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Sample records for histocompatibility complex dqb

  1. Identification and characterization of the major histocompatibility complex class II DQB (MhcMath-DQB1) alleles in Tibetan macaques (Macaca thibetana).

    PubMed

    Yao, Y-F; Zhao, J-J; Dai, Q-X; Li, J-Y; Zhou, L; Wang, Y-T; Ni, Q-Y; Zhang, M-w; Xu, H-L

    2013-08-01

    Tibetan macaque (Macaca thibetana), an endangered primate species endemic to China, have been used as experimental animal model for various human diseases. Major histocompatibility complex (MHC) genes play a crucial role in the susceptibility and/or resistance to many human diseases, but little is known about Tibetan macaques. To gain an insight into the MHC background and to facilitate the experimental use of Tibetan macaques, the second exon of Mhc-DQB1 gene was sequenced in a cohort of wild Tibetan macaques living in the Sichuan province of China. A total of 23 MhcMath-DQB1 alleles were identified for the first time, illustrating a marked allelic polymorphism at the DQB1 locus for these macaques. Most of the sequences (74%) observed in this study belong to DQB1*06 (9 alleles) and DQB1*18 (8 alleles) lineages, and the rest (26%) belong to DQB1*15 (3 alleles) and DQB1*17 (3 alleles) lineages. The most frequent alleles detected among these macaques were MhcMath-DQB1*15:02:02 (17.9%), followed by Math-DQB1*06:06, 17:03 and 18:01, which were detected in 9 (16.1%) of the monkeys, respectively. Non-synonymous substitutions occurred at a significantly higher frequency than synonymous substitutions in the peptide-binding region, suggesting balancing selection for maintaining polymorphisms at the MHC class II DQB1 locus. Phylogenetic analyses confirms the trans-species model of evolution of the Mhc-DQB1 genes in non-human primates, and in particular, the extensive allele sharing is observed between Tibetan and other macaque species.

  2. Characterization of the major histocompatibility complex class II DQB (MhcMamu-DQB1) alleles in a cohort of Chinese rhesus macaques (Macaca mulatta).

    PubMed

    Qiu, Chen-Li; Yang, Gui-Bo; Yu, Kai; Li, Yue; Li, Xiao-Li; Liu, Qiang; Zhao, Hui; Xing, Hui; Shao, Yiming

    2008-08-01

    Rhesus macaques have long been used in animal models for various human diseases, the susceptibility and/or resistance to some of which have been associated with the major histocompatibilty complex (MHC). To gain insight into the MHC background and to facilitate the experimental use of Chinese rhesus macaques, the second exon of MhcMamu-DQB1 genes in 105 rhesus macaques were characterized by cloning and sequencing. A total of 37 MhcMamu-DQB1 alleles were identified, illustrating a marked allelic polymorphism at DQB1 in these monkeys. In addition to 10 alleles were novel sequences that had not been documented in earlier reports, at least 14 alleles reported in earlier studies were not detected in this study. Most of the sequences (73%) observed in this study belong to DQB1 06 (13 alleles) and DQB1 18 (14 alleles) lineages, and the rest (27%) belong to DQB1 15, DQB1 16 and DQB1 17 lineages. The most frequent allele detected among these monkeys was MhcMamu-DQB1 06111 (22%), followed by DQB1 1503 (19%); and most of the novel alleles were present at a frequency of less than 2.5%. As for individual animals, 24 of 105 (23%) were homozygous whereas 81 of 105 (77%) were heterozygous at the MhcMamu-DQB1 locus. These data indicated significant differences in MhcMamu-DQB1 allele distribution between the Chinese rhesus macaques and the previously reported rhesus macaques, which were mostly of Indian origin. This information will not only promote the understanding of rhesus macaque MHC diversity and polymorphism but will also facilitate the use of Chinese rhesus macaques in human disease studies, especially those that may be associated with HLA-DQB genes.

  3. Extensive polymorphism and evidence of selection pressure on major histocompatibility complex DLA-DRB1, DQA1 and DQB1 class II genes in Croatian grey wolves.

    PubMed

    Arbanasić, H; Huber, Đ; Kusak, J; Gomerčić, T; Hrenović, J; Galov, A

    2013-01-01

    The genes of the major histocompatibility complex (MHC) are a key component of the mammalian immune system and have become important molecular markers for measuring fitness-related genetic variation in wildlife populations. Because of human persecution and habitat fragmentation, the grey wolf has become extinct from a large part of Western and Central Europe, and remaining populations have become isolated. In Croatia, the grey wolf population, part of the Dinaric-Balkan population, shrank nearly to extinction during the 20th century, and is now legally protected. Using the cloning-sequencing method, we investigated the genetic diversity and evolutionary history of exon 2 of MHC class II DLA-DRB1, DQA1 and DQB1 genes in 77 individuals. We identified 13 DRB1, 7 DQA1 and 11 DQB1 highly divergent alleles, and 13 DLA-DRB1/DQA1/DQB1 haplotypes. Selection analysis comparing the relative rates of non-synonymous to synonymous mutations (d(N)/d(S)) showed evidence of positive selection pressure acting on all three loci. Trans-species polymorphism was found, suggesting the existence of balancing selection. Evolutionary codon models detected considerable difference between alpha and beta chain gene selection patterns: DRB1 and DQB1 appeared to be under stronger selection pressure, while DQA1 showed signs of moderate selection. Our results suggest that, despite the recent contraction of the Croatian wolf population, genetic variability in selectively maintained immune genes has been preserved.

  4. Genetic diversity and differentiation of the rhesus macaque (Macaca mulatta) population in western Sichuan, China, based on the second exon of the major histocompatibility complex class II DQB (MhcMamu-DQB1) alleles

    PubMed Central

    2014-01-01

    Abstracts Background Rhesus macaques living in western Sichuan, China, have been separated into several isolated populations due to habitat fragmentation. Previous studies based on the neutral or nearly neutral markers (mitochondrial DNA or microsatellites) showed high levels of genetic diversity and moderate genetic differentiation in the Sichuan rhesus macaques. Variation at the major histocompatibility complex (MHC) loci is widely accepted as being maintained by balancing selection, even with a low level of neutral variability in some species. However, in small and isolated or bottlenecked populations, balancing selection may be overwhelmed by genetic drift. To estimate microevolutionary forces acting on the isolated rhesus macaque populations, we examined genetic variation at Mhc-DQB1 loci in 119 wild rhesus macaques from five geographically isolated populations in western Sichuan, China, and compared the levels of MHC variation and differentiation among populations with that previously observed at neutral microsatellite markers. Results 23 Mamu-DQB1 alleles were identified in 119 rhesus macaques in western Sichuan, China. These macaques exhibited relatively high levels of genetic diversity at Mamu-DQB1. The Hanyuan population presented the highest genetic variation, whereas the Heishui population was the lowest. Analysis of molecular variance (AMOVA) and pairwise FST values showed moderate genetic differentiation occurring among the five populations at the Mhc-DQB1 locus. Non-synonymous substitutions occurred at a higher frequency than synonymous substitutions in the peptide binding region. Levels of MHC variation within rhesus macaque populations are concordant with microsatellite variation. On the phylogenetic tree for the rhesus and crab-eating macaques, extensive allele or allelic lineage sharing is observed betweenthe two species. Conclusions Phylogenetic analyses confirm the apparent trans-species model of evolution of the Mhc-DQB1 genes in these

  5. Spatial variation and low diversity in the major histocompatibility complex in walrus (Odobenus rosmarus)

    USGS Publications Warehouse

    Sonsthagen, Sarah A.; Fales, Krystal; Jay, Chadwick V.; Sage, George K.; Talbot, Sandra L.

    2014-01-01

    Increased global temperature and associated changes to Arctic habitats will likely result in the northward advance of species, including an influx of pathogens novel to the Arctic. How species respond to these immunological challenges will depend in part on the adaptive potential of their immune response system. We compared levels of genetic diversity at a gene associated with adaptive immune response [Class II major histocompatibility complex (MHC), DQB exon 2] between populations of walrus (Odobenus rosmarus), a sea ice-dependent Arctic species. Walrus was represented by only five MHC DQB alleles, with frequency differences observed between Pacific and Atlantic populations. MHC DQB alleles appear to be under balancing selection, and most (80 %; n = 4/5) of the alleles were observed in walruses from both oceans, suggesting broad scale differences in the frequency of exposure and diversity of pathogens may be influencing levels of heterozygosity at DQB in walruses. Limited genetic diversity at MHC, however, suggests that walrus may have a reduced capacity to respond to novel immunological challenges associated with shifts in ecological communities and environmental stressors predicted for changing climates. This is particularly pertinent for walrus, since reductions in summer sea ice may facilitate both northward expansion of marine species and associated pathogens from more temperate regions, and exchange of marine mammals and associated pathogens through the recently opened Northwest Passage between the Atlantic and Pacific Oceans in the Canadian high Arctic.

  6. First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus Inia).

    PubMed

    Martínez-Agüero, M; Flores-Ramírez, S; Ruiz-García, M

    2006-07-31

    We report the first major histocompatibility complex (MHC) DQB1 sequences for the two species of pink river dolphins (Inia geoffrensis and Inia boliviensis) inhabiting the Amazon and Orinoco River basins. These sequences were found to be polymorphic within the Inia genus and showed shared homology with cetacean DQB-1 sequences, especially, those of the Monodontidae and Phocoenidae. On the other hand, these sequences were shown to be divergent from those described for other riverine dolphin species, such as Lipotes vexillifer, the Chinese river dolphin. Two main conclusions can be drawn from our results: 1) the Mhc DQB1 sequences seem to evolve more rapidly than other nuclear sequences in cetaceans, and 2) differential positive selective pressures acting on these genes cause concomitant divergent evolutionary histories that derive phylogenetic reconstructions that could be inconsistent with widely accepted intertaxa evolutionary relationships elucidated with other molecular markers subjected to a neutral dynamics.

  7. Genetics of Graft-versus-Host Disease: The Major Histocompatibility Complex

    PubMed Central

    Petersdorf, Effie W.

    2013-01-01

    Graft-versus-host disease (GVHD) is a potentially life-threatening complication of allogeneic hematopoietic cell transplantation. Many genes are presumed to be involved in GVHD, but the best characterized genetic system is that of the human major histocompatibility complex (MHC) located on chromosome 6. Among the hundreds of genes located within the MHC region, the best known and characterized are the classical HLA genes, HLA-A, C, B, DRB1, DQB1, and DPB1. They play a fundamental role in T cell immune responses, and HLA-A, C, and B also function as ligands for the natural killer cell immunoglobulin-like receptors involved in innate immunity. This review highlights the state-of-the art in the field of histocompatibility and immunogenetics of the MHC with respect to genetic risk factors for GVHD. PMID:23182478

  8. Polymorphism and Balancing Selection at Major Histocompatibility Complex Loci

    PubMed Central

    Takahata, N.; Satta, Y.; Klein, J.

    1992-01-01

    Amino acid replacements in the peptide-binding region (PBR) of the functional major histocompatibility complex (Mhc) genes appear to be driven by balancing selection. Of the various types of balancing selection, we have examined a model equivalent to overdominance that confers heterozygote advantage. As discussed by A. Robertson, overdominance selection tends to maintain alleles that have more or less the same degree of heterozygote advantage. Because of this symmetry, the model makes various testable predictions about the genealogical relationships among different alleles and provides ways of analyzing DNA sequences of Mhc alleles. In this paper, we analyze DNA sequences of 85 alleles at the HLA-A, -B, -C, -DRB1 and -DQB1 loci with respect to the number of alleles and extent of nucleotide differences at the PBR, as well as at the synonymous (presumably neutral) sites. Theory suggests that the number of alleles that differ at the sites targeted by selection (presumably the nonsynonymous sites in the PBR) should be equal to the mean number of nucleotide substitutions among pairs of alleles. We also demonstrate that the nucleotide substitution rate at the targeted sites relative to that of neutral sites may be much larger than 1. The predictions of the presented model are in surprisingly good agreement with the actual data and thus provide means for inferring certain population parameters. For overdominance selection in a finite population at equilibrium, the product of selection intensity (s) against homozygotes and the effective population size (N) is estimated to be 350-3000, being largest at the B locus and smallest at the C locus. We argue that N is of the order of 10(5) and s is several percent at most, if the mutation rate per site per generation is 10(-8). PMID:1582567

  9. Reproductive failure and the major histocompatibility complex

    SciTech Connect

    Jin, K.; Gill, T.J. III; Ho, H.N.

    1995-06-01

    The association between HLA sharing and recurrent spontaneous abortion (RSA) was tested in 123 couples and the association between HLA sharing, and the outcome of treatment for unexplained infertility by in vitro fertilization (IVF) was tested in 76 couples, by using a new shared-allele test in order to identify more precisely the region of the major histocompatibility complex (MHC) influencing these reproductive defects. The shared-allele test circumvents the problem of rare alleles at HLA loci and at the same time provides a substantial gain in power over the simple {chi}{sup 2} test. Two statistical methods, a corrected homogeneity test and a bootstrap approach, were developed to compare the allele frequencies at each of the HLA-A, HLA-B, HLA-DR, and HLA-DQ loci; they were not statistically different amount the three patient groups and the control group. There was a significant excess of HLA-DR sharing in couples with RSA and a significant excess of HLA-DQ sharing in couples with unexplained infertility who failed treatment by IVF. These findings indicate that genes located in different parts of the class II region of the MHC affect different aspects of reproduction and strongly suggest that the sharing of HLA antigens per se is not the mechanism involved in the reproductive defects. The segment of the MHC that has genes affecting reproduction also has genes associated with different autoimmune diseases, and this juxtaposition may explain the association between reproductive defects and autoimmune diseases. 58 refs., 1 fig., 7 tabs.

  10. Organization and characteristics of the major histocompatibility complex class II region in the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis)

    PubMed Central

    Ruan, Rui; Ruan, Jue; Wan, Xiao-Ling; Zheng, Yang; Chen, Min-Min; Zheng, Jin-Song; Wang, Ding

    2016-01-01

    Little is known about the major histocompatibility complex (MHC) in the genome of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) (YFP) or other cetaceans. In this study, a high-quality YFP bacterial artificial chromosome (BAC) library was constructed. We then determined the organization and characterization of YFP MHC class II region by screening the BAC library, followed by sequencing and assembly of positive BAC clones. The YFP MHC class II region consists of two segregated contigs (218,725 bp and 328,435 bp respectively) that include only eight expressed MHC class II genes, three pseudo MHC genes and twelve non-MHC genes. The YFP has fewer MHC class II genes than ruminants, showing locus reduction in DRB, DQA, DQB, and loss of DY. In addition, phylogenic and evolutionary analyses indicated that the DRB, DQA and DQB genes might have undergone birth-and-death evolution, whereas the DQB gene might have evolved under positive selection in cetaceans. These findings provide an essential foundation for future work, such as estimating MHC genetic variation in the YFP or other cetaceans. This work is the first report on the MHC class II region in cetaceans and offers valuable information for understanding the evolution of MHC genome in cetaceans. PMID:26932528

  11. Genetic characterization of MHC class II DQB exon 2 variants in gayal (Bos frontalis).

    PubMed

    Sun, Yongke; Xi, Dongmei; Li, Guozhi; Hao, Tiantian; Chen, Yuhan; Yang, Yuai

    2014-09-03

    In the present study, exon 2 of major histocompatibility complex (MHC) class II DQB gene from 39 gayals (Bos frontalis) was isolated, characterized and compared with previously reported patterns for other bovidae. It was revealed by sequence analyses that there are 36 DQB exon 2 variants among 39 gayals. These variants exhibited a high degree of nucleotide and amino acid substitutions with most amino acid variations occurring at positions forming the peptide-binding sites (PBS). The DQB loci were analysed for patterns of synonymous (dS) and non-synonymous (dN) substitution. The gayals were observed to be under strong balancing selection in the DQB exon 2 PBS (dN = 0.094, P = 0.001). It appears that this variability among gayals could confer the ability to mount immune responses to a wide variety of peptides or pathogens.

  12. Genetic characterization of MHC class II DQB exon 2 variants in gayal (Bos frontalis)

    PubMed Central

    Sun, Yongke; Xi, Dongmei; Li, Guozhi; Hao, Tiantian; Chen, Yuhan; Yang, Yuai

    2014-01-01

    In the present study, exon 2 of major histocompatibility complex (MHC) class II DQB gene from 39 gayals (Bos frontalis) was isolated, characterized and compared with previously reported patterns for other bovidae. It was revealed by sequence analyses that there are 36 DQB exon 2 variants among 39 gayals. These variants exhibited a high degree of nucleotide and amino acid substitutions with most amino acid variations occurring at positions forming the peptide-binding sites (PBS). The DQB loci were analysed for patterns of synonymous (d S) and non-synonymous (d N) substitution. The gayals were observed to be under strong balancing selection in the DQB exon 2 PBS (d N = 0.094, P = 0.001). It appears that this variability among gayals could confer the ability to mount immune responses to a wide variety of peptides or pathogens. PMID:26019566

  13. Identification of the expressed MHC class II DQB gene of the Asiatic black bear, Ursus thibetanus, in Japan.

    PubMed

    Yasukochi, Yoshiki; Kurosaki, Toshifumi; Yoneda, Masaaki; Koike, Hiroko

    2010-04-01

    Genetic diversity estimation of the major histocompatibility complex (MHC) gene may be an important tool in the assessment of immune response ability against infectious disease. We were able to identify a near full-length expressed DQB sequence by RACE-PCR method from the Asiatic black bear, Ursus thibetanus in Japan. This is the first such full length expression in the Ursidae. The bear had at least one functional DQB locus. In phylogenetic tree analysis its DQB amino acid sequence formed a monophyletic group with DQB sequences from members of the order Carnivora and had a 90% nucleotide sequence similarity with the DQB allele of the California sea lion, Zalophus californianus. We compared the DQB amino acid composition of U. thibetanus with those of several other mammalian species including Homo sapiens. Amino acid residues known to be functionally important for human MHC genes, tended to be also conserved among other mammalian species while PBRs in the beta1 domain were heterogeneous among mammalian species. The DQB sequence obtained from the bear had not only no putative frameshifts or deletions but also no abnormal amino acid mutations such as had been observed in human DQB molecules. This suggests that the bear DQB sequence was an apparently functional DQB allele. As a preliminary study, we sequenced the exon 2 region of DQB alleles from genomic DNA, and succeeded to amplify the exon 2 of DQB loci. Our study will provide useful information for conservation genetics of the U. thibetanus as well as more generally regarding the mammalian MHC region.

  14. Major histocompatibility complex diversity in the endangered Ethiopian wolf (Canis simensis).

    PubMed

    Kennedy, L J; Randall, D A; Knobel, D; Brown, J J; Fooks, A R; Argaw, K; Shiferaw, F; Ollier, W E R; Sillero-Zubiri, C; Macdonald, D W; Laurenson, M K

    2011-02-01

    The major histocompatibility complex (MHC) influences immune response to infection and vaccination. In most species, MHC genes are highly polymorphic, but few wild canid populations have been investigated. In Ethiopian wolves, we identified four DLA (dog leucocyte antigen)-DRB1, two DLA-DQA1 and five DQB1 alleles. Ethiopian wolves, the world's rarest canids with fewer than 500 animals worldwide, are further endangered and threatened by rabies. Major rabies outbreaks in the Bale Mountains of southern Ethiopia (where over half of the Ethiopian wolf population is located) have killed over 75% of wolves in the affected sub-populations. In 2004, following a rabies outbreak, 77 wolves were vaccinated, and 19 were subsequently recaptured to monitor the effectiveness of the intervention. Pre- and post-vaccination rabies antibody titres were available for 18 animals, and all of the animals sero-converted after vaccination. We compared the haplotype frequencies of this group of 18 with the post-vaccination antibody titre, and showed that one haplotype was associated with a lower response (uncorrected P < 0.03). In general, Ethiopian wolves probably have an adequate amount of MHC variation to ensure the survival of the species. However, we sampled only the largest Ethiopian wolf population in Bale, and did not take the smaller populations further north into consideration.

  15. Major histocompatibility complex class II polymorphisms in forest musk deer (Moschus berezovskii) and their probable association with purulent disease.

    PubMed

    Li, L; Wang, B B; Ge, Y F; Wan, Q H

    2014-10-01

    Genes of the major histocompatibility complex (MHC) family are crucial in immune responses because they present pathogenic peptides to T cells. In this study, we analysed the genetic variation in forest musk deer (Moschus berezovskii) MHC II genes and its potential association with musk deer purulent disease. In total, 53 purulent disease-susceptible and 46 purulent disease-resistant individuals were selected for MHC II exon 2 fragment analysis. Among them, 16 DQ alleles and four additional DR alleles were identified, with DQ exon 2 fragments displaying a low level of polymorphism. The nonsynonymous substitutions exceeded the synonymous substitutions in the peptide-binding sites of DQA2, DQB1 and DQB2. Then, 28 MHC II alleles were used to analyse the distribution patterns of purulent disease between the susceptible and resistant groups. Among them, three alleles (DQA1*01, DQA1*02 and DQA2*04) were found to be resistant, and five alleles (DRB3*07, DQA1*03, DQA1*04, DQA2*05 and DQA2*06) were found to increase susceptibility. Additionally, three haplotypes were found to be putatively associated with musk deer purulent disease. However, these three haplotypes were only found in the resistant or susceptible group, and their frequencies were low. The results from our study support a contributory role of MHC II polymorphisms in the development of purulent disease in forest musk deer.

  16. Major histocompatibility complex and mate choice in sand lizards.

    PubMed Central

    Olsson, Mats; Madsen, Thomas; Nordby, Jessica; Wapstra, Erik; Ujvari, Beata; Wittsell, Håkan

    2003-01-01

    In mice and man, females prefer males with a major histocompatibility complex (MHC) genotype different to their own. We tested whether this phenomenon also occurs in the Swedish sand lizard (Lacerta agilis). Females in a laboratory experiment preferred to associate with odour samples obtained from more distantly related males at the MHC class 1 loci. Data on free-ranging lizards suggest that associations between males and females are nonrandom with respect to MHC genotype. However, male spatial distribution and mobility during the mating season suggest that the non-random pairing process in the wild may also be driven by corresponding genetic benefits to males pairing with less related females. PMID:14667398

  17. Low Major Histocompatibility Complex Class II Variation in the Endangered Indo-Pacific Humpback Dolphin (Sousa chinensis): Inferences About the Role of Balancing Selection.

    PubMed

    Zhang, Xiyang; Lin, Wenzhi; Zhou, Ruilian; Gui, Duan; Yu, Xinjian; Wu, Yuping

    2016-03-01

    It has been widely reported that the major histocompatibility complex (MHC) is under balancing selection due to its immune function across terrestrial and aquatic mammals. The comprehensive studies at MHC and other neutral loci could give us a synthetic evaluation about the major force determining genetic diversity of species. Previously, a low level of genetic diversity has been reported among the Indo-Pacific humpback dolphin (Sousa chinensis) in the Pearl River Estuary (PRE) using both mitochondrial marker and microsatellite loci. Here, the expression and sequence polymorphism of 2 MHC class II genes (DQB and DRB) in 32 S. chinensis from PRE collected between 2003 and 2011 were investigated. High ratios of non-synonymous to synonymous substitution rates, codon-based selection analysis, and trans-species polymorphism (TSP) support the hypothesis that balancing selection acted on S. chinensis MHC sequences. However, only 2 haplotypes were detected at either DQB or DRB loci. Moreover, the lack of deviation from the Hardy-Weinberg expectation at DRB locus combined with the relatively low heterozygosity at both DQB locus and microsatellite loci suggested that balancing selection might not be sufficient, which further suggested that genetic drift associated with historical bottlenecks was not mitigated by balancing selection in terms of the loss of MHC and neutral variation in S. chinensis. The combined results highlighted the importance of maintaining the genetic diversity of the endangered S. chinensis.

  18. Major histocompatibility complex variation in the endangered Przewalski's horse.

    PubMed Central

    Hedrick, P W; Parker, K M; Miller, E L; Miller, P S

    1999-01-01

    The major histocompatibility complex (MHC) is a fundamental part of the vertebrate immune system, and the high variability in many MHC genes is thought to play an essential role in recognition of parasites. The Przewalski's horse is extinct in the wild and all the living individuals descend from 13 founders, most of whom were captured around the turn of the century. One of the primary genetic concerns in endangered species is whether they have ample adaptive variation to respond to novel selective factors. In examining 14 Przewalski's horses that are broadly representative of the living animals, we found six different class II DRB major histocompatibility sequences. The sequences showed extensive nonsynonymous variation, concentrated in the putative antigen-binding sites, and little synonymous variation. Individuals had from two to four sequences as determined by single-stranded conformation polymorphism (SSCP) analysis. On the basis of the SSCP data, phylogenetic analysis of the nucleotide sequences, and segregation in a family group, we conclude that four of these sequences are from one gene (although one sequence codes for a nonfunctional allele because it contains a stop codon) and two other sequences are from another gene. The position of the stop codon is at the same amino-acid position as in a closely related sequence from the domestic horse. Because other organisms have extensive variation at homologous loci, the Przewalski's horse may have quite low variation in this important adaptive region. PMID:10430594

  19. Natural selection coupled with intragenic recombination shapes diversity patterns in the major histocompatibility complex class II genes of the giant panda.

    PubMed

    Chen, Yi-Yan; Zhang, Ying-Ying; Zhang, He-Min; Ge, Yun-Fa; Wan, Qiu-Hong; Fang, Sheng-Guo

    2010-05-15

    Ample variations of the major histocompatibility complex (MHC) genes are essential for vertebrates to adapt to various environmental conditions. In this study, we investigated the genetic variations and evolutionary patterns of seven functional MHC class II genes (one DRA, two DRB, two DQA, and two DQB) of the giant panda. The results showed the presence of two monomorphic loci (DRA and DQB2) and five polymorphic loci with different numbers of alleles (seven at DRB1, six at DRB3, seven at DQA1, four at DQA2, six at DQB1). The presence of balancing selection in the giant panda was supported by the following pieces of evidence: (1) The observed heterozygosity was higher than expected. (2) Amino acid heterozygosity was significantly higher at antigen-binding sites (ABS) compared with non-ABS sequences. (3) The selection parameter omega (d(N)/d(S)) was significantly higher at ABS compared with non-ABS sequences. (4) Approximately 95.45% of the positively selected codons (P>0.95) were located at or adjacent to an ABS. Furthermore, this study showed that (1) The Qinling subspecies exhibited high omega values across each locus (all >1), supporting its extensive positive selection. (2) The Sichuan subspecies displayed small omega at DRB1 (omega<0.72) and DQA2 (omega<0.48), suggesting that these sites underwent strong purifying selection. (3) Intragenic recombination was detected in DRB1, DQA1, and DQB1. The molecular diversity in classic Aime-MHC class II genes implies that the giant panda had evolved relatively abundant variations in its adaptive immunity along the history of host-pathogen co-evolution. Collectively, these findings indicate that natural selection accompanied by recombination drives the contrasting diversity patterns of the MHC class II genes between the two studied subspecies of giant panda.

  20. The evolutionary ecology of the major histocompatibility complex.

    PubMed

    Piertney, S B; Oliver, M K

    2006-01-01

    The major histocompatibility complex (MHC) has become a paradigm for how selection can act to maintain adaptively important genetic diversity in natural populations. Here, we review the contribution of studies on the MHC in non-model species to our understanding of how selection affects MHC diversity, emphasising how ecological and ethological processes influence the tempo and mode of evolution at the MHC, and conversely, how variability at the MHC affects individual fitness, population dynamics and viability. We focus on three main areas: the types of information that have been used to detect the action of selection on MHC genes; the relative contributions of parasite-mediated and sexual selection on the maintenance of MHC diversity; and possible future lines of research that may help resolve some of the unanswered issues associated with MHC evolution.

  1. Analysis of Major Histocompatibility Complex (MHC) Immunopeptidomes Using Mass Spectrometry*

    PubMed Central

    Caron, Etienne; Kowalewski, Daniel J.; Chiek Koh, Ching; Sturm, Theo; Schuster, Heiko; Aebersold, Ruedi

    2015-01-01

    The myriad of peptides presented at the cell surface by class I and class II major histocompatibility complex (MHC) molecules are referred to as the immunopeptidome and are of great importance for basic and translational science. For basic science, the immunopeptidome is a critical component for understanding the immune system; for translational science, exact knowledge of the immunopeptidome can directly fuel and guide the development of next-generation vaccines and immunotherapies against autoimmunity, infectious diseases, and cancers. In this mini-review, we summarize established isolation techniques as well as emerging mass spectrometry-based platforms (i.e. SWATH-MS) to identify and quantify MHC-associated peptides. We also highlight selected biological applications and discuss important current technical limitations that need to be solved to accelerate the development of this field. PMID:26628741

  2. Analysis of Major Histocompatibility Complex (MHC) Immunopeptidomes Using Mass Spectrometry.

    PubMed

    Caron, Etienne; Kowalewski, Daniel J; Chiek Koh, Ching; Sturm, Theo; Schuster, Heiko; Aebersold, Ruedi

    2015-12-01

    The myriad of peptides presented at the cell surface by class I and class II major histocompatibility complex (MHC) molecules are referred to as the immunopeptidome and are of great importance for basic and translational science. For basic science, the immunopeptidome is a critical component for understanding the immune system; for translational science, exact knowledge of the immunopeptidome can directly fuel and guide the development of next-generation vaccines and immunotherapies against autoimmunity, infectious diseases, and cancers. In this mini-review, we summarize established isolation techniques as well as emerging mass spectrometry-based platforms (i.e. SWATH-MS) to identify and quantify MHC-associated peptides. We also highlight selected biological applications and discuss important current technical limitations that need to be solved to accelerate the development of this field.

  3. MOLECULAR GENETICS OF THE SWINE MAJOR HISTOCOMPATIBILITY COMPLEX, THE SLA COMPLEX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The swine major histocompatibility complex (MHC) or swine leukocyte antigen (SLA) complex is one of the most gene-dense regions in the swine genome. It consists of three major gene clusters, the SLA class I, class III and class II regions, that span ~1.1, 0.7 and 0.5 Mb, respectively, making the swi...

  4. The Major Histocompatibility Complex in Bovines: A Review

    PubMed Central

    Behl, Jyotsna Dhingra; Verma, N. K.; Tyagi, Neha; Mishra, Priyanka; Behl, Rahul; Joshi, B. K.

    2012-01-01

    Productivity in dairy cattle and buffaloes depends on the genetic factors governing the production of milk and milk constituents as well as genetic factors controlling disease resistance or susceptibility. The immune system is the adaptive defense system that has evolved in vertebrates to protect them from invading pathogens and also carcinomas. It is remarkable in the sense that it is able to generate an enormous variety of cells and biomolecules which interact with each other in numerous ways to form a complex network that helps to recognize, counteract, and eliminate the apparently limitless number of foreign invading pathogens/molecules. The major histocompatibility complex which is found to occur in all mammalian species plays a central role in the development of the immune system. It is an important candidate gene involved in susceptibility/resistance to various diseases. It is associated with intercellular recognition and with self/nonself discrimination. It plays major role in determining whether transplanted tissue will be accepted as self or rejected as foreign. PMID:23738132

  5. Major histocompatibility complex variation in the Arabian oryx.

    PubMed

    Hedrick, P W; Parker, K M; Gutiérrez-Espeleta, G A; Rattink, A; Lievers, K

    2000-12-01

    In the 1960s, the Arabian oryx was one of the most endangered species in the world, extinct in the wild and surviving in only a few captive herds. The present day population of over 2000 descends from a small number of founders and may have restricted genetic variation for important adaptive genes. We have examined the amount of genetic variation for a class II gene in the major histocompatibility complex thought to be the most important genetic basis for pathogen resistance in vertebrates. We found three very divergent alleles, which on average, differed by 24 nucleotides and 15 amino acids in the 236-bp fragment we examined. Using single-strand conformation polymorphism, we found that in a sample of 57 animals, the alleles were in Hardy-Weinberg proportions, although one allele was found only in four heterozygous individuals. The average heterozygosity for the 22 amino acid positions involved in antigen binding was 0.165, three times as high as that for the 56 amino acids not involved with antigen binding. Because the three alleles have such divergent sequences, it is likely that they may recognize peptides from quite different pathogens. As a result, maintenance of these variants should be considered as a goal in the captive breeding program of the Arabian oryx.

  6. Major Histocompatibility Complex (MHC) Markers in Conservation Biology

    PubMed Central

    Ujvari, Beata; Belov, Katherine

    2011-01-01

    Human impacts through habitat destruction, introduction of invasive species and climate change are increasing the number of species threatened with extinction. Decreases in population size simultaneously lead to reductions in genetic diversity, ultimately reducing the ability of populations to adapt to a changing environment. In this way, loss of genetic polymorphism is linked with extinction risk. Recent advances in sequencing technologies mean that obtaining measures of genetic diversity at functionally important genes is within reach for conservation programs. A key region of the genome that should be targeted for population genetic studies is the Major Histocompatibility Complex (MHC). MHC genes, found in all jawed vertebrates, are the most polymorphic genes in vertebrate genomes. They play key roles in immune function via immune-recognition and -surveillance and host-parasite interaction. Therefore, measuring levels of polymorphism at these genes can provide indirect measures of the immunological fitness of populations. The MHC has also been linked with mate-choice and pregnancy outcomes and has application for improving mating success in captive breeding programs. The recent discovery that genetic diversity at MHC genes may protect against the spread of contagious cancers provides an added impetus for managing and protecting MHC diversity in wild populations. Here we review the field and focus on the successful applications of MHC-typing for conservation management. We emphasize the importance of using MHC markers when planning and executing wildlife rescue and conservation programs but stress that this should not be done to the detriment of genome-wide diversity. PMID:21954351

  7. The Major Histocompatibility Complex (MHC) in Schizophrenia: A Review

    PubMed Central

    Mokhtari, Ryan; Lachman, Herbert M

    2017-01-01

    Epidemiological studies and mouse models suggest that maternal immune activation, induced clinically through prenatal exposure to one of several infectious diseases, is a risk factor in the development of schizophrenia. This is supported by the strong genetic association established by genome wide association studies (GWAS) between the human leukocyte antigen (HLA) locus and schizophrenia. HLA proteins (also known in mice as the major histocompatibility complex; MHC) are mediators of the T-lymphocyte responses, and genetic variability is well-established as a risk factor for autoimmune diseases and susceptibility to infectious diseases. Taken together, the findings strongly suggest that schizophrenia risk in a subgroup of patients is caused by an infectious disease, and/or an autoimmune phenomenon. However, this view may be overly simplistic. First, MHC proteins have a non-immune effect on synaptogenesis by modulating synaptic pruning by microglia and other mechanisms, suggesting that genetic variability could be compromising this physiological process. Second, some GWAS signals in the HLA locus map near non-HLA genes, such as the histone gene cluster. On the other hand, recent GWAS data show association signals near B-lymphocyte enhancers, which lend support for an infectious disease etiology. Thus, although the genetic findings implicating the HLA locus are very robust, how genetic variability in this region leads to schizophrenia remains to be elucidated. PMID:28180029

  8. Major histocompatibility complex class I polymorphism in Asiatic lions.

    PubMed

    Sachdev, M; Sankaranarayanan, R; Reddanna, P; Thangaraj, K; Singh, L

    2005-07-01

    Asiatic lions (Panthera leo persica), whose only natural habitat in the world is the Gir forest sanctuary of Gujarat State in India, are highly endangered and are considered to be highly inbred with narrow genetic diversity. An objective assessment of genetic diversity in their immune loci will help in assessing their survivability and may provide vital clues in designing strategies for their scientific management and conservation. We analyzed the comparative sequence polymorphism at exon 2 and exon 3 of major histocompatibility complex (MHC) class I in three groups of lions, i.e. wild Asiatic (from Gir forest), captive-bred Asiatic (from zoological parks in India), and Afro-Asiatic hybrid groups (from zoological parks in India) through polymorphism chain reaction-assisted sequence-based typing. The two exons were amplified, cloned, sequenced, and analyzed for polymorphism at nucleotide and putative translated product level. The analysis revealed extensive sequence polymorphism not only between clones derived from different lions but also the clones derived from a single lion. Furthermore, the wild Asiatic lions of Gir forest exhibited abundant sequence polymorphism at MHC class I comparable with that of Afro-Asiatic hybrid lions and significantly higher than that of captive-bred Asiatic lions. We hypothesize that Asiatic lions of Gir forest are not highly inbred as thought earlier and they possess abundant sequence polymorphism at MHC class I loci. During this study, 52 new sequences of the multigene MHC class I family were also identified among Asiatic lions.

  9. From genome-wide to candidate gene: an investigation of variation at the major histocompatibility complex in common bottlenose dolphins exposed to harmful algal blooms.

