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T Spies

Publications and source records attributed to T Spies.

At least 73 records · Page 4Linked to original sources
PubMed1992

Ancestral haplotypes reveal the role of the central MHC in the immunogenetics of IDDM.

The major histocompatibility complex (MHC) contains multiple and diverse genes which may be relevant to the induction and regulation of autoimmune responses in insulin dependent diabetes mellitus (IDDM). In addition to HLA class I and II, the possible candidates include TNF, C4, and several other poorly defined polymorphic genes in the central MHC region. This study describes two approaches which take advantage of the fact that the relevant genes are carried by highly conserved ancestral haplotypes such as 8.1 (HLA-B8, TNFS, C4AQ0, C4B1, DR3, DQ2). First, three "diabetogenic" haplotypes (two Caucasoid and one Mongoloid) have been compared and it has been shown that all three share a rare allele of BAT3 as well as sharing DR3, DQ2. In 43 sequential patients with IDDM the cross product ratio for BAT3S was 4.8 (p less than 0.01) and 6.9 for HLA-B8 plus BAT3S (p less than 0.001). Second, partial or recombinant ancestral haplotypes with either HLA class I (HLA-B8) or II (HLA-DR3, DQ2) alleles were identified. Third, using haplotypic polymorphisms such as the one in BAT3, we have shown that all the patients carrying recombinants of the 8.1 ancestral haplotype share the central region adjacent to HLA-B. These findings suggest that both HLA and non-HLA genes are involved in conferring susceptibility to IDDM, and that the region between HLA-B and BAT3 contains some of the relevant genes. By contrast, similar approaches suggest that protective genes map to the HLA class II region.

Adult↗
PubMed1992

New genes in the MHC that encode proteins for antigen processing.

Most cells process proteins into short peptides that are displayed on the cell surface bound to class I or class II proteins encoded by the major histocompatibility complex (MHC). These protein-peptide complexes can then be recognized by the circulating lymphocytes of the immune system. Several genes found recently in the MHC encode proteins with possible roles in the supply of peptides to class I molecules. The results imply that the peptides are produced in the cytoplasm by proteasomes and are translocated into the endoplasmic reticulum by 'peptide transporters' related to the multidrug resistance proteins. While there is little biochemical evidence to validate these ideas, Robert DeMars and Thomas Spies discuss here the arguments supporting this view. New data indicate that there may also be factors for class II peptide-processing hidden in the MHC.

Journal Article↗
PubMed1991

Two putative subunits of a peptide pump encoded in the human major histocompatibility complex class II region.

The class II region of the human major histocompatibility complex (MHC) may encode several genes controlling the processing of endogenous antigen and the presentation of peptide epitopes by MHC class I molecules to cytotoxic T lymphocytes. A previously described peptide supply factor (PSF1) is a member of the multidrug-resistance family of transporters and may pump cytosolic peptides into the membrane-bound compartment where class I molecules assemble. A second transporter gene, PSF2, was identified 10 kilobases (kb) from PSF1, near the class II DOB gene. The complete sequences of PSF1 and PSF2 were determined from cDNA clones. The translation products are closely related in sequence and predicted secondary structure. Both contain a highly conserved ATP-binding fold and share 25% homology in a hydrophobic domain with a tentative number of eight membrane-spanning segments. Based on the principle dimeric organization of these two domains in other transporters, PSF1 and PSF2 may function as complementary subunits, independently as homodimers, or both. Taken together with previous genetic evidence, the coregulation of PSF1 and PSF2 by gamma interferon and the to-some-degree coordinate transcription of these genes suggest a common role in peptide-loading of class I molecules, although a distinct function of PSF2 cannot be ruled out.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Restored expression of major histocompatibility class I molecules by gene transfer of a putative peptide transporter.

