Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genes, MHC Class II”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources
PubMed1989

HLA genes associated with rheumatoid arthritis. Identification of susceptibility alleles using specific oligonucleotide probes.

We examined the association of individual HLA genes with rheumatoid arthritis (RA), using oligonucleotide probes that identified both DR4-associated and non-DR4-associated genes. Two distinct HLA-DR beta alleles (Dw4 and Dw14) were found in DR4+ RA patients compared with controls (Dw4 50% versus 17%; Dw14 35% versus 5%; total DR4 73% versus 30%), indicating that these 2 alleles are independent susceptibility genes. Remarkably, the majority of the DR4- RA patients also demonstrated a linear DNA sequence, apparently "shuffled" between different susceptibility alleles, identified with an oligonucleotide probe to a key portion of the Dw14 gene.

Adult↗
PubMed1988

Isolation of antigen-specific T cell clones from nonresponder mice.

The mechanisms responsible for major histocompatibility complex (MHC)-linked unresponsiveness are still poorly understood. Here we examine the cellular events that follow when B10. A mice are immunized with cow insulin, an antigen to which they make no apparent immunologic response. Despite the fact that there is no detectable antibody or T cell proliferative response to cow insulin, we have been able to clone out responding T cells after priming and restimulating in vitro with this "nonimmunogenic" antigen. These cells are L3T4+, and co-recognize specific antigen and class II MHC gene products. The data demonstrate that "nonresponder" mice to cow insulin have both the capacity to present antigen and T cells capable of recognizing that antigen. The diversity within this population was investigated by analyzing various parameters of cellular activation. These include fine specificity of both antigen and MHC recognition, as well as recognition of allogeneic MHC and M1s determinants. In addition, the antigen-presenting cell requirements were studied. The results demonstrate that this population comprise a surprisingly heterogeneous group in terms of its repertoire of receptors.

Animals↗
PubMed1985

Demonstration of a common major gene with pleiotropic effects on immunoglobulin E levels and allergy.

Atopic disease is generally recognized to be familial, although specific genetic components have yet to be identified. High levels of a unique class of immunoglobulins, immunoglobulin E (IgE), have been shown to be associated with allergies. Several investigators have reported evidence indicating a recessive regulatory locus where an individual with the homozygous recessive genotype has persistently elevated levels of IgE. Willcox and Marsh [1978] have proposed a hypothesis relating IgE production and liability to become allergic. A test of this hypothesis was carried out in the present study. Bivariate segregation analysis of IgE levels and allergy was performed on 173 nuclear families, and the results indicate that an IgE regulatory locus contributes to the familial transmission of allergy. The results are further discussed in the context of the Willcox and Marsh hypothesis.

Adult↗
PubMed1993

Novel members and germline polymorphisms in the human T-cell receptor Vb6 family.

The human T-cell receptor (Tcr) Vb6 family has been scrutinized for polymorphisms, both in coding as well as in intronic sequences by polymerase chain reaction (PCR), subsequent multiple electroblot hybridizations, and sequence analysis. Multiplex PCR is an efficient means of screening for Tcr variability. Four novel loci could be distinguished and several new alleles are described including two pseudogenes. The Vb6 family is characterized by an intronic stretch of simple repetitive (gt)n sequences. These elements are hypervariable, especially in the Vb6.7 subfamily, where they are particularly long. The unexpected persistence of simple repetitive sequences in Tcr and major histocompatibility complex (MHC) class II genes over extended periods of the vertebrate evolutionary history can be interpreted in parallel terms in both gene families.

Amino Acid Sequence↗
PubMed1979

XY gonadal dysgenesis and the H-Y antigen. Report on 12 cases.

H-Y antigen was determined in 12 patients affected by XY gonadal dysgenesis. Of these, three proved to be H-Y negative, and nine, including two sisters, were H-Y positive; two of the unrelated positive cases exhibited a reduced antigen titer. Therefore, this clinical condition must be genetically heterogeneous. It is assumed that in the negative cases and possibly in those with reduced antigen titer, the H-Y generating system is affected by mutation, while in the regular positive cases the target cells are unable to respond due to a defect of the gonad-specific H-Y antigen receptor.

Adolescent↗
PubMed1981

Studies of the MHC-linked "CT" alloantigenic system in rats. II. Evidence for more than one locus and several different determinants.