    PubMed

    Cammen, Kristina M; Wilcox, Lynsey A; Rosel, Patricia E; Wells, Randall S; Read, Andrew J

    2015-02-01

    The role the major histocompatibility complex (MHC) plays in response to exposure to environmental toxins is relatively poorly understood, particularly in comparison to its well-described role in pathogen immunity. We investigated associations between MHC diversity and resistance to brevetoxins in common bottlenose dolphins (Tursiops truncatus). A previous genome-wide association study investigating an apparent difference in harmful algal bloom (HAB) resistance among dolphin populations in the Gulf of Mexico identified genetic variation associated with survival in close genomic proximity to multiple MHC class II loci. Here, we characterized genetic variation at DQA, DQB, DRA, and DRB loci in dolphins from central-west Florida and the Florida Panhandle, including dolphins that died during HABs and dolphins presumed to have survived HAB exposure. We found that DRB and DQB exhibited patterns of genetic differentiation among geographic regions that differed from neutral microsatellite loci. In addition, genetic differentiation at DRB across multiple pairwise comparisons of live and dead dolphins was greater than differentiation observed at neutral loci. Our findings at these MHC loci did not approach the strength of association with survival previously described for a nearby genetic variant. However, the results provide evidence that selective pressures at the MHC vary among dolphin populations that differ in the frequency of HAB exposure and that the overall composition of DRB variants differs between dolphin survivors and non-survivors of HABs. These results may suggest a potential role of MHC diversity in variable survival of bottlenose dolphins exposed to HABs.

  10. Extended major histocompatibility complex haplotypes in type I diabetes mellitus.

    PubMed Central

    Raum, D; Awdeh, Z; Yunis, E J; Alper, C A; Gabbay, K H

    1984-01-01

    We have studied major histocompatibility complex markers in Caucasian patients with type I diabetes mellitus and their families. The frequencies of extended haplotypes that were composed of specific HLA-B, HLA-DR, BF, C2, C4A, and C4B allelic combinations, which occurred more commonly than expected, were compared on random diabetic and normal chromosomes in the study families. We demonstrated that all of the previously recognized increases in HLA-B8, B18, B15, DR3, and perhaps DR4 could be ascribed to the increase among diabetic haplotypes of a few extended haplotypes: [HLA B8, DR3, SC01, GLO2]; [HLA-B18, DR3, F1C30]; [HLA-B15, DR4, SC33]; and [HLA-BW38, DR4, SC21]. In fact, HLA-DR3 on nonextended haplotypes was "protective", with a relative risk considerably less than 1.0. There was a paucity or absence among diabetic patients of several extended haplotypes of normal chromosomes, notably [HLA-B7, DR2, SC31] and [HLA-BW44, DR4, SC30]. The extended haplotype [HLA-BW38, DR4, SC21] is found only in Ashkenazi Jewish patients, which suggests that extended haplotypes mark specific mutations that arise in defined ethnic groups. The data show that no known MHC allele, including HLA-DR3 and possibly HLA-DR4, is per se a marker for or itself a susceptibility gene for type I diabetes. Rather, extended haplotypes, with relatively fixed alleles, are either carriers or noncarriers of susceptibility genes for this disease. Thus, the increased frequency (association) or the decreased frequency (protection) of individual MHC alleles is largely explainable by these extended haplotypes. PMID:6746903

  11. Major histocompatibility complex conformational epitopes are peptide specific

    PubMed Central

    1992-01-01

    Serologically distinct forms of H-2Kb are stabilized by loading cells expressing "empty" class I major histocompatibility complex (MHC) molecules with different H-2Kb binding peptides. The H-2Kb epitope recognized by monoclonal antibody (mAb) 28.8.6 was stabilized by ovalbumin (OVA) (257-264) and murine cytomegalovirus (MCMV) pp89 (168- 176) peptides, but not by vesicular stomatic virus nucleoprotein (VSV NP) (52-59) and influenza NP (Y345-360) peptides. The H-2Kb epitope recognized by mAb 34.4.20 was stabilized by VSV NP (52-59) peptide but not by OVA (257-264), MCMV pp89 (168-176), or influenza NP (Y345-360) peptides. Immunoprecipitation of H-2Kb molecules from normal cells showed that 28.8.6 and 34.4.20 epitopes were only present on a subset of all conformationally reactive H-2Kb molecules. Using alanine- substituted derivatives of the VSV peptide, the 28.8.6 epitope was completely stabilized by substitution of the first residue and partially stabilized by substitution of the third or the fifth residues in the peptides. These results indicate that distinct conformational MHC epitopes are dependent on the specific peptide that occupies the antigenic peptide binding groove on individual MHC molecules. The changes in MHC epitopes observed may also be important in understanding the diversity of T cell receptors used in an immune response and the influence of peptides on development of the T cell repertoire. PMID:1281212

  12. Major Histocompatibility Complex and Malaria: Focus on Plasmodium vivax Infection

    PubMed Central

    Lima-Junior, Josué da Costa; Pratt-Riccio, Lilian Rose

    2016-01-01

    The importance of host and parasite genetic factors in malaria resistance or susceptibility has been investigated since the middle of the last century. Nowadays, of all diseases that affect man, malaria still plays one of the highest levels of selective pressure on human genome. Susceptibility to malaria depends on exposure profile, epidemiological characteristics, and several components of the innate and adaptive immune system that influences the quality of the immune response generated during the Plasmodium lifecycle in the vertebrate host. But it is well known that the parasite’s enormous capacity of genetic variation in conjunction with the host genetics polymorphism is also associated with a wide spectrum of susceptibility degrees to complicated or severe forms of the disease. In this scenario, variations in genes of the major histocompatibility complex (MHC) associated with host resistance or susceptibility to malaria have been identified and used as markers in host–pathogen interaction studies, mainly those evaluating the impact on the immune response, acquisition of resistance, or increased susceptibility to infection or vulnerability to disease. However, due to the intense selective pressure, number of cases, and mortality rates, the majority of the reported associations reported concerned Plasmodium falciparum malaria. Studies on the MHC polymorphism and its association with Plasmodium vivax, which is the most widespread Plasmodium and the most prevalent species outside the African continent, are less frequent but equally important. Despite punctual contributions, there are accumulated evidences of human genetic control in P. vivax infection and disease. Herein, we review the current knowledge in the field of MHC and derived molecules (HLA Class I, Class II, TNF-α, LTA, BAT1, and CTL4) regarding P. vivax malaria. We discuss particularly the results of P. vivax studies on HLA class I and II polymorphisms in relation to host susceptibility, naturally

  13. Diversity of MHC DQB and DRB Genes in the Endangered Australian Sea Lion (Neophoca cinerea).

    PubMed

    Lau, Quintin; Chow, Natalie; Gray, Rachael; Gongora, Jaime; Higgins, Damien P

    2015-01-01

    Major histocompatibility complex (MHC) class II molecules have an important role in vertebrate adaptive immunity, being responsible for recognizing, binding, and presenting specific antigenic peptides to T lymphocytes. Here, we study the MHC class II DQB and DRB exon 2 genes of the Australian sea lion (Neophoca cinerea), an endangered pinniped species that experiences high pup mortality. Following characterization of N. cinerea DQB and DRB by molecular cloning, and evaluation of diversity in pups across 2 colonies using variant screening (n = 47), 3 DQB alleles and 10 DRB variants (including 1 pseudogene allele) were identified. The higher diversity at DRB relative to DQB is consistent with other studies in marine mammals. Despite overall lower MHC class II allelic diversity relative to some other pinniped species, we observed similar levels of nucleotide diversity and selection in N. cinerea. In addition, we provide support for recent divergence of MHC class II alleles. The characterization of MHC class II diversity in the Australian sea lion establishes a baseline for further investigation of associations with disease, including endemic hookworm infection, and contributes to the conservation management of this species.

  14. Balancing selection and genetic drift at major histocompatibility complex class II genes in isolated populations of golden snub-nosed monkey (Rhinopithecus roxellana)

    PubMed Central

    2012-01-01

    Background Small, isolated populations often experience loss of genetic variation due to random genetic drift. Unlike neutral or nearly neutral markers (such as mitochondrial genes or microsatellites), major histocompatibility complex (MHC) genes in these populations may retain high levels of polymorphism due to balancing selection. The relative roles of balancing selection and genetic drift in either small isolated or bottlenecked populations remain controversial. In this study, we examined the mechanisms maintaining polymorphisms of MHC genes in small isolated populations of the endangered golden snub-nosed monkey (Rhinopithecus roxellana) by comparing genetic variation found in MHC and microsatellite loci. There are few studies of this kind conducted on highly endangered primate species. Results Two MHC genes were sequenced and sixteen microsatellite loci were genotyped from samples representing three isolated populations. We isolated nine DQA1 alleles and sixteen DQB1 alleles and validated expression of the alleles. Lowest genetic variation for both MHC and microsatellites was found in the Shennongjia (SNJ) population. Historical balancing selection was revealed at both the DQA1 and DQB1 loci, as revealed by excess non-synonymous substitutions at antigen binding sites (ABS) and maximum-likelihood-based random-site models. Patterns of microsatellite variation revealed population structure. FST outlier analysis showed that population differentiation at the two MHC loci was similar to the microsatellite loci. Conclusions MHC genes and microsatellite loci showed the same allelic richness pattern with the lowest genetic variation occurring in SNJ, suggesting that genetic drift played a prominent role in these isolated populations. As MHC genes are subject to selective pressures, the maintenance of genetic variation is of particular interest in small, long-isolated populations. The results of this study may contribute to captive breeding and translocation programs

  15. Genomic structure of the horse major histocompatibility complex class II region resolved using PacBio long-read sequencing technology

    PubMed Central

    Viļuma, Agnese; Mikko, Sofia; Hahn, Daniela; Skow, Loren; Andersson, Göran; Bergström, Tomas F.

    2017-01-01

    The mammalian Major Histocompatibility Complex (MHC) region contains several gene families characterized by highly polymorphic loci with extensive nucleotide diversity, copy number variation of paralogous genes, and long repetitive sequences. This structural complexity has made it difficult to construct a reliable reference sequence of the horse MHC region. In this study, we used long-read single molecule, real-time (SMRT) sequencing technology from Pacific Biosciences (PacBio) to sequence eight Bacterial Artificial Chromosome (BAC) clones spanning the horse MHC class II region. The final assembly resulted in a 1,165,328 bp continuous gap free sequence with 35 manually curated genomic loci of which 23 were considered to be functional and 12 to be pseudogenes. In comparison to the MHC class II region in other mammals, the corresponding region in horse shows extraordinary copy number variation and different relative location and directionality of the Eqca-DRB, -DQA, -DQB and –DOB loci. This is the first long-read sequence assembly of the horse MHC class II region with rigorous manual gene annotation, and it will serve as an important resource for association studies of immune-mediated equine diseases and for evolutionary analysis of genetic diversity in this region. PMID:28361880

  16. Beyond splitting hares and rabbiting on about major histocompatibility complex complexity.

    PubMed

    Oliver, Matthew; Piertney, Stuart

    2010-10-01

    The genes of the major histocompatibility complex (MHC) have become the target of choice for studies wishing to examine adaptively important genetic diversity in natural populations. Within Molecular Ecology alone, there have been 71 papers on aspects of MHC evolution over the past few years, with an increasing year on year trend. This focus on the MHC is partly driven by the hypothesized links between MHC gene dynamics and ecologically interesting and relevant traits, such as mate choice and host–parasite interactions. However, an ability to pin down the evolutionary causes and ecological consequences of MHC variation in natural populations has proven challenging and has been hampered by the very issue that is attractive about MHC genes – their high levels of diversity. Linking high levels of MHC diversity to ecological factors in inherently complex natural populations requires a level of experimental design and analytical rigour that is extremely difficult to achieve owing to a plethora of potentially confounding and interacting variables. In this issue of Molecular Ecology, Smith et al. (2010) elegantly overcome the challenge of detecting complex interactions in complex systems by using an intricate analytical approach to demonstrate a role for MHC in the reproductive ability of a natural population of the European hare Lepus europaeus (Fig. 1). Also in this issue, Oppelt et al. (2010) demonstrate a role for MHC variation in determining levels of hepatic coccidian infection in the European rabbit Oryctolagus cuniculus (Fig. 2).

  17. Measuring complexity, nonextensivity and chaos in the DNA sequence of the Major Histocompatibility Complex

    NASA Astrophysics Data System (ADS)

    Pavlos, G. P.; Karakatsanis, L. P.; Iliopoulos, A. C.; Pavlos, E. G.; Xenakis, M. N.; Clark, Peter; Duke, Jamie; Monos, D. S.

    2015-11-01

    We analyze 4 Mb sequences of the Major Histocompatibility Complex (MHC), which is a DNA segment on chromosome 6 with high gene density, controlling many immunological functions and associated with many diseases. The analysis is based on modern theoretical and mathematical tools of complexity theory, such as nonlinear time series analysis and Tsallis non-extensive statistics. The results revealed that the DNA complexity and self-organization can be related to fractional dynamical nonlinear processes with low-dimensional deterministic chaotic and non-extensive statistical character, which generate the DNA sequences under the extremization of Tsallis q-entropy principle. While it still remains an open question as to whether the DNA walk is a fractional Brownian motion (FBM), a static anomalous diffusion process or a non-Gaussian dynamical fractional anomalous diffusion process, the results of this study testify for the latter, providing also a possible explanation for the previously observed long-range power law correlations of nucleotides, as well as the long-range correlation properties of coding and non-coding sequences present in DNA sequences.

  18. Evolution of the major histocompatibility complex: Isolation of class II beta cDNAs from two monotremes, the platypus and the short-beaked echidna.

    PubMed

    Belov, Katherine; Lam, Mary K P; Hellman, Lars; Colgan, Donald J

    2003-09-01

    Extant mammals are composed of three lineages: the eutherians, the marsupials and the monotremes. The majority of the mammalian major histocompatibility complex (MHC) data is based on the eutherian mammals, which generally have three classical MHC class II beta chain gene clusters - DRB, DQB and DPB, as well as the non-classical DMB and DOB. Marsupial DMB, DAB and DBB have been characterised. Confusion still surrounds the relationship of the marsupial DAB and DBB genes with the classical eutherian class II clusters. Here we present the first monotreme MHC class II beta chain sequences. Four MHC class II beta chain sequences were isolated from a spleen cDNA library from the short-beaked echidna, and one from a spleen cDNA library from platypus using a brushtail possum DAB probe. Given the non-orthologous relationship of the monotreme sequences with marsupial and eutherian beta chain clusters, we recommend that the five new monotreme sequences be assigned the nomenclature 'DZB', signifying the description of a new mammalian beta chain cluster. Our analysis suggests that all mammalian beta chain sequences (except DMB) evolved from a common ancestor. Maximum likelihood analysis places the monotreme beta chain sequences at the base of the mammalian clade, indicating their ancestral status. However, within the mammalian clade, monophyletic clades are not robust, and elucidation of the order of gene duplication that gave rise to the present-day gene clusters is not yet possible.

  19. Activation of class I major histocompatibility complex gene expression by hepatitis B virus.

    PubMed Central

    Zhou, D X; Taraboulos, A; Ou, J H; Yen, T S

    1990-01-01

    Normal hepatocytes express very few class I major histocompatibility complex (MHC I) molecules, but MHC I expression is elevated in hepatitis B virus (HBV) infection. We report here that hepatoblastoma cells with replicating HBV genomes express three- to fourfold-higher levels of MHC I protein and mRNA than do parent cells without HBV DNA. Transient transfection assays demonstrated that the HBV X protein trans activated transcription from an MHC I promoter and allowed identification of cis elements important for trans activation. Images PMID:2164611

  20. Rejection of wild-type and genetically engineered major histocompatibility complex-deficient glial cell xenografts in the central nervous system results in bystander demyelination and Wallerian degeneration.

    PubMed

    O'Leary, M T; Bujdoso, R; Blakemore, W F

    1998-07-01

    Mixed glial cell cultures prepared from neonatal wild type and mutant male mice lacking either major histocompatibility complex class I, class II or both class I and II molecules (major histocompatibility complex class I(o/o)II(o/o)), and from syngeneic male rats were transplanted into female rat spinal cord white matter. Graft survival was monitored using DNA probes specific to the Y chromosome. Survival of major histocompatibility complex class-deficient grafts was not prolonged compared to wild-type grafts and in most cases grafts could not be detected at 28 days post-transplantation, at which time syngeneic grafts were still present. However, rejection of xenografts resulted in significant bystander damage to host tissue. In recipients of wild-type and major histocompatibility complex class I(o/o) xenografts the predominant pathology was demyelination. Demyelination was also observed in recipients of major histocompatibility complex class II(o/o) and major histocompatibility complex class I(o/o)II(o/o) xenografts, however in addition there was marked collagen deposition and meningeal cell invasion. Significantly more axons had undergone Wallerian degeneration in recipients of major histocompatibility complex class II(o/o) and major histocompatibility complex class I(o/o)II(o/o) xenografts than recipients of wild-type and major histocompatibility complex class I(o/o) xenografts. These findings were interpreted as evidence of a more destructive immune response associated with rejection of grafts lacking major histocompatibility complex class II molecules. It was proposed that the difference in the severity of bystander damage may be related to the previously demonstrated ability of xenogeneic major histocompatibility complex class II molecules to activate host T cells directly, whereas xenografts lacking major histocompatibility complex class II molecules were capable of activating host T cells only by the indirect pathway.

  1. Extended major histocompatibility complex haplotypes in patients with gluten-sensitive enteropathy.

    PubMed Central

    Alper, C A; Fleischnick, E; Awdeh, Z; Katz, A J; Yunis, E J

    1987-01-01

    We have studied major histocompatibility complex markers in randomly ascertained Caucasian patients with gluten-sensitive enteropathy and their families. The frequencies of extended haplotypes, defined as haplotypes of specific HLA-B, DR, BF, C2, C4A, and C4B allelic combinations, occurring more frequently than expected, were compared on patient chromosomes, on normal chromosomes from the study families, and on chromosomes from normal families. Over half of patient chromosomes consisted almost entirely of two extended haplotypes [HLA-B8, DR3, SC01] and [HLA-B44, DR7, FC31] which, with nonextended HLA-DR7, accounted for the previously observed HLA markers of this disease: HLA-B8, DR3, and DR7. There was no increase in HLA-DR3 on nonextended haplotypes or in other extended haplotypes with HLA-DR3 or DR7. The distribution of homozygotes and heterozygotes for HLA-DR3 and DR7 was consistent with recessive inheritance of the major histocompatibility complex-linked susceptibility gene for gluten-sensitive enteropathy. On the other hand, by odds ratio analysis and from the sum of DR3 and DR7 homozygotes compared with DR3/DR7 heterozygotes, there was an increase in heterozygotes and a decrease in homozygotes suggesting the presence of modifying phenomena. PMID:3793924

  2. Macrophage cell lines derived from major histocompatibility complex II-negative mice

    NASA Technical Reports Server (NTRS)

    Beharka, A. A.; Armstrong, J. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1998-01-01

    Two bone-marrow-derived macrophage cell lines, C2D and C2Dt, were isolated from major histocompatibility class II negative knock-out mice. The C2D cell line was stabilized by continuous culture in colony-stimulating factor-1 and the C2Dt cell line was transformed with SV40 virus large T antigen. These cells exhibited phenotypic properties of macrophages including morphology and expression of Mac 1 and Mac 2 cell surface molecules. These cells also had comparable growth to the bone-marrow-derived macrophage cell line B6MP102. These new cell lines were not spontaneously cytotoxic and were only capable of modest killing of F5b tumor cells when stimulated with LPS and interferon-gamma, but not when stimulated with LPS alone or with staphylococcal exotoxin. C2D and C2Dt cells phagocytosed labeled Staphylococcus aureus similarly to B6MP102 cells but less well than C2D peritoneal macrophages. These cell lines secreted interleukin-6, but not tumor necrosis factor or nitric oxide in response to LPS or staphlococcal enterotoxins A or B C2D(t) cells were tumorigenic in C2D and C57BL/6J mice but C2D cells were not. These data suggest that macrophage cell lines can be established from bone marrow cells of major histocompatibility complex II-negative mice.

  3. Molecular analysis of HLA-DRB1, DQA1, DQB1, DQ promoter polymorphism and extended class I/class II haplotypes in the Seri Indians from Northwest Mexico.

    PubMed

    Alaez, C; Infante, E; Pujol, J; Duran, C; Navarro, J L; Gorodezky, C

    2002-05-01

    The study of the genetics of the Major Histocompatibility Complex (MHC) in Amerindians is of great value in understanding the origins and migrations of these native groups, as well as the impact of immunogenetics on the epidemiology of diseases affecting these populations. We analyzed, using Polymerase Chain Reaction and Sequence Specific Oligonucleotide Probes (PCR-SSOP), DRB1, DQA1, DQB1 alleles and the promoter regions of DQA1 and DQB1 genes in 31 unrelated and 24 related Seri, a Mexican Indian group, from the state of Sonora (Northwest Mexico). The class II genotypes of this population were found to be in genetic equilibrium. The allele frequency (AF) of the prevalent DRB1 alleles were DRB1*0407 (48.4%), DRB1*0802 (33.9%) and DRB1*1402 (16.1%). The most frequent DQA1 and DQB1 alleles were DQA1*03011 (AF = 50.00%), DQA1*0401 (AF = 33.87%) and DQA1*0501 (AF = 16.13%); DQB1*0302 (AF = 50.00%), DQB1*0402 (33.87%) and DQB1*0301 (16.13%); which were in combination with DRB1*0407, DRB1*0802 and DRB1*1402, respectively. Three QAP and three QBP alleles were present (QAP 3.1, 4.1, 4.2; QBP 3.1, 3.21, 4.1) associated with the typical published DQA1 and DQB1 alleles. Four class II haplotypes were present in family members: DRB1*0407-QAP-3.1-DQA1*03011-QBP-3.21-DQB1*0302; DRB1*0802-QAP-4.2-DQA1*0401-QBP-4.1-DQB1*0402; DRB1*1402-QAP-4.1-DQA1*0501-QBP-3.1-DQB1*0301 and DRB1*0701-QAP-2.1-DQA1*0201-QBP-2.1-DQB1*0201. The family data were used to confirm extended haplotypes. A total of 21 haplotypes were found when A* and B* loci were also considered. The three most frequent combinations included A*0201-B*3501-DRB1*0407, A*3101-B*5101-DRB1*0802, and A*0201-B*40-DRB1*1402.

  4. Characterisation of Major Histocompatibility Complex Class I in the Australian Cane Toad, Rhinella marina

    PubMed Central

    Lillie, Mette; Shine, Richard; Belov, Katherine

    2014-01-01

    The Major Histocompatibility Complex (MHC) class I is a highly variable gene family that encodes cell-surface receptors vital for recognition of intracellular pathogens and initiation of immune responses. The MHC class I has yet to be characterised in bufonid toads (Order: Anura; Suborder: Neobatrachia; Family: Bufonidae), a large and diverse family of anurans. Here we describe the characterisation of a classical MHC class I gene in the Australian cane toad, Rhinella marina. From 25 individuals sampled from the Australian population, we found only 3 alleles at this classical class I locus. We also found large number of class I alpha 1 alleles, implying an expansion of class I loci in this species. The low classical class I genetic diversity is likely the result of repeated bottleneck events, which arose as a result of the cane toad's complex history of introductions as a biocontrol agent and its subsequent invasion across Australia. PMID:25093458

  5. Genetic Variation at Exon 2 of the MHC Class II DQB Locus in Blue Whale (Balaenoptera musculus) from the Gulf of California.

    PubMed

    Moreno-Santillán, Diana D; Lacey, Eileen A; Gendron, Diane; Ortega, Jorge

    2016-01-01

    The genes of the Major Histocompatibility Complex (MHC) play an important role in the vertebrate immune response and are among the most polymorphic genes known in vertebrates. In some marine mammals, MHC genes have been shown to be characterized by low levels of polymorphism compared to terrestrial taxa; this reduction in variation is often explained as a result of lower pathogen pressures in marine habitats. To determine if this same reduction in variation applies to the migratory population of blue whales (Balaenoptera musculus) that occurs in the Gulf of California, we genotyped a 172 bp fragment of exon 2 of the MHC Class II DQB locus for 80 members of this population. Twenty-two putatively functional DQB allotypes were identified, all of which were homologous with DQB sequences from other cetacean species. Up to 5 putative alleles per individual were identified, suggesting that gene duplication has occurred at this locus. Rates of non-synonymous to synonymous substitutions (ω) and maximum likelihood analyses of models of nucleotide variation provided potential evidence of ongoing positive selection at this exon. Phylogenetic analyses of DQB alleles from B. musculus and 16 other species of cetaceans revealed trans-specific conservation of MHC variants, suggesting that selection has acted on this locus over prolonged periods of time. Collectively our findings reveal that immunogenic variation in blue whales is comparable to that in terrestrial mammals, thereby providing no evidence that marine taxa are subject to reduced pathogen-induced selective pressures.

  6. Genetic Variation at Exon 2 of the MHC Class II DQB Locus in Blue Whale (Balaenoptera musculus) from the Gulf of California

    PubMed Central

    Moreno-Santillán, Diana D.; Lacey, Eileen A.; Gendron, Diane; Ortega, Jorge

    2016-01-01

    The genes of the Major Histocompatibility Complex (MHC) play an important role in the vertebrate immune response and are among the most polymorphic genes known in vertebrates. In some marine mammals, MHC genes have been shown to be characterized by low levels of polymorphism compared to terrestrial taxa; this reduction in variation is often explained as a result of lower pathogen pressures in marine habitats. To determine if this same reduction in variation applies to the migratory population of blue whales (Balaenoptera musculus) that occurs in the Gulf of California, we genotyped a 172 bp fragment of exon 2 of the MHC Class II DQB locus for 80 members of this population. Twenty-two putatively functional DQB allotypes were identified, all of which were homologous with DQB sequences from other cetacean species. Up to 5 putative alleles per individual were identified, suggesting that gene duplication has occurred at this locus. Rates of non-synonymous to synonymous substitutions (ω) and maximum likelihood analyses of models of nucleotide variation provided potential evidence of ongoing positive selection at this exon. Phylogenetic analyses of DQB alleles from B. musculus and 16 other species of cetaceans revealed trans-specific conservation of MHC variants, suggesting that selection has acted on this locus over prolonged periods of time. Collectively our findings reveal that immunogenic variation in blue whales is comparable to that in terrestrial mammals, thereby providing no evidence that marine taxa are subject to reduced pathogen-induced selective pressures. PMID:26761201

  7. Canine parvovirus enteritis, canine distemper, and major histocompatibility complex genetic variation in Mexican wolves.

    PubMed

    Hedrick, Philip W; Lee, Rhonda N; Buchanan, Colleen

    2003-10-01

    The endangered Mexican wolf (Canis lupus baileyi) was recently reintroduced into Arizona and New Mexico (USA). In 1999 and 2000, pups from three litters that were part of the reintroduction program died of either canine parvovirus or canine distemper. Overall, half (seven of 14) of the pups died of either canine parvovirus or canine distemper. The parents and their litters were analyzed for variation at the class II major histocompatibility complex (MHC) gene DRB1. Similar MHC genes are related to disease resistance in other species. All six of the surviving pups genotyped for the MHC gene were heterozygous while five of the pups that died were heterozygous and one was homozygous. Resistance to pathogens is an important aspect of the management and long-term survival of endangered taxa, such as the Mexican wolf.

  8. Major histocompatibility complex variation in the endangered crested ibis Nipponia nippon and implications for reintroduction.

    PubMed

    Zhang, Bei; Fang, Sheng-Guo; Xi, Yong-Mei

    2006-04-01

    The major histocompatibility complex (MHC), with its extraordinary levels of genetic variation, is thought to be an essential aspect of the ability of an organism to recognize different parasites and pathogens. It has also been proposed to regulate reproductive processes in many aspects. Here we examine the genetic variation of the second exon of the MHC class II B genes of the crested ibis, an endangered species known to descend from just two breeding pairs rediscovered in 1981. Only five alleles are identified by single-strand conformation polymorphism (SSCP) analysis of 36 samples taken from both wild and captive populations, and a comparatively low level of divergence between MHC alleles is observed. We suggest that representative sampling of individuals with most of the different MHC allele genotypes to constitute a founder population, together with the monitoring of the pathogen status of candidate sites before release, is of great importance for raising the success rate of reintroduction for the crested ibis.

  9. Isolation and characterization of major histocompatibility complex class II B genes in cranes.

    PubMed

    Kohyama, Tetsuo I; Akiyama, Takuya; Nishida, Chizuko; Takami, Kazutoshi; Onuma, Manabu; Momose, Kunikazu; Masuda, Ryuichi

    2015-11-01

    In this study, we isolated and characterized the major histocompatibility complex (MHC) class II B genes in cranes. Genomic sequences spanning exons 1 to 4 were amplified and determined in 13 crane species and three other species closely related to cranes. In all, 55 unique sequences were identified, and at least two polymorphic MHC class II B loci were found in most species. An analysis of sequence polymorphisms showed the signature of positive selection and recombination. A phylogenetic reconstruction based on exon 2 sequences indicated that trans-species polymorphism has persisted for at least 10 million years, whereas phylogenetic analyses of the sequences flanking exon 2 revealed a pattern of concerted evolution. These results suggest that both balancing selection and recombination play important roles in the crane MHC evolution.

  10. Expression of major histocompatibility complex class II and costimulatory molecules in oral carcinomas in vitro.

    PubMed

    Villarroel-Dorrego, Mariana; Speight, Paul M; Barrett, A William

    2005-01-01

    Recognition in the 1980 s that keratinocytes can express class II molecules of the Major Histocompatibility Complex (MHC) first raised the possibility that these cells might have an immunological function, and may even act as antigen presenting cells (APC). For effective T lymphocyte activation, APC require, in addition to MHC II, appropriate costimulatory signals. The aim of this study was to determine the expression of MHC class II and the co-stimulatory molecules CD40, CD80 and CD86 in keratinocytes derived from healthy oral mucosa and oral carcinomas. Using flow cytometry, it was confirmed that oral keratinocytes, switch on, expression of MHC class II molecules after stimulation with IFNgamma in vitro. All keratinocyte lines expressed CD40 constitutively; by contrast, CD80 and CD86 were universally absent. Loss of CD80 and CD86 may be one means whereby tumours escape immunological surveillance.

  11. Polymorphism and selection in the major histocompatibility complex DRA and DQA genes in the family Equidae.

    PubMed

    Janova, Eva; Matiasovic, Jan; Vahala, Jiri; Vodicka, Roman; Van Dyk, Enette; Horin, Petr

    2009-07-01

    The major histocompatibility complex genes coding for antigen binding and presenting molecules are the most polymorphic genes in the vertebrate genome. We studied the DRA and DQA gene polymorphism of the family Equidae. In addition to 11 previously reported DRA and 24 DQA alleles, six new DRA sequences and 13 new DQA alleles were identified in the genus Equus. Phylogenetic analysis of both DRA and DQA sequences provided evidence for trans-species polymorphism in the family Equidae. The phylogenetic trees differed from species relationships defined by standard taxonomy of Equidae and from trees based on mitochondrial or neutral gene sequence data. Analysis of selection showed differences between the less variable DRA and more variable DQA genes. DRA alleles were more often shared by more species. The DQA sequences analysed showed strong amongst-species positive selection; the selected amino acid positions mostly corresponded to selected positions in rodent and human DQA genes.

  12. Characterisation of four major histocompatibility complex class II genes of the koala (Phascolarctos cinereus).

    PubMed

    Lau, Quintin; Jobbins, Sarah E; Belov, Katherine; Higgins, Damien P

    2013-01-01

    Major histocompatibility complex (MHC) class II molecules have an integral role in the adaptive immune response, as they bind and present antigenic peptides to T helper lymphocytes. In this study of koalas, species-specific primers were designed to amplify exon 2 of the MHC class II DA and DB genes, which contain much of the peptide-binding regions of the α and β chains. A total of two DA α1 domain variants and eight DA β1 (DAB), three DB α1 and five DB β1 variants were amplified from 20 koalas from two free-living populations from South East Queensland and the Port Macquarie region in northern New South Wales. We detected greater variation in the β1 than in the α1 domains as well as evidence of positive selection in DAB. The present study provides a springboard to future investigation of the role of MHC in disease susceptibility in koalas.

  13. Variability with altitude of major histocompatibility complex-related microsatellite loci in goats from Southwest China.

    PubMed

    E, G X; Huang, Y F; Zhao, Y J; Na, R S

    2015-11-19

    We aimed to use microsatellite BM1258 loci of the major histocompatibility complex (MHC) as an indicator of the influence of genetic diversity of immunity in goats (Dazu Black, Hechuan White, Meigu, and Tibetan goat). In total, 132 animals comprising 50 Dazu Black goats, 24 Hechuan White goats, 34 Meigu goats, and 24 Tibetan goats were examined. Collectively, 18 different alleles and 42 genotypes were found. The overall observed levels of heterozygosity showed large divergence from the expected levels in the four breeds, and an increase in the mean number of alleles of BM1258 accompanied decreasing altitude of the livestock's habitat. Our results indicate that low-altitude regions or plains were more conducive to genetic material exchange and gene flow between different populations. In addition, it seems that the breeds from low-altitude regions were less susceptible to problems introduced by commercial animals.

  14. Genetic Variation of Major Histocompatibility Complex and Microsatellite Loci: A Comparison in Bighorn Sheep

    PubMed Central

    Boyce, W. M.; Hedrick, P. W.; Muggli-Cockett, N. E.; Kalinowski, S.; Penedo, MCT.; Ramey-II, R. R.

    1997-01-01

    Examining and comparing genetic variation for major histocompatibility complex (MHC) and microsatellite (MS) loci in the same individuals provides an opportunity to understand the forces influencing genetic variation. We examined five MHC and three MS loci in 235 bighorn sheep (Ovis canadensis) from 14 populations and found that both types of loci were highly variable and were in Hardy-Weinberg proportions. Mean F(ST) values for both markers were very similar and MHC and MS genetic variability was predominantly distributed within rather than among populations. However, analyses of genetic distances and tree topologies revealed different spatial patterns of variation for the two types of loci. Collectively, these results indicated that neutral forces substantially influenced MS and MHC variation, and they provided limited evidence for selection acting on the MHC. PMID:9071595

  15. Genetic variation of major histocompatibility complex and microsatellite loci: a comparison in bighorn sheep.

    PubMed

    Boyce, W M; Hedrick, P W; Muggli-Cockett, N E; Kalinowski, S; Penedo, M C; Ramey, R R

    1997-02-01

    Examining and comparing genetic variation for major histocompatibility complex (MHC) and micro-satellite (MS) loci in the same individuals provides an opportunity to understand the forces influencing genetic variation. We examined five MHC and three MS loci in 235 bighorn sheep (Ovis canadensis) from 14 populations and found that both types of loci were highly variable and were in Hardy-Weinberg proportions. Mean FST values for both markers were very similar and MHC and MS genetic variability was predominantly distributed within rather than among populations. However, analyses of genetic distances and tree topologies revealed different spatial patterns of variation for the two types of loci. Collectively, these results indicated that neutral forces substantially influenced MS and MHC variation, and they provided limited evidence for selection acting on the MHC.

  16. Class II major histocompatibility complex tetramer staining: progress, problems, and prospects

    PubMed Central

    Vollers, Sabrina S; Stern, Lawrence J

    2008-01-01

    The use of major histocompatibility complex (MHC) tetramers in the detection and analysis of antigen-specific T cells has become more widespread since its introduction 11 years ago. Early challenges in the application of tetramer staining to CD4+ T cells centred around difficulties in the expression of various class II MHC allelic variants and the detection of low-frequency T cells in mixed populations. As many of the technical obstacles to class II MHC tetramer staining have been overcome, the focus has returned to uncertainties concerning how oligomer valency and T-cell receptor/MHC affinity affect tetramer binding. Such issues have become more important with an increase in the number of studies relying on direct ex vivo analysis of antigen-specific CD4+ T cells. In this review we discuss which problems in class II MHC tetramer staining have been solved to date, and which matters remain to be considered. PMID:18251991

  17. Transcriptional and posttranscriptional regulation of class I major histocompatibility complex genes following transformation with human adenoviruses.

    PubMed Central

    Shemesh, J; Rotem-Yehudar, R; Ehrlich, R

    1991-01-01

    Transformation of rodent cells by human adenoviruses is a well-established model system for studying the expression, regulation, and function of class I antigens. In this report, we demonstrate that the highly oncogenic adenovirus type 12 operates at the transcriptional and posttranscriptional levels in regulating the activity of major histocompatibility complex class I genes and products in transformed cells. Adenovirus type 12 suppresses the cell surface expression of class I antigens in most cell lines. Nevertheless, in a number of cell lines suppression is the result of reduction in the amount of stable specific mRNA, while in another group of cell lines suppression involves interference with processing of a posttranscriptional product. The two mechanisms operate both for the endogenous H-2 genes and for a miniature swine class I transgene that is expressed in the cells. Images PMID:1895404

  18. Molecular characterization of major histocompatibility complex class 1 (MHC-I) from squirrel monkeys (Saimiri sciureus).

    PubMed

    Pascalis, Hervé; Heraud, Jean-Michel; Fendel, Rolf; Lavergne, Anne; Kazanji, Mirdad

    2003-12-01

    Little is known about the major histocompatibility complex (MHC) class 1 in squirrel monkeys ( Saimiri sciureus). We cloned, sequenced and characterized two alleles and the cDNA of the coding region of MHC class 1 in these New World monkeys. Phylogenetic analyses showed that these sequences are related to HLA class 1 genes ( HLA-A and HLA-G). The structure and organization of one of the two identified clones was similar to that of a class 1 MHC gene ( HLA-A2). All the exon/intron splice acceptor/donor sites are conserved and their locations correspond to the HLA-A2 gene. The sequences of the newly described cDNAs reveal that they code for the characteristic class 1 MHC proteins, with all the features thought necessary for cell surface expression. Typical sequences for the leader peptide, alpha(1), alpha(2), alpha(3), transmembrane and cytoplasmic domains were found.