Cytotoxic T lymphocytes recognize antigen-derived peptides bound to major histocompatibility complex (MHC) class I molecules with which they assemble in the endoplasmic reticulum or in an undefined subcompartment. There is genetic evidence that the peptides that are products of cytosolic protein degradation are transported into this compartment by a peptide supply factor (PSF), encoded in the MHC class II region. Like the corresponding genes RING4, HAM1 and mtp1, PSF is related to the multidrug-resistance family of transporters and may be a peptide pump, as translocation of peptides across membranes must occur independently of the secretory pathway. There is, however, no functional evidence for this role so far. Here we report gene transfer experiments showing that expression of PSF complementary DNA in the human lymphoblastoid cell line mutant 721.134 restores normal levels of surface HLA-A2 and -B5. No similar effect was observed in 721.174 mutant cells, in which a homozygous deletion includes PSF among several other closely linked genes. At least one of these genes may therefore also be required for PSF function.

Animals↗
PubMed1991

Association of polymorphisms in the HLA-B region with extended haplotypes.

Genomic probes from the HLA-B region of the major histocompatibility complex (MHC) were used to study the association of restriction fragment length polymorphisms (RFLPs) with various MHC alleles, complotypes, and extended haplotypes. The two DNA probes, M20A and R5A, were derived from previously cloned cosmids and are located 38 and 110 kilobases (kb) centromeric to HLA-B, respectively. Five different RFLP variants occurring in five different haplotypic combinations were detected within a panel of 40 homozygous-typing cells and cells from 21 families using Bst EII. In two informative families with HLA-B/DR recombinations the inheritance of the RFLP variants was consistent with their mapping between HLA-B and complotypes. The R5A/M20A haplotypic pattern 6.5 kb/3.0 kb (A) had a normal Caucasian frequency of approximately 0.43 and was found in all independent examples of the extended haplotypes [HLA-B8,SC01,DR3], [HLA-B18,F1C30,DR3], [HLA-Bw62,SC33,DR4], [HLA-B44,SC30,DR4], and [HLA-Bw47,FC91,0,DR7]. The patterns 6.9 kb/3.0 kb (B), 6.5 kb/4.7 kb (C), 1.45 kb/3.0 kb (D), and 6.9 kb/4.7 kb (E) had normal Caucasian frequencies of approximately 0.23, 0.15, 0.15, and 0.04 and were found on all independent examples of [HLA-B38,SC21,DR4], [HLA-Bw57,SC61,DR7], [HLA-B7,SC31,DR2], and [HLA-B44,FC31,DR7], respectively. Individual complotypes or HLA-B alleles which were markers of extended haplotypes showed variable associations. For example, HLA-B7 and the complotype SC31 were associated with all R5A/M20A RFLP haplotypes except haplotype E, although [HLA-B7,SC31,DR7] was associated exclusively with haplotype D. HLA-B27, not known to be part of an extended haplotype, was surprisingly exclusively associated with the 6.5 kb/4.7 kb or C haplotypic pattern in all five instances tested. These findings support the concept of regional conservation of DNA on independent examples of extended haplotypes. The results also further characterize these haplotypes.

Alleles↗
PubMed1991

Association of four HLA class III region genomic markers with HLA haplotypes.

