Search results for " present"
showing 10 items of 566 documents
IL-10 down-regulates T cell activation by antigen-presenting liver sinusoidal endothelial cells through decreased antigen uptake via the mannose rece…
1998
SUMMARYOur study demonstrates that antigen-presenting liver sinusoidal endothelial cells (LSEC) induce production of interferon-gamma (IFN-γ) from cloned Th1 CD4+ T cells. We show that LSEC used the mannose receptor for antigen uptake, which further strengthened the role of LSEC as antigen-presenting cell (APC) population in the liver. The ability of LSEC to activate cloned CD4+ T cells antigen-specifically was down-regulated by exogenous prostaglandin E2 (PGE2) and by IL-10. We identify two separate mechanisms by which IL-10 down-regulated T cell activation through LSEC. IL-10 decreased the constitutive surface expression of MHC class II as well as of the accessory molecules CD80 and CD86 …
SISTEMI VERDI COME CULTURA RIGENERATIVA: STRUMENTI E TECNOLOGIE
2021
The study analyzes and proposes in the historical and in the area immediately to it adjacent, the "values-nature" of the buildings through the creation of gardens wall and vertical gardens in the elevatiloy of non-monumental buildings. The study deepens in particular the specificity of the garden roof and the garden vertical, recognizing benefits and critical issues that distinguish these green systems for construction. It also deepens the concept of resilience in close relationship sustainability and regenerative design applied to the built environment. The theme of regenerative design is studied and promoted as an adaptive strategy at the design stage; it requires you to leave nature stre…
Coincident airway exposure to low-potency allergen and cytomegalovirus sensitizes for allergic airway disease by viral activation of migratory dendri…
2019
Despite a broad cell-type tropism, cytomegalovirus (CMV) is an evidentially pulmonary pathogen. Predilection for the lungs is of medical relevance in immunocompromised recipients of hematopoietic cell transplantation, in whom interstitial CMV pneumonia is a frequent and, if left untreated, fatal clinical manifestation of human CMV infection. A conceivable contribution of CMV to airway diseases of other etiology is an issue that so far attracted little medical attention. As the route of primary CMV infection upon host-to-host transmission in early childhood involves airway mucosa, coincidence of CMV airway infection and exposure to airborne environmental antigens is almost unavoidable. For i…
Antigen-processing machinery breakdown and tumor growth.
2000
Defects in the major histocompatibility complex (MHC) class I antigen-processing machinery (APM) have been described in tumors of different histology. Murine data suggest that defects in the MHC class II APM might also be associated with malignant transformation of human cells. This article describes the pathophysiology of the MHC class I and II APM, reviews APM abnormalities in tumor cells and discusses their role in the escape of tumor cells from in vitro recognition by T cells.
Major histocompatibility complex class I-restricted activation of cloned T cells by a soluble protein in the absence of accessory cells.
1989
A T-cell clone, 10BK.1, was established from the draining lymph nodes of (B10 x B10.BR)F1 mice immunized with ovalbumin (OVA) according to standard protocols. Upon coculture with the antigen, 10BK.1 cells reacted by production of lymphokines and by proliferation despite the absence of additional antigen-presenting cells. These T cells do not express major histocompatibility complex (MHC) class II molecules on the cell surface as assessed on the basis of several criteria: by cytofluorometric analysis I-A and I-E determinants were not detectable; 10BK.1 cells could not act as antigen-presenting cells for long-term-cultured MHC class II-restricted T-cell clones; and monoclonal antibodies direc…
Evidence for T cell receptor-HLA class II molecule interaction in the response to superantigenic bacterial toxins
1991
The staphylococcal enterotoxins and related microbial T cell mitogens stimulate T cells by cross-linking variable parts of the T cell receptor (TcR) with MHC class II molecules on accessory or target cells. In this report we describe that a given combination of T cell, accessory cell (AC) and toxin can be non-stimulatory. However, the same T cell can respond to the same toxin on another AC and the same AC can present the same toxin to another T cell. This indicates that in the complex formed between TcR, toxin and class II molecule an interaction between TcR and class II molecule takes place.
Requirements of Exogenous Protein Antigens for Presentation to CD4+ T lymphocytes By MHC Class II-Positive APC
1993
The antigen-specific activation of CD4-positive T helper cells depends on the recognition of a complex of MHC class II molecules and an antigen-derived peptide on the surface of antigen-presenting cells (APC). For most antigens generation of this MHC/peptide complex requires the uptake of the respective antigen by APC, followed by intracellular processing. The latter leads to suitable peptides of the antigen which are able to bind to MHC class ll-molecules. Subsequently the resulting complexes are transported to the cell surface. Evidence supporting this concept came mainly from the finding that agents such as chloroquine1, interfering with the function of endosomes and lysosomes, can block…
Processing and Presentation of Protein and Parasite-Derived Antigens by 4F7+ Dendritic Cells
1995
The dendritic cell (DC), a trace component of splenocytes is the principal cell type required for a primary mixed lymphocyte reaction.1 Splenic DC are described as antigen presenting cells (APC) capable to generate immunogenic fragments of intact protein antigens for presentation to MHC class II restricted T cells,2 in contrast to former findings.3 Langerhans cells (LC) as potent APC are members of the dendritic cell lineage forming a system of potent APC, first identified by Steinman and Conn.4 Importanly Schuler and Steinman have subsequently presented experimental evidence suggesting that LC represent immature DC.3 During infectious diseases caused by parasites of the genus Leishmania LC…
Toxoplasma gondii down-regulates MHC class II gene expression and antigen presentation by murine macrophages via interference with nuclear translocat…
2001
The obligate intracellular protozoan parasite Toxoplasma gondii is able to establish persistent infections within human and animal hosts. We have shown recently that T. gondii down-regulates IFN-γ-induced MHC class II expression in murine bone marrow-derived macrophages (BMMΦ). As shown in this study, the capacity of IFN-γ-activated murine BMMΦ to present ovalbumin to CD4+ T cell hybridomas was dose-dependently inhibited by T. gondii. IFN-γ-induced up-regulation of H2-Aa, H2-Ab, H2-Eb, H2-Ma, H2-Mb, H2-Oa and invariant chain transcripts was prominently down-regulated by T. gondii. Furthermore, mRNA levels of class II transactivator and interferon-regulatory factor-1 were significantly dimin…
The Hsc/Hsp70 Co-Chaperone Network Controls Antigen Aggregation and Presentation during Maturation of Professional Antigen Presenting Cells
2011
The maturation of mouse macrophages and dendritic cells involves the transient deposition of ubiquitylated proteins in the form of dendritic cell aggresome-like induced structures (DALIS). Transient DALIS formation was used here as a paradigm to study how mammalian cells influence the formation and disassembly of protein aggregates through alterations of their proteostasis machinery. Co-chaperones that modulate the interplay of Hsc70 and Hsp70 with the ubiquitin-proteasome system (UPS) and the autophagosome-lysosome pathway emerged as key regulators of this process. The chaperone-associated ubiquitin ligase CHIP and the ubiquitin-domain protein BAG-1 are essential for DALIS formation in mou…