Search results for "Histocompatibility"

Augmented antigen presentation by mouse Ia + T clone cells BK-BI-2.6.O4.1 mediated by transferrin receptors.

1996

The murine T clone cells BK-BI-2.6.O4.1 (BI/O4.1) synthesize and express MHC class II molecules constitutively. BI/O4.1 cells are able to present various protein antigens to antigen-specific CD4 + T cells. However, a 10-fold higher concentration of antigen is needed to activate specific T cells to lymphokine secretion by BI/O4.1 cells in comparison with spleen cells or with the more homogeneous population of bone marrow-derived macrophages (BMMph). The authors tested whether the reduced antigen presentation potential of BI/O4.1 cells was augmented by transferrin-mediated uptake of the model antigen ovalbumin (OVA) coupled to human ferric transferrin. It was shown that 240-fold less OVA was …

Common variants conferring risk of schizophrenia

2009

Schizophrenia is a complex disorder, caused by both genetic and environmental factors and their interactions. Research on pathogenesis has traditionally focused on neurotransmitter systems in the brain, particularly those involving dopamine. Schizophrenia has been considered a separate disease for over a century, but in the absence of clear biological markers, diagnosis has historically been based on signs and symptoms. A fundamental message emerging from genome-wide association studies of copy number variations (CNVs) associated with the disease is that its genetic basis does not necessarily conform to classical nosological disease boundaries. Certain CNVs confer not only high relative ris…

Isolation and Characterization of CD276+/HLA-E+ Human Subendocardial Mesenchymal Stem Cells from Chronic Heart Failure Patients: Analysis of Differen…

2012

Mesenchymal stem cells (MSCs) are virtually present in all postnatal organs as well as in perinatal tissues. MSCs can be differentiated toward several mature cytotypes and interestingly hold potentially relevant immunomodulatory features. Myocardial infarction results in severe tissue damage, cardiomyocyte loss, and eventually heart failure. Cellular cardiomyoplasty represents a promising approach for myocardial repair. Clinical trials using MSCs are underway for a number of heart diseases, even if their outcomes are hampered by low long-term improvements and the possible presence of complications related to cellular therapy administration. Therefore, elucidating the presence and role of MS…

Surface phenotype and functions of tumor-infiltrating dendritic cells: CD8 expression by a cell subpopulation.

1993

Although the function and significance of tumor-infiltrating dendritic cells (TIDC) in the immune response to tumor have never been clearly demonstrated, their location suggests that they play a critical role in the presentation of tumor antigen to specific T cells. We studied the morphological and functional characteristics of interstitial dendritic cells (DC) located inside tumors obtained by injection of cancer cells into syngeneic rats. Single and double immunostaining of tumor sections revealed a dense network of cells which expressed class II major histocompatibility complex (MHC II) molecules. Cell morphology and surface markers were characteristic of DC populations in other tissues.…

In vitro analysis of the phenotypical and functional properties of the 4F7+ cutaneous accessory dendritic cell

1995

The monoclonal antibody 4F7 detects a molecule on dermal and epidermal Ia+ dendritic cells (DCs), and some of these cells are Birbeck granule-containing cells. Here we report on the phenotypical and functional characteristics of these cells which were highly enriched by 4F7-labelled immunomagnetic beads. The ultrastructural, immunocytochemical and cytochemical analyses of these preparations showed cells with the typical characteristics of DCs. The cells were found to express the DC marker NLDC145, but not 33D1. The C3bi receptor and marker F4/80 were only expressed by epidermal 4F7+ cells. The capacity of freshly isolated 4F7+ epidermal and dermal DCs to activate allogeneic T cells in a mix…

Acquired IFNγ resistance impairs anti-tumor immunity and gives rise to T-cell-resistant melanoma lesions

2016

Melanoma treatment has been revolutionized by antibody-based immunotherapies. IFNγ secretion by CD8+ T cells is critical for therapy efficacy having anti-proliferative and pro-apoptotic effects on tumour cells. Our study demonstrates a genetic evolution of IFNγ resistance in different melanoma patient models. Chromosomal alterations and subsequent inactivating mutations in genes of the IFNγ signalling cascade, most often JAK1 or JAK2, protect melanoma cells from anti-tumour IFNγ activity. JAK1/2 mutants further evolve into T-cell-resistant HLA class I-negative lesions with genes involved in antigen presentation silenced and no longer inducible by IFNγ. Allelic JAK1/2 losses predisposing to …

Third Keystone Symposium on Cellular Immunology and the Immunotherapy of Cancer Antigen Processing and Presentation Autologous Human Dendriphages Pul…

1998

The recent identification of tumor-associated antigens and tumor-associated antigen-derived peptide epitopes recognized by cytolytic T lymphocytes (CTLs) in the context of major histocompatibility complex (MHC) class I molecules has prompted the development of peptide-based vaccines for the treatment of human cancers, particularly melanoma. The design of such clinical protocols requires an understanding of the inherent immunogenicity of the peptide(s) and a choice of a facilitating adjuvant promoting cellular immunity against these peptides. We have evaluated the abilities of a series of defined synthetic peptide epitopes derived from MART- I/Melan-A, gp100, tyrosinase. and MAGE-3 or unfrac…

Effects of gamma interferon on a B16 melanoma cell line and its doxorubicin-resistant variant.

1992

Effects of triterpenes on the immune system.

2010

Ethnopharmacological relevance: Triterpenes, which comprise a broad chemical group of active principles, are implicated in the mechanisms of action and pharmacological effects of many medicinal plants used in folk medicine against diseases in which the immune system is implicated. They have been described as anti-inflammatory, antiviral, antimicrobial, and antitumoral agents, as well as being immunomodulator compounds. Several of them are implicated in the resolution of immune diseases, although their effects have not always been clearly correlated. Aim of the review: The aim of this review is to compile relevant data on the mechanisms of action of triterpenes isolated from active ethnomedi…

Enhanced in vivo targeting of murine nonparenchymal liver cells with monophosphoryl lipid A functionalized microcapsules.

2014

A broad spectrum of infectious liver diseases emphasizes the need of microparticles for targeted delivery of immunomodulatory substances to the liver. Microcapsules (MCs) are particularly attractive for innovative drug and vaccine formulations, enabling the combination of antigen, drugs, and adjuvants. The present study aimed to develop microcapsules characterized by an enhanced liver deposition and accelerated uptake by nonparenchymal liver cells (NPCs). Initially, two formulations of biodegradable microcapsules were synthesized from either hydroxyethyl starch (HES) or mannose. Notably, HES-MCs accumulated primarily in the liver, while mannose particles displayed a lung preference. Functio…