We have studied restriction fragment length polymorphism (RFLP) in the region 300 kb centromeric to the HLA-B locus. Four probes were used: one was genomic DNA derived from the tumor-necrosis factor (TNF)-beta gene, one was a cDNA for the BAT3 gene, and two single-copy genomic probes, R5A and M20A. The order of these markers from HLA-B towards the centromere is M20A, R5A, TNF and BAT3. The BAT3 and TNF-beta probes each detected two allelic bands with Taq I and Nco I digestion, respectively; the R5A and M20A probes each detected three polymorphic allelic bands with BstEII digestion. To determine if these restriction polymorphisms are preferentially associated with certain HLA-B and -DR haplotypes, a total of 153 HLA haplotypes was analyzed. The haplotypes A1, B8, DR3 and A3, B7, DR2 were each associated with a distinct combination of polymorphisms identified at these four sites, thereby demonstrating that the strong linkage disequilibrium characteristic of these haplotypes extends also to this segment of the class III region. In contrast, haplotypes that are not in positive linkage disequilibrium, such as A1,B8,DR4 and A2,B7,DR3, showed no preferential association with any of these polymorphisms. The antigens HLA-B27 and B35 were also found to be in positive linkage disequilibrium with RFLP patterns at three of these sites, and HLA-B14,B35,B44,Bw57 and Bw62 were found preferentially associated with polymorphisms at one or two of these sites, independent of the DR antigen present. These data further demonstrate that genetic linkage disequilibrium in the HLA class III region is complex and variable among different HLA haplotypes.

Chromosome Mapping↗
PubMed1990

Regulation of the class II-associated invariant chain gene in normal and mutant B lymphocytes.

The invariant chain protein is intracellularly associated with class II major histocompatibility proteins. In many cases, the expression of these molecules appears to be regulated in a similar manner. Contained within the promoter of the invariant chain gene are sequences (X and I gamma 1) that are similar to the X and Y box elements of class II genes, suggesting that these sequences might be involved in its regulation. DNase I footprinting reveals additional cis-acting elements (I gamma 2 and I gamma 3) that contain sequence similarities to NF-kappa B and/or H2TF1/KBF1 recognition sequences. A series of fusion constructs with the chloramphenicol acetyltransferase reporter gene were used to analyze the role of these sequences (I gamma 1, I gamma 2, I gamma 3, and X and Y elements) in both normal and mutant B lymphocytes. These data suggest the likelihood of multiple X box proteins in B cells, which can act as both negative and positive regulatory factors.

Animals↗
PubMed1990

A gene pair from the human major histocompatibility complex encodes large proline-rich proteins with multiple repeated motifs and a single ubiquitin-like domain.

A large number of genes has been identified previously between the class I and class II gene families within the class III region of the human major histocompatibility complex. The complete sequences of two of these genes, BAT2 and BAT3 (where BAT is HLA-B-associated transcript), which are closely linked, were determined from cDNA clones. The putative BAT2 and BAT3 proteins are 228 and 110 kDa, respectively, and do not appear to be members of any known family of proteins. However, BAT3 contains an amino-terminal ubiquitin-like domain. Both BAT2 and BAT3 are very rich in proline and include short tracts of polyproline, polyglycine, and charged amino acids. In addition, these proteins contain several unrelated families of similar repeated segments. BAT2 and BAT3 are similar to other proteins with large proline-rich domains, such as some nuclear proteins, collagens, elastin, and synapsin. BAT2 also contains four Arg-Gly-Asp (RGD) motifs typical of the integrin receptor family.

Amino Acid Sequence↗
PubMed1990

Restriction fragment length polymorphism (RFLP) of two HLA-B-associated transcripts (BATs) genes in healthy Danes.

The restriction fragment length polymorphism (RFLP) of the two human HLA-B-associated transcripts (BATs) genes, BAT1 and BAT2, was investigated using 5 different restriction enzymes and two human BAT1 and BAT2 cDNA probes. Two of the enzymes, NcoI and RsaI, revealed polymorphic patterns which were investigated in healthy Danes. The cDNA/restriction enzyme combination BAT1/NcoI identifies polymorphic bands at 12 kb, 8 kb, 2.5 kb, and 1.1 kb, while the BAT2/RsaI combination identifies polymorphic bands at 3.3 kb, 2.7 kb, 2.3 kb, and 0.9 kb. The frequencies of these markers were determined in 90 unrelated Danes. Co-dominant segregation and allelic behavior was seen for the BAT1/NcoI 12 kb and 8 kb bands and the BAT2/RsaI 2.7 kb and 2.3 kb bands, respectively. It is possible that the BAT2/RsaI 3.3 kb band represents a rare allele of the BAT2/RsaI system. The BAT2/RsaI 2.3 kb marker was strongly negatively associated with HLA-B8 and HLA-DR3 while there were no strong associations between the BAT1 and BAT2 markers, but the BAT2/RsaI 2.7 kb marker was strongly positively associated with the TNF alpha/NcoI 5.5 kb marker, which in turn is positively associated with HLA-B8 and HLA-DR3. The negative associations between the BAT2/RsaI 2.3 kb marker and HLA-B8 and HLA-DR3 raise the question as to whether this BAT allele may play a role in protecting against certain autoimmune diseases.