  19. Toxic shock syndrome toxin 1 binds to major histocompatibility complex class II molecules.

    PubMed Central

    Scholl, P; Diez, A; Mourad, W; Parsonnet, J; Geha, R S; Chatila, T

    1989-01-01

    Toxic shock syndrome toxin 1 (TSST-1) is a 22-kDa exotoxin produced by strains of Staphylococcus aureus and implicated in the pathogenesis of toxic shock syndrome. In common with other staphylococcal exotoxins, TSST-1 has diverse immunological effects. These include the induction of interleukin 2 receptor expression, interleukin 2 synthesis, proliferation of human T lymphocytes, and stimulation of interleukin 1 synthesis by human monocytes. In the present study, we demonstrate that TSST-1 binds with saturation kinetics and with a dissociation constant of 17-43 nM to a single class of binding sites on human mononuclear cells. There was a strong correlation between the number of TSST-1 binding sites and the expression of major histocompatibility complex class II molecules, and interferon-gamma induced the expression of class II molecules as well as TSST-1 binding sites on human skin-derived fibroblasts. Monoclonal antibodies to HLA-DR, but not to HLA-DP or HLA-DQ, strongly inhibited TSST-1 binding. Affinity chromatography of 125I-labeled cell membranes over TSST-1-agarose resulted in the recovery of two bands of 35 kDa and 31 kDa that comigrated, respectively, with the alpha and beta chains of HLA-DR and that could be immunoprecipitated with anti-HLA-DR monoclonal antibodies. Binding of TSST-1 was demonstrated to HLA-DR and HLA-DQ L-cell transfectants. These results indicate that major histocompatibility complex class II molecules represent the major binding site for TSST-1 on human cells. Images PMID:2542966

  20. Structural Evidence for a Germline-Encoded T Cell Receptor - Major Histocompatibility Complex Interaction 'Codon'

    SciTech Connect

    Feng, D.; Bond, C.J.; Ely, L.K.; Maynard, J.; Garcia, K.C.

    2009-06-02

    All complexes of T cell receptors (TCRs) bound to peptide-major histocompatibility complex (pMHC) molecules assume a stereotyped binding 'polarity', despite wide variations in TCR-pMHC docking angles. However, existing TCR-pMHC crystal structures have failed to show broadly conserved pairwise interaction motifs. Here we determined the crystal structures of two TCRs encoded by the variable {beta}-chain 8.2 (V{sub {beta}}8.2), each bound to the MHC class II molecule I-A{sup u}, and did energetic mapping of V{sub {alpha}} and V{sub {beta}} contacts with I-A{sup u}. Together with two previously solved structures of V{sub {beta}}8.2-containing TCR-MHC complexes, we found four TCR-I-A complexes with structurally superimposable interactions between the V{sub {beta}} loops and the I-A {alpha}-helix. This examination of a narrow 'slice' of the TCR-MHC repertoire demonstrates what is probably one of many germline-derived TCR-MHC interaction 'codons'.

  1. Subtle conformational changes induced in major histocompatibility complex class II molecules by binding peptides.

    PubMed

    Chervonsky, A V; Medzhitov, R M; Denzin, L K; Barlow, A K; Rudensky, A Y; Janeway, C A

    1998-08-18

    Intracellular trafficking of major histocompatibility complex (MHC) class II molecules is characterized by passage through specialized endocytic compartment(s) where antigenic peptides replace invariant chain fragments in the presence of the DM protein. These changes are accompanied by structural transitions of the MHC molecules that can be visualized by formation of compact SDS-resistant dimers, by changes in binding of mAbs, and by changes in T cell responses. We have observed that a mAb (25-9-17) that is capable of staining I-Ab on the surface of normal B cells failed to interact with I-Ab complexes with a peptide derived from the Ealpha chain of the I-E molecule but bound a similar covalent complex of I-Ab with the class II binding fragment (class II-associated invariant chain peptides) of the invariant chain. Moreover, 25-9-17 blocked activation of several I-Ab-reactive T cell hybridomas but failed to block others, suggesting that numerous I-Ab-peptide complexes acquire the 25-9-17(+) or 25-9-17(-) conformation. Alloreactive T cells were also able to discriminate peptide-dependent variants of MHC class II molecules. Thus, peptides impose subtle structural transitions upon MHC class II molecules that affect T cell recognition and may thus be critical for T cell selection and autiommunity.

  2. Dynamics of Major Histocompatibility Complex Class II Compartments during B Cell Receptor–mediated Cell Activation

    PubMed Central

    Lankar, Danielle; Vincent-Schneider, Hélène; Briken, Volker; Yokozeki, Takeaki; Raposo, Graça; Bonnerot, Christian

    2002-01-01

    Antigen recognition by clonotypic B cell receptor (BcR) is the first step of B lymphocytes differentiation into plasmocytes. This B cell function is dependent on efficient major histocompatibility complex (MHC) class II–restricted presentation of BcR-bound antigens. In this work, we analyzed the subcellular mechanisms underlying antigen presentation after BcR engagement on B cells. In quiescent B cells, we found that MHC class II molecules mostly accumulated at the cell surface and in an intracellular pool of tubulovesicular structures, whereas H2-M molecules were mostly detected in distinct lysosomal compartments devoid of MHC class II. BcR stimulation induced the transient intracellular accumulation of MHC class II molecules in newly formed multivesicular bodies (MVBs), to which H2-M was recruited. The reversible downregulation of cathepsin S activity led to the transient accumulation of invariant chain–MHC class II complexes in MVBs. A few hours after BcR engagement, cathepsin S activity increased, the p10 invariant chain disappeared, and MHC class II–peptide complexes arrived at the plasma membrane. Thus, BcR engagement induced the transient formation of antigen-processing compartments, enabling antigen-specific B cells to become effective antigen-presenting cells. PMID:11854359

  3. Diacylglycerol kinase α regulates tubular recycling endosome biogenesis and major histocompatibility complex class I recycling.

    PubMed

    Xie, Shuwei; Naslavsky, Naava; Caplan, Steve

    2014-11-14

    Major histocompatibility complex class I (MHC I) presents intracellular-derived peptides to cytotoxic T lymphocytes and its subcellular itinerary is important in regulating the immune response. While a number of diacylglycerol kinase isoforms have been implicated in clathrin-dependent internalization, MHC I lacks the typical motifs known to mediate clathrin-dependent endocytosis. Here we show that depletion of diacylglycerol kinase α (DGKα), a kinase devoid of a clathrin-dependent adaptor protein complex 2 binding site, caused a delay in MHC I recycling to the plasma membrane without affecting the rate of MHC I internalization. We demonstrate that DGKα knock-down causes accumulation of intracellular and surface MHC I, resulting from decreased degradation. Furthermore, we provide evidence that DGKα is required for the generation of phosphatidic acid required for tubular recycling endosome (TRE) biogenesis. Moreover, we show that DGKα forms a complex with the TRE hub protein, MICAL-L1. Given that MICAL-L1 and the F-BAR-containing membrane-tubulating protein Syndapin2 associate selectively with phosphatidic acid, we propose a positive feedback loop in which DGKα generates phosphatidic acid to drive its own recruitment to TRE via its interaction with MICAL-L1. Our data support a novel role for the involvement of DGKα in TRE biogenesis and MHC I recycling.

  4. How a T Cell Receptor-like Antibody Recognizes Major Histocompatibility Complex-bound Peptide

    SciTech Connect

    Mareeva, T.; Martinez-Hackert, E; Sykulev, Y

    2008-01-01

    We determined the crystal structures of the T cell receptor (TCR)-like antibody 25-D1.16 Fab fragment bound to a complex of SIINFEKL peptide from ovalbumin and the H-2Kb molecule. Remarkably, this antibody directly 'reads' the structure of the major histocompatibility complex (MHC)-bound peptide, employing the canonical diagonal binding mode utilized by most TCRs. This is in marked contrast with another TCR-like antibody, Hyb3, bound to melanoma peptide MAGE-A1 in association with HLA-A1 MHC class I. Hyb3 assumes a non-canonical orientation over its cognate peptide-MHC and appears to recognize a conformational epitope in which the MHC contribution is dominant. We conclude that TCR-like antibodies can recognize MHC-bound peptide via two different mechanisms: one is similar to that exploited by the preponderance of TCRs and the other requires a non-canonical antibody orientation over the peptide-MHC complex.

  5. Molecular genetic diversity and evolution at the MHC DQB locus in four species of pinnipeds.

    PubMed

    Hoelzel, A R; Stephens, J C; O'Brien, S J

    1999-05-01

    Variation was investigated at exon 2 (including part of the putative peptide-binding region) of the class II major histocompatibility complex (MHC) DQB locus for two congeneric phocid seal species and two congeneric otariid seal species. Polymorphism in one phocid species, the southern elephant seal (Mirounga leonina), was comparable to that seen in human populations, while the other phocid, the northern elephant seal (Mirounga angustirostris), has been through a severe population bottleneck and exhibited much less variation at this locus. A phylogenetic comparison of the four species was consistent with the trans-specific pattern of evolution described for other taxa at this locus, and relative nonsynonymous and synonymous substitution rates suggest the maintenance of polymorphisms by natural selection. A comparison of sequence patterns also suggested that some variation could have been generated through recombinational events, primarily within genera. These results suggest a pattern of evolution of the immune response in pinnipeds similar to that in terrestrial mammal species.

  6. Major histocompatibility complex linked databases and prediction tools for designing vaccines.

    PubMed

    Singh, Satarudra Prakash; Mishra, Bhartendu Nath

    2016-03-01

    Presently, the major histocompatibility complex (MHC) is receiving considerable interest owing to its remarkable role in antigen presentation and vaccine design. The specific databases and prediction approaches related to MHC sequences, structures and binding/nonbinding peptides have been aggressively developed in the past two decades with their own benchmarks and standards. Before using these databases and prediction tools, it is important to analyze why and how the tools are constructed along with their strengths and limitations. The current review presents insights into web-based immunological bioinformatics resources that include searchable databases of MHC sequences, epitopes and prediction tools that are linked to MHC based vaccine design, including population coverage analysis. In T cell epitope forecasts, MHC class I binding predictions are very accurate for most of the identified MHC alleles. However, these predictions could be further improved by integrating proteasome cleavage (in conjugation with transporter associated with antigen processing (TAP) binding) prediction, as well as T cell receptor binding prediction. On the other hand, MHC class II restricted epitope predictions display relatively low accuracy compared to MHC class I. To date, pan-specific tools have been developed, which not only deliver significantly improved predictions in terms of accuracy, but also in terms of the coverage of MHC alleles and supertypes. In addition, structural modeling and simulation systems for peptide-MHC complexes enable the molecular-level investigation of immune processes. Finally, epitope prediction tools, and their assessments and guidelines, have been presented to immunologist for the design of novel vaccine and diagnostics.

  7. DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history.

    PubMed Central

    Yuhki, N; O'Brien, S J

    1990-01-01

    The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. We present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations. Images PMID:1967831

  8. Chicken major histocompatibility complex class II molecules of the B haplotype present self and foreign peptides.

    PubMed

    Cumberbatch, J A; Brewer, D; Vidavsky, I; Sharif, S

    2006-08-01

    The chicken major histocompatibility complex (MHC), or B-complex, mediates genetic resistance and susceptibility to infectious disease. For example, the B19 haplotype is associated with susceptibility to Marek's disease. Here, we describe the sequencing and analysis of peptides presented by B19 MHC class II molecules. A B19/B19 B-cell line was used for the immunoaffinity purification of MHC class II molecules, which was followed by acid elution of the bound peptides. The eluted peptides were then analysed using tandem mass spectrometry. Thirty peptide sequences were obtained, ranging from 11 to 25 amino acids in length. Source protein cellular localization included the plasma membrane, cytosol and endosomal pathway. In addition, five peptides from the envelope glycoprotein of chicken syncytial virus (CSV) were identified. Chicken syncytial virus had been used as a helper virus along with reticuloendotheliosis virus strain T for transformation of B19/B19B cells. Alignment and analysis of the peptide sequence pool provided a putative peptide-binding motif for the B19 MHC class II.

  9. Prediction of peptide binding to a major histocompatibility complex class I molecule based on docking simulation.

    PubMed

    Ishikawa, Takeshi

    2016-10-01

    Binding between major histocompatibility complex (MHC) class I molecules and immunogenic epitopes is one of the most important processes for cell-mediated immunity. Consequently, computational prediction of amino acid sequences of MHC class I binding peptides from a given sequence may lead to important biomedical advances. In this study, an efficient structure-based method for predicting peptide binding to MHC class I molecules was developed, in which the binding free energy of the peptide was evaluated by two individual docking simulations. An original penalty function and restriction of degrees of freedom were determined by analysis of 361 published X-ray structures of the complex and were then introduced into the docking simulations. To validate the method, calculations using a 50-amino acid sequence as a prediction target were performed. In 27 calculations, the binding free energy of the known peptide was within the top 5 of 166 peptides generated from the 50-amino acid sequence. Finally, demonstrative calculations using a whole sequence of a protein as a prediction target were performed. These data clearly demonstrate high potential of this method for predicting peptide binding to MHC class I molecules.

  10. A general model of invariant chain association with class II major histocompatibility complex proteins.

    PubMed Central

    Lee, C; McConnell, H M

    1995-01-01

    The binding of invariant chain to major histocompatibility complex (MHC) proteins is an important step in processing of MHC class II proteins and in antigen presentation. The question of how invariant chain can bind to all MHC class II proteins is central to understanding these processes. We have employed molecular modeling to predict the structure of class II-associated invariant chain peptide (CLIP)-MHC protein complexes and to ask whether the predicted mode of association could be general across all MHC class II proteins. CLIP fits identically into the MHC class II alleles HLA-DR3, I-Ak, I-Au, and I-Ad, with a consistent pattern of hydrogen bonds, contacts, and hydrophobic burial and without bad contacts. Our model predicts the burial of CLIP residues Met-91 and Met-99 in the deep P1 and P9 anchor pockets and other detailed interactions, which we have compared with available data. The predicted pattern of I-A allele-specific effects on CLIP binding is very similar to that observed experimentally by alanine-scanning mutations of CLIP. Together, these results indicate that CLIP may bind in a single, general way across products of MHC class II alleles. Images Fig. 1 Fig. 2 Fig. 3 PMID:7667280

  11. DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history.

    PubMed

    Yuhki, N; O'Brien, S J

    1990-01-01

    The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. We present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations.

  12. Ii Chain Controls the Transport of Major Histocompatibility Complex Class II Molecules to and from Lysosomes

    PubMed Central

    Brachet, Valérie; Raposo, Graça; Amigorena, Sebastian; Mellman, Ira

    1997-01-01

    Major histocompatibility complex class II molecules are synthesized as a nonameric complex consisting of three αβ dimers associated with a trimer of invariant (Ii) chains. After exiting the TGN, a targeting signal in the Ii chain cytoplasmic domain directs the complex to endosomes where Ii chain is proteolytically processed and removed, allowing class II molecules to bind antigenic peptides before reaching the cell surface. Ii chain dissociation and peptide binding are thought to occur in one or more postendosomal sites related either to endosomes (designated CIIV) or to lysosomes (designated MIIC). We now find that in addition to initially targeting αβ dimers to endosomes, Ii chain regulates the subsequent transport of class II molecules. Under normal conditions, murine A20 B cells transport all of their newly synthesized class II I-Ab αβ dimers to the plasma membrane with little if any reaching lysosomal compartments. Inhibition of Ii processing by the cysteine/serine protease inhibitor leupeptin, however, blocked transport to the cell surface and caused a dramatic but selective accumulation of I-Ab class II molecules in lysosomes. In leupeptin, I-Ab dimers formed stable complexes with a 10-kD NH2-terminal Ii chain fragment (Ii-p10), normally a transient intermediate in Ii chain processing. Upon removal of leupeptin, Ii-p10 was degraded and released, I-Ab dimers bound antigenic peptides, and the peptide-loaded dimers were transported slowly from lysosomes to the plasma membrane. Our results suggest that alterations in the rate or efficiency of Ii chain processing can alter the postendosomal sorting of class II molecules, resulting in the increased accumulation of αβ dimers in lysosome-like MIIC. Thus, simple differences in Ii chain processing may account for the highly variable amounts of class II found in lysosomal compartments of different cell types or at different developmental stages. PMID:9105036

  13. Persistent Ehrlichia chaffeensis infection occurs in the absence of functional major histocompatibility complex class II genes

    NASA Technical Reports Server (NTRS)

    Ganta, Roman Reddy; Wilkerson, Melinda J.; Cheng, Chuanmin; Rokey, Aaron M.; Chapes, Stephen K.

    2002-01-01

    Human monocytic ehrlichiosis is an emerging tick-borne disease caused by the rickettsia Ehrlichia chaffeensis. We investigated the impact of two genes that control macrophage and T-cell function on murine resistance to E. chaffeensis. Congenic pairs of wild-type and toll-like receptor 4 (tlr4)- or major histocompatibility complex class II (MHC-II)-deficient mice were used for these studies. Wild-type mice cleared the infection within 2 weeks, and the response included macrophage activation and the synthesis of E. chaffeensis-specific Th1-type immunoglobulin G response. The absence of a functional tlr4 gene depressed nitric oxide and interleukin 6 secretion by macrophages and resulted in short-term persistent infections for > or =30 days. In the absence of MHC-II alleles, E. chaffeensis infections persisted throughout the entire 3-month evaluation period. Together, these data suggest that macrophage activation and cell-mediated immunity, orchestrated by CD4(+) T cells, are critical for conferring resistance to E. chaffeensis.

  14. Major histocompatibility complex loci are associated with susceptibility of Atlantic salmon to infectious hematopoietic necrosis virus

    USGS Publications Warehouse

    Miller, Kristina M.; Winton, James R.; Schulze, Angela D.; Purcell, Maureen K.; Ming, Tobi J.

    2004-01-01

    Infectious hematopoietic necrosis virus (IHNV) is one of the most significant viral pathogens of salmonids and is a leading cause of death among cultured juvenile fish. Although several vaccine strategies have been developed, some of which are highly protective, the delivery systems are still too costly for general use by the aquaculture industry. More cost effective methods could come from the identification of genes associated with IHNV resistance for use in selective breeding. Further, identification of susceptibility genes may lead to an improved understanding of viral pathogenesis and may therefore aid in the development of preventive and therapeutic measures. Genes of the major histocompatibility complex (MHC), involved in the primary recognition of foreign pathogens in the acquired immune response, are associated with resistance to a variety of diseases in vertebrate organisms. We conducted a preliminary analysis of MHC disease association in which an aquaculture strain of Atlantic salmon was challenged with IHNV at three different doses and individual fish were genotyped at three MHC loci using denaturing gradient gel electrophoresis (PCR-DGGE), followed by sequencing of all differentiated alleles. Nine to fourteen alleles per exon-locus were resolved, and alleles potentially associated with resistance or susceptibility were identified. One allele (Sasa-B-04) from a potentially non-classical class I locus was highly associated with resistance to infectious hematopoietic necrosis (p < 0.01). This information can be used to design crosses of specific haplotypes for family analysis of disease associations.

  15. Efficient major histocompatibility complex class I presentation of exogenous antigen upon phagocytosis by macrophages.

    PubMed Central

    Kovacsovics-Bankowski, M; Clark, K; Benacerraf, B; Rock, K L

    1993-01-01

    Antigens in extracellular fluids can be processed and presented with major histocompatibility complex (MHC) class I molecules by a subset of antigen presenting cells (APCs). Chicken egg ovalbumin (Ova) linked to beads was presented with MHC class I molecules by these cells up to 10(4)-fold more efficiently than soluble Ova. This enhanced presentation was observed with covalently or noncovalently linked Ova and with beads of different compositions. A key parameter in the activity of these conjugates was the size of the beads. The APC that is responsible for this form of presentation is a macrophage. These cells internalize the antigen constructs through phagocytosis, since cytochalasin B inhibited presentation. Processing of the antigen and association with MHC class I molecules appears to occur intracellularly as presentation was observed under conditions where there was no detectable release of peptides into the extracellular fluids. When injected in vivo in C57BL/6 mice, Ova-beads, but not soluble Ova, primed CD4- CD8+ cytotoxic T lymphocytes (CTLs). Similar results were obtained in BALB/c mice immunized with beta-galactosidase-beads. The implications of these findings for development of nonliving vaccines that stimulate CTL immunity are discussed. PMID:8506338

  16. THE HUMAN MAJOR HISTOCOMPATIBILITY COMPLEX AS A PARADIGM IN GENOMICS RESEARCH

    PubMed Central

    Vandiedonck, Claire; Knight, Julian C

    2010-01-01

    Since its discovery more than 50 years ago, the human Major Histocompatibility Complex (MHC) on chromosome 6p21.3 has been at the forefront of human genetic research. Here, we review from a historical perspective the major advances in our understanding of the nature and consequences of genetic variation which have involved the MHC, as well as highlighting likely future directions. As a consequence of its particular genomic structure, its remarkable polymorphism and its early implication in numerous diseases, the MHC has been considered as a model region for genomics, being the first substantial region to be sequenced and establishing fundamental concepts of linkage disequilibrium, haplotypic structure and meiotic recombination. Recently, the MHC became the first genomic region to be entirely re-sequenced for common haplotypes, while studies mapping gene expression phenotypes across the genome have strongly implicated variation in the MHC. This review shows how the MHC continues to provide new insights and remains in the vanguard of contemporary research in human genomics. PMID:19468039

  17. Diversity at the major histocompatibility complex Class II in the platypus, Ornithorhynchus anatinus.

    PubMed

    Lillie, Mette; Woodward, Rachael E; Sanderson, Claire E; Eldridge, Mark D B; Belov, Katherine

    2012-07-01

    The platypus (Ornithorhynchus anatinus) is the sole survivor of a previously widely distributed and diverse lineage of ornithorhynchid monotremes. Its dependence on healthy water systems imposes an inherent sensitivity to habitat degradation and climate change. Here, we compare genetic diversity at the major histocompatibility complex (MHC) Class II-DZB gene and 3 MHC-associated microsatellite markers with diversity at 6 neutral microsatellite markers in 70 platypuses from across their range, including the mainland of Australia and the isolated populations of Tasmania, King Island, and Kangaroo Island. Overall, high DZB diversity was observed in the platypus, with 57 DZB β1 alleles characterized. Significant positive selection was detected within the DZB peptide-binding region, promoting variation in this domain. Low levels of genetic diversity were detected at all markers in the 2 island populations, King Island (endemic) and Kangaroo Island (introduced), with the King Island platypuses monomorphic at the DZB locus. Loss of MHC diversity on King Island is of concern, as the population may have compromised immunological fitness and reduced ability to resist changing environmental conditions.

  18. Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males

    PubMed Central

    Løvlie, Hanne; Gillingham, Mark A. F.; Worley, Kirsty; Pizzari, Tommaso; Richardson, David S.

    2013-01-01

    Cryptic female choice may enable polyandrous females to avoid inbreeding or bias offspring variability at key loci after mating. However, the role of these genetic benefits in cryptic female choice remains poorly understood. Female red junglefowl, Gallus gallus, bias sperm use in favour of unrelated males. Here, we experimentally investigate whether this bias is driven by relatedness per se, or by similarity at the major histocompatibility complex (MHC), genes central to vertebrate acquired immunity, where polymorphism is critical to an individual's ability to combat pathogens. Through experimentally controlled natural matings, we confirm that selection against related males' sperm occurs within the female reproductive tract but demonstrate that this is more accurately predicted by MHC similarity: controlling for relatedness per se, more sperm reached the eggs when partners were MHC-dissimilar. Importantly, this effect appeared largely owing to similarity at a single MHC locus (class I minor). Further, the effect of MHC similarity was lost following artificial insemination, suggesting that male phenotypic cues might be required for females to select sperm differentially. These results indicate that postmating mechanisms that reduce inbreeding may do so as a consequence of more specific strategies of cryptic female choice promoting MHC diversity in offspring. PMID:24004935

  19. Regulation of a transfected human class II major histocompatibility complex gene in human fibroblasts.

    PubMed Central

    Boss, J M; Strominger, J L

    1986-01-01

    To investigate the cis-acting DNA elements that are involved in regulation of class II major histocompatibility complex genes, including gamma-interferon (gamma-IFN) induction, 5' flanking DNA deletions of a DQ beta "minigene" were analyzed in stable transfected cell lines. At least four elements 5' to the gene were found to be involved in DQ beta regulation. Deletion of sequences from -2500 to -159 base pairs (bp) resulted in increased transcription, suggesting that negative regulatory elements resided in the deleted region. These clones were all capable of responding to gamma-IFN. Further deletion of sequences from -159 to -128 bp resulted in constitutive high level transcription and the inability of these constructions to respond to gamma-IFN. A deletion to -107 bp resulted in a decrease in the basal level of expression that was restored by removal of the 5' DNA sequence to -82 bp, suggesting the presence of a second negative element. Finally, deletion to -64 bp caused a marked decrease in expression, suggesting the loss of an element necessary for high levels of transcription. The gamma-IFN control and the transcription control elements contain the conserved upstream sequences found in all class II genes, suggesting a role for these sequences. Images PMID:3097644

  20. Recombination and selection in the major histocompatibility complex of the endangered forest musk deer (Moschus berezovskii)

    PubMed Central

    Cai, Ruibo; Shafer, Aaron B.A.; Laguardia, Alice; Lin, Zhenzhen; Liu, Shuqiang; Hu, Defu

    2015-01-01

    The forest musk deer (Moschus berezovskii) is a high elevation species distributed across western China and northern Vietnam. Once abundant, habitat loss and poaching has led to a dramatic decrease in population numbers prompting the IUCN to list the species as endangered. Here, we characterized the genetic diversity of a Major Histocompatibility Complex (MHC) locus and teased apart driving factors shaping its variation. Seven DRB exon 2 alleles were identified among a group of randomly sampled forest musk deer from a captive population in the Sichuan province of China. Compared to other endangered or captive ungulates, forest musk deer have relatively low levels of MHC genetic diversity. Non-synonymous substitutions primarily occurred in the putative peptide-binding region (PBR), with analyses suggesting that recombination and selection has shaped the genetic diversity across the locus. Specifically, inter-allelic recombination generated novel allelic combinations, with evidence for both positive selection acting on the PBR and negative selection on the non-PBR. An improved understanding of functional genetic variability of the MHC will facilitate better design and management of captive breeding programs for this endangered species. PMID:26603338

  1. Polymorphism of alternative splicing of major histocompatibility complex transcripts in wild tiger salamanders.

    PubMed

    Bulut, Zafer; McCormick, Cory R; Bos, David H; DeWoody, J Andrew

    2008-07-01

    Alternative splicing (AS) of mRNA transcripts is increasingly recognized as a source of transcriptome diversity. To date, most AS studies have focused either on comparisons across taxa or on intragenomic comparisons across gene families. We generated a novel data set that represents one of the first population genetic comparisons of AS across individuals. In ambystomatid salamanders, AS of the major histocompatibility complex (MHC) class IIbeta gene (Amti-DAB) produces two transcripts, one full-length and one truncated. The full-length transcript is functional, but the truncated transcript is missing the critical beta1 domain that forms half of the peptide binding region in the intact MHC class II molecule. We captured wild salamander larvae (Ambystoma tigrinum tigrinum) and genotyped them at Amti-DAB via DNA sequencing. From these same larvae, we extracted RNA from gill and spleen and evaluated the relative expression level of Amti-DAB in each tissue. Across individuals, 21% of the transcripts were truncated (alternatively spliced), and the absolute level of alternative transcript expression was higher in gill. The high level of nucleotide variation among seven Amti-DAB alleles provides the ability to detect substitutions (or linked DNA polymorphisms) that might have influenced AS. The data reveal no correlation between AS and haplotype, allele, or zygosity. However, indirect evidence (comparative expression patterns across 3 million years of evolution) suggests that the truncated Amti-DAB transcript may be functional and maintained by natural selection.

  2. Microsatellite and major histocompatibility complex variation in an endangered rattlesnake, the Eastern Massasauga (Sistrurus catenatus).

    PubMed

    Jaeger, Collin P; Duvall, Melvin R; Swanson, Bradley J; Phillips, Christopher A; Dreslik, Michael J; Baker, Sarah J; King, Richard B

    2016-06-01

    Genetic diversity is fundamental to maintaining the long-term viability of populations, yet reduced genetic variation is often associated with small, isolated populations. To examine the relationship between demography and genetic variation, variation at hypervariable loci (e.g., microsatellite DNA loci) is often measured. However, these loci are selectively neutral (or near neutral) and may not accurately reflect genomewide variation. Variation at functional trait loci, such as the major histocompatibility complex (MHC), can provide a better assessment of adaptive genetic variation in fragmented populations. We compared patterns of microsatellite and MHC variation across three Eastern Massasauga (Sistrurus catenatus) populations representing a gradient of demographic histories to assess the relative roles of natural selection and genetic drift. Using 454 deep amplicon sequencing, we identified 24 putatively functional MHC IIB exon 2 alleles belonging to a minimum of six loci. Analysis of synonymous and nonsynonymous substitution rates provided evidence of historical positive selection at the nucleotide level, and Tajima's D provided support for balancing selection in each population. As predicted, estimates of microsatellite allelic richness, observed, heterozygosity, and expected heterozygosity varied among populations in a pattern qualitatively consistent with demographic history and abundance. While MHC allelic richness at the population and individual levels revealed similar trends, MHC nucleotide diversity was unexpectedly high in the smallest population. Overall, these results suggest that genetic variation in the Eastern Massasauga populations in Illinois has been shaped by multiple evolutionary mechanisms. Thus, conservation efforts should consider both neutral and functional genetic variation when managing captive and wild Eastern Massasauga populations.

  3. Binding and activation of major histocompatibility complex class II-deficient macrophages by staphylococcal exotoxins

    NASA Technical Reports Server (NTRS)

    Beharka, A. A.; Armstrong, J. W.; Iandolo, J. J.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Macrophages from C2D transgenic mice deficient in the expression of major histocompatibility complex (MHC) class II proteins were used to identify binding sites for superantigens distinct from the MHC class II molecule. Iodinated staphylococcal enterotoxins A and B (SEA and SEB) and exfoliative toxins A and B (ETA and ETB) bound to C2D macrophages in a concentration-dependent and competitive manner. All four toxins increased F-actin concentration within 30 s of their addition to C2D macrophages, indicating that signal transduction occurred in response to toxin in the absence of class II MHC. Furthermore, ETA, ETB, SEA, and, to a lesser extent, SEB induced C2D macrophages to produce interleukin 6. Several molecular species on C2D macrophages with molecular masses of 140, 97, 61, 52, 43, and 37 kDa bound SEA in immunoprecipitation experiments. These data indicate the presence of novel, functionally active toxin binding sites on murine macrophages distinct from MHC class II molecules.

  4. Recognition of class I major histocompatibility complex molecules by Ly- 49: specificities and domain interactions

    PubMed Central

    1996-01-01

    Ly-49 is a family type II transmembrane proteins encoded by a gene cluster on murine chromosome 6. One member of this family, Ly-49A, is expressed by a natural killer (NK) cell subset, binds to class I major histocompatibility complex (MHC) molecules, and blocks the killing of target cells bearing the appropriate H-2 antigens. Here we show that another member of this family which is expressed by an NK cell subset, Ly-49C, recognizes H-2b and H-2d structures which are distinct from and overlapping with those recognized by Ly-49A. Interactions between Ly- 49A and C and their class I ligands are entirely blocked by the antibodies 5E6, YE1/48, YE1/32, and A1, all of which were found to recognize epitopes contained within the carbohydrate recognition domain (CRD). However, cell-cell binding assays revealed that class I binding specificity is conferred by a combination of sequences within both the CRD and a 19-amino acid adjacent region. We also investigated the question of whether Ly-49A and C form dimers on cells which express both receptors. When coexpressed on COS cells, sequential immunoprecipitation demonstrated that these receptors pair exclusively as homodimers, with no evidence for heterodimeric structures. These observations provide insight into both the biochemical nature of the Ly- 49 family as well as the receptor functions of Ly-49C on NK cells. PMID:8666913

  5. Influence of major histocompatibility complex genotype on mating success in a free-ranging reptile population

    PubMed Central

    Miller, Hilary C.; Moore, Jennifer A.; Nelson, Nicola J.; Daugherty, Charles H.

    2009-01-01

    Major histocompatibility complex (MHC) genes are highly polymorphic components of the vertebrate immune system, which play a key role in pathogen resistance. MHC genes may also function as odour-related cues for mate choice, thus ensuring optimal MHC diversity in offspring. MHC-associated mate choice has been demonstrated in some fish, bird and mammal species but it is not known whether this is a general vertebrate phenomenon. We investigated whether MHC-associated mate choice occurs in a wild population of tuatara (Sphenodon punctatus), a territorial and sexually dimorphic reptile. We found weak evidence for MHC-disassortative mating, based on amino acid genotypic distance between pairs, when mated pairs were directly compared with potential pairs in close spatial proximity. No significant association was found between male mating success, number of MHC sequences, microsatellite heterozygosity or MHC lineage. The major determinant of mating success in tuatara was male body size, which was not related to MHC lineage or microsatellite heterozygosity. Our results suggest that male competitive ability is the primary driver of mating success in tuatara. However, MHC-associated preferences also appear to play a role, possibly as a kin avoidance mechanism during territory formation. PMID:19324833

  6. Does intra-individual major histocompatibility complex diversity keep a golden mean?

    PubMed Central

    Woelfing, Benno; Traulsen, Arne; Milinski, Manfred; Boehm, Thomas

    2008-01-01

    An adaptive immune response is usually initiated only if a major histocompatibility complex (MHC) molecule presents pathogen-derived peptides to T-cells. Every MHC molecule can present only peptides that match its peptide-binding groove. Thus, it seems advantageous for an individual to express many different MHC molecules to be able to resist many different pathogens. However, although MHC genes are the most polymorphic genes of vertebrates, each individual has only a very small subset of the diversity at the population level. This is an evolutionary paradox. We provide an overview of the current data on infection studies and mate-choice experiments and conclude that overall evidence suggests that intermediate intra-individual MHC diversity is optimal. Selective forces that may set an upper limit to intra-individual MHC diversity are discussed. An updated mathematical model based on recent findings on T-cell selection can predict the natural range of intra-individual MHC diversity. Thus, the aim of our review is to evaluate whether the number of MHC alleles usually present in individuals may be optimal to balance the advantages of presenting an increased range of peptides versus the disadvantages of an increased loss of T-cells. PMID:18926972

  7. Signals of major histocompatibility complex overdominance in a wild salmonid population

    PubMed Central

    Kekäläinen, Jukka; Vallunen, J. Albert; Primmer, Craig R.; Rättyä, Jouni; Taskinen, Jouni

    2009-01-01

    The major histocompatibility complex (MHC) contains the most variable genes in vertebrates, but despite extensive research, the mechanisms maintaining this polymorphism are still unresolved. One hypothesis is that MHC polymorphism is a result of balancing selection operating by overdominance, but convincing evidence for overdominant selection in natural populations has been lacking. We present strong evidence consistent with MHC-specific overdominance in a free-living population of Arctic charr (Salvelinus alpinus) in northernmost Europe. In this population, where just two MHC alleles were observed, MHC heterozygous fish had a lower parasite load, were in better condition (as estimated by a fatness indicator) and had higher survival under stress than either of the homozygotes. Conversely, there was no consistent association between these fitness measures and assumedly neutral microsatellite variability, indicating an MHC-specific effect. Our results provide convincing empirical evidence consistent with the notion that overdominance can be an important evolutionary mechanism contributing to MHC polymorphism in wild animal populations. They also support a recent simulation study indicating that the number of alleles expected to be maintained at an MHC loci can be low, even under strong heterozygote advantage. PMID:19515657

  8. Lifetime reproductive success is maximized with optimal major histocompatibility complex diversity

    PubMed Central

    Kalbe, Martin; Eizaguirre, Christophe; Dankert, Ilka; Reusch, Thorsten B.H.; Sommerfeld, Ralf D.; Wegner, K. Mathias; Milinski, Manfred

    2008-01-01

    Individual diversity at the major histocompatibility complex (MHC) is predicted to be optimal at intermediate rather than at maximal levels. We showed previously in sticklebacks that an intermediate MHC diversity is predominant in natural populations and provides maximal resistance in experimental multiple parasite infections in the laboratory. However, what counts ultimately is the lifetime reproductive success (LRS). Here, we measured LRS of six laboratory-bred sib-groups—to minimize the influence of non-MHC genes—three-spined sticklebacks (Gasterosteus aculeatus) during their entire breeding period, each in a seminatural enclosure in the lake of their parents, where they were exposed to the natural spectrum of parasites. We collected developing clutches at regular intervals and determined parenthood for a representative number of eggs (2279 in total) per clutch with 18 microsatellites. Both males and females with an intermediate MHC class IIB variant number had the highest LRS. The mechanistic link of MHC diversity and LRS differed between the sexes: in females, we found evidence for a trade-off between number of eggs and immunocompentence, whereas in males this correlation was concealed by different timing strategies of reproduction. PMID:19033141

  9. Major histocompatibility complex based resistance to a common bacterial pathogen of amphibians.

    PubMed

    Barribeau, Seth M; Villinger, Jandouwe; Waldman, Bruce

    2008-07-16

    Given their well-developed systems of innate and adaptive immunity, global population declines of amphibians are particularly perplexing. To investigate the role of the major histocompatibility complex (MHC) in conferring pathogen resistance, we challenged Xenopus laevis tadpoles bearing different combinations of four MHC haplotypes (f, g, j, and r) with the bacterial pathogen Aeromonas hydrophila in two experiments. In the first, we exposed ff, fg, gg, gj, and jj tadpoles, obtained from breeding MHC homozygous parents, to one of three doses of A. hydrophila or heat-killed bacteria as a control. In the second, we exposed ff, fg, fr, gg, rg, and rr tadpoles, obtained from breeding MHC heterozygous parents and subsequently genotyped by PCR, to A. hydrophila, heat-killed bacteria or media alone as controls. We thereby determined whether the same patterns of MHC resistance emerged within as among families, independent of non-MHC heritable differences. Tadpoles with r or g MHC haplotypes were more likely to die than were those with f or j haplotypes. Growth rates varied among MHC types, independent of exposure dose. Heterozygous individuals with both susceptible and resistant haplotypes were intermediate to either homozygous genotype in both size and survival. The effect of the MHC on growth and survival was consistent between experiments and across families. MHC alleles differentially confer resistance to, or tolerance of, the bacterial pathogen, which affects tadpoles' growth and survival.