Previous studies have defined a novel, MHC-linked alloantigenic system in the rat (CT) detectable with cytotoxic T cells (CTL) generated by alloimmunization and restimulation using strain combinations thought to be RT1-compatible, for instance, Lewis and Fischer 344. CTLs generated in this way are able to lyse targets from a variety of different strains without any evidence of MHC-restricted interactions, and yet these CT determinants possess properties unlike conventional class I and class II MHC gene products. The present studies employ cold target competition assays to derive a minimal estimate of the number of different CT determinants detected with Lewis anti-Fischer 344 CTLs, the number of loci involved in their expression, and their strain distribution. The results indicate that Lewis anti-Fischer CTLs define at least four different determinants encoded by at least two different loci.

Animals↗
PubMed1981

Regulation of the production of murine IgG2a by an H-2-linked gene and other unlinked genes.

Alleles of at least two loci (rig-1 and Rig-2) regulate the levels of serum immunoglobulin of the Igh-1b class and allotype in BALB/c Igb (BAB/14) and (BALB/c x BAB/14)F1 mice. The combined effect of the BALB/c alleles at these two loci is to lower Igh-1b levels significantly below those observed in other strains and below their own levels of Igh-1a in allotype heterozygous mice. The rig-1 locus is closely linked to or within the H-2 complex. Two alleles have been defined: rig-1d and rig-1b in H-2d and H-2b haplotypes, respectively. Homozygous rig-1d animals heterozygous for the BALB/c Rig-2 allele(s) have very low levels of Igh-1b. The designation of Rig-2 is provisional since it has not been mapped or defined as a single locus.

Animals↗
PubMed1994

Cloning and characterization of human phosphatase inhibitor-2 (IPP-2) sequences.

cDNA clones similar to rabbit muscle phosphatase inhibitor-2 (IPP-2) were isolated from human libraries. On Northern blots two transcripts of approximately 2kbp and approximately 4kbp were detected in all tissues tested. Analysis of cDNA sequences showed that the longer transcripts were similar to the shorter clones but contained extended 3' ends. The human nucleotide sequence was highly homologous (94% identity) to the rabbit IPP-2 sequence and encoded a peptide of 205 amino acids. IPP-2 sequences were highly conserved throughout vertebrates. Southern hybridization results were consistent with the existence of a family of related IPP-2 sequences in the human genome. Most of these are likely to be pseudogenes, since all of the cDNA clones examined could have originated from a single gene. By in situ hybridization IPP-2 sequences were mapped to several different human chromosomes. We sequenced one gene located in the major histocompatibility complex (MHC) on Chromosome (Chr) 6 that contained the entire coding region of IPP-2.

Amino Acid Sequence↗
PubMed1985

Functional analysis of the mouse H-2Kb gene promoter in embryonal carcinoma cells.

Mouse embryonal carcinoma (EC) cells do not express the major H-2 class I transplantation antigens. The latter, however, become detectable upon in vitro differentiation of EC cells. Neither class I H-2 genes nor the gene coding for beta-2 microglobulin (beta 2m) is transcribed in EC cells. We have constructed two hybrid plasmids containing the 5' flanking region of an H-2Kb gene followed by the coding regions of either the herpes simplex virus thymidine kinase (H-2 tk) or the chloramphenicol acetyl transferase (H-2 CAT) genes. Upon transfer into EC cells, the H-2 tk hybrid gene is expressed in F9 tk- cell lines which thus acquire a stable tk+ phenotype. When such transformed clones are induced to differentiate in vitro, tk activity shows a moderate increase, which reflects an increase in transcription of the hybrid gene. In transient transformation experiments, EC cells were found to express the H-2 CAT hybrid gene as well. We conclude that the 2 kilobase pair region of the H-2Kb gene which we used contains an active promoter region, but does not include all the elements required for the correct regulation of the H-2Kb gene.

Acetyltransferases↗
PubMed1989

Activation of genetically major histocompatibility complex (MHC) class II-deficient B lymphocytes.

It has been suggested that MHC class II molecules can transduce signals required for B-cell activation. Enhancement or inhibition of B-cell stimulation by anti-MHC class II molecule antibodies has likewise been reported. The study of B cells from patients with a combined immune deficiency due to a defective expression of MHC class II genes provides a useful tool for approaching the functional role of B-cell HLA class II molecules. We have thus analyzed the specific and nonspecific, cognate and noncognate B-cell activation of genetically HLA class II-deficient lymphocytes. B lymphocytes from 14 tested patients were able to synthesize RNA following stimulation with ionomycin and phorbol myristate acetate or anti-mu antibodies and with mannan, a T cell-independent polysaccharidic antigen. They were also able to synthetize DNA following the addition of ionomycin and PMA or of anti-mu antibodies in the presence of recombinant interleukin 2. Pokeweed mitogen failed to induce B-lymphocyte terminal differentiation into immunoglobulin-producing cells in the presence of normal T lymphocytes, while a combination of anti-CD2 antibodies were capable of triggering IgG synthesis. B-cell activation, whatever the condition used, did not induce HLA class II expression. Mannan-specific T cell-dependent antibody production (IgM) was detected in 6 of 14 patients. Anti-influenza virus antibody production was always found absent. These results are compatible with the hypothesis that B-cell activation events that do not require a cognate interaction with T cells can occur in the absence of HLA class II molecule expression, while the absence of HLA class II molecule expression prevents T-B cognate interaction.