DNA Probes, HLA↗
PubMed1989

A new cluster of genes within the human major histocompatibility complex.

A 435-kilobase (kb) DNA segment, which is centromeric to HLA-B in the human major histocompatibility complex, was isolated by chromosome walking with overlapping cosmids. Within the cloned region, the genes for the tumor necrosis factors (TNFs) alpha and beta and HLA-B were 210 kb apart. The human homolog of a mouse gene, B144, was located next to TNF alpha. Moreover, the presence of additional genes was suggested by a large cluster of CpG islands. With cosmid probes, several distinct transcripts were detected in RNA samples from a variety of cell lines. Altogether, five novel genes were identified by isolation of corresponding complementary DNA clones. These "HLA-B-associated transcripts" (BATs) were mapped to different locations within a 160-kb region that includes the genes for TNF alpha and TNF beta. The presence of the genes for BAT1 and BAT5 in the vicinity of HLA-B again raises the question of which gene in this region determines susceptibility to ankylosing spondylitis.

Animals↗
PubMed1989

Human major histocompatibility complex contains a minimum of 19 genes between the complement cluster and HLA-B.

A 600-kilobase (kb) DNA segment from the human major histocompatibility complex (MHC) class III region was isolated by extension of a previous 435-kb chromosome walk. The contiguous series of cloned overlapping cosmids contains the entire 555-kb interval between C2 in the complement gene cluster and HLA-B. This region is known to encode the tumor necrosis factors (TNFs) alpha and beta, B144, and the major heat shock protein HSP70. Moreover, a cluster of genes, BAT1-BAT5 (HLA-B-associated transcripts) has been localized in the vicinity of the genes for TNF alpha and TNF beta. An additional four genes were identified by isolation of corresponding cDNA clones with cosmid DNA probes. These genes for BAT6-BAT9 were mapped near the gene for C2 within a 120-kb region that includes a HSP70 gene pair. These results, together with complementary data from a similar recent study, indicated the presence of a minimum of 19 genes within the C2-HLA-B interval of the MHC class III region. Although the functional properties of most of these genes are yet unknown, they may be involved in some aspects of immunity. This idea is supported by the genetic mapping of the hemopoietic histocompatibility locus-1 (Hh-1) in recombinant mice between TNF alpha and H-2S, which is homologous to the complement gene cluster in humans.

Cell Line↗
PubMed1988

Restriction fragment length polymorphisms and an HLA-DRw52-associated split.

The restriction fragment length polymorphism technique, employing seven restriction endonucleases, and a DR-specific repeated element probe were used to study a large panel of homozygous typing cells in order to delineate haplotypic differences within the HLA-DRw52 supertype. Most of the restriction endonucleases revealed the presence of two allelic restriction fragment length polymorphisms correlating with and splitting the HLA-DRw52 supertypic specificity. One designated A, correlated with the HLA-DRw52 typing in HLA-DR5, HLA-DR3, (non-A1, B8), and some HLA-DRw6 haplotypes. The other, designated a, correlated with the HLA-DRw52 typing in HLA-DR5, HLA-DRw8, HLA-DR3 (A1, B8), and the remaining HLA-DRw6 haplotypes. The general applicability of these findings was validated in 47 HLA-typed laboratory controls.