  10. Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males.

    PubMed

    Løvlie, Hanne; Gillingham, Mark A F; Worley, Kirsty; Pizzari, Tommaso; Richardson, David S

    2013-10-22

    Cryptic female choice may enable polyandrous females to avoid inbreeding or bias offspring variability at key loci after mating. However, the role of these genetic benefits in cryptic female choice remains poorly understood. Female red junglefowl, Gallus gallus, bias sperm use in favour of unrelated males. Here, we experimentally investigate whether this bias is driven by relatedness per se, or by similarity at the major histocompatibility complex (MHC), genes central to vertebrate acquired immunity, where polymorphism is critical to an individual's ability to combat pathogens. Through experimentally controlled natural matings, we confirm that selection against related males' sperm occurs within the female reproductive tract but demonstrate that this is more accurately predicted by MHC similarity: controlling for relatedness per se, more sperm reached the eggs when partners were MHC--dissimilar. Importantly, this effect appeared largely owing to similarity at a single MHC locus (class I minor). Further, the effect of MHC similarity was lost following artificial insemination, suggesting that male phenotypic cues might be required for females to select sperm differentially. These results indicate that postmating mechanisms that reduce inbreeding may do so as a consequence of more specific strategies of cryptic female choice promoting MHC diversity in offspring.

  11. Major histocompatibility complex gene product expression on pancreatic beta cells in acutely diabetic BB rats.

    PubMed Central

    Issa-Chergui, B.; Yale, J. F.; Vigeant, C.; Seemayer, T. A.

    1988-01-01

    Type I diabetes mellitus was induced in young, diabetes-prone BB rats by the passive transfer of concanavalin A-activated T lymphocytes from the spleens of acutely diabetic BB rats. The pancreas of the recipients was examined 1-2 days after the onset of glycosuria by immunocytochemistry by means of monoclonal antibodies for determining whether 1) Class I and/or II major histocompatibility gene complex (MHC) products were expressed on beta cells and 2) the mononuclear cell infiltrates were represented by T cells. Marked expression of Class I MHC gene products was evident on beta cells. In contrast, Class II MHC gene products were not identified on normal-appearing beta cells. Dendritic cells dispersed throughout the acinar and interstitial pancreas were markedly increased in number. The mononuclear cell infiltrate contained few cells (1-15%) recognized by a pan-T cell marker. Although it is possible that this passive transfer model might differ considerably from the spontaneously occurring diabetic state in the rat, this study suggests that 1) Class I, rather than Class II, MHC gene expression may be pivotal to beta-cell injury in diabetic rats, and 2) non-T cells may constitute an effector cell population central to beta-cell necrosis in Type I diabetes mellitus. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:3276208

  12. Peptide influences the folding and intracellular transport of free major histocompatibility complex class I heavy chains

    PubMed Central

    1995-01-01

    Class I major histocompatibility complex molecules require both beta 2- microglobulin (beta 2m) and peptide for efficient intracellular transport. With the exception of H-2Db and Ld, class I heavy chains have not been detectable at the surface of cells lacking beta 2m. We show that properly conformed class I heavy chains can be detected in a terminally glycosylated form indicative of cell surface expression in H- 2b, H-2d, and H-2s beta 2m-/- concanavalin A (Con A)-stimulated splenocytes incubated at reduced temperature. Furthermore, we demonstrate the presence of Kb molecules at the surface of beta 2m-/- cells cultured at 37 degrees C. The mode of assembly of class I molecules encompasses two major pathways: binding of peptide to preformed "empty" heterodimers, and binding of peptide to free heavy chains, followed by recruitment of beta 2m. In support of the existence of the latter pathway, we provide evidence for a role of peptide in intracellular transport of free class I heavy chains, through analysis of Con A-stimulated splenocytes from transporter associated with antigen processing 1 (TAP1)-/-, beta 2m-/-, and double-mutant TAP1/beta 2m-/- mice. PMID:7869032

  13. Major histocompatibility complex class I genes of the coelacanth Latimeria chalumnae.

    PubMed

    Betz, U A; Mayer, W E; Klein, J

    1994-11-08

    The coelacanth fish Latimeria chalumnae is the sole surviving species of a phylogenetic lineage that was founded more than 400 million years ago and that has changed morphologically very little since that time. Little is known about the molecular evolution of this "living fossil," considered by some taxonomists to be the closest living relative of tetrapods. Here we describe the isolation and characterization of L. chalumnae major histocompatibility complex (MHC) class I genes. The exon-intron organization of these genes is the same as that of their mammalian counterparts. The genes fall into four families, which we designate Lach-UA through Lach-UD. There are multiple loci in all of the families. Genes of the first two families are transcribed. The Lach-UA family bears the characteristics of functional, polymorphic class I genes; the other three families may be represented by nonclassical genes. All the Lach loci arose by duplication from an ancestral gene after the foundation of the coelacanth lineage. Intergenic variation is highest at positions corresponding to the mammalian peptide-binding region. The closest relatives of the Lach genes among the MHC genes sequenced thus far are those of the amphibian Xenopus.

  14. Structure and polymorphisms of the major histocompatibility complex in the Oriental stork, Ciconia boyciana.

    PubMed

    Tsuji, Hiroki; Taniguchi, Yukio; Ishizuka, Shintaro; Matsuda, Hirokazu; Yamada, Takahisa; Naito, Kazuaki; Iwaisaki, Hiroaki

    2017-02-17

    The major histocompatibility complex (MHC) is highly polymorphic and plays a central role in the vertebrate immune system. Despite its functional consistency, the MHC genomic structure differs substantially among organisms. In birds, the MHCs of Galliformes and the Japanese crested ibis (Pelecaniformes) are well-characterized, but information about other avian MHCs remains scarce. The Oriental stork (Ciconia boyciana, order Ciconiiformes) is a large endangered migrant. The current Japanese population of this bird originates from a few founders; thus, understanding the genetic diversity among them is critical for effective population management. We report the structure and polymorphisms in C. boyciana MHC. One contig (approximately 128 kb) was assembled by screening of lambda phage genomic library and its complete sequence was determined, revealing a gene order of COL11A2, two copies of MHC-IIA/IIB pairs, BRD2, DMA/B1/B2, MHC-I, TAP1/2, and two copies each of pseudo MHC-I and TNXB. This structure was highly similar to that of the Japanese crested ibis, but largely different from that of Galliformes, at both the terminal regions. Genotyping of the MHC-II region detected 10 haplotypes among the six founders. These results provide valuable insights for future studies on the evolution of the avian MHCs and for conservation of C. boyciana.

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

    PubMed

    Hanson, I M; Poustka, A; Trowsdale, J

    1991-06-01

    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.

  16. Molecular characterization of the Pb recombination hotspot in the mouse major histocompatibility complex class II region.

    PubMed

    Isobe, Taku; Yoshino, Masayasu; Mizuno, Ken-Ichi; Lindahl, Kirsten Fischer; Koide, Tsuyoshi; Gaudieri, Silvana; Gojobori, Takashi; Shiroishi, Toshihiko

    2002-08-01

    In the mouse major histocompatibility complex (MHC) class II region, meiotic recombination breakpoints are clustered in four specific sites known as hotspots. Here we reveal the primary structure of a hotspot near the Pb gene. A total of 12 crossover points were found to be confined to a 15-kb DNA segment of the Pb pseudogene. Moreover, the crossover points are concentrated in a 341-bp segment, which includes a part of exon 4 and intron 4 of the Pb gene. All four MHC hotspots appear to be located within genes or at the 3' end of genes, contrasting with characterized hotspots in budding yeast, which are mostly located at the 5'-promoter regions of genes. The Pb hotspot has several consensus motifs, an octamer transcription factor-binding sequence, the B-motif-like transcription factor-binding sequence, and tandem repeats of tetramer sequence-all of which are shared by the other three hotspots. Systematic analysis of the public database demonstrated that the full motif set occurs rarely in the nucleotide sequence of the entire MHC class II region. All results suggest that the motif set has an indispensable role in determining their site specificity.

  17. Major-histocompatibility-complex variation in two species of cichlid fishes from Lake Malawi.

    PubMed

    Ono, H; O'hUigin, C; Tichy, H; Klein, J

    1993-09-01

    Lake Malawi in eastern Africa harbors > 500 endemic species of cichlid fishes, all of which are believed to have emerged from a single founding population in the past 2 Myr. Molecular characterization of differences among the species could provide important information about the nature of speciation in the period of adaptive radiation. Because of the close relationship, however, molecular variation among the species has been difficult to ascertain. In this communication, we provide evidence for extensive differences, in major-histocompatibility-complex (Mhc) class II genes, between two related species, Pseudotropheus zebra and Melanochromis auratus. We used specific primers to amplify and sequence intron 1 and exon 2 of the class II genes from 18 individuals. Although we found 20 different sequences among the 42 that we produced, there was not a single sequence shared by the two species. Thus the study suggests that different cichlid species of Lake Malawi have different profiles of class II alleles, presumably because the polymorphism present in the ancestral founding population segregated differentially into the various species. These results make Mhc genes an important tool for elucidating speciation.

  18. Major histocompatibility complex diversity influences parasite resistance and innate immunity in sticklebacks.

    PubMed Central

    Kurtz, Joachim; Kalbe, Martin; Aeschlimann, Peter B.; Häberli, Michael A.; Wegner, K. Mathias; Reusch, Thorsten B. H.; Milinski, Manfred

    2004-01-01

    Proteins of the major histocompatibility complex (MHC) play a central role in the presentation of antigens to the adaptive immune system. The MHC also influences the odour-based choice of mates in humans and several animal taxa. It has recently been shown that female three-spined sticklebacks (Gasterosteus aculeatus) aim at a moderately high MHC diversity in their offspring when choosing a mate. Do they optimize the immune systems of their offspring? Using three-spined sticklebacks that varied in their individual numbers of MHC class IIB molecules, we tested, experimentally, whether allelic diversity at the MHC influences parasite resistance and immune parameters. We found that sticklebacks with low MHC diversity suffered more from parasite infection after experimental exposure to Schistocephalus solidus tapeworms and Glugea anomala microsporidians. They also showed the highest proportion of granulocytes and the strongest respiratory burst reaction, which are correlates of innate immunity. This indicates a strong activity of the innate immune system after challenge by parasites when MHC diversity is suboptimal. Individuals with very high allelic diversity at the MHC seemed inferior to those with moderately high diversity. Such a pattern is consistent with theoretical expectations of an optimal balance between the number of recognizable antigens and self-tolerance. PMID:15058398

  19. Effects of major histocompatibility complex class II knockout on mouse bone mechanical properties during development

    NASA Technical Reports Server (NTRS)

    Simske, Steven J.; Bateman, Ted A.; Smith, Erin E.; Ferguson, Virginia L.; Chapes, Stephen K.

    2002-01-01

    We investigated the effect of major histocompatibility complex class II (MHC II) knockout on the development of the mouse peripheral skeleton. These C2D mice had less skeletal development at 8, 12 and 16 weeks of age compared to wild-type C57BL/6J (B6) male mice. The C2D mice had decreased femur mechanical, geometric and compositional measurements compared to wild type mice at each of these ages. C2D femur stiffness (S), peak force in 3-pt bending (Pm), and mineral mass (Min-M) were 74%, 64% and 66%, respectively, of corresponding B6 values at 8 weeks of age. Similar differences were measured at 12 weeks (for which C2D femoral S, Pm and Min-M were 71%, 72% and 73%, respectively, of corresponding B6 values) and at 16 weeks (for which C2D femoral S, Pm and Min-M were 80%, 66% and 61%, respectively, of corresponding B6 values). MHC II knockout delays the development of adult bone properties and is accompanied by lower body mass compared to wild-type controls.

  20. Linkage mapping and physical localization of the major histocompatibility complex region of the marsupial Monodelphis domestica.

    PubMed

    Gouin, N; Deakin, J E; Miska, K B; Miller, R D; Kammerer, C M; Graves, J A M; VandeBerg, J L; Samollow, P B

    2006-01-01

    We used genetic linkage mapping and fluorescence in situ hybridization (FISH) to conduct the first analysis of genic organization and chromosome localization of the major histocompatibility complex (MHC) of a marsupial, the gray, short-tailed opossum Monodelphis domestica. Family based linkage analyses of two M. domestica MHC Class I genes (UA1, UG) and three MHC Class II genes (DAB, DMA, and DMB) revealed that these genes were tightly linked and positioned in the central region of linkage group 3 (LG3). This cluster of MHC genes was physically mapped to the centromeric region of chromosome 2q by FISH using a BAC clone containing the UA1 gene. An interesting finding from the linkage analyses is that sex-specific recombination rates were virtually identical within the MHC region. This stands in stark contrast to the genome-wide situation, wherein males exhibit approximately twice as much recombination as females, and could have evolutionary implications for maintaining equality between males and females in the ability to generate haplotype diversity in this region. These analyses also showed that three non-MHC genes that flank the MHC region on human chromosome 6, myelin oligodendrocyte glycoprotein (MOG), bone morphogenetic protein 6 (BMP6), and prolactin (PRL), are split among two separate linkage groups (chromosomes) in M. domestica. Comparative analysis with eight other vertebrate species suggests strong conservation of the BMP6-PRL synteny among birds and mammals, although the BMP6-PRL-MHC-ME1 synteny is not conserved.

  1. A structural transition in class II major histocompatibility complex proteins at mildly acidic pH

    PubMed Central

    1996-01-01

    Peptide binding by class II major histocompatibility complex proteins is generally enhanced at low pH in the range of hydrogen ion concentrations found in the endosomal compartments of antigen- presenting cells. We and others have proposed that class II molecules undergo a reversible conformational change at low pH that is associated with enhanced peptide loading. However, no one has previously provided direct evidence for a structural change in class II proteins in the mildly acidic pH conditions in which enhanced peptide binding is observed. In this study, susceptibility to denaturation induced by sodium dodecyl sulfate (SDS) detergent or heat was used to probe the conformation of class II at different hydrogen ion concentrations. Class II molecules became sensitive to denaturation at pH 5.5-6.5 depending on the allele and experimental conditions. The observed structural transition was fully reversible if acidic pH was neutralized before exposure to SDS or heat. Experiments with the environment- sensitive fluorescent probe ANS (8-anilino-1-naphthalene-sulfonic acid) provided further evidence for a reversible structural transition at mildly acidic pH associated with an increase in exposed hydrophobicity in class II molecules. IAd conformation was found to change at a higher pH than IEd, IEk, or IAk, which correlates with the different pH optimal for peptide binding by these molecules. We conclude that pH regulates peptide binding by influencing the structure of class II molecules. PMID:8551215

  2. Maintaining functional major histocompatibility complex diversity under inbreeding: the case of a selfing vertebrate

    PubMed Central

    Ellison, A.; Allainguillaume, J.; Girdwood, S.; Pachebat, J.; Peat, K. M.; Wright, P.; Consuegra, S.

    2012-01-01

    Major histocompatibility complex (MHC) genes encode proteins that present pathogen-derived antigens to T-cells, initiating the adaptive immune response in vertebrates. Although populations with low MHC diversity tend to be more susceptible to pathogens, some bottlenecked populations persist and even increase in numbers despite low MHC diversity. Thus, the relative importance of MHC diversity versus genome-wide variability for the long-term viability of populations after bottlenecks and/or under high inbreeding is controversial. We tested the hypothesis that genome-wide inbreeding (estimated using microsatellites) should be more critical than MHC diversity alone in determining pathogen resistance in the self-fertilizing fish Kryptolebias marmoratus by analysing MHC diversity and parasite loads in natural and laboratory populations with different degrees of inbreeding. Both MHC and neutral diversities were lost after several generations of selfing, but we also found evidence of parasite selection acting on MHC diversity and of non-random loss of alleles, suggesting a possible selective advantage of those individuals with functionally divergent MHC, in accordance with the hypothesis of divergent allele advantage. Moreover, we found that parasite loads were better explained by including MHC diversity in the model than by genome-wide (microsatellites) heterozygosity alone. Our results suggest that immune-related overdominance could be the key in maintaining variables rates of selfing and outcrossing in K. marmoratus and other mixed-mating species. PMID:23075838

  3. Maintaining functional major histocompatibility complex diversity under inbreeding: the case of a selfing vertebrate.

    PubMed

    Ellison, A; Allainguillaume, J; Girdwood, S; Pachebat, J; Peat, K M; Wright, P; Consuegra, S

    2012-12-22

    Major histocompatibility complex (MHC) genes encode proteins that present pathogen-derived antigens to T-cells, initiating the adaptive immune response in vertebrates. Although populations with low MHC diversity tend to be more susceptible to pathogens, some bottlenecked populations persist and even increase in numbers despite low MHC diversity. Thus, the relative importance of MHC diversity versus genome-wide variability for the long-term viability of populations after bottlenecks and/or under high inbreeding is controversial. We tested the hypothesis that genome-wide inbreeding (estimated using microsatellites) should be more critical than MHC diversity alone in determining pathogen resistance in the self-fertilizing fish Kryptolebias marmoratus by analysing MHC diversity and parasite loads in natural and laboratory populations with different degrees of inbreeding. Both MHC and neutral diversities were lost after several generations of selfing, but we also found evidence of parasite selection acting on MHC diversity and of non-random loss of alleles, suggesting a possible selective advantage of those individuals with functionally divergent MHC, in accordance with the hypothesis of divergent allele advantage. Moreover, we found that parasite loads were better explained by including MHC diversity in the model than by genome-wide (microsatellites) heterozygosity alone. Our results suggest that immune-related overdominance could be the key in maintaining variables rates of selfing and outcrossing in K. marmoratus and other mixed-mating species.

  4. Molecular characterization of major histocompatibility complex class II alleles in wild tiger salamanders (Ambystoma tigrinum).

    PubMed

    Bos, David H; DeWoody, J Andrew

    2005-11-01

    Major histocompatibility complex (MHC) class II genes are usually among the most polymorphic in vertebrate genomes because of their critical role (antigen presentation) in immune response. Prior to this study, the MHC was poorly characterized in tiger salamanders (Ambystoma tigrinum), but the congeneric axolotl (Ambystoma mexicanum) is thought to have an unusual MHC. Most notably, axolotl class II genes lack allelic variation and possess a splice variant without a full peptide binding region (PBR). The axolotl is considered immunodeficient, but it is unclear how or to what extent MHC genetics and immunodeficiency are interrelated. To study the evolution of MHC genes in urodele amphibians, we describe for the first time an expressed polymorphic class II gene in wild tiger salamanders. We sequenced the PBR of a class II gene from wild A. tigrinum (n=33) and identified nine distinct alleles. Observed heterozygosity was 73%, and there were a total of 46 polymorphic sites, most of which correspond to amino acid positions that bind peptides. Patterns of nucleotide substitutions exhibit the signature of diversifying selection, but no recombination was detected. Not surprisingly, trans-species evolution of tiger salamander and axolotl class II alleles was apparent. We have no direct data on the immunodeficiency of tiger salamanders, but the levels of polymorphism in our study population should suffice to bind a variety of foreign peptides (unlike axolotls). Our tiger salamander data suggest that the monomorphism and immunodeficiencies associated with axolotl class II genes is a relic of their unique historical demography, not their phylogenetic legacy.

  5. Role of human major histocompatibility complex DQ molecules in superantigenicity of streptococcus-derived protein.

    PubMed Central

    Esaki, Y; Fukui, Y; Sudo, T; Yamamoto, K; Inamitsu, T; Nishimura, Y; Hirokawa, K; Kimura, A; Sasazuki, T

    1994-01-01

    Antigenicity of peptic extract from type 12 group A streptococci (PEAST12) for T cells was examined in major histocompatibility complex (MHC) class II transgenic mice. PEAST12 was mitogenic for murine T cells when antigen-presenting cells were obtained from human MHC (HLA)-DQ4 alpha beta transgenic mice or from DQ6 alpha beta transgenic mice but was not mitogenic in DR alpha transgenic, DR51 alpha beta transgenic, E alpha transgenic, or nontransgenic mice. In addition, PEAST12 showed mitogenicity for murine T cells in DQ4 alpha singly transgenic mice but not in DQ4 beta singly transgenic mice. T-cell stimulation by PEAST12 was unrestricted by but dependent on the expression of HLA-DQ molecules on antigen-presenting cells, and PEAST12 selectively activated T-cell receptor V beta 11-, V beta 15-, and V beta 18-positive T cells in mice. We propose that PEAST12 contains a superantigen which binds preferentially to the alpha-chain of HLA-DQ molecules. The well-known phenomenon that peptic extracts from group A streptococci are mitogenic in humans but not in mice is likely due to structural differences in MHC class II molecules between these two species of mammals. Images PMID:8132329

  6. Enhanced Direct Major Histocompatibility Complex Class I Self-Antigen Presentation Induced by Chlamydia Infection.

    PubMed

    Cram, Erik D; Simmons, Ryan S; Palmer, Amy L; Hildebrand, William H; Rockey, Daniel D; Dolan, Brian P

    2015-11-23

    The direct major histocompatibility complex (MHC) class I antigen presentation pathway ensures intracellular peptides are displayed at the cellular surface for recognition of infected or transformed cells by CD8(+) cytotoxic T lymphocytes. Chlamydia spp. are obligate intracellular bacteria and, as such, should be targeted by CD8(+) T cells. It is likely that Chlamydia spp. have evolved mechanisms to avoid the CD8(+) killer T cell responses by interfering with MHC class I antigen presentation. Using a model system of self-peptide presentation which allows for posttranslational control of the model protein's stability, we tested the ability of various Chlamydia species to alter direct MHC class I antigen presentation. Infection of the JY lymphoblastoid cell line limited the accumulation of a model host protein and increased presentation of the model-protein-derived peptides. Enhanced self-peptide presentation was detected only when presentation was restricted to defective ribosomal products, or DRiPs, and total MHC class I levels remained unaltered. Skewed antigen presentation was dependent on a bacterial synthesized component, as evidenced by reversal of the observed phenotype upon preventing bacterial transcription, translation, and the inhibition of bacterial lipooligosaccharide synthesis. These data suggest that Chlamydia spp. have evolved to alter the host antigen presentation machinery to favor presentation of defective and rapidly degraded forms of self-antigen, possibly as a mechanism to diminish the presentation of peptides derived from bacterial proteins.

  7. Emerging Major Histocompatibility Complex Class I-Related Functions of NLRC5.

    PubMed

    Chelbi, S T; Dang, A T; Guarda, G

    2017-01-01

    Recent evidence demonstrates a key role for the nucleotide-binding oligomerization domain-like receptor (NLR) family member NLRC5 (NLR family, CARD domain containing protein 5) in the transcriptional regulation of major histocompatibility complex (MHC) class I and related genes. Detailed information on NLRC5 target genes in various cell types and conditions is emerging. Thanks to its analogy to CIITA (class II major MHC transactivator), a NLR family member known for over 20 years to be the master regulator of MHC class II gene transcription, also the molecular mechanisms underlying NLRC5 function are being rapidly unraveled. MHC class I molecules are crucial in regulating innate and adaptive cytotoxic responses. Whereas CD8(+) T cells detect antigens presented on MHC class I molecules by infected or transformed cells, natural killer (NK) lymphocytes eliminate target cells with downregulated MHC class I expression. Data uncovering the relevance of NLRC5 in homeostasis and activity of these two lymphocyte subsets have been recently reported. Given the importance of CD8(+) T and NK cells in controlling infection and cancer, it is not surprising that NLRC5 is also starting to emerge as a central player in these diseases. This chapter summarizes and discusses novel insights into the molecular mechanisms underlying NLRC5 activity and its relevance to pathological conditions. A thorough understanding of both aspects is essential to evaluate the clinical significance and therapeutic potential of NLRC5.

  8. Characterisation of major histocompatibility complex class I genes in Japanese Ranidae frogs.

    PubMed

    Lau, Quintin; Igawa, Takeshi; Komaki, Shohei; Satta, Yoko

    2016-11-01

    The major histocompatibility complex (MHC) is a key component of adaptive immunity in all jawed vertebrates, and understanding the evolutionary mechanisms that have shaped these genes in amphibians, one of the earliest terrestrial tetrapods, is important. We characterised MHC class I variation in three common Japanese Rana species (Rana japonica, Rana ornativentris and Rana tagoi tagoi) and identified a total of 60 variants from 21 individuals. We also found evolutionary signatures of gene duplication, recombination and balancing selection (including trans-species polymorphism), all of which drive increased MHC diversity. A unique feature of MHC class I from these three Ranidae species includes low synonymous differences per site (d S) within species, which we attribute to a more recent diversification of these sequences or recent gene duplication. The resulting higher d N/d S ratio relative to other anurans studied could be related to stronger selection pressure at peptide binding sites. This is one of the first studies to investigate MHC in Japanese amphibians and permits further exploration of the polygenetic factors associated with resistance to infectious diseases.

  9. Broadly targeted CD8+ T cell responses restricted by major histocompatibility complex E

    SciTech Connect

    Hansen, Scott G.; Wu, Helen L.; Burwits, Benjamin J.; Hughes, Colette M.; Hammond, Katherine B.; Ventura, Abigail B.; Reed, Jason S.; Gilbride, Roxanne M.; Ainslie, Emily; Morrow, David W.; Ford, Julia C.; Selseth, Andrea N.; Pathak, Reesab; Malouli, Daniel; Legasse, Alfred W.; Axthelm, Michael K.; Nelson, Jay A.; Gillespie, Geraldine M.; Walters, Lucy C.; Brackenridge, Simon; Sharpe, Hannah R.; Lopez, Cesar Augusto; Fruh, Klaus; Korber, Bette Tina; McMichael, Andrew J.; Gnanakaran, Sandrasegaram; Sacha, Jonah B.; Picker, Louis J.

    2016-02-12

    Major histocompatibility complex (MHC)-E is a highly conserved, ubiquitously expressed, nonclassical, MHC-Ib molecule with limited polymorphism primarily involved in regulation of NK cell reactivity via interaction with NKG2/CD94 receptors. We found that vaccination of rhesus macaques with Rh157.5/.4 gene-deleted rhesus Cytomegalovirus (RhCMV) vectors uniquely diverts MHC-E function to presentation of highly diverse peptide epitopes to CD8α/β+ T cells, approximately 4 distinct epitopes per 100 amino acids, in all tested protein antigens. Computational structural analysis revealed that a relatively stable, open binding groove in MHC-E attains broad peptide binding specificity by imposing a similar backbone configuration on bound peptides with few restrictions based on amino acid side chains. Since MHC-E is up-regulated on cells infected with HIV/SIV and other persistent viruses to evade NK cell activity, MHC-E-restricted CD8+ T cell responses have the potential to exploit pathogen immune evasion adaptations, a capability that might endow these unconventional responses with superior efficacy.

  10. Broadly targeted CD8+ T cell responses restricted by major histocompatibility complex E

    DOE PAGES

    Hansen, Scott G.; Wu, Helen L.; Burwits, Benjamin J.; ...

    2016-02-12

    Major histocompatibility complex (MHC)-E is a highly conserved, ubiquitously expressed, nonclassical, MHC-Ib molecule with limited polymorphism primarily involved in regulation of NK cell reactivity via interaction with NKG2/CD94 receptors. We found that vaccination of rhesus macaques with Rh157.5/.4 gene-deleted rhesus Cytomegalovirus (RhCMV) vectors uniquely diverts MHC-E function to presentation of highly diverse peptide epitopes to CD8α/β+ T cells, approximately 4 distinct epitopes per 100 amino acids, in all tested protein antigens. Computational structural analysis revealed that a relatively stable, open binding groove in MHC-E attains broad peptide binding specificity by imposing a similar backbone configuration on bound peptides with fewmore » restrictions based on amino acid side chains. Since MHC-E is up-regulated on cells infected with HIV/SIV and other persistent viruses to evade NK cell activity, MHC-E-restricted CD8+ T cell responses have the potential to exploit pathogen immune evasion adaptations, a capability that might endow these unconventional responses with superior efficacy.« less

  11. Class I major histocompatibility complex antigens and tumor ploidy in breast and bronchogenic carcinomas.

    PubMed

    Redondo, M; Concha, A; Ruiz-Cabello, F; Morell, M; Esteban, F; Talavera, P; Garrido, F

    1997-01-01

    We determined the frequency of expression of the major histocompatibility complex antigens HLA-A,B,C in tumor cells from 207 primary tumor lesions of breast and bronchogenic carcinomas, to see if the expression of theses antigens was linked with several clinicopathological parameters associated with tumor aggressivity, such as abnormal cellular DNA content. We compared tumor tissues with nonneoplastic tissues and tissues from 15 benign breast lesions. HLA class I expressor and nonexpressor tumor cells were determined by using immunohistochemical stains (PAP and APAAP methods) and antibodies against these antigens. Reduction of HLA class I antigen was detected in 65 tumors (31.7%) and was significantly associated with poor tumor differentiation and abnormal cellular DNA content (p < 0.001). These characteristics might define a group of aggressive tumors in which the decrease of HLA class I antigens would enable tumor cells to avoid eliciting host immune responses. On the other hand, the altered regulatory mechanisms, of tumors with abnormal cellular DNA content, might modulate the expression of HLA class I molecules.

  12. Recombination and selection in the major histocompatibility complex of the endangered forest musk deer (Moschus berezovskii).

    PubMed

    Cai, Ruibo; Shafer, Aaron B A; Laguardia, Alice; Lin, Zhenzhen; Liu, Shuqiang; Hu, Defu

    2015-11-25

    The forest musk deer (Moschus berezovskii) is a high elevation species distributed across western China and northern Vietnam. Once abundant, habitat loss and poaching has led to a dramatic decrease in population numbers prompting the IUCN to list the species as endangered. Here, we characterized the genetic diversity of a Major Histocompatibility Complex (MHC) locus and teased apart driving factors shaping its variation. Seven DRB exon 2 alleles were identified among a group of randomly sampled forest musk deer from a captive population in the Sichuan province of China. Compared to other endangered or captive ungulates, forest musk deer have relatively low levels of MHC genetic diversity. Non-synonymous substitutions primarily occurred in the putative peptide-binding region (PBR), with analyses suggesting that recombination and selection has shaped the genetic diversity across the locus. Specifically, inter-allelic recombination generated novel allelic combinations, with evidence for both positive selection acting on the PBR and negative selection on the non-PBR. An improved understanding of functional genetic variability of the MHC will facilitate better design and management of captive breeding programs for this endangered species.

  13. Structure and polymorphisms of the major histocompatibility complex in the Oriental stork, Ciconia boyciana

    PubMed Central

    Tsuji, Hiroki; Taniguchi, Yukio; Ishizuka, Shintaro; Matsuda, Hirokazu; Yamada, Takahisa; Naito, Kazuaki; Iwaisaki, Hiroaki

    2017-01-01

    The major histocompatibility complex (MHC) is highly polymorphic and plays a central role in the vertebrate immune system. Despite its functional consistency, the MHC genomic structure differs substantially among organisms. In birds, the MHCs of Galliformes and the Japanese crested ibis (Pelecaniformes) are well-characterized, but information about other avian MHCs remains scarce. The Oriental stork (Ciconia boyciana, order Ciconiiformes) is a large endangered migrant. The current Japanese population of this bird originates from a few founders; thus, understanding the genetic diversity among them is critical for effective population management. We report the structure and polymorphisms in C. boyciana MHC. One contig (approximately 128 kb) was assembled by screening of lambda phage genomic library and its complete sequence was determined, revealing a gene order of COL11A2, two copies of MHC-IIA/IIB pairs, BRD2, DMA/B1/B2, MHC-I, TAP1/2, and two copies each of pseudo MHC-I and TNXB. This structure was highly similar to that of the Japanese crested ibis, but largely different from that of Galliformes, at both the terminal regions. Genotyping of the MHC-II region detected 10 haplotypes among the six founders. These results provide valuable insights for future studies on the evolution of the avian MHCs and for conservation of C. boyciana. PMID:28211522

  14. Comparative genome organization of the major histocompatibility complex: lessons from the Felidae.

    PubMed

    O'Brien, S J; Yuhki, N

    1999-02-01

    The mammalian major histocompatibility complex (MHC) has taught both immunologists and evolutionary biologists a great deal about the patterns and processes that have led to immune defenses. Driven principally by human and mouse studies, comparative MHC projects among other mammalian species offer certain advantages in connecting MHC genome characters to natural situations. We have studied the MHC in the domestic cat and in several wild species of Felidae. Our observations affirm class I and class II homology with other mammalian orders, derivative gene duplications during the Felidae radiation, abundant persistent trans-species allele polymorphism, recombination-derived amino acid motifs, and inverted ratios of non-synonymous to silent substitutions in the MHC peptide-binding regions, consistent with overdominant selection in class I and II genes. MHC diversity as quantified in population studies is a powerful barometer of historic demographic reduction for several endangered species including cheetahs, Asiatic lions, Florida panthers and tigers. In two cases (Florida panther and cheetah), reduced MHC variation may be contributing to uniform population sensitivity to emerging infectious pathogens. The Felidae species, nearly all endangered and monitored for conservation concerns, have allowed a glimpse of species adaptation, mediated by MHC divergence, using comparative inferences drawn from human and mouse models.

  15. Adaptive tolerance to a pathogenic fungus drives major histocompatibility complex evolution in natural amphibian populations

    PubMed Central

    Savage, Anna E.; Zamudio, Kelly R.

    2016-01-01

    Amphibians have been affected globally by the disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), and we are just now beginning to understand how immunogenetic variability contributes to disease susceptibility. Lineages of an expressed major histocompatibility complex (MHC) class II locus involved in acquired immunity are associated with chytridiomycosis susceptibility in controlled laboratory challenge assays. Here, we extend these findings to natural populations that vary both in exposure and response to Bd. We find that MHC alleles and supertypes associated with Bd survival in the field show a molecular signal of positive selection, while those associated with susceptibility do not, supporting the hypothesis that heritable Bd tolerance is rapidly evolving. We compare MHC supertypes to neutral loci to demonstrate where selection versus demography is shaping MHC variability. One population with Bd tolerance in nature shows a significant signal of directional selection for the same allele (allele Q) that was significantly associated with survival in an earlier laboratory study. Our findings indicate that selective pressure for Bd survival drives rapid immunogenetic adaptation in some natural populations, despite differences in environment and demography. Our field-based analysis of immunogenetic variation confirms that natural amphibian populations have the evolutionary potential to adapt to chytridiomycosis. PMID:27009220

  16. Enhanced Direct Major Histocompatibility Complex Class I Self-Antigen Presentation Induced by Chlamydia Infection

    PubMed Central

    Cram, Erik D.; Simmons, Ryan S.; Palmer, Amy L.; Hildebrand, William H.; Rockey, Daniel D.

    2015-01-01

    The direct major histocompatibility complex (MHC) class I antigen presentation pathway ensures intracellular peptides are displayed at the cellular surface for recognition of infected or transformed cells by CD8+ cytotoxic T lymphocytes. Chlamydia spp. are obligate intracellular bacteria and, as such, should be targeted by CD8+ T cells. It is likely that Chlamydia spp. have evolved mechanisms to avoid the CD8+ killer T cell responses by interfering with MHC class I antigen presentation. Using a model system of self-peptide presentation which allows for posttranslational control of the model protein's stability, we tested the ability of various Chlamydia species to alter direct MHC class I antigen presentation. Infection of the JY lymphoblastoid cell line limited the accumulation of a model host protein and increased presentation of the model-protein-derived peptides. Enhanced self-peptide presentation was detected only when presentation was restricted to defective ribosomal products, or DRiPs, and total MHC class I levels remained unaltered. Skewed antigen presentation was dependent on a bacterial synthesized component, as evidenced by reversal of the observed phenotype upon preventing bacterial transcription, translation, and the inhibition of bacterial lipooligosaccharide synthesis. These data suggest that Chlamydia spp. have evolved to alter the host antigen presentation machinery to favor presentation of defective and rapidly degraded forms of self-antigen, possibly as a mechanism to diminish the presentation of peptides derived from bacterial proteins. PMID:26597986

  17. Ancient, highly polymorphic human major histocompatibility complex DQA1 intron sequence

    SciTech Connect

    McGinnis, M.D.; Quinn, D.L.; Lebo, R.V.; Simons, M.J.

