documents
Mapping and expression pattern analysis of key components of the major histocompatibility complex class I antigen processing and presentation pathway…
2001
Renal cell carcinoma (RCC) represent approximately 5% of all cancer deaths. At the time of presentation, over 50% of the patients have already developed locally advanced or metastatic disease with five-year survival rates of less than 20%. Although relative resistant to conventional regimens, RCC are partially susceptible to T cell-based immunotherapy. To further develop this treatment modality, two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) was applied for both the mapping of the key components of the major histocompatibility complex (MHC) class I antigen processing and presentation machinery (APM) and the characterization of the constitutive and cytokine-regulated protein e…
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…
Tumor associated antigens in human renal cell carcinoma: MHC restricted recognition by cytotoxic T lymphocytes.
1996
Based on previous studies in human melanoma leading to the molecular cloning of genes encoding peptide antigens recognized by MHC-restricted cytotoxic T lymphocytes (CTL) we extended our efforts to renal cancer systems established in tissue culture. In two patients we obtained stable CD8+ CTL clones with high cytolytic activity for the corresponding autologous tumor cell line in vitro. Neither autologous EBV-transformed B lymphocytes or PHA-activated PBL nor natural killer targets K562 were lysed by these CTL clones. MZ1257-RCC CTL5-30 lysed autologous tumor cells as well as normal kidney cell cultures in an HLA-A2 restricted fashion. Further specificity analysis showed cross reactivity wit…
Tonic T cell signalling and T cell tolerance as opposite effects of self-recognition on dendritic cells.
2010
Naive T cells spend most of their time scanning the surface of dendritic cells (DCs), indicating that self-MHC/T cell receptor (TCR) interactions between these immune cells occur routinely in peripheral organs during the steady state. Peripheral self-MHC recognition on DCs drives seemingly opposing effects in the absence of inflammatory stimuli such as deletion of certain self-reactive T cells as well as maintenance of the T cell responsiveness to antigen, both of which shape the T cell repertoire and regulate T cell responses. Here we review recent data on the role of self-MHC recognition on steady-state DCs in the periphery and propose that interactions between T cells and steady-state DC…
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…
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…
Gene transfer of the Co-stimulatory molecules B7-1 and B7-2 enhances the immunogenicity of human renal cell carcinoma to a different extent.
1999
Stimulation of a specific antitumour immune response with recruitment and induction of T-cell effector functions represents an attractive concept in human cancer therapy. Different cytokines and the B7 co-stimulatory molecules are both able to provide proliferation and activation signals for T cells. In the present study, we first demonstrated the absence of both B7-1 and B7-2 expression in human renal cell carcinoma (RCC) cell lines. The lack of B7 expression was associated with a low or absent proliferative response of allogeneic and autologous T cells upon stimulation with tumour cells. In order to investigate the role of B7-1 and B7-2, the human RCC cell line, MZ1257RC, which expresses …
Mechanical Regulation of the Cytotoxic Activity of Natural Killer Cells
2020
AbstractMechanosensing has been recently explored for T cells and B cells and is believed to be part of their activation mechanism. Here, we explore the mechanosensing of the third type of lymphocytes – Natural Killer (NK) cells, by showing that they modulate their immune activity in response to changes in the stiffness of a stimulating surface. Interestingly, we found that this immune response is bell-shaped, and peaks for a stiffness of a few hundreds of kPa. This bell-shape behavior was observed only for surfaces functionalized with the activating ligand MHC class I polypeptide-related sequence A (MICA), but not for control surfaces lacking immunoactive functionalities. We found that sti…
HLA-DR phenotypes and blood levels of T cell subsets
1984
Blood mononuclear cell and T cell subsets values were analyzed in 53 Sicilian individuals according to HLA-DR phenotypes. The results demonstrate that DR1-positive subjects show a significant increase of blood T cell subsets whereas DR3-positive subjects show a non-significant decrease of these values. These results suggest that gene(s) associated with HLA-DR could be one of the factors which affect blood levels of T cell subsets.
Disruption of T helper 2-immune responses in Epstein–Barr virus-induced gene 3-deficient mice
2002
Epstein–Barr virus-induced gene 3 (EBI3) is a widely expressed IL-12p40-related protein that associates as a heterodimer with either IL-12p35 or an IL-12p35 homologue, p28, to create a new cytokine (IL-27). To define the function of EBI3in vivo, we generated knockout mice in which theebi3gene was targeted by homologous recombination. EBI3−/−mice exhibited normal numbers of both naive and mature CD4+and CD8+T cells and B cells, but markedly decreased numbers of invariant natural killer T cells (iNKT) as defined by staining with an α-galactosylceramide (αGalCer)-loaded CD1d-tetramer. iNKT cells from EBI3−/−mice exhibited decreased IL-4 and, to a lesser extent, IFN-γ production after αGalCer s…