Alleles↗
PubMed1987

A highly diverged beta 1 exon in the DR region of the human MHC: sequence and evolutionary implications.

The DR subregion of the human major histocompatibility complex from a DR4 haplotype includes the well-characterized DR alpha, DR4 beta, DR(MT3)beta psi genes. In addition, the region between the DR alpha and the proximal DR(MT3)beta contains several copies of conserved DR beta-related sequences. These repeated elements, numbered II, III, and IV, include the DR beta signal sequence and a region located further upstream. Further examination of these conserved sequences showed that DR beta first intron sequences are present at the 3' ends of these repeats. Progressively longer portions of the DR beta first intron are conserved from repeat II to repeat IV, producing a gradient of conservation. The most complete repeat element of repeats II, III, and IV is associated with a lone beta 1 exon (DR beta 1). Upon sequencing, DR beta 1 was found to contain several deleterious mutations, indicating that it is nonfunctional. DR beta 1 has accumulated a large number of replacement substitutions and mutations at positions which are invariant in beta 1 domains from expressed DR beta genes: 77.8% of the nucleotide substitutions were replacement substitutions, and 41.5% of the amino acids at invariant positions have been altered. Calculations based on these figures suggest that DR beta 1 may have become inactive approximately 25 million years ago. There are, however, two histidine residues within a variable region which are unique to DR beta 1 and the DR4 beta gene, suggesting that they represent a gene pair which probably evolved by duplication of a single DR beta chain gene.

Amino Acid Sequence↗
PubMed1987

Linkage map of the human major histocompatibility complex including the tumor necrosis factor genes.

The tumor necrosis factor (TNF) alpha and beta gene pair has been linked in the human major histocompatibility complex to HLA-B, HLA-C, and, tentatively, HLA-E and HLA-A on one side and to the class III complement/steroid 21-hydroxylase gene cluster on the other by pulsed-field gel electrophoresis. The TNF genes are located 200 kilobases (kb) centromeric of HLA-B and about 350 kb telomeric of the class III cluster. Together with previous data on the linkage and structures of the class II and class III regions, a restriction map of the entire human major histocompatibility complex of about 3500 kb has been prepared.

Chromosome Mapping↗
PubMed1986

Genes for the tumor necrosis factors alpha and beta are linked to the human major histocompatibility complex.

The human major histocompatibility complex (MHC) includes the closely linked genes for the tumor necrosis factors alpha and beta. Their location is within the chromosomal segment between HLA-DR and HLA-A or centromeric of HLA-DP. This assignment is based on Southern blot analysis of a number of different MHC deletion mutants and is corroborated by chromosome in situ hybridization.

Chromosome Deletion↗
PubMed1985

SB subregion of the human major histocompatibility complex: gene organization, allelic polymorphism and expression in transformed cells.

The SB region of the human major histocompatibility complex (MHC) has been cloned from cosmid and lambda phage libraries made from the human B-lymphoblastoid cell line Priess (DR4/4, DC4/4, SB3/4). Two alpha genes and two beta genes are encoded in the 100 kb long SB region in the order SB alpha-SB beta-SX alpha-SX beta. The SB alpha and SB beta genes encode the alpha and beta subunits of the SB subset of class II MHC molecules. Both the SX alpha and the SX beta genes are pseudogenes in the haplotype examined. From the isolated clones, the two haplotypes of the Priess cell line, SB3 and SB4, are distinguished by nucleotide sequencing and blot hybridization analyses. Restriction site polymorphisms between the SB3 and SB4 clones were observed only in relatively small regions of the SB beta and SX beta genes. A mouse macrophage cell line was transfected with one of the cosmid clones containing both SB alpha and SB beta genes. Expression of the alpha and beta genes was detected by fluorescene-activated cell sorting (FACS) and two-dimensional gel electrophoresis using SB-specific monoclonal antibodies.

Alleles↗