    1994-10-01

    A 438 basepair intron 1 sequence adjacent to exon 2 in the human major histocompatibility complex DQA1 gene defined 16 allelic variants in 69 individuals from wide ethnic backgrounds. In contrast, the most variable coding region spanned by the 247 basepair exon 2 defined 11 allelic variants. Our phylogenetic human intron 1 tree derived by the Bootstrap algorithm reflects the same relative allelic relationships as the reported DQA1 exon 2 have cosegregated since divergence of the human races. Comparison of human alleles to a Rhesus monkey DQA1 first intron sequence found only 10 nucleotide substitutions unique to Rhesus, with the other 428 positions (98%) found in at least one human allele. This high degree of homology reflects the evolutionary stability of intron sequences since these two species diverged over 20 million years ago. Because more intron 1 alleles exist than exon 2 alleles, these polymorphic introns can be used to improve tissue typing for transplantation, paternity testing, and forensics and to derive more complete phylogenetic trees. These results suggest that introns represent a previously underutilized polymorphic resource. 42 refs., 3 figs., 1 tab.

  18. The genomic sequence and comparative analysis of the rat major histocompatibility complex.

    PubMed

    Hurt, Peter; Walter, Lutz; Sudbrak, Ralf; Klages, Sven; Müller, Ines; Shiina, Takashi; Inoko, Hidetoshi; Lehrach, Hans; Günther, Eberhard; Reinhardt, Richard; Himmelbauer, Heinz

    2004-04-01

    We have determined the sequence of a 4-Mb interval on rat chromosome 20p12 that encompasses the rat major histocompatibility complex (MHC). This is the first report of a finished sequence for a segment of the rat genome and constitutes one of the largest contiguous sequences thus far for rodent genomes in general. The rat MHC is, next to the human MHC, the second mammalian MHC sequenced to completion. Our analysis has resulted in the identification of at least 220 genes located within the sequenced interval. Although gene content and order are well conserved in the class II and class III gene intervals as well as the framework gene regions, profound rat-specific features were encountered within the class I gene regions, in comparison to human and mouse. Class I region-associated differences were found both at the structural level, the number, and organization of class I genes and gene families, and, in a more global context, in the way that evolution worked to shape the present-day rat MHC.

  19. Detection of autoreactive CD4 T cells using major histocompatibility complex class II dextramers

    PubMed Central

    2011-01-01

    Background Tetramers are useful tools to enumerate the frequencies of antigen-specific T cells. However, unlike CD8 T cells, CD4 T cells - especially self-reactive cells - are challenging to detect with major histocompatibility complex (MHC) class II tetramers because of low frequencies and low affinities of their T cell receptors to MHC-peptide complexes. Here, we report the use of fluorescent multimers, designated MHC dextramers that contain a large number of peptide-MHC complexes per reagent. Results The utility of MHC dextramers was evaluated in three autoimmune disease models: 1) proteolipid protein (PLP) 139-151-induced experimental autoimmune encephalomyelitis in SJL/J (H-2s) mice; 2) myelin oligodendrocyte glycoprotein (MOG) 35-55-induced experimental autoimmune encephalomyelitis in C57Bl/6 (H-2b) mice; and 3) cardiac myosin heavy chain (Myhc)-α 334-352-induced experimental autoimmune myocarditis in A/J (H-2a) mice. Flow cytometrically, we demonstrate that IAs/PLP 139-151, IAb/MOG 35-55 and IAk/Myhc-α 334-352 dextramers detect the antigen-sensitized cells with specificity, and with a detection sensitivity significantly higher than that achieved with conventional tetramers. Furthermore, we show that binding of dextramers, but not tetramers, is less dependent on the activation status of cells, permitting enumeration of antigen-specific cells ex vivo. Conclusions The data suggest that MHC dextramers are useful tools to track the generation and functionalities of self-reactive CD4 cells in various experimental systems. PMID:21767394

  20. Allelic polymorphism in transcriptional regulatory regions of HLA-DQB genes

    PubMed Central

    1991-01-01

    Class II genes of the human major histocompatibility complex (MHC) are highly polymorphic. Allelic variation of structural genes provides diversity in immune cell interactions, contributing to the formation of the T cell repertoire and to susceptibility to certain autoimmune diseases. We now report that allelic polymorphism also exists in the promoter and upstream regulatory regions (URR) of human histocompatibility leukocyte antigen (HLA) class II genes. Nucleotide sequencing of these regulatory regions of seven alleles of the DQB locus reveals a number of allele-specific polymorphisms, some of which lie in functionally critical consensus regions thought to be highly conserved in class II promoters. These sequence differences also correspond to allelic differences in binding of nuclear proteins to the URR. Fragments of the URR of two DQB alleles were analyzed for binding to nuclear proteins extracted from human B lymphoblastoid cell lines (B- LCL). Gel retardation assays showed substantially different banding patterns to the two promoters, including prominent variation in nuclear protein binding to the partially conserved X box regions and a novel upstream polymorphic sequence element. Comparison of these two polymorphic alleles in a transient expression system demonstrated a marked difference in their promoter strengths determined by relative abilities to initiate transcription of the chloramphenicol acetyltransferase reporter gene in human B-LCL. Shuttling of URR sequences between alleles showed that functional variation corresponded to both the X box and upstream sequence polymorphic sites. These findings identify an important source of MHC class II diversity, and suggest the possibility that such regulatory region polymorphisms may confer allelic differences in expression, inducibility, and/or tissue specificity of class II molecules. PMID:1985121

  1. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation

    PubMed Central

    Wieczorek, Marek; Abualrous, Esam T.; Sticht, Jana; Álvaro-Benito, Miguel; Stolzenberg, Sebastian; Noé, Frank; Freund, Christian

    2017-01-01

    Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors—tapasin for class I and HLA-DM for class II—contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity. PMID:28367149

  2. Disruption and pseudoautosomal localization of the major histocompatibility complex in monotremes

    PubMed Central

    Dohm, Juliane C; Tsend-Ayush, Enkhjargal; Reinhardt, Richard; Grützner, Frank; Himmelbauer, Heinz

    2007-01-01

    Background The monotremes, represented by the duck-billed platypus and the echidnas, are the most divergent species within mammals, featuring a flamboyant mix of reptilian, mammalian and specialized characteristics. To understand the evolution of the mammalian major histocompatibility complex (MHC), the analysis of the monotreme genome is vital. Results We characterized several MHC containing bacterial artificial chromosome clones from platypus (Ornithorhynchus anatinus) and the short-beaked echidna (Tachyglossus aculeatus) and mapped them onto chromosomes. We discovered that the MHC of monotremes is not contiguous and locates within pseudoautosomal regions of two pairs of their sex chromosomes. The analysis revealed an MHC core region with class I and class II genes on platypus and echidna X3/Y3. Echidna X4/Y4 and platypus Y4/X5 showed synteny to the human distal class III region and beyond. We discovered an intron-containing class I pseudogene on platypus Y4/X5 at a genomic location equivalent to the human HLA-B,C region, suggesting ancestral synteny of the monotreme MHC. Analysis of male meioses from platypus and echidna showed that MHC chromosomes occupy different positions in the meiotic chains of either species. Conclusion Molecular and cytogenetic analyses reveal new insights into the evolution of the mammalian MHC and the multiple sex chromosome system of monotremes. In addition, our data establish the first homology link between chicken microchromosomes and the smallest chromosomes in the monotreme karyotype. Our results further suggest that segments of the monotreme MHC that now reside on separate chromosomes must once have been syntenic and that the complex sex chromosome system of monotremes is dynamic and still evolving. PMID:17727704

  3. A second lineage of mammalian major histocompatibility complex class I genes.

    PubMed Central

    Bahram, S; Bresnahan, M; Geraghty, D E; Spies, T

    1994-01-01

    Major histocompatibility complex (MHC) class I genes typically encode polymorphic peptide-binding chains which are ubiquitously expressed and mediate the recognition of intracellular antigens by cytotoxic T cells. They constitute diverse gene families in different species and include the numerous so-called nonclassical genes in the mouse H-2 complex, of which some have been adapted to variously modified functions. We have identified a distinct family of five related sequences in the human MHC which are distantly homologous to class I chains. These MIC genes (MHC class I chain-related genes) evolved in parallel with the human class I genes and with those of most if not all mammalian orders. The MICA gene in this family is located near HLA-B and is by far the most divergent mammalian MHC class I gene known. It is further distinguished by its unusual exon-intron organization and preferential expression in fibroblasts and epithelial cells. However, the presence of diagnostic residues in the MICA amino acid sequence translated from cDNA suggests that the putative MICA chain folds similarly to typical class I chains and may have the capacity to bind peptide or other short ligands. These results define a second lineage of evolutionarily conserved MHC class I genes. This implies that MICA and possibly other members in this family have been selected for specialized functions that are either ancient or derived from those of typical MHC class I genes, in analogy to some of the nonclassical mouse H-2 genes. Images PMID:8022771

  4. Staphylococcus-mediated T-cell activation and spontaneous natural killer cell activity in the absence of major histocompatibility complex class II molecules

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Hoynowski, S. M.; Woods, K. M.; Armstrong, J. W.; Beharka, A. A.; Iandolo, J. J.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    We used major histocompatibility complex class II antigen-deficient transgenic mice to show that in vitro natural killer cell cytotoxicity and T-cell activation by staphylococcal exotoxins (superantigens) are not dependent upon the presence of major histocompatibility complex class II molecules. T cells can be activated by exotoxins in the presence of exogenously added interleukin 1 or 2 or in the presence of specific antibody without exogenously added cytokines.

  5. Positive selection drives the evolution of a major histocompatibility complex gene in an endangered Mexican salamander species complex.

    PubMed

    Tracy, Karen E; Kiemnec-Tyburczy, Karen M; DeWoody, J Andrew; Parra-Olea, Gabriela; Zamudio, Kelly R

    2015-06-01

    Immune gene evolution can be critical to species survival in the face of infectious disease. In particular, polymorphism in the genes of the major histocompatibility complex (MHC) helps vertebrates combat novel and diverse pathogens by increasing the number of pathogen-derived proteins that can initiate the host's acquired immune response. In this study, we used a combination of presumably adaptive and neutral markers to investigate MHC evolution in populations of five salamander species within the Ambystoma velasci complex, a group consisting of 15 recently diverged species, several of which are endangered. We isolated 31 unique MHC class II β alleles from 75 total individuals from five species in this complex. MHC heterozygosity was significantly lower than expected for all five species, and we found no clear relationship between number of MHC alleles and species range, life history, or level of heterozygosity. We inferred a phylogeny representing the evolutionary history of Ambystoma MHC, with which we found signatures of positive selection on the overall gene, putative peptide-binding residues, and allelic lineages. We identified several instances of trans-species polymorphism, a hallmark of balancing selection observed in other groups of closely related species. In contrast, we did not detect comparable allelic diversity or signatures of selection on neutral loci. Additionally, we identified 17 supertypes among the 44 unique Ambystoma alleles, indicating that these sequences may encode functionally distinct MHC variants. We therefore have strong evidence that positive selection is a major evolutionary force driving patterns of MHC polymorphism in this recently radiated species complex.

  6. Sequences, annotation and single nucleotide polymorphism of the major histocompatibility complex in the domestic cat.

    PubMed

    Yuhki, Naoya; Mullikin, James C; Beck, Thomas; Stephens, Robert; O'Brien, Stephen J

    2008-07-16

    Two sequences of major histocompatibility complex (MHC) regions in the domestic cat, 2.976 and 0.362 Mbps, which were separated by an ancient chromosome break (55-80 MYA) and followed by a chromosomal inversion were annotated in detail. Gene annotation of this MHC was completed and identified 183 possible coding regions, 147 human homologues, possible functional genes and 36 pseudo/unidentified genes) by GENSCAN and BLASTN, BLASTP RepeatMasker programs. The first region spans 2.976 Mbp sequence, which encodes six classical class II antigens (three DRA and three DRB antigens) lacking the functional DP, DQ regions, nine antigen processing molecules (DOA/DOB, DMA/DMB, TAPASIN, and LMP2/LMP7,TAP1/TAP2), 52 class III genes, nineteen class I genes/gene fragments (FLAI-A to FLAI-S). Three class I genes (FLAI-H, I-K, I-E) may encode functional classical class I antigens based on deduced amino acid sequence and promoter structure. The second region spans 0.362 Mbp sequence encoding no class I genes and 18 cross-species conserved genes, excluding class I, II and their functionally related/associated genes, namely framework genes, including three olfactory receptor genes. One previously identified feline endogenous retrovirus, a baboon retrovirus derived sequence (ECE1) and two new endogenous retrovirus sequences, similar to brown bat endogenous retrovirus (FERVmlu1, FERVmlu2) were found within a 140 Kbp interval in the middle of class I region. MHC SNPs were examined based on comparisons of this BAC sequence and MHC homozygous 1.9x WGS sequences and found that 11,654 SNPs in 2.84 Mbp (0.00411 SNP per bp), which is 2.4 times higher rate than average heterozygous region in the WGS (0.0017 SNP per bp genome), and slightly higher than the SNP rate observed in human MHC (0.00337 SNP per bp).

  7. Major histocompatibility complex haplotype studies in Ashkenazi Jewish patients with pemphigus vulgaris.

    PubMed Central

    Ahmed, A R; Yunis, E J; Khatri, K; Wagner, R; Notani, G; Awdeh, Z; Alper, C A

    1990-01-01

    Of 26 Ashkenazi Jewish patients with pemphigus vulgaris, 24 (92.3%) carried the major histocompatibility complex (MHC) class II alleles HLA-DR4, DQw3, of which all were of the subtype DR4, DQw8. From studies of the patients and their families, haplotypes were defined. It was found that, of the patients who carried HLA-DR4, DQw8, 75% carried one or the other (and in one case, both) of two haplotypes [HLA-B38, SC21, DR4] or HLA-B35, SC31, DR4. The former is a known extended haplotype among normal Jews, with a frequency of 0.102, and the latter may also be an extended haplotype in this ethnic group, with a frequency of 0.017 among normal haplotypes from Jews. Of the remaining DR4-positive patients, all but one had a presumed D-region segment (defined as SC21, DR4, DQw8 or SC31, DR4, DQw8 with variable HLA-B) of these haplotypes. Only one patient had DR4, DQw8 without any other markers of the extended haplotypes. The number of homozygotes and heterozygotes for DR4, DQw8 was consistent with dominant but not recessive (P less than 0.01) inheritance of a class II or a class II-linked susceptibility gene for the disease. Since the disease is entirely attributable to the presence of an antibody to an intraepidermal intercellular cement substance, it is likely that the class II susceptibility gene (on [HLA-B38, SC21, DR4, DQw8], HLA-B35, SC31, DR4, DQw8, or their segments, in Jewish patients) controls the production of the antibody as a dominantly expressed immune response gene. Images PMID:2217197

  8. Fine Mapping Major Histocompatibility Complex Associations in Psoriasis and Its Clinical Subtypes

    PubMed Central

    Okada, Yukinori; Han, Buhm; Tsoi, Lam C.; Stuart, Philip E.; Ellinghaus, Eva; Tejasvi, Trilokraj; Chandran, Vinod; Pellett, Fawnda; Pollock, Remy; Bowcock, Anne M.; Krueger, Gerald G.; Weichenthal, Michael; Voorhees, John J.; Rahman, Proton; Gregersen, Peter K.; Franke, Andre; Nair, Rajan P.; Abecasis, Gonçalo R.; Gladman, Dafna D.; Elder, James T.; de Bakker, Paul I.W.; Raychaudhuri, Soumya

    2014-01-01

    Psoriasis vulgaris (PsV) risk is strongly associated with variation within the major histocompatibility complex (MHC) region, but its genetic architecture has yet to be fully elucidated. Here, we conducted a large-scale fine-mapping study of PsV risk in the MHC region in 9,247 PsV-affected individuals and 13,589 controls of European descent by imputing class I and II human leukocyte antigen (HLA) genes from SNP genotype data. In addition, we imputed sequence variants for MICA, an MHC HLA-like gene that has been associated with PsV, to evaluate association at that locus as well. We observed that HLA-C∗06:02 demonstrated the lowest p value for overall PsV risk (p = 1.7 × 10−364). Stepwise analysis revealed multiple HLA-C∗06:02-independent risk variants in both class I and class II HLA genes for PsV susceptibility (HLA-C∗12:03, HLA-B amino acid positions 67 and 9, HLA-A amino acid position 95, and HLA-DQα1 amino acid position 53; p < 5.0 × 10−8), but no apparent risk conferred by MICA. We further evaluated risk of two major clinical subtypes of PsV, psoriatic arthritis (PsA; n = 3,038) and cutaneous psoriasis (PsC; n = 3,098). We found that risk heterogeneity between PsA and PsC might be driven by HLA-B amino acid position 45 (pomnibus = 2.2 × 10−11), indicating that different genetic factors underlie the overall risk of PsV and the risk of specific PsV subphenotypes. Our study illustrates the value of high-resolution HLA and MICA imputation for fine mapping causal variants in the MHC. PMID:25087609

  9. Major histocompatibility complex class II expression distinguishes two distinct B cell developmental pathways during ontogeny

    PubMed Central

    1994-01-01

    All mature B cells coexpress major histocompatibility complex (MHC) class II molecules, I-A and I-E, which are restriction elements required for antigen presentation to CD4+ T cells. However, the expression of class II during the early stages of B cell development has been unclear. We demonstrate here that there is a difference in the expression of class II during murine B cell development in the fetal liver and adult bone marrow (BM). These differences define two distinct B cell developmental pathways. The Fetal-type (FT) pathway is characterized by pre-B and immature IgM+ B cells generated in the fetal liver which initially lack all class II expression. In contrast, the Adult-type (AT) pathway is typified by B cells developing in the adult BM which express class II molecules from the pre-B cell stage. In vitro stromal cell cultures of sorted fetal liver and adult BM pro-B cells indicated that the difference in I-A expression during B cell development is intrinsic to the progenitors. In addition, we show that FT B cell development is not restricted to the fetal liver but occurs in the peritoneal cavities, spleens, liver, and BM of young mice up to at least 1 mo of age. The AT B cell development begins to emerge after birth but is, however, restricted to the BM environment. These findings indicate that there are two distinct B cell developmental pathways during ontogeny, each of which could contribute differentially to the immune repertoire and thus the functions of B cell subsets and lineages. PMID:7913950

  10. Remarkably low affinity of CD4/peptide-major histocompatibility complex class II protein interactions

    PubMed Central

    Jönsson, Peter; Southcombe, Jennifer H.; Santos, Ana Mafalda; Huo, Jiandong; Fernandes, Ricardo A.; McColl, James; Lever, Melissa; Evans, Edward J.; Hudson, Alexander; Chang, Veronica T.; Hanke, Tomáš; Godkin, Andrew; Dunne, Paul D.; Horrocks, Mathew H.; Palayret, Matthieu; Screaton, Gavin R.; Petersen, Jan; Rossjohn, Jamie; Fugger, Lars; Dushek, Omer; Xu, Xiao-Ning; Davis, Simon J.; Klenerman, David

    2016-01-01

    The αβ T-cell coreceptor CD4 enhances immune responses more than 1 million-fold in some assays, and yet the affinity of CD4 for its ligand, peptide-major histocompatibility class II (pMHC II) on antigen-presenting cells, is so weak that it was previously unquantifiable. Here, we report that a soluble form of CD4 failed to bind detectably to pMHC II in surface plasmon resonance-based assays, establishing a new upper limit for the solution affinity at 2.5 mM. However, when presented multivalently on magnetic beads, soluble CD4 bound pMHC II-expressing B cells, confirming that it is active and allowing mapping of the native coreceptor binding site on pMHC II. Whereas binding was undetectable in solution, the affinity of the CD4/pMHC II interaction could be measured in 2D using CD4- and adhesion molecule-functionalized, supported lipid bilayers, yielding a 2D Kd of ∼5,000 molecules/μm2. This value is two to three orders of magnitude higher than previously measured 2D Kd values for interacting leukocyte surface proteins. Calculations indicated, however, that CD4/pMHC II binding would increase rates of T-cell receptor (TCR) complex phosphorylation by threefold via the recruitment of Lck, with only a small, 2–20% increase in the effective affinity of the TCR for pMHC II. The affinity of CD4/pMHC II therefore seems to be set at a value that increases T-cell sensitivity by enhancing phosphorylation, without compromising ligand discrimination. PMID:27114505

  11. The major histocompatibility complex genes impact pain response in DA and DA.1U rats.

    PubMed

    Guo, Yuan; Yao, Fan-Rong; Cao, Dong-Yuan; Li, Li; Wang, Hui-Sheng; Xie, Wen; Zhao, Yan

    2015-08-01

    Our recent studies have shown that the difference in basal pain sensitivity to mechanical and thermal stimulation between Dark-Agouti (DA) rats and a novel congenic DA.1U rats is major histocompatibility complex (MHC) genes dependent. In the present study, we further used DA and DA.1U rats to investigate the role of MHC genes in formalin-induced pain model by behavioral, electrophysiological and immunohistochemical methods. Behavioral results showed biphasic nociceptive behaviors increased significantly following the intraplantar injection of formalin in the hindpaw of DA and DA.1U rats. The main nociceptive behaviors were lifting and licking, especially in DA rats (P<0.001 and P<0.01). The composite pain scores (CPS) in DA rats were significantly higher than those in DA.1U rats in both phases of the formalin test (P<0.01). Electrophysiological results also showed the biphasic increase in discharge rates of C and Aδ fibers of L5 dorsal root in the two strains, and the net change of the discharge rate of DA rats was significantly higher than that of DA.1U rats (P<0.05). The mechanical thresholds decreased after formalin injection in both strains (P<0.01), and the net change in the mechanical threshold in DA was greater than that in DA.1U rats (P<0.05). The expression of RT1-B, representation of MHC class II molecule, in laminae I-II of L4/5 spinal cord in DA rats was significantly higher than that in DA.1U rats in the respective experimental group (P<0.05). These results suggested that both DA and DA.1U rats exhibited nociceptive responses in formalin-induced pain model and DA rats were more sensitive to noxious chemical stimulus than DA.1U rats, indicating that MHC genes might contribute to the difference in pain sensitivity.

  12. Pathogen burden, co-infection and major histocompatibility complex variability in the European badger (Meles meles).

    PubMed

    Sin, Yung Wa; Annavi, Geetha; Dugdale, Hannah L; Newman, Chris; Burke, Terry; MacDonald, David W

    2014-10-01

    Pathogen-mediated selection is thought to maintain the extreme diversity in the major histocompatibility complex (MHC) genes, operating through the heterozygote advantage, rare-allele advantage and fluctuating selection mechanisms. Heterozygote advantage (i.e. recognizing and binding a wider range of antigens than homozygotes) is expected to be more detectable when multiple pathogens are considered simultaneously. Here, we test whether MHC diversity in a wild population of European badgers (Meles meles) is driven by pathogen-mediated selection. We examined individual prevalence (infected or not), infection intensity and co-infection of 13 pathogens from a range of taxa and examined their relationships with MHC class I and class II variability. This population has a variable, but relatively low, number of MHC alleles and is infected by a variety of naturally occurring pathogens, making it very suitable for the investigation of MHC-pathogen relationships. We found associations between pathogen infections and specific MHC haplotypes and alleles. Co-infection status was not correlated with MHC heterozygosity, but there was evidence of heterozygote advantage against individual pathogen infections. This suggests that rare-allele advantages and/or fluctuating selection, and heterozygote advantage are probably the selective forces shaping MHC diversity in this species. We show stronger evidence for MHC associations with infection intensity than for prevalence and conclude that examining both pathogen prevalence and infection intensity is important. Moreover, examination of a large number and diversity of pathogens, and both MHC class I and II genes (which have different functions), provide an improved understanding of the mechanisms driving MHC diversity.

  13. Tolerance and autoimmunity to erythroid differentiation (B-G) major histocompatibility complex alloantigens of the chicken

    PubMed Central

    1982-01-01

    Hematopoietic chimeras were produced at four different stages of ontogeny between two allogeneic strains of chickens. All chimeras produced by parabiosis at day 12 of embryogenesis and the majority (83%) of the ones produced at day 15 by intravenous injection of allogeneic stem cells remained healthy, chimeric, and specifically tolerant at both the humoral and cell-mediated level throughout a long examination period. Chimeras generated at day 17 of embryogenesis demonstrated specific unresponsiveness at the cell-mediated level but produced specific anti-donor alloantibodies directed against erythrocyte-associated major histocompatibility complex (MHC) (B-G) antigens. These chimeras and a minority (17%) of the chimeras generated at day 15 of embryogenesis developed severe antibody-mediated autoimmune hemolytic anemia after the 5th mo of age and succumbed to massive bursal lymphomas and metastases by the 10th mo of age. The immunological and pathological characteristics of these birds appear to reflect an autoimmune state rather than one of tolerance. Erythroid chimeras generated at day 21 of ontogenic development displayed normal levels of GVH reactivity. These birds were eventually able to eliminate the chimeric state and remained healthy until deliberately killed. These results show that there is a critical period in embryogenesis during which the induction of allogeneic erythrocytic chimerism leads to the development, in adult life, of severe autoimmune anemia, B cell lymphomas, and death. B-G MHC antigens are erythroid differentiation antigens of the chicken. Polymorphic determinants on B-G antigens appear to be important cross-reactive determinants (with environmental bacteria), against which a high background immunity exists. Evidence is presented that the immune response to B-G antigens is responsible for the development of autoimmunity and other pathological events that follow and that tolerance to class I MHC antigens (B-F antigens) shared by lymphocytes

  14. The tammar wallaby major histocompatibility complex shows evidence of past genomic instability

    PubMed Central

    2011-01-01

    Background The major histocompatibility complex (MHC) is a group of genes with a variety of roles in the innate and adaptive immune responses. MHC genes form a genetically linked cluster in eutherian mammals, an organization that is thought to confer functional and evolutionary advantages to the immune system. The tammar wallaby (Macropus eugenii), an Australian marsupial, provides a unique model for understanding MHC gene evolution, as many of its antigen presenting genes are not linked to the MHC, but are scattered around the genome. Results Here we describe the 'core' tammar wallaby MHC region on chromosome 2q by ordering and sequencing 33 BAC clones, covering over 4.5 MB and containing 129 genes. When compared to the MHC region of the South American opossum, eutherian mammals and non-mammals, the wallaby MHC has a novel gene organization. The wallaby has undergone an expansion of MHC class II genes, which are separated into two clusters by the class III genes. The antigen processing genes have undergone duplication, resulting in two copies of TAP1 and three copies of TAP2. Notably, Kangaroo Endogenous Retroviral Elements are present within the region and may have contributed to the genomic instability. Conclusions The wallaby MHC has been extensively remodeled since the American and Australian marsupials last shared a common ancestor. The instability is characterized by the movement of antigen presenting genes away from the core MHC, most likely via the presence and activity of retroviral elements. We propose that the movement of class II genes away from the ancestral class II region has allowed this gene family to expand and diversify in the wallaby. The duplication of TAP genes in the wallaby MHC makes this species a unique model organism for studying the relationship between MHC gene organization and function. PMID:21854592

  15. Expression in L cells of transfected class I genes from the mouse major histocompatibility complex.

    PubMed Central

    Schepart, B S; Woodward, J G; Palmer, M J; Macchi, M J; Basta, P; McLaughlin-Taylor, E; Frelinger, J A

    1985-01-01

    One of the major surprises of the molecular analysis of major histocompatibility complex (MHC) genes is the large number of class I (K/D)-related sequences in the genome. Both restriction fragment length polymorphisms and cosmid cloning experiments showed them all to be closely linked to the MHC. Until now little information was available concerning either their expression or recognition by the immune system. Here we report that these non-K/D genes can provoke antibody responses and be recognized by cytolytic T cells. Immunization of C3H mice with L cells transfected with class I genomic clones resulted in antisera that reacted preferentially with cells from strain B10.P (the gene donor). Thus, these genes can be expressed by L cells. These products were recognized by cytolytic T cells produced by mixed lymphocyte culture with B10.P stimulators. One gene, represented in clone lambda 3a, was chosen for further analysis. A restriction fragment length polymorphism, detected between B10.P (KpDp) and B10.F(14R) (KbDp) and between B10 (KbDb) and B10.F(13R) (KpDb), has enabled us to map the lambda 3a sequence to the D or Tla region. Restriction endonuclease mapping of the lambda 3a clone shows that the gene is intact and that, although many restriction sites are conserved, the gene in lambda 3a differs from other class I genes. When the lambda 3a clone was transfected into mouse L cells, a new product was expressed. Cells expressing this product (designated L3a cells) were killed by primary D-end-reactive, allospecific cytolytic T lymphocytes. The L3a cells were unreactive with monoclonal antibodies specific for the Kp,Dp,Qa-2, Tla.3, and Tla.5 molecules. Images PMID:2991930

  16. Introgression from domestic goat generated variation at the major histocompatibility complex of Alpine ibex.

    PubMed

    Grossen, Christine; Keller, Lukas; Biebach, Iris; Croll, Daniel

    2014-06-01

    The major histocompatibility complex (MHC) is a crucial component of the vertebrate immune system and shows extremely high levels of genetic polymorphism. The extraordinary genetic variation is thought to be ancient polymorphisms maintained by balancing selection. However, introgression from related species was recently proposed as an additional mechanism. Here we provide evidence for introgression at the MHC in Alpine ibex (Capra ibex ibex). At a usually very polymorphic MHC exon involved in pathogen recognition (DRB exon 2), Alpine ibex carried only two alleles. We found that one of these DRB alleles is identical to a DRB allele of domestic goats (Capra aegagrus hircus). We sequenced 2489 bp of the coding and non-coding regions of the DRB gene and found that Alpine ibex homozygous for the goat-type DRB exon 2 allele showed nearly identical sequences (99.8%) to a breed of domestic goats. Using Sanger and RAD sequencing, microsatellite and SNP chip data, we show that the chromosomal region containing the goat-type DRB allele has a signature of recent introgression in Alpine ibex. A region of approximately 750 kb including the DRB locus showed high rates of heterozygosity in individuals carrying one copy of the goat-type DRB allele. These individuals shared SNP alleles both with domestic goats and other Alpine ibex. In a survey of four Alpine ibex populations, we found that the region surrounding the DRB allele shows strong linkage disequilibria, strong sequence clustering and low diversity among haplotypes carrying the goat-type allele. Introgression at the MHC is likely adaptive and introgression critically increased MHC DRB diversity in the genetically impoverished Alpine ibex. Our finding contradicts the long-standing view that genetic variability at the MHC is solely a consequence of ancient trans-species polymorphism. Introgression is likely an underappreciated source of genetic diversity at the MHC and other loci under balancing selection.

  17. Major histocompatibility complex class II genetic variation in forest musk deer (Moschus berezovskii) in China.

    PubMed

    Yao, Gang; Zhu, Ying; Wan, Qiu-Hong; Fang, Sheng-Guo

    2015-10-01

    The major histocompatibility complex (MHC) plays an important role in the immune system of vertebrates. We used the second exon of four MHC class II genes (DRA, DQA1, DQA2 and DRB3) to assess the overall MHC variation in forest musk deer (Moschus berezovskii). We also compared the MHC variation in captive and wild populations. We observed 22 alleles at four loci (four at DRA, four at DQA1, four at DQA2 and 10 at DRB3), 15 of which were newly identified alleles. Results suggest that forest musk deer maintain relatively high MHC variation, which may result from balancing selection. Moreover, considerable diversity was observed at the DRA locus. We found a high frequency of Mobe-DRA*02, Mobe-DQA1*01 and Mobe-DQA2*05 alleles, which may be important for pathogen resistance. A Ewens-Watterson test showed that the DRB3 locus in the wild population had experienced recent balancing selection. We detected a small divergence at the DRA locus, suggesting the effect of weak positive selection on the DRA gene. Alternatively, this locus may be young and not yet adapted a wide spectrum of alleles for pathogen resistance. The significant heterozygosity deficit observed at the DQA1 and DRB3 loci in the captive population and at all four loci in the wild population may be the result of a population bottleneck. Additionally, MHC genetic diversity was higher in the wild population than in the captive, suggesting that the wild population may have the ability to respond to a wider range of pathogens.

  18. Major histocompatibility complex alleles associated with parasite susceptibility in wild giant pandas

    PubMed Central

    Zhang, L; Wu, Q; Hu, Y; Wu, H; Wei, F

    2015-01-01

    Major histocompatibility complex (MHC) polymorphism is thought to be driven by antagonistic coevolution between pathogens and hosts, mediated through either overdominance or frequency-dependent selection. However, investigations under natural conditions are still rare for endangered mammals which often exhibit depleted variation, and the mechanism of selection underlying the maintenance of characteristics remains a considerable debate. In this study, 87 wild giant pandas were used to investigate MHC variation associated with parasite load. With the knowledge of the MHC profile provided by the genomic data of the giant panda, seven DRB1, seven DQA1 and eight DQA2 alleles were identified at each single locus. Positive selection evidenced by a significantly higher number of non-synonymous substitutions per non-synonymous codon site relative to synonymous substitutions per synonymous codon site could only be detected at the DRB1 locus, which leads to the speculation that DRB1 may have a more important role in dealing with parasite infection for pandas. Coprological analyses revealed that 55.17% of individuals exhibited infection with 1–2 helminthes and 95.3% of infected pandas carried Baylisascaris shroederi. Using a generalized linear model, we found that Aime-DRB1*10 was significantly associated with parasite infection, but no resistant alleles could be detected. MHC heterozygosity of the pandas was found to be uncorrelated with the infection status or the infection intensity. These results suggested that the possible selection mechanisms in extant wild pandas may be frequency dependent rather than being determined by overdominance selection. Our findings could guide the candidate selection for the ongoing reintroduction or translocation of pandas. PMID:25248466

  19. Major histocompatibility complex (MHC) variation in the endangered Mexican wolf and related canids.

    PubMed

    Hedrick, P W; Lee, R N; Parker, K M

    2000-12-01

    We have examined in Mexican wolves and related canids the amount of genetic variation for a class II gene in the major histocompatibility complex (MHC), thought to be part of the most important genetic basis for pathogen resistance in vertebrates. In Mexican wolves, descended from only seven founders over three lineages, there were five different alleles. These were in three phylogenetic groups, only one of which was shared between lineages. Using single stand conformation polymorphism (SSCP), we found that in samples of animals from the two polymorphic lineages, the observed heterozygosity was 0.74 and the genotypes were not different statistically from Hardy-Weinberg proportions. The Ghost Ranch lineage of Mexican wolves was monomorphic for the locus, consistent with the lower level of variation found previously for microsatellite loci and predicted from pedigree analysis. Samples of grey wolves, red wolves, and coyotes had 16 additional alleles. One Mexican wolf allele was also found in grey wolves and another allele was shared between grey and red wolves. Most of the nucleotide variation resulted in amino acid variation and there were five different amino acids found at two different positions. Only two of the 21 variable amino acid positions had solely synonymous nucleotide variation. The average heterozygosity for eight individual amino acid positions in the Mexican wolves was greater than 0.4. The estimated rate of nonsynonymous substitution was 2.5 times higher than that for synonymous substitution for the putative antigen binding site positions, indicative of positive selection acting on these positions. Examination of the known dog sequences for this locus showed that one of the Mexican wolf alleles was found in dogs and that the allele found in both grey and red wolves is also found in dogs.

  20. Major histocompatibility complex variation in red wolves: evidence for common ancestry with coyotes and balancing selection.

    PubMed

    Hedrick, P W; Lee, R N; Garrigan, D

    2002-10-01

    We examined variation at a class II major histocompatibility complex (MHC) gene (DRB1) in the captive red wolf population and samples of coyotes from Texas and North Carolina. We found 4 alleles in the 48 red wolves, 8 alleles in the 10 coyotes from Texas and 15 alleles in the 29 coyotes from North Carolina. Two of the four alleles found in red wolves, Caru-2 and Caru-4, were found in both the Texas and North Carolina coyote samples. Allele Caru-1, previously found in gray wolves, was also found in the North Carolina sample. The most frequent red wolf allele, Caru-3, was not found in any of the coyote samples. However, an allele found in both the Texas and North Carolina coyote samples is only one nucleotide (one amino acid) different from this red wolf allele. Overall, it appears from examination of this MHC gene that red wolves are more closely related to coyotes than to gray wolves. There were a number of different types of evidence supporting the action of balancing selection in red wolves. Namely, there was: (i) an excess of heterozygotes compared with expectations; (ii) a higher rate of nonsynonymous than synonymous substitution for the functionally important antigen-binding site positions; (iii) an eight times higher average heterozygosity of individual amino acids at the positions identified as part of the antigen-binding site than those not associated with it; (iv) the amino acid divergence of four red wolf alleles was greater than that expected from a simulation of genetic drift; and (v) the distribution of alleles, and the distributions of amino acids at many positions were more even than expected from neutrality. Examination of the level and pattern of linkage disequilibria between pairs of sites suggest that the heterozygosity, substitution and frequencies at individual amino acids are not highly dependent upon each other.

