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J Trowsdale

Publications and source records attributed to J Trowsdale.

At least 181 records · Page 10Linked to original sources
PubMed1991

Colinearity of novel genes in the class II regions of the MHC in mouse and human.

To examine the degree of conservation of gene organization in and around the class II regions of the major histocompatibility complexes of mouse and human, we have established the positions of sequences homologous to five human non-class II genes (RING1-5) in mouse, and the positions of sequences homologous to three mouse non-class II genes (KE3-5) in human. The resulting comparative map reveals that the organization of genes in the entire proximal region of the MHCs of mouse and human is remarkably conserved, apart from the H-2K gene pair in mouse, which can be accounted for by a 60 kilobase (kb) insertion. The characterization of the novel human gene RING5 is also presented. This gene, which is widely expressed, maps 85 kb proximal to the DPB2 gene. Partial nucleotide sequencing of a RING5 cDNA clone reveals that it is the human homolog of the mouse KE4 gene.

Amino Acid Sequence↗
PubMed1991

Novel detection of restriction fragment length polymorphisms in the human major histocompatibility complex.

Cosmid genomic DNA clones have been used as hybridization probes in genomic Southern blot analysis to define restriction fragment length polymorphisms (RFLPs) in the major histocompatibility complex (MHC). Using 14 different enzymes and three overlapping cosmid clones we have detected six RFLPs in a 100 kilobase (kb) segment of DNA in the class III region extending centromeric of the TNFA gene toward HLA-DR. Four of the five RFLPs, defined using the enzymes Taq I, Rsa I, Hinc II, and Hind III, and detected by the cosmid clone cosM7B, map to a 29 kb segment of DNA that includes all of the recently described G2 (BAT2) gene and a large portion of the 3' end of the G3 (BAT3) gene. The different RFLP variants were established by analyzing the DNA from three informative families and a panel of 51 HLA-homozygous typing cell lines. CosM7B detects Taq I variants of 4.3 kb, and 2.9 kb or 2.8 kb, Rsa I variants of 2.9 kb or 2.4 kb, Hinc II variants of 5.8 kb or 3.8 kb and 1.4 kb, and a Hind III variant of 4.8 kb, while cosOT2 detects Taq I variants of 4.5 kb or 4 kb. The distribution of the Rsa I, Hinc II and Taq I RFLPs detected by cosM7B, and the Taq I RFLP detected with cosOT2, within the panel of cell line DNAs was assessed by Southern blotting. The 4.3 kb Taq I variant was observed in only one cell line with the extended haplotype HLA-A29, C-, B44, SC30, DR4. The other RFLPs, however, occurred much more frequently. The 2.8 kb Taq I variant was observed in 20% of haplotypes, the 2.9 kb Rsa I variant was observed in 42% of haplotypes, and the 5.8 kb Hinc II variant was observed in 12% of haplotypes analyzed. The 4.5 kb Taq I variant detected by the overlapping cosmid cosOT2 was present in 21% of haplotypes. Analysis of the RFLP variants with each other revealed seven different haplotypic combinations. Three of the haplotypic combinations were each subdivided into two subsets on the basis of the Nco I RFLP variant they carried at the TNF-B locus. These haplotypic combinations potentially allow differentiation among different extended haplotypes such as HLA-B8, SC01, DR3, HLA-B18, F1C30, DR3, and HLA-B44, FC31, DR7. The RFLPs detected by the cosmid clones thus provide new tools which will be useful in the further genetic analysis of the MHC class III region.

Alleles↗
PubMed1991

The human ICAM2 gene maps to 17q23-25.

The intercellular adhesion molecules ICAM1 and ICAM2 are the cell-surface ligands for the lymphocyte function-associated antigen LFA-1 (CD11a/CD18) and are thought to mediate cell-cell adhesion interactions required by the immune system. However, differences in tissue distribution, inducibility of expression, and overall structure of the two ICAMs may point to their having distinct functional roles. We have used a panel of somatic cell hybrids and chromosome-mediated gene transfectants to establish the chromosomal location of the gene for ICAM2. Hybridization of an ICAM2 cDNA clone to Southern blots from this panel indicates that the human ICAM2 gene maps to chromosome 17 region q23-25.

Antigens, CD↗
PubMed1991

New genes in the class II region of the human major histocompatibility complex.

