Search results for "MHC Class II"
showing 10 items of 82 documents
Microglial activation milieu controls regulatory T cell responses.
2013
Abstract Although mechanisms leading to brain-specific inflammation and T cell activation have been widely investigated, regulatory mechanisms of local innate immune cells in the brain are only poorly understood. In this study, to our knowledge we show for the first time that MHC class II+CD40dimCD86dimIL-10+ microglia are potent inducers of Ag-specific CD4+Foxp3+ regulatory T cells (Tregs) in vitro. Microglia differentially regulated MHC class II expression, costimulatory molecules, and IL-10 depending on the amount of IFN-γ challenge and Ag dose, promoting either effector T cell or Treg induction. Microglia-induced Tregs were functionally active in vitro by inhibiting Ag-specific prolifer…
H2-Mβ1 and H2-Mβ2 Heterodimers Equally Promote CLIP Removal in I-Aq Molecules from Autoimmune-prone DBA/1 Mice
2001
Antigen-presenting cells degrade endocytosed antigens, e.g. collagen type II, into peptides that are bound and presented to arthritogenic CD4(+) helper T cells by major histocompatibility complex (MHC) class II molecules. Efficient loading of many MHC class II alleles with peptides requires the assistance of H2-M (HLA-DM in humans), a heterodimeric MHC class II-like molecule that facilitates CLIP removal from MHC class II molecules and aids to shape the peptide repertoire presented by MHC class II to CD4(+) T cells. In contrast to the HLA-DM region in humans, the beta-chain locus is duplicated in mice, with the H2-Mb1 beta-chain distal to H2-Mb2 and the H2-Ma alpha-chain gene. H2-M alleles …
Glycopeptide-functionalized gold nanoparticles for antibody induction against the tumor associated mucin-1 glycoprotein
2015
We report the preparation of gold nanoparticle (AuNP)-based vaccine candidates against the tumor-associated form of the mucin-1 (MUC1) glycoprotein. Chimeric peptides, consisting of a glycopeptide sequence derived from MUC1 and the T-cell epitope P30 sequence were immobilized on PEGylated AuNPs and the ability to induce selective antibodies in vivo was investigated. After immunization, mice showed significant MHC-II mediated immune responses and their antisera recognized human MCF-7 breast cancer cells. Nanoparticles designed according to this report may become key players in the development of anticancer vaccines.
Axolotl MHC class II β chain: predominance of one allele and alternative splicing of the β1 domain
2001
The axolotl MHC is composed of multiple polymorphic class I loci linked to class II B loci. In this report, evidence of the existence of one class II B locus (Amme-DAB) that codes for two different transcripts is given. A 2.1-kb transcript is translated to a complete β chain and a shorter transcript of 1.8 kb encodes a molecule lacking the β1 domain. For two complete class II B mRNA synthesized, up to one mRNA devoid of the β1 domain is synthesized. Alternative splicing involving a peptide binding domain at a class II B locus evidenced in axolotl (Ambystoma mexicanum) is also observed for A. trigrinum, the tiger salamander. Very little variability is found among various axolotl MHC class II…
MHC class II genes influence the susceptibility to chronic active hepatitis C
1997
Chronic hepatitis C develops in more than 70% of hepatitis C virus infected subjects. Viral factors influence the disease course, but little is known about the importance of host factors.Frequencies of major histocompatibility complex (MHC) class I and class II antigens were analyzed in two groups of patients with chronic hepatitis C virus infection and in control subjects. MHC class I typing was done by standard microlymphocytotoxicity assays. DRB1 and DQA1 genotyping was done by PCR based typing methods.DRB1*0301 was found in 26 of 75 patients with chronic hepatitis C virus infection (34.7%) and in 12 of 101 control subjects (11.9%) (relative risk 3.9; p0.001). Homozygosity for this allel…
Contact Sensitizers Specifically Increase MHC Class II Expression on Murine Immature Dendritic Cells
2000
Contact sensitivity is a T-cell-mediated immune disease that can occur when low-molecular-weight chemicals penetrate the skin. In vivo topical application of chemical sensitizers results in morphological modification of Langerhans cells (LC). Moreover, within 18 h, LC increase their major histocompatibility complex (MHC) class II antigens expression and migrate to lymph nodes where they present the sensitizer to T lymphocytes. We wanted to determine if such an effect could also be observed in vitro. However, because of the high genetic diversity encountered in humans, assays were performed with dendritic cells (DC) obtained from a Balb/c mouse strain. The capacity of a strong sensitizer, DN…
Costimulatory signalling potential of murine MHC class II‐positive T‐clone cells
1996
Activated human and rat T cells as well as mouse T-cell clones have been reported to synthesize and express major histocompatibility complex (MHC) class II molecules. However, the capacity of class II+ antigen (Ag) presenting T cells to induce proliferation of Ag-specific cloned T cells has been controversial. We analysed whether the failure of some T-cell clones to proliferate in response to Ag presented by class II+ T cells is because of a lack of costimulatory cytokine production by the antigen-presenting cells (APC). As a model system the mouse class II+ cloned BI/O4.1 T cells were used as APC in order to activate the T cell clone KIII5. This T-helper 1 (Th1) type, GAT (synthetic copoly…
Synthesis and expression of MHC class II molecules in the absence of attached invariant chains by recombinant-interferon-gamma-activated bone-marrow-…
1987
Pure populations of in vitro propagated bone marrow-derived macrophages are constitutively Ia negative. Co-culturing of these cells with recombinant interferon-gamma (rIFN-gamma) resulted in the appearance of high amounts of Ia antigens at the cell surface of essentially all cells. The continuous presence of the stimulus was a prerequisite for sustained Ia expression because removal of the stimulus resulted in rapid decline of surface Ia. Two-dimensional (2D) gel analysis (1D isoelectric focusing, 2D sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of class II molecules synthesized by rIFN-gamma-stimulated bone marrow macrophages (BMM phi) revealed that, in contrast to class II co…
Flow-cytometric screening for the modulation of receptor-mediated endocytosis in human dendritic cells: implications for the development of an in vit…
1997
The aim of this study was to explore the usefulness of human blood dendritic cells (DC) in the development of an in vitro model for predictive testing of contact sensitizers. A method was established to monitor the influence of chemicals on the intracellular targeting of antibody-crosslinked MHC class II molecules after their uptake by human DC. Using a three-colour flow-cytometric technique, freshly prepared DC were distinguished from other MHC class II-bearing cell types such as B-cells and monocytes in unseparated mononuclear cell suspensions of healthy volunteers. The assay is based on the pH-sensitivity of internalized fluorescein-coupled MHC class II specific antibodies. Quenching of …
Cellular and molecular mechanisms in the induction phase of contact sensitivity.
1995
During the induction phase of contact sensitivity, hapten-specific Th1 cells are primed by epidermal Langerhans cells. These Langerhans cells present hapten on MHC class II molecules and provide costimulatory signals. This presentation discusses the induction of cytokines in Langerhans cells and keratinocytes by haptens and their regulatory effects on contact sensitivity. Haptens were painted on the skin of normal BALB/c mice and epidermal cells were prepared at various times thereafter. Langerhans cell-derived interleukin (IL)-1 beta mRNA was observed as early as 15 min after hapten paining. In keratinocytes, tumor necrosis factor-alpha, IL-1 alpha, IP-10, MIP-2 and IL-10 were found to be …