  1. Binding of a soluble alpha beta T-cell receptor to superantigen/major histocompatibility complex ligands.

    PubMed Central

    Kappler, J; White, J; Kozono, H; Clements, J; Marrack, P

    1994-01-01

    The genes for the alpha and beta chains of a murine T-cell receptor were truncated just prior to the portions encoding the transmembrane regions and introduced into baculovirus by recombination. Insect cells infected with the virus secreted a soluble form of the receptor that could be purified to homogeneity. This soluble receptor reacted with a set of six monoclonal antibodies originally raised to different epitopes on the natural transmembrane-region-containing receptor and bound with appropriate specificity to a cell surface complex of the human major histocompatibility complex class II molecule DR1 with the bacterial superantigen staphylococcal enterotoxin B. Images PMID:8078904

  2. Major Histocompatibility Complex Class I Chain-Related A (MICA) Molecules: Relevance in Solid Organ Transplantation

    PubMed Central

    Baranwal, Ajay Kumar; Mehra, Narinder K.

    2017-01-01

    An ever growing number of reports on graft rejection and/or failure even with good HLA matches have highlighted an important role of non-HLA antigens in influencing allograft immunity. The list of non-HLA antigens that have been implicated in graft rejection in different types of organ transplantation has already grown long. Of these, the Major Histocompatibility Complex class I chain-related molecule A (MICA) is one of the most polymorphic and extensively studied non-HLA antigenic targets especially in the kidney transplantation. Humoral response to MICA antigens has repeatedly been associated with lower graft survival and an increased risk of acute and chronic rejection following kidney and liver transplantation with few studies showing conflicting results. Although there are clear indications of MICA antibodies being associated with adverse graft outcome, a definitive consensus on this relationship has not been arrived yet. Furthermore, only a few studies have dealt with the impact of MICA donor-specific antibodies as compared to those that are not donor specific on graft outcome. In addition to the membrane bound form, a soluble isoform of MICA (sMICA), which has the potential to engage the natural killer cell-activating receptor NKG2D resulting in endocytosis and degradation of receptor–ligand interaction complex leading to suppression of NKG2D-mediated host innate immunity, has been a subject of intense discussion. Most studies on sMICA have been directed toward understanding their influence on tumor growth, with limited literature focusing its role in transplant biology. Furthermore, a unique dimorphism (methionine to valine) at position 129 in the α2 domain categorizes MICA alleles into strong (MICA-129 met) and weak (MICA-129 val) binders of NKG2D receptor depending on whether they have methionine or valine at this position. Although the implications of MICA 129 dimorphism have been highlighted in hematopoietic stem cell transplantation, its role in

  3. Adaptive molecular evolution of the Major Histocompatibility Complex genes, DRA and DQA, in the genus Equus

    PubMed Central

    2011-01-01

    Background Major Histocompatibility Complex (MHC) genes are central to vertebrate immune response and are believed to be under balancing selection by pathogens. This hypothesis has been supported by observations of extremely high polymorphism, elevated nonsynonymous to synonymous base pair substitution rates and trans-species polymorphisms at these loci. In equids, the organization and variability of this gene family has been described, however the full extent of diversity and selection is unknown. As selection is not expected to act uniformly on a functional gene, maximum likelihood codon-based models of selection that allow heterogeneity in selection across codon positions can be valuable for examining MHC gene evolution and the molecular basis for species adaptations. Results We investigated the evolution of two class II MHC genes of the Equine Lymphocyte Antigen (ELA), DRA and DQA, in the genus Equus with the addition of novel alleles identified in plains zebra (E. quagga, formerly E. burchelli). We found that both genes exhibited a high degree of polymorphism and inter-specific sharing of allele lineages. To our knowledge, DRA allelic diversity was discovered to be higher than has ever been observed in vertebrates. Evidence was also found to support a duplication of the DQA locus. Selection analyses, evaluated in terms of relative rates of nonsynonymous to synonymous mutations (dN/dS) averaged over the gene region, indicated that the majority of codon sites were conserved and under purifying selection (dN

  4. A complete DNA sequence map of the ovine Major Histocompatibility Complex

    PubMed Central

    2010-01-01

    Background The ovine Major Histocompatibility Complex (MHC) harbors clusters of genes involved in overall resistance/susceptibility of an animal to infectious pathogens. However, only a limited number of ovine MHC genes have been identified and no adequate sequence information is available, as compared to those of swine and bovine. We previously constructed a BAC clone-based physical map that covers entire class I, class II and class III region of ovine MHC. Here we describe the assembling of a complete DNA sequence map for the ovine MHC by shotgun sequencing of 26 overlapping BAC clones. Results DNA shotgun sequencing generated approximately 8-fold genome equivalent data that were successfully assembled into a finished sequence map of the ovine MHC. The sequence map spans approximately 2,434,000 nucleotides in length, covering almost all of the MHC loci currently known in the sheep and cattle. Gene annotation resulted in the identification of 177 protein-coding genes/ORFs, among which 145 were not previously reported in the sheep, and 10 were ovine species specific, absent in cattle or other mammals. A comparative sequence analyses among human, sheep and cattle revealed a high conservation in the MHC structure and loci order except for the class II, which were divided into IIa and IIb subregions in the sheep and cattle, separated by a large piece of non-MHC autosome of approximately 18.5 Mb. In addition, a total of 18 non-protein-coding microRNAs were predicted in the ovine MHC region for the first time. Conclusion An ovine MHC DNA sequence map was successfully assembled by shotgun sequencing of 26 overlapping BAC clone. This makes the sheep the second ruminant species for which the complete MHC sequence information is available for evolution and functional studies, following that of the bovine. The results of the comparative analysis support a hypothesis that an inversion of the ancestral chromosome containing the MHC has shaped the MHC structures of ruminants

  5. Polarisation of major histocompatibility complex II host genotype with pathogenesis of European Brown Hare syndrome virus.

    PubMed

    Iacovakis, Christos; Mamuris, Zissis; Moutou, Katerina A; Touloudi, Antonia; Hammer, Anne Sofie; Valiakos, George; Giannoulis, Themis; Stamatis, Costas; Spyrou, Vassiliki; Athanasiou, Labrini V; Kantere, Maria; Asferg, Tommy; Giannakopoulos, Alexios; Salomonsen, Charlotte M; Bogdanos, Dimitrios; Birtsas, Periklis; Petrovska, Liljana; Hannant, Duncan; Billinis, Charalambos

    2013-01-01

    A study was conducted in order to determine the occurrence of European Brown Hare Syndrome virus (EBHSV) in Denmark and possible relation between disease pathogenesis and Major Histocompatibility Complex (MHC) host genotype. Liver samples were examined from 170 brown hares (hunted, found sick or dead), collected between 2004 and 2009. Macroscopical and histopathological findings consistent with EBHS were detected in 24 (14.1%) hares; 35 (20.6%) had liver lesions not typical of the syndrome, 50 (29.4%) had lesions in other tissues and 61 (35.9%) had no lesions. Sixty five (38.2%) of 170 samples were found to be EBHSV-positive (RT-PCR, VP60 gene). In order to investigate associations between viral pathogenesis and host genotype, variation within the exon 2 DQA gene of MHC was assessed. DQA exon 2 analysis revealed the occurrence of seven different alleles in Denmark. Consistent with other populations examined so far in Europe, observed heterozygosity of DQA (H o = 0.1180) was lower than expected (H e = 0.5835). The overall variation for both nucleotide and amino acid differences (2.9% and 14.9%, respectively) were lower in Denmark than those assessed in other European countries (8.3% and 16.9%, respectively). Within the peptide binding region codons the number of nonsynonymous substitutions (dN) was much higher than synonymous substitutions (dS), which would be expected for MHC alleles under balancing selection. Allele frequencies did not significantly differ between EBHSV-positive and -negative hares. However, allele Leeu-DQA*30 was detected in significantly higher (P = 0.000006) frequency among the positive hares found dead with severe histopathological lesions than among those found sick or apparently healthy. In contrast, the latter group was characterized by a higher frequency of the allele Leeu-DQA*14 as well as the proportion of heterozygous individuals (P = 0.000006 and P = 0.027). These data reveal a polarisation between EBHSV

  6. Resistance, susceptibility, and immunity to Eimeria tenella in major histocompatibility (B) complex congenic lines.

    PubMed

    Caron, L A; Abplanalp, H; Taylor, R L

    1997-05-01

    The major histocompatibility (B) complex influence on resistance, susceptibility, and immunity to Eimeria tenella was examined in UCD B complex congenic chicken lines. In Experiment 1, 6-wk-old chicks from 12 UCD congenic lines were weighed and assigned to either challenge or control groups. The challenge group received a dose of 10,000 E. tenella oocysts. Response to challenge was evaluated by body weight gain and cecal lesion scores. Cecal lesion scores in B3B3 chickens were significantly lower than those of all other genotypes. Genotype B2B2 had the highest lesion scores, which were significantly different from the lesion scores calculated for B3B3, B18B18, and B21B21 chickens but were not significantly different from B14B14, B15B15, B17B17, B19B19, B24B24, BCBC, BJBJ, and BQBQ genotypes. The B21B21 chickens had significantly lower lesion scores than B2B2, B14B14, and BCBC chickens. No other significant lesion score differences were found among the remaining lines. The highest weight gain found in B19B19 chickens was significantly different from that of B3B3, B14B14, B15B15, B17B17, B18B18, B24B24, and BCBC chickens. The B15B15 chickens had the lowest weight gain, which was significantly different from that of B2B2, B19B19, B21B21, B24B24, BJBJ, and BQBQ chickens. Experiment 2 tested the immune response to E. tenella after low dose oocyst immunization. Chicks from 10 UCD 003 congenic lines were divided into three groups: control, challenge, and immune. At 5 wk of age, the immune group was immunized with 500 E. tenella oocysts for 5 consecutive d. Fourteen days after the last immunization all chicks were weighed, and 10,000 E. tenella oocysts were administered to the challenge and immune groups. Significant lesion score differences existed among all three treatments: control (0), immune (2.14 +/- 0.1); challenge (3.13 +/- 0.1). Among immune birds, B3B3 and BQBQ chickens had significantly lower lesion scores than B19B19, B24B24, B14B14, and B2B2 chickens. Neither

  7. Reassociation with beta 2-microglobulin is necessary for Kb class I major histocompatibility complex binding of exogenous peptides.

    PubMed Central

    Rock, K L; Rothstein, L E; Gamble, S R; Benacerraf, B

    1990-01-01

    T lymphocytes recognize endogenously produced antigenic peptides in association with major histocompatibility complex (MHC)-encoded molecules. Peptides from the extracellular fluid can be displayed in association with class I and class II MHC molecules. Here we report that mature Kb class I MHC molecules bind peptides upon dissociation and reassociation of their light chain. Intact Kb heterodimers, unlike class II MHC molecules, are relatively unreceptive to binding peptides. This property may maintain segregation of class I and class II MHC-restricted peptides and has implications for the use of peptides as vaccines. Images PMID:2217182

  8. Allele-dependent recombination frequency: homology requirement in meiotic recombination at the hot spot in the mouse major histocompatibility complex.

    PubMed

    Yoshino, M; Sagai, T; Lindahl, K F; Toyoda, Y; Moriwaki, K; Shiroishi, T

    1995-05-20

    Meiotic recombination break joints in the mouse major histocompatibility complex (MHC) are clustered within short segments known as hot spots. We systematically investigated the requirement for sequence homology between two chromosomes for recombination activity at the hot spot next to the Lmp2 gene. The results indicated that a high rate of recombination required a high degree of similarity of overall genome structure at the hot spot. In particular, the same copy number of repetitive sequences within the hot spot was essential for a high frequency of recombination, suggesting that recombination in mouse meiosis is more sensitive to heterozygous deletion or insertion of DNA than to mismatches of single-base substitutions.

  9. A Simple and Rapid Method for Quality Control of Major Histocompatibility Complex-Peptide Monomers by Flow Cytometry.

    PubMed

    Chandran, P Anoop; Heidu, Sonja; Zelba, Henning; Schmid-Horch, Barbara; Rammensee, Hans-Georg; Pascolo, Steve; Gouttefangeas, Cécile

    2017-01-01

    Major histocompatibility complex (MHC) multimers are essential tools in T cell immunomonitoring, which are employed both in basic and clinical research, as well as for assessing clinical samples during therapy. The generation of MHC monomers loaded with synthetic peptides is an elaborate and time-consuming process. It would be beneficial to assess the quality of these monomers prior to downstream applications. In this technical note, we describe a novel flow cytometry-based, cell-free, quick, and robust assay to check the quality of MHC monomers directly after refolding or after long-term storage.

  10. The DQB1 *03:02 HLA haplotype is associated with increased risk of chronic pain after inguinal hernia surgery and lumbar disc herniation.

    PubMed

    Dominguez, Cecilia A; Kalliomäki, Maija; Gunnarsson, Ulf; Moen, Aurora; Sandblom, Gabriel; Kockum, Ingrid; Lavant, Ewa; Olsson, Tomas; Nyberg, Fred; Rygh, Lars Jørgen; Røe, Cecilie; Gjerstad, Johannes; Gordh, Torsten; Piehl, Fredrik

    2013-03-01

    Neuropathic pain conditions are common after nerve injuries and are suggested to be regulated in part by genetic factors. We have previously demonstrated a strong genetic influence of the rat major histocompatibility complex on development of neuropathic pain behavior after peripheral nerve injury. In order to study if the corresponding human leukocyte antigen complex (HLA) also influences susceptibility to pain, we performed an association study in patients that had undergone surgery for inguinal hernia (n=189). One group had developed a chronic pain state following the surgical procedure, while the control group had undergone the same type of operation, without any persistent pain. HLA DRB1genotyping revealed a significantly increased proportion of patients in the pain group carrying DRB1*04 compared to patients in the pain-free group. Additional typing of the DQB1 gene further strengthened the association; carriers of the DQB1*03:02 allele together with DRB1*04 displayed an increased risk of postsurgery pain with an odds risk of 3.16 (1.61-6.22) compared to noncarriers. This finding was subsequently replicated in the clinical material of patients with lumbar disc herniation (n=258), where carriers of the DQB1*03:02 allele displayed a slower recovery and increased pain. In conclusion, we here for the first time demonstrate that there is an HLA-dependent risk of developing pain after surgery or lumbar disc herniation; mediated by the DRB1*04 - DQB1*03:02 haplotype. Further experimental and clinical studies are needed to fine-map the HLA effect and to address underlying mechanisms.

  11. Characterization of class I- and class II-like major histocompatibility complex loci in pedigrees of North Atlantic right whales.

    PubMed

    Gillett, Roxanne M; Murray, Brent W; White, Bradley N

    2014-01-01

    North Atlantic right whales have one of the lowest levels of genetic variation at minisatellite loci, microsatellite loci, and mitochondrial control region haplotypes among mammals. Here, adaptive variation at the peptide binding region of class I and class II DRB-like genes of the major histocompatibility complex was assessed. Amplification of a duplicated region in 222 individuals revealed at least 11 class II alleles. Six alleles were assigned to the locus Eugl-DRB1 and 5 alleles were assigned to the locus Eugl-DRB2 by assessing segregation patterns of alleles from 81 parent/offspring pedigrees. Pedigree analysis indicated that these alleles segregated into 12 distinct haplotypes. Genotyping a smaller subset of unrelated individuals (n = 5 and 10, respectively) using different primer sets revealed at least 2 class II pseudogenes (with ≥ 4 alleles) and at least 3 class I loci (with ≥ 6 alleles). Class II sequences were significantly different from neutrality at peptide binding sites suggesting loci may be under the influence of balancing selection. Trans-species sharing of alleles was apparent for class I and class II sequences. Characterization of class II loci represents the first step in determining the relationship between major histocompatibility complex variability and factors affecting health and reproduction in this species.

  12. Clarifying the association of genes within the major histocompatibility complex with narcolepsy

    SciTech Connect

    Acton, R.T.; Watson, B.; Rivers, C.

    1994-09-01

    HLA-DR2 and DQwl has been reported to be strongly associated with narcolepsy. The particular phenotype and strength of these associations varies between races. For example DQB*0601 has been reported associated with some African American (AA) narcoleptics while some Caucasian American (CA) narcoleptics do not possess DR2 or DQw1. We have sought to clarify the relationship of MHC genes with narcolepsy in the local CA and AA population. There was no significant difference in the frequency of DR phenotypes in CA or AA narcoleptics compared to race, age, sex and geographic region-matched controls. DR2 was increased in CA cataplexy positive (Cat+) narcoleptics compared to controls (p=0.028, odds ratio (OR)=2.4) and to Cat- narcoleptics (p=<0.001, OR=8.8). DR11 was increased in AA Cat+ narcoleptics compared to controls (p=0.004, OR=11.2) and to Cat- narcoleptics (p=0.002). DQB1*0601 was not significantly associated with narcolepsy in our AA population. We have assessed the frequency of the TNFa (13 alleles, 1.1Mb telomeric to DQ{alpha}), D6S105 (13 alleles, 1kb telomeric of HLA-A), and GLP-1R (19 alleles, 18.5 Mb centromeric of DQ{alpha}), dinucleotide repeats in narcoleptics compared to controls. The TNFa allele 117 was increased in CA Cat+ vs. controls (p=0.003). The GLP-1R allele 144 was increased in CA Cat- vs. controls (p=0.02). In AA narcoleptics, the TNFa allele 109 was significantly increased (p=0.04) along with the D6S105 allele 130 (p=0.02) compared to controls. The D6S105 allele 130 was increased in AA Cat- vs. controls (p=0.03). The GLP-1R allele 154 was significantly decreased in AA Cat+ vs. Cat- (p=0.04). These data suggest that DR and/or DQ genes are not responsible for narcolepsy and that cataplexy is associated with different regions around the MHC in various racial groups.

  13. Crystal structure of staphylococcal enterotoxin I (SEI) in complex with a human major histocompatibility complex class II molecule.

    PubMed

    Fernández, Marisa M; Guan, Rongjin; Swaminathan, Chittoor P; Malchiodi, Emilio L; Mariuzza, Roy A

    2006-09-01

    Superantigens are bacterial or viral proteins that elicit massive T cell activation through simultaneous binding to major histocompatibility complex (MHC) class II and T cell receptors. This activation results in uncontrolled release of inflammatory cytokines, causing toxic shock. A remarkable property of superantigens, which distinguishes them from T cell receptors, is their ability to interact with multiple MHC class II alleles independently of MHC-bound peptide. Previous crystallographic studies have shown that staphylococcal and streptococcal superantigens belonging to the zinc family bind to a high affinity site on the class II beta-chain. However, the basis for promiscuous MHC recognition by zinc-dependent superantigens is not obvious, because the beta-chain is polymorphic and the MHC-bound peptide forms part of the binding interface. To understand how zinc-dependent superantigens recognize MHC, we determined the crystal structure, at 2.0 A resolution, of staphylococcal enterotoxin I bound to the human class II molecule HLA-DR1 bearing a peptide from influenza hemagglutinin. Interactions between the superantigen and DR1 beta-chain are mediated by a zinc ion, and 22% of the buried surface of peptide.MHC is contributed by the peptide. Comparison of the staphylococcal enterotoxin I.peptide.DR1 structure with ones determined previously revealed that zinc-dependent superantigens achieve promiscuous binding to MHC by targeting conservatively substituted residues of the polymorphic beta-chain. Additionally, these superantigens circumvent peptide specificity by engaging MHC-bound peptides at their conformationally conserved N-terminal regions while minimizing sequence-specific interactions with peptide residues to enhance cross-reactivity.

  14. Diversity and duplication of DQB and DRB-like genes of the MHC in baleen whales (suborder: Mysticeti).

    PubMed

    Baker, C S; Vant, M D; Dalebout, M L; Lento, G M; O'Brien, S J; Yuhki, N

    2006-05-01

    The molecular diversity and phylogenetic relationships of two class II genes of the baleen whale major histocompatibility complex were investigated and compared to toothed whales and out-groups. Amplification of the DQB exon 2 provided sequences showing high within-species and between-species nucleotide diversity and uninterrupted reading frames consistent with functional class II loci found in related mammals (e.g., ruminants). Cloning of amplified products indicated gene duplication in the humpback whale and triplication in the southern right whale, with average nucleotide diversity of 5.9 and 6.3%, respectively, for alleles of each species. Significantly higher nonsynonymous divergence at sites coding for peptide binding (32% for humpback and 40% for southern right) suggested that these loci were subject to positive (overdominant) selection. A population survey of humpback whales detected 23 alleles, differing by up to 21% of their inferred amino acid sequences. Amplification of the DRB exon 2 resulted in two groups of sequences. One was most similar to the DRB3 of the cow and present in all whales screened to date, including toothed whales. The second was most similar to the DRB2 of the cow and was found only in the bowhead and right whales. Both loci showed low diversity among species and apparent loss of function or altered function including interruption of reading frames. Finally, comparison of inferred protein sequence of the DRB3-like locus suggested convergence with the DQB, perhaps resulting from intergenic conversion or recombination.

  15. Specific suppression of major histocompatibility complex class I and class II genes in astrocytes by brain-enriched gangliosides

    PubMed Central

    1993-01-01

    The effect of brain-enriched gangliosides on constitutive and cytokine- inducible expression of major histocompatibility complex (MHC) class I and II genes in cultured astrocytes was studied. Before treatment with gangliosides, astrocytes expressed constitutive MHC class I but not class II molecules, however, the expression of both MHC class I and II cell surface molecules on astrocytes was induced to high levels by interferon gamma (IFN-gamma). Constitutive and IFN-gamma-inducible expression of MHC class I and II molecules was suppressed by treatment of astrocytes with exogenous bovine brain gangliosides in a dose- dependent manner. Constitutive and induced MHC class I and II mRNA levels were also suppressed by gangliosides, indicating control through transcriptional mechanisms. This was consistent with the ability of gangliosides to suppress the binding activity of transcription factors, especially NF-kappa B-like binding activity, important for the expression of both MHC class I and II genes. These studies may be important for understanding mechanisms of central nervous system (CNS)- specific regulation of major histocompatibility molecules in neuroectodermal cells and the role of gangliosides in regulating MHC- restricted antiviral and autoimmune responses within the CNS. PMID:8376939

  16. Reassociation with beta 2-microglobulin is necessary for Db class I major histocompatibility complex binding of an exogenous influenza peptide.

    PubMed Central

    Rock, K L; Gamble, S; Rothstein, L; Benacerraf, B

    1991-01-01

    A synthetic peptide corresponding to residues 365-380 of the influenza nucleoprotein (NP365-380) has been previously shown to associate with class I major histocompatibility complex-encoded molecules and to stimulate cytotoxic T lymphocytes [Townsend, A. R. M., Rothbard, J., Gotch, F. M., Bahadur, G., Wraith, D. & McMichael, A. J. (1986) Cell 44, 959-968]. We find that intact Db class I heterodimers on the cell surface are unreceptive to binding this antigen. However, NP365-380 readily associates with Db molecules on the plasma membrane in the presence of exogenous beta 2-microglobulin. In addition, there is a second pathway through which this peptide associates with class I molecules that requires energy and de novo protein synthesis. These findings have implications for maintaining the immunological identity of cells and for the use of peptides as vaccines for priming cytolytic T-cell immunity. Images PMID:1986378

  17. Identification and characterization of major histocompatibility complex class IIB alleles from three species of European ranid frogs

    PubMed Central

    A. Marosi, Béla; M. Kiemnec-Tyburczy, Karen; V. Ghira, Ioan; Sos, Tibor; Popescu, Octavian

    2014-01-01

    Immune genes of the major histocompatibility complex (MHC) are among the most polymorphic genes in the vertebrate genome. Due to their polymorphic nature, they are often used to assess the adaptive genetic variability of natural populations. This study describes the first molecular characterization of 13 partial MHC class IIB sequences from three European ranid frogs. The utility of previously published primers was expanded by using them to successfully amplify eight exon 2 alleles from Rana arvalis.We also designed a novel primer set that successfully amplified exon 2 from Pelophylax kurtmuelleri. Pelophylax lessonae was also designed as part of this study. Results indicate the presence of one or two class IIB loci in these three species. In R. arvalis, significant evidence of positive selection acting on MHC antigen binding sites was found. Many European ranid populations are experiencing disease-related declines; the newly developed primers can, therefore, be used for further population analyses of native frogs. PMID:27843985

  18. Data on genetic analysis of atherosclerosis identifies a major susceptibility locus in the major histocompatibility complex of mice.

    PubMed

    Grainger, Andrew T; Jones, Michael B; Li, Jing; Chen, Mei-Hua; Manichaikul, Ani; Shi, Weibin

    2016-12-01

    The data presented here are related to the research article, entitled Genetic analysis of atherosclerosis identifies a major susceptibility locus in the major histocompatibility complex of mice, published in Atherosclerosis 2016;254:124 (A.T. Grainger, M.B. Jones, J. Li, M.H. Chen, A. Manichaikul, W. Shi, 2016) [1]. The supporting materials include original genotypic and phenotypic data obtained from 206 female F2 mice derived from an intercross between BALB and SMJ inbred mice. The F2 mice were fed 12 weeks of Western diet, starting at 6 weeks of age. Atherosclerotic lesion size in the aortic root of each mouse is the sum of the top 8 lesion areas. The data is provided in the format required for determining QTLs using two independent programs, J/QTL and PLINK.

  19. Extensive polymorphism of the major histocompatibility complex DRA gene in Balkan donkeys: perspectives on selection and genealogy.

    PubMed

    Arbanasić, Haidi; Galov, Ana; Ambriović-Ristov, Andreja; Grizelj, Juraj; Arsenos, Georgios; Marković, Božidarka; Dovenski, Toni; Vince, Silvijo; Curik, Ino

    2013-12-01

    The major histocompatibility complex (MHC) contains genes important for immune response in mammals, and these genes exhibit high polymorphism and diversity. The DRA gene, a member of the MHC class II family, is highly conserved across a large number of mammalian species, but it displays exceptionally rich sequence variations in Equidae members. We analyzed allelic polymorphism of the DRA locus in 248 donkeys sampled across the Balkan Peninsula (Albania, Bulgaria, Croatia, Macedonia, Greece and Montenegro). Five known alleles and two new alleles were identified. The new allele Eqas-DRA*0601 was found to carry a synonymous mutation, and new allele Eqas-DRA*0701, a non-synonymous mutation. We further analyzed the historical selection and allele genealogy at the DRA locus in equids. Signals of positive selection obtained by various tests were ambiguous. A conservative conclusion is that DRA polymorphism occurred relatively recently and that positive selection has been acting on the DRA locus for a relatively brief period.

  20. Low major histocompatibility complex diversity in the Tasmanian devil predates European settlement and may explain susceptibility to disease epidemics.

    PubMed

    Morris, Katrina; Austin, Jeremy J; Belov, Katherine

    2013-02-23

    The Tasmanian devil (Sarcophilus harrisii) is at risk of extinction owing to the emergence of a contagious cancer known as devil facial tumour disease (DFTD). The emergence and spread of DFTD has been linked to low genetic diversity in the major histocompatibility complex (MHC). We examined MHC diversity in historical and ancient devils to determine whether loss of diversity is recent or predates European settlement in Australia. Our results reveal no additional diversity in historical Tasmanian samples. Mainland devils had common modern variants plus six new variants that are highly similar to existing alleles. We conclude that low MHC diversity has been a feature of devil populations since at least the Mid-Holocene and could explain their tumultuous history of population crashes.

  1. B-lymphoma cells process and present their endogenous immunoglobulin to major histocompatibility complex-restricted T cells.

    PubMed Central

    Weiss, S; Bogen, B

    1989-01-01

    Antigen-presenting B-lymphoma cells were transfected with the gene encoding the immunoglobulin lambda 2 light chain of MOPC315 cells (lambda 2(315). The lambda 2 chain is expressed on the cell surface of the transfectants together with the endogenous heavy chain. The transfectants present an idiotope of the lambda 2(315) light chain to class II-restricted T-cell clones. Recognition by the T cells requires processing of the lambda 2(315) light chain. From these data we conclude that B-lymphoma cells constitutively process and present their immunoglobulins. Secretion and reuptake of the light chain was not necessary for the presentation. Thus, B cells bear two types of idiotypes on their membrane, a native form as surface immunoglobulin and a processed form in the context of products of the major histocompatibility complex. Images PMID:2492101

  2. Evolution of the major histocompatibility complex: isolation of class II A cDNA clones from the cartilaginous fish.

    PubMed Central

    Kasahara, M; Vazquez, M; Sato, K; McKinney, E C; Flajnik, M F

    1992-01-01

    Along with the T-cell receptor and immunoglobulin, the major histocompatibility complex (MHC) plays a key role in mounting immune responses to foreign antigen. To gain insights into the evolution of the MHC, class II A cDNA clones were isolated from nurse sharks, a member of the class of cartilaginous fish. Two closely related cDNA clones, which might encode allelic products, were identified; of the three amino acid substitutions found in the alpha 1 domain, two were located at positions postulated to interact with processed peptides. The deduced nurse shark MHC class II alpha chains showed conspicuous structural similarity to their mammalian counterparts. Isolation of cDNA clones encoding typical MHC class II alpha chains was unexpected since no direct evidence for T-cell-mediated immune responses has been obtained in the cartilaginous fish. The cartilaginous fish is phylogenetically the most primitive class of vertebrates from which any MHC gene has been isolated. PMID:1495958

  3. Facial Nerve Recovery in KbDb and C1q Knockout Mice: A Role for Histocompatibility Complex 1

    PubMed Central

    Akdagli, Seden; Williams, Ryan A.; Kim, Hyun J.; Yan, Yuling; Mustapha, Mirna

    2016-01-01

    Background: Understanding the mechanisms in nerve damage can lead to better outcomes for neuronal rehabilitation. The purpose of our study was to assess the effect of major histocompatibility complex I deficiency and inhibition of the classical complement pathway (C1q) on functional recovery and cell survival in the facial motor nucleus (FMN) after crush injury in adult and juvenile mice. Methods: A prospective blinded analysis of functional recovery and cell survival in the FMN after a unilateral facial nerve crush injury in juvenile and adult mice was undertaken between wild-type, C1q knockout (C1q−/−), and KbDb knockout (KbDb−/−) groups. Whisker function was quantified to assess functional recovery. Neuron counts were performed to determine neuron survival in the FMN after recovery. Results: After facial nerve injury, all adult wild-type mice fully recovered. Juvenile mice recovered incompletely corresponding to a greater neuron loss in the FMN of juveniles compared with adults. The C1q−/− juvenile and adult groups did not differ from wild type. The KbDb−/− adults demonstrated 50% recovery of whisker movement and decreased cell survival in FMN. The KbDb−/− juvenile group did not demonstrate any difference from control group. Conclusion: Histocompatibility complex I plays a role for neuroprotection and enhanced facial nerve recovery in adult mice. Inhibition of the classical complement pathway alone does not affect functional recovery or neuronal survival. The alternative and mannose binding pathways pose alternative means for activating the final components of the pathway that may lead to acute nerve damage. PMID:28293529

  4. Zinc Induces Dimerization of the Class II Major Histocompatibility Complex Molecule That Leads to Cooperative Binding to a Superantigen

    SciTech Connect

    Li,H.; Zhao, Y.; Guo, Y.; Li, Z.; Eislele, L.; Mourad, W.

    2007-01-01

    Dimerization of class II major histocompatibility complex (MHC) plays an important role in the MHC biological function. Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing specific T cell receptor V{beta} elements. Here we have used structural, sedimentation, and surface plasmon resonance detection approaches to investigate the molecular interactions between MAM and the class II MHC molecule HLA-DR1 in the context of a hemagglutinin peptide-(306-318) (HA). Our results revealed that zinc ion can efficiently induce the dimerization of the HLA-DR1/HA complex. Because the crystal structure of the MAM/HLA-DR1/hemagglutinin complex in the presence of EDTA is nearly identical to the structure of the complex crystallized in the presence of zinc ion, Zn{sup 2+} is evidently not directly involved in the binding between MAM and HLA-DR1. Sedimentation and surface plasmon resonance studies further revealed that MAM binds the HLA-DR1/HA complex with high affinity in a 1:1 stoichiometry, in the absence of Zn{sup 2+}. However, in the presence of Zn{sup 2+}, a dimerized MAM/HLA-DR1/HA complex can arise through the Zn{sup 2+}-induced DR1 dimer. In the presence of Zn{sup 2+}, cooperative binding of MAM to the DR1 dimer was also observed.

  5. Expression of bovine non-classical major histocompatibility complex class 1 proteins in mouse P815 and human K562 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Major histocompatibility complex class I (MHC-I) proteins can be expressed as cell surface or secreted proteins. To investigate whether bovine non-classical MHC-I proteins are expressed as cell surface or secreted proteins, and to assess the reactivity pattern of monoclonal antibodies with non-class...

  6. Characterization, polymorphism and selection of major histocompatibility complex (MHC) DAB genes in vulnerable Chinese egret (Egretta eulophotes).

    PubMed

    Wang, Zeng; Zhou, Xiaoping; Lin, Qingxian; Fang, Wenzhen; Chen, Xiaolin

    2013-01-01

    The major histocompatibility complex (MHC) is an excellent molecular marker for the studies of evolutionary ecology and conservation genetics because it is a family of highly polymorphic genes that play a key role in vertebrate immune response. In this study, the functional genes of MHC Class II B (DAB) were isolated for the first time in a vulnerable species, the Chinese egret (Egrettaeulophotes). Using a full length DNA and cDNA produced by PCR and RACE methods, four potential MHC DAB loci were characterized in the genome of this egret and all four were expressed in liver and blood. At least four copies of the MHC gene complex were similar to two copies of the minimal essential MHC complex of chicken, but are less complex than the multiple copies expressed in passerine species. In MHC polymorphism, 19 alleles of exon 2 were isolated from 48 individuals using PCR. No stop codons or frameshift mutations were found in any of the coding regions. The signatures of positive selection detected in potential peptide-binding regions by Bayesian analysis, suggesting that all of these genes were functional. These data will provide the fundamental basis for further studies to elucidate the mechanisms and significance of MHC molecular adaptation in vulnerable Chinese egret and other ardeids.

  7. Transcription of a subset of human class II major histocompatibility complex genes is regulated by a nucleoprotein complex that contains c-fos or an antigenically related protein.

    PubMed Central

    Ono, S J; Bazil, V; Levi, B Z; Ozato, K; Strominger, J L

    1991-01-01

    Transcriptional regulation of the human major histocompatibility complex class II genes requires at least two upstream elements, the X and Y boxes, located in the -50- to -150-base-pair region of all class II promoters. The DRA and DPB promoters contain phorbol ester-responsive elements overlapping the 3' side of their X boxes. Mutation of this sequence down-regulates the efficiency of the DRA promoter, suggesting that a positive regulator(s) binds to this site. In this report, anti-sense c-fos RNA and an anti-c-fos antibody were used to show that the product of the protooncogene c-fos or an antigenically related protein is a component of a complex that binds to the X box and is required for maximal transcription from the DRA and DPB promoters. As c-fos (or its related proteins) cannot bind alone to DNA, these results suggest that it may dimerize with other members of the JUN/AP-1 family, such as hXBP1, to participate in the activation of a subset of class II major histocompatibility complex genes. Images PMID:1709740

  8. T cell receptor recognition of a 'super-bulged' major histocompatibility complex class I-bound peptide

    SciTech Connect

    Tynan, Fleur E; Burrows, Scott R; Buckle, Ashley M; Clements, Craig S; Borg, Natalie A; Miles, John J; Beddoe, Travis; Whisstock, James C; Wilce, Matthew C; Silins, Sharon L; Burrows, Jacqueline M; Kjer-Nielsen, Lars; Kostenko, Lyudmila; Purcell, Anthony W; McCluskey, James; Rossjohn, Jamie

    2010-07-20

    Unusually long major histocompatibility complex (MHC) class I-restricted epitopes are important in immunity, but their 'bulged' conformation represents a potential obstacle to {alpha}{beta} T cell receptor (TCR)-MHC class I docking. To elucidate how such recognition is achieved while still preserving MHC restriction, we have determined here the structure of a TCR in complex with HLA-B*3508 presenting a peptide 13 amino acids in length. This complex was atypical of TCR-peptide-MHC class I interactions, being dominated at the interface by peptide-mediated interactions. The TCR assumed two distinct orientations, swiveling on top of the centrally bulged, rigid peptide such that only limited contacts were made with MHC class I. Although the TCR-peptide recognition resembled an antibody-antigen interaction, the TCR-MHC class I contacts defined a minimal 'generic footprint' of MHC-restriction. Thus our findings simultaneously demonstrate the considerable adaptability of the TCR and the 'shape' of MHC restriction.