A detailed map of the class II region of the human major histocompatibility complex has been constructed by pulsed-field gel electrophoresis. This map revealed clusters of sites for enzymes that cut preferentially in unmethylated CpG-rich DNA often found at the 5' ends of genes. Three of these clusters have been cloned by cosmid walking and chromosome jumping. Analysis of the clones encompassing these regions through the use of zoo blots, Northern blots, and cDNA libraries resulted in the discovery of four novel genes. The D6S111E and D6S112E genes are centromeric to the HLA-DPB2 gene, while D6S113E and D6S114E are between HLA-DNA and HLA-DOB. Preliminary characterization of the new genes indicates that they are unrelated to the class II genes themselves, although D6S114E expression, like class II expression, is inducible with interferon. In addition, the HLA-DNA gene has been accurately positioned and oriented for the first time.

Animals↗
PubMed1991

Isolation of probes specific to human chromosomal region 6p21 from immunoselected irradiation-fusion gene transfer hybrids.

A hybrid cell line (R21/B1) containing a truncated human chromosome 6 (6pter-6q21) and a human Y chromosome on a hamster background was irradiated and fused to A23 (TK-) or W3GH (HPRT-) hamster cells. Clones containing expressed HLA class I genes (4/40) were selected using monoclonal antibodies. These clones were recloned and analyzed with a panel of probes from the HLA region. One hybrid (4G6) contained the entire HLA complex. Two other hybrids (4J4 and 4H2) contained only the HLA class I region, while the fourth hybrid (5P9) contained HLA class I and III genes in addition to other genes located in the 6p21 chromosomal region. In situ hybridization showed that the hybrid cells contained more than one fragment of human DNA. Alu and LINE PCR products were derived from these cells and compared to each other as well as to products from two somatic cell hybrids having the 6p21 region in common. The PCR fragments were then screened on conventional Southern blots of the somatic cell hybrids to select a panel of novel probes encompassing the 6p21 region. In addition, the origin of the human DNA fragments in hybrid 4J4 was determined by regional mapping of PCR products.

Animals↗
PubMed1991

HLA and disease.

It is nearly 20 years since the first reports appeared linking genes within the human major histocompatibility complex, the HLA region, with disease. The literature now contains many hundreds of papers confirming an increased frequency of different HLA antigens in a diverse spectrum of conditions, ranging from narcolepsy to diabetes. Over the years many different hypotheses have been proposed to explain this association, but none has been proven. Nevertheless, our knowledge of the HLA region and the function of its many genes is expanding rapidly and the pathogenesis of many HLA-linked diseases may soon become apparent. In this review we aim to provide clinicians with a broad understanding of the basis for the association between HLA and disease. We will describe the genes of the HLA region before discussing the diseases with which they are linked. Finally, we will explore mechanisms through which HLA genes might influence disease.

Autoimmune Diseases↗
PubMed1990

Effect of isotypes and allelic polymorphism on the binding of staphylococcal exotoxins to MHC class II molecules.

Interaction of staphylococcal exotoxins (SE) with MHC class II molecules plays a central role in the activation of immune cells by SE. We have recently demonstrated directly that toxic shock syndrome toxin-1 (TSST-1) binds to MHC class II molecules with high affinity, and similar results have been reported for SEA and SEB. The ability of T cells to respond to individual SE is associated with the expression of particular TCR-V beta gene elements. In the present study we have examined the effect of polymorphism on the ability of MHC class II molecules to bind SEB and TSST-1. We have used a panel of L cell transfectants that express different allelic forms of each of the three human class II isotypes. Radioligand binding assays detected binding of SEB and TSST-1 to most, but not all of the MHC class II molecules examined. Toxin-driven MHC class II-dependent T cell proliferation occurred with all transfectants examined even in the absence of detectable toxin binding. These results indicate that SE can bind to human MHC class II molecules of diverse phenotypes.

Antibodies, Monoclonal↗
PubMed1990

A mouse zinc finger gene which is transiently expressed during spermatogenesis.

Zinc finger proteins are polypeptides with sequence-specific, nucleic acid-binding properties. Substantial evidence has established them as a class of trans-acting molecules with regulatory roles in cellular growth and differentiation. We have screened an 11.5 day post coitum urogenital ridge cDNA library with an oligonucleotide encoding a sequence conserved between a variety of zinc finger proteins. By cDNA cloning and sequencing we show that a novel mouse gene, Zfp-35, encodes a protein with a block of 18 zinc finger domains and an N-terminal region rich in acidic residues. The 2.4 kb mRNA encoding this polypeptide is selectively expressed in adult testis, by comparison with other organs. We have analysed Zfp-35 expression in whole testes of sex-reversed mice, whole testes of prepuberal XY animals, germ cell fractions from XY adult testes and by in situ hybridization to sections from adult XY testes. Our studies show that a considerable increase in expression is restricted to spermatocytes at the pachytene stage of meiotic prophase. These experiments suggest that Zfp-35 may act to control gene activity during this particular stage of spermatogenesis.