Adolescent↗
PubMed1999

Murine mercury-induced autoimmunity: a model of chemically related autoimmunity in humans.

Human exposure to certain compounds or therapeutic drugs can result in the development of an autoimmune syndrome. Mercury (Hg) induced autoimmunity is one of the few animal models in which administration of a chemical induces a specific loss of tolerance to self-antigens. After receiving subtoxic doses of Hg or other heavy metals, susceptible mouse strains rapidly develop highly specific antibodies to nucleolar antigens. In addition, these animals display a general activation of the immune system, especially pronounced for the Th2 subset and a transient glomerulonephritis with immunoglobulin deposits. Like many human autoimmune diseases, this syndrome is associated with the expression of susceptible major histocompatibility complex (MHC) class II genes. In this article, we review the essential features of this model, and we discuss the putative mechanisms by which Hg creates such a severe immune dysfunction.

Animals↗
PubMed2003

Rapid assignment of swine leukocyte antigen haplotypes in pedigreed herds using a polymerase chain reaction-based assay.

We present a simple assay to determine the swine leukocyte antigen (SLA) haplotypes of animals within two experimental populations of MHC defined miniature pigs. The Yucatan miniature pigs have four founder haplotypes ( w, x, y, z) and one recombinant haplotype ( q). The NIH miniature pigs have three founder haplotypes ( a, c, d) and two recombinant haplotypes ( f, g). Because most crossovers occur between the class I and class II regions, haplotypes can be assigned by typing one class I locus and one class II locus for practical purposes. We have previously characterized these seven founder haplotypes by sequencing the cDNA of three SLA class I loci, designated as SLA-1, SLA-3 and SLA-2 and four SLA class II loci, SLA-DQA1, SLA-DQB1, SLA-DRA1 and SLA-DRB1. These sequences were used to design allele-specific primers to amplify one MHC class I and one MHC class II gene for each haplotype. Primers were tested for specificity in homozygous and heterozygous animals. Positive control primers were also designed to amplify a portion of the E-selectin or alpha-actin gene and multiplexed with the allele-specific primers to check for false negatives. This combination of allele-specific and positive control primers produced specific and robust PCR-site-specific primer assays for assigning SLA haplotypes in the two populations.

Animals↗
PubMed1991

Immunogenetic prediction of pulmonary fibrosis in systemic sclerosis.

75 systemic sclerosis patients were independently tested for pulmonary fibrosis, autoantibodies, and MHC class II genes. 24 of 42 (57%) patients with pulmonary fibrosis had either HLA DR3/DRw52a or anti-Scl-70 vs 2 of 33 (6%) patients without pulmonary fibrosis. The presence of DR3/DRw52a or anti-Scl-70 gives a relative risk of 16.7 for the development of pulmonary fibrosis in a patient with scleroderma--a risk substantial enough to require careful monitoring of these patients and treatment at an early stage of disease.

Autoantibodies↗
PubMed1994

A reduced level of multiple mutation in a shuttle vector passaged in Sjögren's syndrome cells.

Sjögren's syndrome is a systemic disorder with unknown etiology, displaying many signs of autoimmunity. Although the basic mechanism of this disease is unknown, a defect in somatic mutagenesis of antibody genes has been suggested. Using a shuttle vector plasmid, we here show that the number of vectors with multiple base changes in a marker gene was reduced in B cell lines from two patients with Sjögren's syndrome (8% in both), as compared with values reported for cell lines from normal human donors (16-27%). This finding suggests that a reduction of the rate of somatic mutagenesis may influence the development of symptoms in Sjögren patients.

B-Lymphocytes↗
PubMed1991

The Lake Casitas wild mouse: evolving genetic resistance to retroviral disease.

A small colony of feral mice from California continues to flourish in spite of a virulent epizootic of pathological retrovirus. Epidemiological and genetic studies revealed that the viral infection is strongly balanced by the polymorphic resistance locus, Fv-4, a transcriptionally active but truncated provirus that originated in the East Asian ancestors of the Californian mice. The natural history of these populations represents a graphic example of genomic adaptation in free-ranging populations to regulate and delimit infectious disease.

Animals↗