  9. Hard wiring of T cell receptor specificity for the major histocompatibility complex is underpinned by TCR adaptability

    SciTech Connect

    Burrows, Scott R.; Chen, Zhenjun; Archbold, Julia K.; Tynan, Fleur E.; Beddoe, Travis; Kjer-Nielsen, Lars; Miles, John J.; Khanna, Rajiv; Moss, Denis J.; Liu, Yu Chih; Gras, Stephanie; Kostenko, Lyudmila; Brennan, Rebekah M.; Clements, Craig S.; Brooks, Andrew G.; Purcell, Anthony W.; McCluskey, James; Rossjohn, Jamie

    2010-07-07

    {alpha}{beta} T cell receptors (TCRs) are genetically restricted to corecognize peptide antigens bound to self-major histocompatibility complex (pMHC) molecules; however, the basis for this MHC specificity remains unclear. Despite the current dogma, evaluation of the TCR-pMHC-I structural database shows that the nongermline-encoded complementarity-determining region (CDR)-3 loops often contact the MHC-I, and the germline-encoded CDR1 and -2 loops frequently participate in peptide-mediated interactions. Nevertheless, different TCRs adopt a roughly conserved docking mode over the pMHC-I, in which three MHC-I residues (65, 69, and 155) are invariably contacted by the TCR in one way or another. Nonetheless, the impact of mutations at these three positions, either individually or together, was not uniformly detrimental to TCR recognition of pHLA-B*0801 or pHLA-B*3508. Moreover, when TCR-pMHC-I recognition was impaired, this could be partially restored by expression of the CD8 coreceptor. The structure of a TCR-pMHC-I complex in which these three (65, 69, and 155) MHC-I positions were all mutated resulted in shifting of the TCR footprint relative to the cognate complex and formation of compensatory interactions. Collectively, our findings reveal the inherent adaptability of the TCR in maintaining peptide recognition while accommodating changes to the central docking site on the pMHC-I.

  10. The contribution of major histocompatibility complex contacts to the affinity and kinetics of T cell receptor binding

    PubMed Central

    Zhang, Hao; Lim, Hong-Sheng; Knapp, Berhard; Deane, Charlotte M.; Aleksic, Milos; Dushek, Omer; van der Merwe, P. Anton

    2016-01-01

    The interaction between the T cell antigen receptor (TCR) and antigenic peptide in complex with major histocompatibility complex (MHC) molecules is a crucial step in T cell activation. The relative contributions of TCR:peptide and TCR:MHC contacts to the overall binding energy remain unclear. This has important implications for our understanding of T cell development and function. In this study we used site directed mutagenesis to estimate the contribution of HLA-A2 side-chains to the binding of four TCRs. Our results show that these TCRs have very different energetic ‘footprints’ on HLA-A2, with no residues contributing to all TCR interactions. The estimated overall contribution of MHC side-chains to the total interaction energy was variable, with lower limits ranging from 11% to 50%. Kinetic analysis suggested a minor and variable contribution of MHC side-chains to the transition state complex, arguing against a two-step mechanism for TCR binding. PMID:27734930

  11. Definitions of histocompatibility typing terms.

    PubMed

    Nunes, Eduardo; Heslop, Helen; Fernandez-Vina, Marcelo; Taves, Cynthia; Wagenknecht, Dawn R; Eisenbrey, A Bradley; Fischer, Gottfried; Poulton, Kay; Wacker, Kara; Hurley, Carolyn Katovich; Noreen, Harriet; Sacchi, Nicoletta

    2011-12-01

    Histocompatibility testing for stem cell and solid organ transplantation has become increasingly complex as newly discovered HLA alleles are described. HLA typing assignments reported by laboratories are used by physicians and donor registries for matching donors and recipients. To communicate effectively, a common language for histocompatibility terms should be established. In early 2010, representatives from Clinical, Registry, and Histocompatibility organizations joined together as the Harmonization of Histocompatibility Typing Terms Working Group to define a consensual language for laboratories, physicians, and registries to communicate histocompatibility typing information. The Working Group defined terms for HLA typing resolution, HLA matching, and a format for reporting HLA assignments. In addition, definitions of verification typing and extended typing were addressed. The original draft of the Definitions of Histocompatibility Typing Terms was disseminated to colleagues from each organization to gain feedback and create a collaborative document. Commentary gathered during this 90-day review period were discussed and implemented for preparation of this report. Histocompatibility testing continues to evolve; thus, the definitions agreed on today probably will require refinement and perhaps additional terminology in the future.

  12. Cellular expression and crystal structure of the murine cytomegalovirus major histocompatibility complex class I-like glycoprotein, m153.

    PubMed

    Mans, Janet; Natarajan, Kannan; Balbo, Andrea; Schuck, Peter; Eikel, Daniel; Hess, Sonja; Robinson, Howard; Simic, Hrvoje; Jonjic, Stipan; Tiemessen, Caroline T; Margulies, David H

    2007-11-30

    Mouse cytomegalovirus (MCMV), a beta-herpesvirus that establishes latent and persistent infections in mice, is a valuable model for studying complex virus-host interactions. MCMV encodes the m145 family of putative immunoevasins with predicted major histocompatibility complex, class I (MHC-I) structure. Functions attributed to some family members include down-regulation of host MHC-I (m152) and NKG2D ligands (m145, m152, and m155) and interaction with inhibitory or activating NK receptors (m157). We present the cellular, biochemical, and structural characterization of m153, which is a heavily glycosylated homodimer, that does not require beta2m or peptide and is expressed at the surface of MCMV-infected cells. Its 2.4-A crystal structure confirms that this compact molecule preserves an MHC-I-like fold and reveals a novel mode of dimerization, confirmed by site-directed mutagenesis, and a distinctive disulfide-stabilized extended N terminus. The structure provides a useful framework for comparative analysis of the divergent members of the m145 family.

  13. Need for tripeptidyl-peptidase II in major histocompatibility complex class I viral antigen processing when proteasomes are detrimental.

    PubMed

    Guil, Sara; Rodríguez-Castro, Marta; Aguilar, Francisco; Villasevil, Eugenia M; Antón, Luis C; Del Val, Margarita

    2006-12-29

    CD8(+) T lymphocytes recognize infected cells that display virus-derived antigenic peptides complexed with major histocompatibility complex class I molecules. Peptides are mainly byproducts of cellular protein turnover by cytosolic proteasomes. Cytosolic tripeptidyl-peptidase II (TPPII) also participates in protein degradation. Several peptidic epitopes unexpectedly do not require proteasomes, but it is unclear which proteases generate them. We studied antigen processing of influenza virus nucleoprotein epitope NP(147-155), an archetype epitope that is even destroyed by a proteasome-mediated mechanism. TPPII, with the assistance of endoplasmic reticulum trimming metallo-aminopeptidases, probably ERAAP (endoplasmic reticulum aminopeptidase associated with antigen processing), was crucial for nucleoprotein epitope generation both in the presence of functional proteasomes and when blocked by lactacystin, as shown with specific chemical inhibitors and gene silencing. Different protein contexts and subcellular targeting all allowed epitope processing by TPPII as well as trimming. The results show the plasticity of the cell's assortment of proteases for providing ligands for recognition by antiviral CD8(+) T cells. Our observations identify for the first time a set of proteases competent for antigen processing of an epitope that is susceptible to destruction by proteasomes.

  14. IPD-MHC 2.0: an improved inter-species database for the study of the major histocompatibility complex.

    PubMed

    Maccari, Giuseppe; Robinson, James; Ballingall, Keith; Guethlein, Lisbeth A; Grimholt, Unni; Kaufman, Jim; Ho, Chak-Sum; de Groot, Natasja G; Flicek, Paul; Bontrop, Ronald E; Hammond, John A; Marsh, Steven G E

    2017-01-04

    The IPD-MHC Database project (http://www.ebi.ac.uk/ipd/mhc/) collects and expertly curates sequences of the major histocompatibility complex from non-human species and provides the infrastructure and tools to enable accurate analysis. Since the first release of the database in 2003, IPD-MHC has grown and currently hosts a number of specific sections, with more than 7000 alleles from 70 species, including non-human primates, canines, felines, equids, ovids, suids, bovins, salmonids and murids. These sequences are expertly curated and made publicly available through an open access website. The IPD-MHC Database is a key resource in its field, and this has led to an average of 1500 unique visitors and more than 5000 viewed pages per month. As the database has grown in size and complexity, it has created a number of challenges in maintaining and organizing information, particularly the need to standardize nomenclature and taxonomic classification, while incorporating new allele submissions. Here, we describe the latest database release, the IPD-MHC 2.0 and discuss planned developments. This release incorporates sequence updates and new tools that enhance database queries and improve the submission procedure by utilizing common tools that are able to handle the varied requirements of each MHC-group.

  15. Accumulation of Major Histocompatibility Complex Class II Molecules in Mast Cell Secretory Granules and Their Release upon Degranulation

    PubMed Central

    Raposo, Graça; Tenza, Danielle; Mecheri, Salahedine; Peronet, Roger; Bonnerot, Christian; Desaymard, Catherine

    1997-01-01

    To investigate the relationship between major histocompatibility complex (MHC) class II compartments, secretory granules, and secretory lysosomes, we analyzed the localization and fate of MHC class II molecules in mast cells. In bone marrow-derived mast cells, the bulk of MHC class II molecules is contained in two distinct compartments, with features of both lysosomal compartments and secretory granules defined by their protein content and their accessibility to endocytic tracers. Type I granules display internal membrane vesicles and are accessed by exogenous molecules after a time lag of 20 min; type II granules are reached by the endocytic tracer later and possess a serotonin-rich electron-dense core surrounded by a multivesicular domain. In these type I and type II granules, MHC class II molecules, mannose-6-phosphate receptors and lysosomal membrane proteins (lamp1 and lamp2) localize to small intralumenal vesicles. These 60–80-nm vesicles are released along with inflammatory mediators during mast cell degranulation triggered by IgE-antigen complexes. These observations emphasize the intimate connection between the endocytic and secretory pathways in cells of the hematopoietic lineage which allows regulated secretion of the contents of secretory lysosomes, including membrane proteins associated with small vesicles. PMID:9398681

  16. Accumulation of major histocompatibility complex class II molecules in mast cell secretory granules and their release upon degranulation.

    PubMed

    Raposo, G; Tenza, D; Mecheri, S; Peronet, R; Bonnerot, C; Desaymard, C

    1997-12-01

    To investigate the relationship between major histocompatibility complex (MHC) class II compartments, secretory granules, and secretory lysosomes, we analyzed the localization and fate of MHC class II molecules in mast cells. In bone marrow-derived mast cells, the bulk of MHC class II molecules is contained in two distinct compartments, with features of both lysosomal compartments and secretory granules defined by their protein content and their accessibility to endocytic tracers. Type I granules display internal membrane vesicles and are accessed by exogenous molecules after a time lag of 20 min; type II granules are reached by the endocytic tracer later and possess a serotonin-rich electron-dense core surrounded by a multivesicular domain. In these type I and type II granules, MHC class II molecules, mannose-6-phosphate receptors and lysosomal membrane proteins (lamp1 and lamp2) localize to small intralumenal vesicles. These 60-80-nm vesicles are released along with inflammatory mediators during mast cell degranulation triggered by IgE-antigen complexes. These observations emphasize the intimate connection between the endocytic and secretory pathways in cells of the hematopoietic lineage which allows regulated secretion of the contents of secretory lysosomes, including membrane proteins associated with small vesicles.

  17. Major histocompatibility complex harbors widespread genotypic variability of non-additive risk of rheumatoid arthritis including epistasis

    PubMed Central

    Wei, Wen-Hua; Bowes, John; Plant, Darren; Viatte, Sebastien; Yarwood, Annie; Massey, Jonathan; Worthington, Jane; Eyre, Stephen

    2016-01-01

    Genotypic variability based genome-wide association studies (vGWASs) can identify potentially interacting loci without prior knowledge of the interacting factors. We report a two-stage approach to make vGWAS applicable to diseases: firstly using a mixed model approach to partition dichotomous phenotypes into additive risk and non-additive environmental residuals on the liability scale and secondly using the Levene’s (Brown-Forsythe) test to assess equality of the residual variances across genotype groups per marker. We found widespread significant (P < 2.5e-05) vGWAS signals within the major histocompatibility complex (MHC) across all three study cohorts of rheumatoid arthritis. We further identified 10 epistatic interactions between the vGWAS signals independent of the MHC additive effects, each with a weak effect but jointly explained 1.9% of phenotypic variance. PTPN22 was also identified in the discovery cohort but replicated in only one independent cohort. Combining the three cohorts boosted power of vGWAS and additionally identified TYK2 and ANKRD55. Both PTPN22 and TYK2 had evidence of interactions reported elsewhere. We conclude that vGWAS can help discover interacting loci for complex diseases but require large samples to find additional signals. PMID:27109064

  18. IPD-MHC 2.0: an improved inter-species database for the study of the major histocompatibility complex

    PubMed Central

    Maccari, Giuseppe; Robinson, James; Ballingall, Keith; Guethlein, Lisbeth A.; Grimholt, Unni; Kaufman, Jim; Ho, Chak-Sum; de Groot, Natasja G.; Flicek, Paul; Bontrop, Ronald E.; Hammond, John A.; Marsh, Steven G. E.

    2017-01-01

    The IPD-MHC Database project (http://www.ebi.ac.uk/ipd/mhc/) collects and expertly curates sequences of the major histocompatibility complex from non-human species and provides the infrastructure and tools to enable accurate analysis. Since the first release of the database in 2003, IPD-MHC has grown and currently hosts a number of specific sections, with more than 7000 alleles from 70 species, including non-human primates, canines, felines, equids, ovids, suids, bovins, salmonids and murids. These sequences are expertly curated and made publicly available through an open access website. The IPD-MHC Database is a key resource in its field, and this has led to an average of 1500 unique visitors and more than 5000 viewed pages per month. As the database has grown in size and complexity, it has created a number of challenges in maintaining and organizing information, particularly the need to standardize nomenclature and taxonomic classification, while incorporating new allele submissions. Here, we describe the latest database release, the IPD-MHC 2.0 and discuss planned developments. This release incorporates sequence updates and new tools that enhance database queries and improve the submission procedure by utilizing common tools that are able to handle the varied requirements of each MHC-group. PMID:27899604

  19. Engineering and characterization of a stabilized alpha1/alpha2 module of the class I major histocompatibility complex product Ld.

    PubMed

    Jones, Lindsay L; Brophy, Susan E; Bankovich, Alexander J; Colf, Leremy A; Hanick, Nicole A; Garcia, K Christopher; Kranz, David M

    2006-09-01

    The major histocompatibility complex (MHC) is the most polymorphic locus known, with thousands of allelic variants. There is considerable interest in understanding the diversity of structures and peptide-binding features represented by this class of proteins. Although many MHC proteins have been crystallized, others have not been amenable to structural or biochemical studies due to problems with expression or stability. In the present study, yeast display was used to engineer stabilizing mutations into the class I MHC molecule, Ld. The approach was based on previous studies that showed surface levels of yeast-displayed fusion proteins are directly correlated with protein stability. To engineer a more stable Ld, we selected Ld mutants with increased surface expression from randomly mutated yeast display libraries using anti-Ld antibodies or high affinity, soluble T-cell receptors (TCRs). The most stable Ld mutant, Ld-m31, consisted of a single-chain MHC module containing only the alpha1 and alpha2 domains. The enhanced stability was in part due to a single mutation (Trp-97 --> Arg), shown previously to be present in the allele Lq. Mutant Ld-m31 could bind to Ld peptides, and the specific peptide.Ld-m31 complex (QL9.Ld-m31) was recognized by alloreactive TCR 2C. A soluble form of the Ld-m31 protein was expressed in Escherichia coli and refolded from inclusion bodies at high yields. Surface plasmon resonance showed that TCRs bound to peptide.Ld-m31 complexes with affinities similar to those of native full-length Ld. The TCR and QL9.Ld-m31 formed complexes that could be resolved by native gel electrophoresis, suggesting that stabilized alpha1/alpha2 class I platforms may enable various structural studies.

  20. Major histocompatibility complex diversity is positively associated with stream water temperatures in proximate populations of sockeye salmon.

    PubMed

    Larson, W A; Lisi, P J; Seeb, J E; Seeb, L W; Schindler, D E

    2016-09-01

    Local adaptation to heterogeneous environments generates population diversity within species, significantly increasing ecosystem stability and flows of ecosystem services. However, few studies have isolated the specific mechanisms that create and maintain this diversity. Here, we examined the relationship between water temperature in streams used for spawning and genetic diversity at a gene involved in immune function [the major histocompatibility complex (MHC)] in 14 populations of sockeye salmon (Oncorhynchus nerka) sampled across the Wood River basin in south-western Alaska. The largest influence on MHC diversity was lake basin, but we also found a significant positive correlation between average water temperature and MHC diversity. This positive relationship between temperature and MHC diversity appears to have been produced by natural selection at very local scales rather than neutral processes, as no correlation was observed between temperature and genetic diversity at 90 neutral markers. Additionally, no significant relationship was observed between temperature variability and MHC diversity. Although lake basin was the largest driver of differences in MHC diversity, our results also demonstrate that fine-scale differences in water temperature may generate variable selection regimes in populations that spawn in habitats separated by as little as 1 km. Additionally, our results indicated that some populations may be reaching a maximum level of MHC diversity. We postulate that salmon from populations in warm streams may delay spawning until late summer to avoid thermal stress as well as the elevated levels of pathogen prevalence and virulence associated with warm temperatures earlier in the summer.

  1. A complex alloantigen system in Florida sandhill cranes, Grus canadensis pratensis: Evidence for the major histocompatibility (B) system

    USGS Publications Warehouse

    Jarvi, S.I.; Gee, G.F.; Miller, M.M.; Briles, W.E.

    1995-01-01

    The B blood group system constitutes the major histocompatibility complex (Mhc) in birds. The Mhc is a cluster of genes largely devoted to the processing and presentation of antigen. The Mhc is highly polymorphic in many species and, thus, useful in the evaluation of genetic diversity for fitness traits within populations of a variety of animals. Correlations found between particular Mhc haplotypes and resistance to certain diseases emphasize the importance of understanding the functional significance of diversity of the Mhc, particularly in species threatened with extinction. As part of studies focused on genetic diversity in wild birds, serological techniques were used to define a highly polymorphic alloantigen system in seven families of Florida sandhill cranes (Grus canadensis pratensis). The results of analyses with antisera produced within the crane families and with chicken Mhc antigen-specific reagents revealed a single major alloantigen system that is likely the Mhc of the Florida sandhill crane. Preliminary experiments indicate that these crane alloantisera will provide a means of defining .the Mhc in other species of cranes.

  2. Proteasome subtypes and regulators in the processing of antigenic peptides presented by class I molecules of the major histocompatibility complex.

    PubMed

    Vigneron, Nathalie; Van den Eynde, Benoît J

    2014-11-18

    The proteasome is responsible for the breakdown of cellular proteins. Proteins targeted for degradation are allowed inside the proteasome particle, where they are cleaved into small peptides and released in the cytosol to be degraded into amino acids. In vertebrates, some of these peptides escape degradation in the cytosol, are loaded onto class I molecules of the major histocompatibility complex (MHC) and displayed at the cell surface for scrutiny by the immune system. The proteasome therefore plays a key role for the immune system: it provides a continued sampling of intracellular proteins, so that CD8-positive T-lymphocytes can kill cells expressing viral or tumoral proteins. Consequently, the repertoire of peptides displayed by MHC class I molecules at the cell surface depends on proteasome activity, which may vary according to the presence of proteasome subtypes and regulators. Besides standard proteasomes, cells may contain immunoproteasomes, intermediate proteasomes and thymoproteasomes. Cells may also contain regulators of proteasome activity, such as the 19S, PA28 and PA200 regulators. Here, we review the effects of these proteasome subtypes and regulators on the production of antigenic peptides. We also discuss an unexpected function of the proteasome discovered through the study of antigenic peptides: its ability to splice peptides.

  3. Major histocompatibility complex (MHC) heterozygote superiority to natural multi-parasite infections in the water vole (Arvicola terrestris).

    PubMed

    Oliver, M K; Telfer, S; Piertney, S B

    2009-03-22

    The fundamental role of the major histocompatibility complex (MHC) in immune recognition has led to a general consensus that the characteristically high levels of functional polymorphism at MHC genes is maintained by balancing selection operating through host-parasite coevolution. However, the actual mechanism by which selection operates is unclear. Two hypotheses have been proposed: overdominance (or heterozygote superiority) and negative frequency-dependent selection. Evidence for these hypotheses was evaluated by examining MHC-parasite relationships in an island population of water voles (Arvicola terrestris). Generalized linear mixed models were used to examine whether individual variation at an MHC class II DRB locus explained variation in the individual burdens of five different parasites. MHC genotype explained a significant amount of variation in the burden of gamasid mites, fleas (Megabothris walkeri) and nymphs of sheep ticks (Ixodes ricinus). Additionally, MHC heterozygotes were simultaneously co-infected by fewer parasite types than homozygotes. In each case where an MHC-dependent effect on parasite burden was resolved, the heterozygote genotype was associated with fewer parasites, and the heterozygote outperformed each homozygote in two of three cases, suggesting an overall superiority against parasitism for MHC heterozygote genotypes. This is the first demonstration of MHC heterozygote superiority against multiple parasites in a natural population, a mechanism that could help maintain high levels of functional MHC genetic diversity in natural populations.

  4. Major histocompatibility complex variation and evolution at a single, expressed DQA locus in two genera of elephants.

    PubMed

    Archie, Elizabeth A; Henry, Tammy; Maldonado, Jesus E; Moss, Cynthia J; Poole, Joyce H; Pearson, Virginia R; Murray, Suzan; Alberts, Susan C; Fleischer, Robert C

    2010-02-01

    Genes of the vertebrate major histocompatibility complex (MHC) are crucial to defense against infectious disease, provide an important measure of functional genetic diversity, and have been implicated in mate choice and kin recognition. As a result, MHC loci have been characterized for a number of vertebrate species, especially mammals;however, elephants are a notable exception. Our study is the first to characterize patterns of genetic diversity and natural selection in the elephant MHC. We did so using DNA sequences from a single, expressed DQA locus in elephants.We characterized six alleles in 30 African elephants(Loxodonta africana) and four alleles in three Asian elephants (Elephas maximus). In addition, for two of the African alleles and three of the Asian alleles, we characterized complete coding sequences (exons 1-5) and nearly complete non-coding sequences (introns 2-4) for the class II DQA loci. Compared to DQA in other wild mammals, we found moderate polymorphism and allelic diversity and similar patterns of selection; patterns of non-synonymous and synonymous substitutions were consistent with balancing selection acting on the peptides involved in antigen binding in the second exon. In addition, balancing selection has led to strong trans-species allelism that has maintained multiple allelic lineages across both genera of extant elephants for at least 6 million years. We discuss our results in the context of MHC diversity in other mammals and patterns of evolution in elephants.

  5. Myelin-oligodendrocyte glycoprotein is a member of a subset of the immunoglobulin superfamily encoded within the major histocompatibility complex

    SciTech Connect

    Pham-Dinh, D.; Dautigny, A. ); Mattei, M.G.; Roeckel, N. ); Nussbaum, J.H.; Roussel, G. ); Pontarotti, P. ); Mather, I.H. ); Artzt, K. ); Lindahl, K.F. )

    1993-09-01

    Myelin/oligodendrocyte glycoprotein (MOG) is found on the surface of myelinating oligodendrocytes and external lamellae of myelin sheaths in the central nervous system, and it is target antigen in experimental autoimmune encephalomyelitis and multiple sclerosis. The authors have isolated bovine, mouse, and rat MOG cDNA clones and shown that the developmental pattern of MOG expression in the rat central nervous system coincides with the late stages of myelination. The amino-terminal, extracellular domain of MOG has characteristics of an immunoglobulin variable domain and is 46% and 41% identical with the amino terminus of bovine butyrophilin (expressed in the lactating mammary gland) and B-G antigens of the chicken major histocompatibility complex (MHC), respectively; these proteins thus form a subset of the immunoglobulin superfamily. The homology between MOG and B-G extends beyond their structure and genetic mapping to their ability to induce strong antibody responses and has implications for the role of MOG in pathological, autoimmune conditions. The authors colocalized the MOG and BT genes to the human MHC on chromosome 6p21.3-p22. The mouse MOG gene was mapped to the homologous band C of chromosome 17, within the M region of the mouse MHC. 38 refs., 6 figs.

  6. Major histocompatibility complex class I molecules protect motor neurons from astrocyte-induced toxicity in amyotrophic lateral sclerosis.

    PubMed

    Song, SungWon; Miranda, Carlos J; Braun, Lyndsey; Meyer, Kathrin; Frakes, Ashley E; Ferraiuolo, Laura; Likhite, Shibi; Bevan, Adam K; Foust, Kevin D; McConnell, Michael J; Walker, Christopher M; Kaspar, Brian K

    2016-04-01

    Astrocytes isolated from individuals with amyotrophic lateral sclerosis (ALS) are toxic to motor neurons (MNs) and play a non-cell autonomous role in disease pathogenesis. The mechanisms underlying the susceptibility of MNs to cell death remain unclear. Here we report that astrocytes derived from either mice bearing mutations in genes associated with ALS or human subjects with ALS reduce the expression of major histocompatibility complex class I (MHCI) molecules on MNs; reduced MHCI expression makes these MNs susceptible to astrocyte-induced cell death. Increasing MHCI expression on MNs increases survival and motor performance in a mouse model of ALS and protects MNs against astrocyte toxicity. Overexpression of a single MHCI molecule, HLA-F, protects human MNs from ALS astrocyte-mediated toxicity, whereas knockdown of its receptor, the killer cell immunoglobulin-like receptor KIR3DL2, on human astrocytes results in enhanced MN death. Thus, our data indicate that, in ALS, loss of MHCI expression on MNs renders them more vulnerable to astrocyte-mediated toxicity.

  7. Major histocompatibility complex monomorphism and low levels of DNA fingerprinting variability in a reintroduced and rapidly expanding population of beavers.

    PubMed Central

    Ellegren, H; Hartman, G; Johansson, M; Andersson, L

    1993-01-01

    Loss of genetic variation due to population bottlenecks may be a severe threat for the survival of endangered species. Assessment and maintenance of genetic variability are thus crucial for conservation programs related to endangered populations. Scandinavian beavers went through an extensive bottleneck during the last century due to overhunting. In Sweden the species became extirpated but in Norway extinction was avoided by legal protection. Following reintroductions of small numbers of remaining Norwegian animals in 1922-1939, the Swedish population has increased tremendously, now harboring 100,000 animals. We show here that this viable population of beavers possesses extremely low levels of genetic variability at DNA fingerprinting loci and monomorphism at major histocompatibility complex (MHC) class I and class II loci. A similar pattern was also evident among Norwegian beavers but low levels of genetic variability were not a characteristic of the species since Russian conspecifics displayed substantial DNA fingerprinting polymorphism. However, the Russian animals were monomorphic at MHC loci, indicating that the European beaver is exceptional in its low level of MHC variability. The results demonstrate that a conservation program can be successful despite low levels of genetic variation in the founder population. Images Fig. 2 PMID:8367476

  8. Genetic variation of the major histocompatibility complex (MHC class II B gene) in the threatened Hume's pheasant, Syrmaticus humiae.

    PubMed

    Chen, Weicai; Bei, Yongjian; Li, Hanhua

    2015-01-01

    Major histocompatibility complex (MHC) genes are the most polymorphic genes in vertebrates and encode molecules that play a crucial role in pathogen resistance. As a result of their diversity, they have received much attention in the fields of evolutionary and conservation biology. Here, we described the genetic variation of MHC class II B (MHCIIB) exon 2 in a wild population of Hume's pheasant (Syrmaticus humiae), which has suffered a dramatic decline in population over the last three decades across its ranges in the face of heavy exploitation and habitat loss. Twenty-four distinct alleles were found in 73 S. humiae specimens. We found seven shared alleles among four geographical groups as well as six rare MHCIIB alleles. Most individuals displayed between one to five alleles, suggesting that there are at least three MHCIIB loci of the Hume's pheasant. The dN ⁄ dS ratio at putative antigen-binding sites (ABS) was significantly greater than one, indicating balancing selection is acting on MHCIIB exon 2. Additionally, recombination and gene conversion contributed to generating MHCIIB diversity in the Hume's pheasant. One to three recombination events and seventy-five significant gene conversion events were observed within the Hume's pheasant MHCIIB loci. The phylogenetic tree and network analysis revealed that the Hume's pheasant alleles do not cluster together, but are scattered through the tree or network indicating a trans-species evolutionary mode. These findings revealed the evolution of the Hume's pheasant MHC after suffering extreme habitat fragmentation.

  9. Female major histocompatibility complex type affects male testosterone levels and sperm number in the horse (Equus caballus)

    PubMed Central

    Burger, D.; Dolivo, G.; Marti, E.; Sieme, H.; Wedekind, C.

    2015-01-01

    Odours of vertebrates often contain information about the major histocompatibility complex (MHC), and are used in kin recognition, mate choice or female investment in pregnancy. It is, however, still unclear whether MHC-linked signals can also affect male reproductive strategies. We used horses (Equus caballus) to study this question under experimental conditions. Twelve stallions were individually exposed either to an unfamiliar MHC-similar mare and then to an unfamiliar MHC-dissimilar mare, or vice versa. Each exposure lasted over a period of four weeks. Peripheral blood testosterone levels were determined weekly. Three ejaculates each were collected in the week after exposure to both mares (i.e. in the ninth week) to determine mean sperm number and sperm velocity. We found high testosterone levels when stallions were kept close to MHC-dissimilar mares and significantly lower ones when kept close to MHC-similar mares. Mean sperm number per ejaculate (but not sperm velocity) was positively correlated to mean testosterone levels and also affected by the order of presentation of mares: sperm numbers were higher if MHC-dissimilar mares were presented last than if MHC-similar mares were presented last. We conclude that MHC-linked signals influence testosterone secretion and semen characteristics, two indicators of male reproductive strategies. PMID:25904670

  10. Characterization of class II β chain major histocompatibility complex genes in a family of Hawaiian honeycreepers: 'amakihi (Hemignathus virens).

    PubMed

    Jarvi, Susan I; Bianchi, Kiara R; Farias, Margaret Em; Txakeeyang, Ann; McFarland, Thomas; Belcaid, Mahdi; Asano, Ashley

    2016-07-01

    Hawaiian honeycreepers (Drepanidinae) have evolved in the absence of mosquitoes for over five million years. Through human activity, mosquitoes were introduced to the Hawaiian archipelago less than 200 years ago. Mosquito-vectored diseases such as avian malaria caused by Plasmodium relictum and Avipoxviruses have greatly impacted these vulnerable species. Susceptibility to these diseases is variable among and within species. Due to their function in adaptive immunity, the role of major histocompatibility complex genes (Mhc) in disease susceptibility is under investigation. In this study, we evaluate gene organization and levels of diversity of Mhc class II β chain genes (exon 2) in a captive-reared family of Hawaii 'amakihi (Hemignathus virens). A total of 233 sequences (173 bp) were obtained by PCR+1 amplification and cloning, and 5720 sequences were generated by Roche 454 pyrosequencing. We report a total of 17 alleles originating from a minimum of 14 distinct loci. We detected three linkage groups that appear to represent three distinct haplotypes. Phylogenetic analysis revealed one variable cluster resembling classical Mhc sequences (DAB) and one highly conserved, low variability cluster resembling non-classical Mhc sequences (DBB). High net evolutionary divergence values between DAB and DBB resemble that seen between chicken BLB system and YLB system genes. High amino acid identity among non-classical alleles from 12 species of passerines (DBB) and four species of Galliformes (YLB) was found, suggesting that these non-classical passerine sequences may be related to the Galliforme YLB sequences.

  11. Gastrointestinal helminths in indigenous and exotic chickens in Vietnam: association of the intensity of infection with the Major Histocompatibility Complex.

    PubMed

    Schou, T W; Permin, A; Juul-Madsen, H R; Sørensen, P; Labouriau, R; Nguyên, T L H; Fink, M; Pham, S L

    2007-04-01

    This study compared the prevalence and intensity of infections of helminths in 2 chicken breeds in Vietnam, the indigenous Ri and the exotic Luong Phuong. Also, possible correlations with the Major Histocompatibility Complex (MHC) were tested. The most prevalent helminths were Ascaridia galli, Heterakis beramporia, Tetrameres mothedai, Capillaria obsignata, Raillietina echinobothrida and Raillietina tetragona. Differences in prevalence and intensity of infection were found between the 2 breeds. Comparing the 2 groups of adult birds, Ri chickens were observed to have higher prevalence and infection intensities of several species of helminths, as well as a higher mean number of helminth species. In contrast, A. galli and C. obsignata were shown to be more prevalent in Luong Phuong chickens. Furthermore, an age-dependent difference was indicated in the group of Ri chickens in which the prevalence and the intensity of infection was higher for the adult than the young chickens for most helminths. The most notable exception was the significantly lower prevalence and intensities of A. galli in the group of adult chickens. In contrast, the prevalence and intensity were very similar in both age groups of Luong Phuong chickens. Using a genetic marker located in the MHC, a statistically significant correlation between several MHC haplotypes and the infection intensity of different helminth species was inferred. This is the first report of an association of MHC haplotype with the intensity of parasite infections in chickens.

  12. Immunohistochemical detection of major histocompatibility complex antigens and quantitative analysis of tumour-infiltrating mononuclear cells in renal cell cancer.

    PubMed Central

    Tomita, Y.; Nishiyama, T.; Fujiwara, M.; Sato, S.

    1990-01-01

    In order to investigate the anti-tumour immune responsiveness of patients with renal cell cancer (RCC), we examined 30 such patients for the degree of expression of major histocompatibility complex (MHC) class I and class II antigens on RCC and the populations of tumour-infiltrating mononuclear cells (TIM). Normal renal tubular cells expressed class I but not class II antigens. Most of the tumour cells expressed class I antigens in 25 (83%) cases, but the proportion of such cells was reduced in five cases, three of which were of granular cell type histologically. Class II antigens were detected in all specimens with class I positivity. Various numbers of TIM were detected in 25 cases, being composed mainly of T cells and a smaller number of macrophages. Examination for the phenotype of T cells showed that CD8-positive cells were the dominant population. B cells were not detected. Quantitative analysis revealed that the numbers of TIM were significantly lower in cases showing class I reduction than in those with normal class I expression. Therefore, it was clear that class I antigens were preserved in RCC cells in most cases. Furthermore, a higher rate of reduction of class I antigens was observed in cases of granular cell type, which has been reported to have a worse prognosis than the clear cell type. The present data suggest that degree of the expression of MHC class I antigen on RCC might influence the host immune responsiveness against it. Images Figure 1 Figure 2 Figure 3 PMID:2206942

  13. Gene flow, effective population size and selection at major histocompatibility complex genes: brown trout in the Hardanger Fjord, Norway.

    PubMed

    Hansen, Michael M; Skaala, Oystein; Jensen, Lasse Fast; Bekkevold, Dorte; Mensberg, Karen-Lise D

    2007-04-01

    Brown trout populations in the Hardanger Fjord, Norway, have declined drastically due to increased exposure to salmon lice from salmonid aquaculture. We studied contemporary samples from seven populations and historical samples (1972 and 1983) from the two largest populations, one of which has declined drastically whereas the other remains stable. We analysed 11 microsatellite loci, including one tightly linked to the UBA gene of the major histocompatibility class I complex (MHC) and another locus linked to the TAP2A gene, also associated with MHC. The results revealed asymmetric gene flow from the two largest populations to the other, smaller populations. This has important conservation implications, and we predict that possible future population recoveries will be mediated primarily by the remaining large population. Tests for selection suggested diversifying selection at UBA, whereas evidence was inconclusive for TAP2A. There was no evidence for temporally fluctuating selection. We assessed the distribution of adaptive divergence among populations. The results showed the most pronounced footprints of selection between the two largest populations subject to the least immigration. We suggest that asymmetric gene flow has an important influence on adaptive divergence and constrains local adaptive responses in the smaller populations. Even though UBA alleles may not affect salmon louse resistance, the results bear evidence of adaptive divergence among populations at immune system genes. This suggests that similar genetic differences could exist at salmon louse resistance loci, thus rendering it a realistic scenario that differential population declines could reflect differences in adaptive variation.

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

    PubMed

    Okada, K; Prentice, H L; Boss, J M; Levy, D J; Kappes, D; Spies, T; Raghupathy, R; Mengler, R A; Auffray, C; Strominger, J L

    1985-03-01

    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.

  15. Female major histocompatibility complex type affects male testosterone levels and sperm number in the horse (Equus caballus).

    PubMed

    Burger, D; Dolivo, G; Marti, E; Sieme, H; Wedekind, C

    2015-05-22

    Odours of vertebrates often contain information about the major histocompatibility complex (MHC), and are used in kin recognition, mate choice or female investment in pregnancy. It is, however, still unclear whether MHC-linked signals can also affect male reproductive strategies. We used horses (Equus caballus) to study this question under experimental conditions. Twelve stallions were individually exposed either to an unfamiliar MHC-similar mare and then to an unfamiliar MHC-dissimilar mare, or vice versa. Each exposure lasted over a period of four weeks. Peripheral blood testosterone levels were determined weekly. Three ejaculates each were collected in the week after exposure to both mares (i.e. in the ninth week) to determine mean sperm number and sperm velocity. We found high testosterone levels when stallions were kept close to MHC-dissimilar mares and significantly lower ones when kept close to MHC-similar mares. Mean sperm number per ejaculate (but not sperm velocity) was positively correlated to mean testosterone levels and also affected by the order of presentation of mares: sperm numbers were higher if MHC-dissimilar mares were presented last than if MHC-similar mares were presented last. We conclude that MHC-linked signals influence testosterone secretion and semen characteristics, two indicators of male reproductive strategies.

