Search results for "MHC"

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…

Alveolar macrophage dynamics in murine lung regeneration

2012

In most mammalian species, the removal of one lung results in dramatic compensatory growth of the remaining lung. To investigate the contribution of alveolar macrophages (AMs) to murine post-pneumonectomy lung growth, we studied bronchoalveolar lavage (BAL)-derived AM on 3, 7, 14 and 21 days after left pneumonectomy. BAL demonstrated a 3.0-fold increase in AM (CD45(+), CD11b(-), CD11c(+), F4/80(+), Gr-1(-)) by 14 days after pneumonectomy. Cell cycle flow cytometry of the BAL-derived cells demonstrated an increase in S + G2 phase cells on days 3 (11.3 ± 2.7%) and 7 (12.1 ± 1.8%) after pneumonectomy. Correspondingly, AM demonstrated increased expression of VEGFR1 and MHC class II between days…

Alveolar Epithelial Dynamics in Postpneumonectomy Lung Growth

2013

The intimate anatomic and functional relationship between epithelial cells and endothelial cells within the alveolus suggests the likelihood of a coordinated response during postpneumonectomy lung growth. To define the population dynamics and potential contribution of alveolar epithelial cells to alveolar angiogenesis, we studied alveolar Type II and I cells during the 21 days after pneumonectomy. Alveolar Type II cells were defined and isolated by flow cytometry using a CD45(-) , MHC class II(+) , phosphine(+) phenotype. These phenotypically defined alveolar Type II cells demonstrated an increase in cell number after pneumonectomy; the increase in cell number preceded the increase in Type …

Il Complesso Maggiore di Istocompatibilità ed il Rigetto dei Trapianti

2009

γδ T cells and their clinical application in colon cancer

2023

In recent years, research has focused on colorectal cancer to implement modern treatment approaches to improve patient survival. In this new era, γδ T cells constitute a new and promising candidate to treat many types of cancer because of their potent killing activity and their ability to recognize tumor antigens independently of HLA molecules. Here, we focus on the roles that γδ T cells play in antitumor immunity, especially in colorectal cancer. Furthermore, we provide an overview of small-scale clinical trials in patients with colorectal cancer employing either in vivo activation or adoptive transfer of ex vivo expanded γδ T cells and suggest possible combinatorial approaches to treat co…

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…

Complete cDNA sequence coding for the MHC class II RT1.B alpha chain of the Lewis rat.

1989

Females tend to prefer genetically similar mates in an island population of house sparrows.

2014

11 pages; International audience; BACKGROUND: It is often proposed that females should select genetically dissimilar mates to maximize offspring genetic diversity and avoid inbreeding. Several recent studies have provided mixed evidence, however, and in some instances females seem to prefer genetically similar males. A preference for genetically similar mates can be adaptive if outbreeding depression is more harmful than inbreeding depression or if females gain inclusive fitness benefits by mating with close kin. Here, we investigated genetic compatibility and mating patterns in an insular population of house sparrow (Passer domesticus), over a three-year period, using 12 microsatellite mar…