Amino Acid Sequence↗
PubMed1990

Genomic analysis of a mouse zinc finger gene, Zfp-35, that is up-regulated during spermatogenesis.

Zinc finger genes are a class of eukaryotic regulatory genes that encode sequence-specific nucleic acid-binding proteins. Members of this large gene family are required for growth and development in a wide range of organisms. We previously identified a mouse zinc finger gene, Zfp-35, that was up-regulated during spermatogenesis at the pachytene spermatocyte stage of development. We now describe the genomic organization of this gene, including its intron-exon structure, the sequence of its flanking regions, and its assignment to a region encompassing bands B3 to C of chromosome 18. The transcription unit has three exons. Intron 1 is within the 5' untranslated region and exon 3 contains the block of all 18 zinc fingers. These two features are common to a number of zinc finger genes. We also show that Zfp-35 is conserved in some placental mammals and that it is a member of a subfamily of related mammalian zinc finger genes.

Amino Acid Sequence↗
PubMed1990

Myelin autoreactivity in multiple sclerosis: recognition of myelin basic protein in the context of HLA-DR2 products by T lymphocytes of multiple-sclerosis patients and healthy donors.

A panel of 20 human myelin basic protein (hMBP)-specific T-lymphocyte lines was generated from the peripheral blood of eight multiple sclerosis (MS) patients and two healthy donors, most of them expressing the HLA-DR2 haplotype, which is associated with an increased susceptibility to MS. Using HLA-DR gene-transfected mouse L-cell lines as antigen-presenting cells, we established that of the 20 hMBP-specific T-lymphocyte lines, 7 were restricted by the DR2a gene products of the DR2Dw2 haplotype. Four T-cell lines recognized hMBP in the context of the DR2b products of the DR2Dw2 haplotype. DR2b-restricted T-cell responses were demonstrable only in T-cell lines derived from MS patients. The hMBP epitopes presented by the DR2a heterodimer were mapped to peptides covering amino acid residues 1-44, 76-91, 131-145, or 139-153 and to a region spanning the thrombin-cleaved bond at Arg130-Ala131. DR2b-restricted T-cell lines recognized epitopes within amino acids 80-99 and 148-162. Peptide 139-153 was also presented in the context of HLA-DR1 molecules. Our data show that (i) in MS patients both the DR2a and DR2b products of the DR2Dw2 haplotype function as restriction elements for the myelin autoantigen hMBP, (ii) the DR2a molecule presents at least five different epitopes to hMBP-specific T lymphocytes, and (iii) anti-hMBP T-cell lines derived from individual donors can differ in their antigen fine specificity as well as in their HLA restriction.

Adult↗
PubMed1990

Direct evidence for a functional role of HLA-DRB1 and -DRB3 gene products in the recognition of Dermatophagoides spp. (house dust mite) by helper T lymphocytes.

The contribution of the HLA-DRB1, -B3, and -B5 gene products in the recognition of Dermatophagoides spp. (house dust mite) by helper T cells isolated from an atopic individual (HLA-DRw12, DR7; DRw52b) with perennial rhinitis was investigated. Using a panel of histocompatible and histoincompatible accessory cells, the restriction specificity obtained for a long term T cell suggested that a component of the dust mite reactive repertoire recognized antigen in association with DRB3 gene products. Oligonucleotide DNA typing of the presenting cell panel demonstrated a correlation between the DRw52b allele and T cell responsiveness. Murine fibroblasts expressing DRw52b, but not DRw52a or -c molecules, presented antigen to both the T cell line and cloned T cells (DE26) derived from the line, indicating that the supertypic specificity DRw52b was able to restrict recognition of dust mite antigens. Additional T cell clones (DE9 and DE41) also isolated from the line were restricted by the products of the B1 gene locus (DRw12B1) as determined by murine fibroblasts transfected with the appropriate HLA-DR genes. Clone DE9 was degenerate in its restriction specificity, also recognizing dust mite presented by accessory cells expressing the DR2 subtypes. Presentation by fibroblasts transfected with DRw12B1, DR2Dw2B5 genes and EBV-transformed B cell lines expressing DR2DW21B1 and -B5 indicated that the functional site restricting recognition may be associated with residues 70 and 71 of the DR beta chain helical wall of the antigen combining site. Furthermore, we have recently demonstrated that both T cell clones DE9 and DE26 induce allergen dependent IgE synthesis in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