Search results for " MHC Class II"
showing 8 items of 28 documents
Induction of anamnestic T cell proliferation by antigen-pulsed, bone marrow-derived macrophages.
1981
Bone marrow-derived macrophages (BMM phi) were grown in a liquid culture system in the presence of L cell-conditioned medium as a source of colony-stimulating factor. After a 4-h pulse with antigen, cultured irradiated BMM phi were capable of presenting the antigen to primed T cells as assessed in a T cell proliferation assay. Proliferation was optimal when BMM phi were used between days 5 and 8 of bone marrow cell culture. T cells of Lyt1 and Lyt123 phenotype had to be present at the start of the culture period to yield an optimal response. Conventional antisera and monoclonal antibodies directed against the H-2 I region and the I-A subregion, respectively, proved inhibitory in this system…
Axolotl MHC architecture and polymorphism.
1999
The MHC of the urodele amphibian Ambystoma mexicanum consists of multiple polymorphic class I loci linked, so far as yet known, to a single class II B locus. This architecture is very different from that of the anuran amphibian Xenopus. The number of class I loci in the axolotl can vary from 6 to 21 according to the haplotypes as shown by cDNA analysis and Southern blot studies in families. These loci can be classified into seven sequence groups with features ranging from the class Ia to the class Ib type. All individuals express genes from at least three of the seven groups, and all individuals possess the class Ia-like type.
Structure Learning in Nested Effects Models
2007
Nested Effects Models (NEMs) are a class of graphical models introduced to analyze the results of gene perturbation screens. NEMs explore noisy subset relations between the high-dimensional outputs of phenotyping studies, e.g., the effects showing in gene expression profiles or as morphological features of the perturbed cell. In this paper we expand the statistical basis of NEMs in four directions. First, we derive a new formula for the likelihood function of a NEM, which generalizes previous results for binary data. Second, we prove model identifiability under mild assumptions. Third, we show that the new formulation of the likelihood allows efficiency in traversing model space. Fourth, we…
Thymoma and paraneoplastic myasthenia gravis
2010
Paraneoplastic autoimmune diseases associate occasionally with small cell lung cancers and gynecologic tumors. However, myasthenia gravis (MG) occurs in at least 30% of all patients with thymomas (usually present at MG diagnosis). These epithelial neoplasms almost always have numerous admixed maturing polyclonal T cells (thymocytes). This thymopoiesis-and export of mature CD4(+)T cells-particularly associates with MG, though there are rare/puzzling exceptions in apparently pure epithelial WHO type A thymomas. Other features potentially leading to inefficient self-tolerance induction include defective epithelial expression of the autoimmune regulator (AIRE) gene and/or of major histocompatib…
Release of dendritic cells from cognate CD4 + T-cell recognition results in impaired peripheral tolerance and fatal cytotoxic T-cell mediated autoimm…
2012
Resting dendritic cells (DCs) induce tolerance of peripheral T cells that have escaped thymic negative selection and thus contribute significantly to protection against autoimmunity. We recently showed that CD4 + Foxp3 + regulatory T cells (Tregs) are important for maintaining the steady-state phenotype of DCs and their tolerizing capacity in vivo. We now provide evidence that DC activation in the absence of Tregs is a direct consequence of missing DC–Treg interactions rather than being secondary to generalized autoimmunity in Treg-less mice. We show that DCs that lack MHC class II and thus cannot make cognate interactions with CD4 + T cells are completely unable to induce peripheral CD8 +…
Analysis of HLA-DRB1,DQA1,DQB1 haplotypes in Sardinian centenarians
2008
Some genetic determinants of longevity might reside in those polymorphisms for the immune system genes that regulate immune responses. Many longevity association studies focused their attention on HLA (the human MHC) polymorphisms, but discordant results have been obtained. Sardinians are a relatively isolate population and represent a suitable population for association studies. Some HLA-DR and DQ alleles form very stable haplotypes with a strong linkage disequilibrium. In a previous study on Sardinian centenarians we have suggested that HLA-DRB1 *15 allele might be marginally associated to longevity. HLA-DR,DQ haplotypes are in strong linkage disequilibrium and well conserved playing a ro…
HLA class II haplotypes differentiate between the adult autoimmune polyglandular syndrome types II and III.
2013
Background: Genetics of the adult autoimmune polyglandular syndrome (APS) is poorly understood. Aim: The aim of this study was to gain further insight into the genetics of the adult APS types. Site: The study was conducted at a university referral center. Methods: The human leukocyte antigen (HLA) class II alleles, haplotypes, and genotypes were determined in a large cohort of patients with APS, autoimmune thyroid disease (AITD), and type 1 diabetes and in healthy controls by the consistent application of high-resolution typing at a four-digit level. Results: Comparison of the allele and haplotype frequencies significantly discriminated patients with APS vs AITD and controls. The HLA class…
H2-M polymorphism in mice susceptible to collagen-induced arthritis involves the peptide binding groove.
1996
The ability to develop type II collagen (CII)-induced arthritis (CIA) in mice is associated with the major histocompatibilityI-A gene and with as yet poorly defined regulatory molecules of the major histocompatibility complex (MHC) class II antigen processing and presentation pathway. H2-M molecules are thought to be involved in the loading of antigenic peptides into the MHC class II binding cleft. We sequencedH2-Ma, H2-Mb1, andH2-Mb2 genes from CIA-susceptible and-resistant mouse strains and identified four differentMa andMb2 alleles and three differentMb1 alleles defined by polymorphic residues within the predicted peptide binding groove. Most CIA-resistant mouse strains share commonMa, M…