  16. SNP Profile within the Human Major Histocompatibility Complex Reveals an Extreme and Interrupted Level of Nucleotide Diversity

    PubMed Central

    Gaudieri, Silvana; Dawkins, Roger L.; Habara, Kaori; Kulski, Jerzy K.; Gojobori, Takashi

    2000-01-01

    The human major histocompatibility complex (MHC) is characterized by polymorphic multicopy gene families, such as HLA and MIC (PERB11); duplications; insertions and deletions (indels); and uneven rates of recombination. Polymorphisms at the antigen recognition sites of the HLA class I and II genes and at associated neutral sites have been attributed to balancing selection and a hitchhiking effect, respectively. We, and others, have previously shown that nucleotide diversity between MHC haplotypes at non-HLA sites is unusually high (>10%) and up to several times greater than elsewhere in the genome (0.08%–0.2%). We report here the most extensive analysis of nucleotide diversity within a continuous sequence in the genome. We constructed a single nucleotide polymorphism (SNP) profile that reveals a pattern of extreme but interrupted levels of nucleotide diversity by comparing a continuous sequence within haplotypes in three genomic subregions of the MHC. A comparison of several haplotypes within one of the genomic subregions containing the HLA-B and -C loci suggests that positive selection is operating over the whole subgenomic region, including HLA and non-HLA genes. [The sequence data for the multiple haplotype comparisons within the class I region have been submitted to DDBJ/EMBL/GenBank under accession nos. AF029061, AF029062, and AB031005–AB031010. Additional sequence data have been submitted to the DDBJ data library under accession nos. AB031005–AB03101 and AF029061–AF029062.] PMID:11042155

  17. Major histocompatibility complex (MHC) heterozygote superiority to natural multi-parasite infections in the water vole (Arvicola terrestris)

    PubMed Central

    Oliver, M.K.; Telfer, S.; Piertney, S.B.

    2008-01-01

    The fundamental role of the major histocompatibility complex (MHC) in immune recognition has led to a general consensus that the characteristically high levels of functional polymorphism at MHC genes is maintained by balancing selection operating through host–parasite coevolution. However, the actual mechanism by which selection operates is unclear. Two hypotheses have been proposed: overdominance (or heterozygote superiority) and negative frequency-dependent selection. Evidence for these hypotheses was evaluated by examining MHC–parasite relationships in an island population of water voles (Arvicola terrestris). Generalized linear mixed models were used to examine whether individual variation at an MHC class II DRB locus explained variation in the individual burdens of five different parasites. MHC genotype explained a significant amount of variation in the burden of gamasid mites, fleas (Megabothris walkeri) and nymphs of sheep ticks (Ixodes ricinus). Additionally, MHC heterozygotes were simultaneously co-infected by fewer parasite types than homozygotes. In each case where an MHC-dependent effect on parasite burden was resolved, the heterozygote genotype was associated with fewer parasites, and the heterozygote outperformed each homozygote in two of three cases, suggesting an overall superiority against parasitism for MHC heterozygote genotypes. This is the first demonstration of MHC heterozygote superiority against multiple parasites in a natural population, a mechanism that could help maintain high levels of functional MHC genetic diversity in natural populations. PMID:19129114

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

    PubMed Central

    Bahram, S; Arnold, D; Bresnahan, M; Strominger, J L; Spies, T

    1991-01-01

    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. Images PMID:1946428

  19. A single nomenclature and associated database for alleles at the major histocompatibility complex class II DRB1 locus of sheep.

    PubMed

    Ballingall, K T; Herrmann-Hoesing, L; Robinson, J; Marsh, S G E; Stear, M J

    2011-06-01

    The development of standardised nomenclatures with associated databases containing reference sequences for alleles at polymorphic loci within the major histocompatibility complex (MHC) has been facilitated by the development of the immuno polymorphism database (IPD). Recently, included within IPD-MHC is information on allelic diversity within sheep species (IPD-MHC-OLA). Here, we present the first report of progress in populating the sheep IPD-MHC database with alleles at the class II MHC DRB1 locus. The sequence of 63 Ovar-DRB1 alleles within 24 allelic families is now held within the database, each meeting the minimum requirement of a complete second exon. These sequences are derived from a combination of genomic and cDNA-based approaches and represent the most extensive collection of validated alleles at the sheep DRB1 locus yet described. Although these 63 alleles probably represent only a fraction of the DRB1 allelic diversity in sheep species worldwide, we encourage the research community to use the official allelic nomenclature and to contribute allelic sequences to the database via its web-based submission tool. In time, the IPD-MHC-OLA resource will underpin population-based MHC genotyping studies and help to simplify meta-analyses of multi-source data from wild and domestic sheep populations.

  20. Biosynthesis of major histocompatibility complex molecules and generation of T cells in Ii TAP1 double-mutant mice.

    PubMed Central

    Tourne, S; van Santen, H M; van Roon, M; Berns, A; Benoist, C; Mathis, D; Ploegh, H

    1996-01-01

    Major histocompatibility complex (MHC) class I and II molecules are loaded with peptides in distinct subcellular compartments. The transporter associated with antigen processing (TAP) is responsible for delivering peptides derived from cytosolic proteins to the endoplasmic reticulum, where they bind to class I molecules, while the invariant chain (Ii) directs class II molecules to endosomal compartments, where they bind peptides originating mostly from exogenous sources. Mice carrying null mutations of the TAP1 or Ii genes (TAP10) or Ii0, respectively) have been useful tools for elucidating the two MHC/peptide loading pathways. To evaluate to what extent these pathways functionally intersect, we have studied the biosynthesis of MHC molecules and the generation of T cells in Ii0TAP10 double-mutant mice. We find that the assembly and expression of class II molecules in Ii0 and Ii0TAP10 animals are indistinguishable and that formation and display of class I molecules is the same in TAP10 and Ii0TAP10 animals. Thymic selection in the double mutants is as expected, with reduced numbers of both CD4+ CD8- and CD4- CD8+ thymocyte compartments. Surprisingly, lymph node T-cell populations look almost normal; we propose that population expansion of peripheral T cells normalizes the numbers of CD4+ and CD8+ cells in Ii0TAP10 mice. Images Fig. 1 Fig. 2 PMID:8643655

  1. Constraints within major histocompatibility complex class I restricted peptides: Presentation and consequences for T-cell recognition

    SciTech Connect

    Theodossis, Alex; Guillonneau, Carole; Welland, Andrew; Ely, Lauren K.; Clements, Craig S.; Williamson, Nicholas A.; Webb, Andrew I.; Wilce, Jacqueline A.; Mulder, Roger J.; Dunstone, Michelle A.; Doherty, Peter C.; McCluskey, James; Purcell, Anthony W.; Turner, Stephen J.; Rossjohn, Jamie

    2010-03-24

    Residues within processed protein fragments bound to major histocompatibility complex class I (MHC-I) glycoproteins have been considered to function as a series of 'independent pegs' that either anchor the peptide (p) to the MHC-I and/or interact with the spectrum of {alpha}{beta}-T-cell receptors (TCRs) specific for the pMHC-I epitope in question. Mining of the extensive pMHC-I structural database established that many self- and viral peptides show extensive and direct interresidue interactions, an unexpected finding that has led us to the idea of 'constrained' peptides. Mutational analysis of two constrained peptides (the HLA B44 restricted self-peptide (B44DP{alpha}-EEFGRAFSF)) and an H2-D{sup b} restricted influenza peptide (D{sup b}PA, SSLENFRAYV) demonstrated that the conformation of the prominently exposed arginine in both peptides was governed by interactions with MHC-I-orientated flanking residues from the peptide itself. Using reverse genetics in a murine influenza model, we revealed that mutation of an MHC-I-orientated residue (SSLENFRAYV {yields} SSLENARAYV) within the constrained PA peptide resulted in a diminished cytotoxic T lymphocyte (CTL) response and the recruitment of a limited pMHC-I specific TCR repertoire. Interactions between individual peptide positions can thus impose fine control on the conformation of pMHC-I epitopes, whereas the perturbation of such constraints can lead to a previously unappreciated mechanism of viral escape.

  2. Major Histocompatibility Complex I Mediates Immunological Tolerance of the Trophoblast during Pregnancy and May Mediate Rejection during Parturition

    PubMed Central

    Rapacz-Leonard, Anna; Dąbrowska, Małgorzata; Janowski, Tomasz

    2014-01-01

    During pregnancy in larger mammals, the maternal immune system must tolerate the fetus for months while resisting external infection. This tolerance is facilitated by immunological communication between the fetus and the mother, which is mediated by Major Histocompatibility Complex I (MHC I) proteins, by leukocytes, and by the cytokines secreted by the leukocytes. Fetal-maternal immunological communication also supports pregnancy by inducing physiological changes in the mother. If the mother “misunderstands” the signal sent by the fetus during pregnancy, the fetus will be miscarried or delivered preterm. Unlike any other maternal organ, the placenta can express paternal antigens. At parturition, paternal antigens are known to be expressed in cows and may be expressed in horses, possibly so that the maternal immune system will reject the placenta and help to expel it. This review compares fetal-maternal crosstalk that is mediated by the immune system in three species with pregnancies that last for nine months or longer: humans, cattle, and horses. It raises the possibility that immunological communication early in pregnancy may prepare the mother for successful expulsion of fetal membranes at parturition. PMID:24812442

  3. Unusual association of beta 2-microglobulin with certain class I heavy chains of the murine major histocompatibility complex.

    PubMed Central

    Bushkin, Y; Tung, J S; Pinter, A; Michaelson, J; Boyse, E A

    1986-01-01

    Class I products of the major histocompatibility complex (MHC) comprise a heavy chain of about 45 kDa noncovalently linked to a 12-kDa beta 2-microglobulin (beta 2m) light chain encoded on a different chromosome. We find that class I products of some mouse strains include an additional 62-kDa molecule which on the following evidence consists of a heavy chain linked covalently with beta 2m. Production of the 62-kDa protein invariably accorded with the occurrence of cysteine at position 121 of the heavy chain (Kb,Kbm1,Kbm3,Dd, and Ld). Substitution of arginine at position 121 invariably accorded with absence of the 62-kDa protein (Kbm6,Kbm7,Kbm9,Kd, and Db). On the basis of observed production versus nonproduction of the 62-kDa molecule, predictions are made regarding residue 121 in class I products for which this is not yet known; namely, Kk, Ks, and Dk, which produce the 62-kDa molecule, as compared with Kj, Qa-2, and TL, which do not. Reported differences in immunologic reactivity between Kb mutant strains with Arg-121 in place of Cys-121 imply that the occurrence of 62-kDa class I products in mice of Cys-121 genotype has functional consequences. Images PMID:3510435

  4. Major histocompatibility complex-unrestricted cytolytic activity of human T cells: analysis of precursor frequency and effector phenotype

    SciTech Connect

    Patel, S.S.; Thiele, D.L.; Lipsky, P.E.

    1987-12-01

    The frequency and phenotype of human T cells that mediate major histocompatibility complex (MHC)-unrestricted cytolysis were analyzed. T cell clones were generated by culturing adherent cell-depleted peripheral blood mononuclear cells at a density of 0.3 cell/well with phytohemagglutinin, recombinant interleukin 2 (rIL-2), and irradiated autologous peripheral blood mononuclear cells and/or Epstein-Barr virus-transformed lymphoblastoid cell lines. All of the 198 clones generated by this method were T cells (CD2/sup +/, CD3/sup +/, CD4/sup +/ or CD2/sup +/, CD3/sup +/, CD8/sup +/) that possessed potent lytic activity against K562, an erythroleukemia line sensitive to lysis by human natural killer cells, and Cur, a renal carcinoma cell line resistant to human natural killer activity. Cytolysis, measured by /sup 51/Cr release, was MHC-unrestricted, since the clones were able to lyse MHC class I or class II negative targets, as well as MHC class I and class II negative targets. Although the clones produced tissue necrosis factor/lymphotoxin-like molecules, lysis of Cur of K562 was not mediated by a soluble factor secreted by the clones. These data indicate that the capacity for MHC-unrestricted tumoricidal activity and expression of NKH1 and CD11b, but not CD 16, are properties common to all or nearly all human peripheral blood-derived T cell clones regardless of CD4 or CD8 phenotype.

  5. Cross-linking staphylococcal enterotoxin A bound to major histocompatibility complex class I is required for TNF-alpha secretion

    NASA Technical Reports Server (NTRS)

    Wright, A. D.; Chapes, S. K.

    1999-01-01

    The mechanism of how superantigens function to activate cells has been linked to their ability to bind and cross-link the major histocompatibility complex class II (MHCII) molecule. Cells that lack the MHCII molecule also respond to superantigens, however, with much less efficiency. Therefore, the purpose of this study was to confirm that staphylococcal enterotoxin A (SEA) could bind the MHCI molecule and to test the hypothesis that cross-linking SEA bound to MHCII-deficient macrophages would induce a more robust cytokine response than without cross-linking. We used a capture enzyme-linked immunosorbent assay and an immunprecipitation assay to directly demonstrate that MHCI molecules bind SEA. Directly cross-linking MHCI using monoclonal antibodies or cross-linking bound SEA with an anti-SEA antibody or biotinylated SEA with avidin increased TNF-alpha and IL-6 secretion by MHCII(-/-) macrophages. The induction of a vigorous macrophage cytokine response by SEA/anti-SEA cross-linking of MHCI offers a mechanism to explain how MHCI could play an important role in superantigen-mediated pathogenesis. Copyright 1999 Academic Press.

  6. Recent advances in Major Histocompatibility Complex (MHC) class I antigen presentation: Plastic MHC molecules and TAPBPR-mediated quality control

    PubMed Central

    van Hateren, Andy; Bailey, Alistair; Elliott, Tim

    2017-01-01

    We have known since the late 1980s that the function of classical major histocompatibility complex (MHC) class I molecules is to bind peptides and display them at the cell surface to cytotoxic T cells. Recognition by these sentinels of the immune system can lead to the destruction of the presenting cell, thus protecting the host from pathogens and cancer. Classical MHC class I molecules (MHC I hereafter) are co-dominantly expressed, polygenic, and exceptionally polymorphic and have significant sequence diversity. Thus, in most species, there are many different MHC I allotypes expressed, each with different peptide-binding specificity, which can have a dramatic effect on disease outcome. Although MHC allotypes vary in their primary sequence, they share common tertiary and quaternary structures. Here, we review the evidence that, despite this commonality, polymorphic amino acid differences between allotypes alter the ability of MHC I molecules to change shape (that is, their conformational plasticity). We discuss how the peptide loading co-factor tapasin might modify this plasticity to augment peptide loading. Lastly, we consider recent findings concerning the functions of the non-classical MHC I molecule HLA-E as well as the tapasin-related protein TAPBPR (transporter associated with antigen presentation binding protein-related), which has been shown to act as a second quality-control stage in MHC I antigen presentation. PMID:28299193

  7. A comparison of cancer stem cell markers and nonclassical major histocompatibility complex antigens in colorectal tumor and noncancerous tissues.

    PubMed

    Özgül Özdemir, Rabia Bilge; Özdemir, Alper Tunga; Oltulu, Fatih; Kurt, Kamile; Yiğittürk, Gürkan; Kırmaz, Cengiz

    2016-12-01

    Colorectal carcinoma (CRC) is one of the most fatal types of cancer in both women and men, and, unfortunately, patients are often diagnosed at an advanced stage. Cancer stem cells (CSCs) are associated with poor prognosis, metastasis, and recurrence, as well as chemotherapy and radiotherapy resistance. Therefore, different treatment alternatives are needed to facilitate the elimination of CSCs. One such approach is immunotherapy; however, tumor cells can evade immune cells by alteration of the expression patterns of human leukocyte antigens (HLA). In this study, we immunohistochemically investigated the expression patterns of CSC-specific markers CD44, CD133, Nanog, and Oct3/4, and immunosuppressive molecules HLA-G and -E in advanced CRC tumor tissues and noncancerous colon biopsies. We found significantly increased CD44, Nanog, Oct3/4, HLA-G, and HLA-E expression in the CRC tumor tissues compared with the noncancerous colon biopsies. These findings suggest that some tumor cells may be CSC-like and that the increased expression of HLA-G and HLA-E may be considered as an immune-evasive adaptation. Therefore, the nonclassical major histocompatibility complex class Ib antigens HLA-G and HLA-E may be potential targets in the elimination of CRC-CSCs. However, more detailed studies are required to support our findings.

  8. Genetic structure and contrasting selection pattern at two major histocompatibility complex genes in wild house mouse populations

    PubMed Central

    Čížková, D; de Bellocq, J Gouy; Baird, S J E; Piálek, J; Bryja, J

    2011-01-01

    The mammalian major histocompatibility complex (MHC) is a tightly linked cluster of immune genes, and is often thought of as inherited as a unit. This has led to the hope that studying a single MHC gene will reveal patterns of evolution representative of the MHC as a whole. In this study we analyse a 1000-km transect of MHC variation traversing the European house mouse hybrid zone to compare signals of selection and patterns of diversification at two closely linked MHC class II genes, H-2Aa and H-2Eb. We show that although they are 0.01 cM apart (that is, recombination is expected only once in 10 000 meioses), disparate evolutionary patterns were detected. H-2Aa shows higher allelic polymorphism, faster allelic turnover due to higher mutation rates, stronger positive selection at antigen-binding sites and higher population structuring than H-2Eb. H-2Eb alleles are maintained in the gene pool for longer, including over separation of the subspecies, some H-2Eb alleles are positively and others negatively selected and some of the alleles are not expressed. We conclude that studies on MHC genes in wild-living vertebrates can give substantially different results depending on the MHC gene examined and that the level of polymorphism in a related species is a poor criterion for gene choice. PMID:20823902

  9. The role of "indirect" recognition in initiating rejection of skin grafts from major histocompatibility complex class II-deficient mice.

    PubMed Central

    Auchincloss, H; Lee, R; Shea, S; Markowitz, J S; Grusby, M J; Glimcher, L H

    1993-01-01

    In vitro studies have revealed several pathways by which T cells can respond to alloantigens, including CD4+ direct responses to allogeneic class II antigens, CD8+ direct responses to allogeneic class I antigens, and CD4+ "indirect" responses to peptides of alloantigens presented in association with responder class II molecules. In vivo studies of skin graft rejection, however, have so far provided clear evidence for the contribution of only the two direct pathways and not for indirect recognition. We have used major histocompatibility complex class II-deficient mice as donors to test the role of indirect recognition in rejection of skin grafts. Class II-deficient skin was always rejected without delay by normal recipients. Removal of recipient CD8+ cells (to leave the animals dependent on CD4+ function) or depletion of recipient CD4+ cells revealed that CD4+ cells were usually involved and sometimes absolutely required in this rapid rejection. Since the donor grafts lacked class II antigens, the CD4+ cells must have recognized donor antigens presented in association with recipient class II molecules. These results therefore indicate that indirect recognition can initiate rapid skin graft rejection. PMID:8475083

  10. Effects of messenger RNA structure and other translational control mechanisms on major histocompatibility complex-I mediated antigen presentation.

    PubMed

    Murat, Pierre; Tellam, Judy

    2015-01-01

    Effective T-cell surveillance of antigen-presenting cells is dependent on the expression of an array of antigenic peptides bound to major histocompatibility complex (MHC) class I (MHC-I) or class II (MHC-II) molecules. Pathogens co-evolving with their hosts exploit crucial translational regulatory mechanisms in order to evade host immune recognition and thereby sustain their infection. Evasion strategies that downregulate viral protein synthesis and thereby restrict antigen presentation to cytotoxic T-cells through the endogenous MHC-I pathway have been implicated in the pathogenesis of viral-associated malignancies. An understanding of the mechanisms by which messenger RNA (mRNA) structure modulates both viral mRNA translation and the antigen processing machinery to escape immune surveillance, will stimulate the development of alternative therapeutic strategies focused on RNA-directed drugs designed to enhance immune responses against infected cells. In this review, we discuss regulatory aspects of the MHC-I pathway and summarize current knowledge of the role attributed by mRNA structure and other translational regulatory mechanisms in immune evasion. In particular we highlight the impact of recently identified G-quadruplex structures within virally encoded transcripts as unique regulatory signals for translational control and antigen presentation.

  11. The cellular environment regulates in situ kinetics of T-cell receptor interaction with peptide major histocompatibility complex.

    PubMed

    Liu, Baoyu; Chen, Wei; Natarajan, Kannan; Li, Zhenhai; Margulies, David H; Zhu, Cheng

    2015-07-01

    T cells recognize antigens at the two-dimensional (2D) interface with antigen-presenting cells (APCs), which trigger T-cell effector functions. T-cell functional outcomes correlate with 2D kinetics of membrane-embedded T-cell receptors (TCRs) binding to surface-tethered peptide-major histocompatibility complex molecules (pMHCs). However, most studies have measured TCR-pMHC kinetics for recombinant TCRs in 3D by surface plasmon resonance, which differs drastically from 2D measurements. Here, we compared pMHC dissociation from native TCR on the T-cell surface to recombinant TCR immobilized on glass surface or in solution. Force on TCR-pMHC bonds regulated their lifetimes differently for native than recombinant TCRs. Perturbing the cellular environment suppressed 2D on-rates but had no effect on 2D off-rate regardless of whether force was applied. In contrast, for the TCR interacting with its monoclonal antibody, the 2D on-rate was insensitive to cellular perturbations and the force-dependent off-rates were indistinguishable for native and recombinant TCRs. These data present novel features of TCR-pMHC kinetics that are regulated by the cellular environment, underscoring the limitations of 3D kinetics in predicting T-cell functions and calling for further elucidation of the underlying molecular and cellular mechanisms that regulate 2D kinetics in physiological settings.

  12. Genetic variation in the major histocompatibility complex of the European brown hare (Lepus europaeus) across distinct phylogeographic areas.

    PubMed

    Koutsogiannouli, Evagelia A; Moutou, Katerina A; Stamatis, Costas; Walter, Lutz; Mamuris, Zissis

    2014-06-01

    The major histocompatibility complex is one of the best studied systems in vertebrates providing evidence for the long-term action of selection. Here, we examined the intra- and inter-population genetic diversity of the MHC class II DRB locus in European brown hare (Lepus europaeus) and correlated the results with genetic variability already estimated from the MHC DQA locus and from maternally (mitochondrial DNA (mtDNA)) and biparentally (allozymes, microsatellites) inherited loci. L. europaeus showed remarkable genetic polymorphism in both DQA and DRB1 loci. The Anatolian populations exhibited the highest genetic polymorphism for both loci. Balancing selection has established increased variability in the European populations despite the founder effects after the last glaciation. Different evolutionary rates were traced for DRB1 and DQA loci, as evidenced by the higher number of common DRB1 than DQA alleles and the greater differences between DRB1 alleles with common origin in comparison with DQA alleles. The high number of rare alleles with low frequencies detected implies that frequency-dependent selection drives MHC evolution in the brown hare through the advantage of rare alleles. Both loci were under the influence of positive selection within the peptide-binding region. The functional polymorphism, recorded as amino acid substitutions within the binding pockets, fell also within distinct geographic patterns, yet it was much narrower than the genetic polymorphism. We hypothesize that certain structural and functional characteristics of the binding pockets set limitations to the actual shape of genetic polymorphism in MHC.

  13. Molecular Architecture of the Major Histocompatibility Complex Class I-Binding Site of Ly49 Natural Killer Cell Receptors

    SciTech Connect

    Deng,L.; Cho, S.; Malchiodi, E.; Kerzic, M.; Dam, J.; Mariuzza, R.

    2008-01-01

    Natural killer (NK) cells play a vital role in the detection and destruction of virally infected and tumor cells during innate immune responses. The highly polymorphic Ly49 family of NK receptors regulates NK cell function by sensing major histocompatibility complex class I (MHC-I) molecules on target cells. Despite the determination of two Ly49-MHC-I complex structures, the molecular features of Ly49 receptors that confer specificity for particular MHC-I alleles have not been identified. To understand the functional architecture of Ly49-binding sites, we determined the crystal structures of Ly49C and Ly49G and completed refinement of the Ly49C-H-2Kb complex. This information, combined with mutational analysis of Ly49A, permitted a structure-based classification of Ly49s that we used to dissect the binding site into three distinct regions, each having different roles in MHC recognition. One region, located at the center of the binding site, has a similar structure across the Ly49 family and mediates conserved interactions with MHC-I that contribute most to binding. However, the preference of individual Ly49s for particular MHC-I molecules is governed by two regions that flank the central region and are structurally more variable. One of the flanking regions divides Ly49s into those that recognize both H-2D and H-2K versus only H-2D ligands, whereas the other discriminates among H-2D or H-2K alleles. The modular design of Ly49-binding sites provides a framework for predicting the MHC-binding specificity of Ly49s that have not been characterized experimentally.

  14. Brief Note Low diversity of the major histocompatibility complex class II DRA gene in domestic goats (Capra hircus) in Southern China.

    PubMed

    Chen, L P; E, G X; Zhao, Y J; Na, R S; Zhao, Z Q; Zhang, J H; Ma, Y H; Sun, Y W; Zhong, T; Zhang, H P; Huang, Y F

    2015-06-18

    DRA encodes the alpha chain of the DR heterodimer, is closely linked to DRB and is considered almost monomorphic in major histocompatibility complex region. In this study, we identified the exon 2 of DRA to evaluate the immunogenetic diversity of Chinese south indigenous goat. Two single nucleotide polymorphisms in an untranslated region and one synonymous substitution in coding region were identified. These data suggest that high immunodiversity in native Chinese population.

  15. Antibody response to sheep red blood cells in major histocompatibility (B) complex aneuploid line of chickens.

    PubMed

    LePage, K T; Bloom, S E; Taylor, R L

    1996-03-01

    An integral part of the immune response is the production of antibodies specific for different antigenic challenges. Genes of the MHC encode products that regulate immunity. This study utilized the FCT-15 line of chickens, which is aneuploid for the chromosome containing the ribosomal RNA genes (rDNA) and the MHC or B complex to determine whether an antibody response to SRBC would vary as a function of B complex gene dose. Mating of trisomic parents (B15B15B15) animals produced progeny having either a disomic (B15B15), trisomic (B15B15B15), or tetrasomic (B15B15B15B15) B complex dosage. The number of B/rDNA chromosomes, and thus the B complex dosage was determined by feather pulp nucleolar typing of chicks at hatch. A 5% SRBC antigenic challenge, which induces a T cell-dependent antibody response, was injected at 6 wk of age. Samples taken prior to SRBC injection as well as 5, 8, and 12 d postinjection were assayed for total and mercaptoethanol-resistant antibody. Peak antibody titers (log2), day of peak titer and rate of titer decline were calculated using a quadratic equation for each bird. Differences among the three B complex dosages were evaluated by analysis of variance. Antibody titers rose from 5 to 8 d postinjection and declined thereafter without significant differences among the three B complex doses. Calculations from the quadratic equations showed that B complex dose affected neither peak antibody titer nor day of peak titer. However, trisomic and tetrasomic animals had significantly more rapid rates of decline from the maximum titer. In aneuploid chickens, changes in antigen processing, antigen presentation, or persistence of processed antigen may maintain levels of antibody production found in disomic chickens and explain the more rapid decline of titer.

  16. Relationship between major histocompatibility complex class I expression and prognosis in canine mammary gland tumors.

    PubMed

    Tanaka, Toshiyuki; Shimada, Terumasa; Akiyoshi, Hideo; Shimizu, Junichiro; Zheng, Cao; Yijyun, Li; Mie, Keiichiro; Hayashi, Akiyoshi; Kuwamura, Mitsuru; Hoshi, Fumio; Ohashi, Fumihito

    2013-10-01

    The aim of this study was to evaluate MHC class I expression and prognosis using tumor tissues surgically removed from 9 dogs with mammary gland carcinomas and from 13 dogs with complex carcinomas. We assessed MHC class I expression and its correlation with tumor size, B2M expression, infiltration of lymphocytes, histological grade and prognosis. Hematoxylin and eosin-stained sections were histologically graded using the Elston and Ellis grading method. MHC class I expression on tumor cells was evaluated using the avidin-biotin peroxidase complex method. Loss of MHC class I expression from canine mammary gland carcinomas was significantly correlated with poor prognosis (P<0.05). Loss of MHC class I expression showed no association with poor prognosis in canine mammary gland complex carcinomas, because the data were not balanced. Only 1 of 13 (7.6%) canine mammary gland complex carcinomas showed loss of MHC class I expression. All 13 of these dogs showed good prognosis. Thus, the low frequency of MHC class I expression loss from canine mammary gland complex carcinomas may be associated with good prognosis. Taken together, these results suggest that loss of MHC class I expression may be associated with poor prognosis in canine mammary gland carcinomas.

  17. Major histocompatibility complex and T cell interactions of a universal T cell epitope from Plasmodium falciparum circumsporozoite protein.

    PubMed

    Parra-López, Carlos; Calvo-Calle, J Mauricio; Cameron, Thomas O; Vargas, Luis E; Salazar, Luz Mary; Patarroyo, Manuel E; Nardin, Elizabeth; Stern, Lawrence J

    2006-05-26

    A 20-residue sequence from the C-terminal region of the circumsporozoite protein of the malaria parasite Plasmodium falciparum is considered a universal helper T cell epitope because it is immunogenic in individuals of many major histocompatibility complex (MHC) haplotypes. Subunit vaccines containing T* and the major B cell epitope of the circumsporozoite protein induce high antibody titers to the malaria parasite and significant T cell responses in humans. In this study we have evaluated the specificity of the T* sequence with regard to its binding to the human class II MHC protein DR4 (HLA-DRB1*0401), its interactions with antigen receptors on T cells, and the effect of natural variants of this sequence on its immunogenicity. Computational approaches identified multiple potential DR4-binding epitopes within T*, and experimental binding studies confirmed the following two tight binding epitopes: one located toward the N terminus (the T*-1 epitope) and one at the C terminus (the T*-5 epitope). Immunization of a human DR4 volunteer with a peptide-based vaccine containing the T* sequence elicited CD4+ T cells that recognize each of these epitopes. Here we present an analysis of the immunodominant N-terminal epitope T*-1. T*-1 residues important for interaction with DR4 and with antigen receptors on T*-specific T cells were mapped. MHC tetramers carrying DR4/T*-1 MHC-peptide complexes stained and efficiently stimulated these cells in vitro. T*-1 overlaps a region of the protein that has been described as highly polymorphic; however, the particular T*-1 residues required for anchoring to DR4 were highly conserved in Plasmodium sequences described to date.

  18. Ethanol Metabolism Alters Major Histocompatibility Complex Class I-Restricted Antigen Presentation In Liver Cells

    PubMed Central

    Osna, Natalia A.; White, Ronda L.; Thiele, Geoffrey M.; Donohue, Terrence M.

    2009-01-01

    The proteasome is a major enzyme that cleaves proteins for antigen presentation. Cleaved peptides traffic to the cell surface, where they are presented in the context of MHC class I. Recognition of these complexes by cytotoxic T lymphocytes is crucial for elimination of cells bearing “non-self” proteins. Our previous studies revealed that ethanol suppresses proteasome function in ethanol-metabolizing liver cells. We hypothesized that proteasome suppression reduces the hydrolysis of antigenic peptides, thereby decreasing the presentation of the peptide-MHC class I-complexes on the cell surface. To test this, we used the mouse hepatocyte cell line (CYP2E1/ADH-transfected HepB5 cells) or primary mouse hepatocytes, both derived from livers of C57Bl/6 mice, which present the ovalbumin peptide, SIINFEKL, complexed with H2Kb. To induce H2Kb expression, HepB5 cells were treated with interferon gamma (IFNγ) and then exposed to ethanol. In these cells, ethanol metabolism decreased not only proteasome activity, but also hydrolysis of the C-extended peptide, SIINFEKL-TE and the presentation of SIINFEKL-H2Kb complexes measured after the delivery of SIINFEKL-TE to cytoplasm. The suppressive effects of ethanol were, in part, attributed to ethanol-elicited impairment of IFNγ signaling. However, in primary hepatocytes, even in the absence of IFNγ, we observed a similar decline in proteasome activity and antigen presentation after ethanol exposure. We conclude that proteasome function is directly suppressed by ethanol metabolism and indirectly, by preventing the activating effects of IFNγ. Ethanol-elicited reduction in proteasome activity contributes to the suppression of SIINFEKL-H2Kb presentation on the surface of liver cells. Immune response to viral antigens plays a crucial role in the pathogenesis of hepatitis C or B viral infections (HCV and HBV, respectively). Professional antigen-presenting cells (dendritic cells and macrophages) are responsible for priming the

  19. Regulation of calreticulin–major histocompatibility complex (MHC) class I interactions by ATP

    PubMed Central

    Wijeyesakere, Sanjeeva Joseph; Gagnon, Jessica K.; Arora, Karunesh; Brooks, Charles L.; Raghavan, Malini

    2015-01-01

    The MHC class I peptide loading complex (PLC) facilitates the assembly of MHC class I molecules with peptides, but factors that regulate the stability and dynamics of the assembly complex are largely uncharacterized. Based on initial findings that ATP, in addition to MHC class I-specific peptide, is able to induce MHC class I dissociation from the PLC, we investigated the interaction of ATP with the chaperone calreticulin, an endoplasmic reticulum (ER) luminal, calcium-binding component of the PLC that is known to bind ATP. We combined computational and experimental measurements to identify residues within the globular domain of calreticulin, in proximity to the high-affinity calcium-binding site, that are important for high-affinity ATP binding and for ATPase activity. High-affinity calcium binding by calreticulin is required for optimal nucleotide binding, but both ATP and ADP destabilize enthalpy-driven high-affinity calcium binding to calreticulin. ATP also selectively destabilizes the interaction of calreticulin with cellular substrates, including MHC class I molecules. Calreticulin mutants that affect ATP or high-affinity calcium binding display prolonged associations with monoglucosylated forms of cellular MHC class I, delaying MHC class I dissociation from the PLC and their transit through the secretory pathway. These studies reveal central roles for ATP and calcium binding as regulators of calreticulin–substrate interactions and as key determinants of PLC dynamics. PMID:26420867

  20. Selection, trans-species polymorphism, and locus identification of major histocompatibility complex class IIβ alleles of New World ranid frogs

    USGS Publications Warehouse

    Kiemnec-Tyburczy, Karen M.; Richmond, Jonathan Q.; Savage, Anna E.; Zamudio, Kelly R.

    2010-01-01

    Genes encoded by the major histocompatibility complex (MHC) play key roles in the vertebrate immune system. However, our understanding of the evolutionary processes and underlying genetic mechanisms shaping these genes is limited in many taxa, including amphibians, a group currently impacted by emerging infectious diseases. To further elucidate the evolution of the MHC in frogs (anurans) and develop tools for population genetics, we surveyed allelic diversity of the MHC class II ??1 domain in both genomic and complementary DNA of seven New World species in the genus Rana (Lithobates). To assign locus affiliation to our alleles, we used a "gene walking" technique to obtain intron 2 sequences that flanked MHC class II?? exon 2. Two distinct intron sequences were recovered, suggesting the presence of at least two class II?? loci in Rana. We designed a primer pair that successfully amplified an orthologous locus from all seven Rana species. In total, we recovered 13 alleles and documented trans-species polymorphism for four of the alleles. We also found quantitative evidence of selection acting on amino acid residues that are putatively involved in peptide binding and structural stability of the ??1 domain of anurans. Our results indicated that primer mismatch can result in polymerase chain reaction (PCR) bias, which influences the number of alleles that are recovered. Using a single locus may minimize PCR bias caused by primer mismatch, and the gene walking technique was an effective approach for generating single-copy orthologous markers necessary for future studies of MHC allelic variation in natural amphibian populations. ?? 2010 Springer-Verlag.

  1. Role of major histocompatibility complex class II in resistance of mice to naturally acquired infection with Syphacia obvelata

    NASA Technical Reports Server (NTRS)

    Stewart, Patricia W.; Chapes, Stephen K.

    2003-01-01

    Genetics plays a substantial role in host resistance in many host-parasite interactions. We examined the prevalence of naturally acquired infection with Syphacia obvelata in a number of mouse strains housed in a non-barrier facility. These mice, which included cross-bred and congenic, inbred strains on various genetic backgrounds, differ in the loci for the immune function genes--major histocompatibility complex class II (MHCII), toll-like receptor 4 (Tlr4), and solute carrier family 11, member 1 (Slc11a1)--which allowed comparisons of the impact of these genes on resistance to pinworm infection. Male and female mice of various ages were sampled over an 18-month period; infection was determined by use of the cellophane tape test. Results indicated that mice that were MHCII+/+ had a significantly lower prevalence of infection than did mice that were MHCII-/-. Differences were not seen between male and female mice. Although MHCII+/+ mice had an age-associated decrease in infection prevalence, such decrease was not seen in MHCII-/- mice. In contrast, infection prevalence in mice with the normal Tlr4 gene (Tlr4(LPS-n/LPS-n)) gene did not differ significantly compared with that in mice that were homozygous for either the point mutation (Tlr4(LPS-d/LPS-d)) or deletion (Tlr4(LPS-del/LPS-del)) of that gene. Likewise, the presence (Sle11a1r/r) or absence (Slc11a1s/s) of functional alleles for Slc11a1 had no effect on the prevalence of infection with S. obvelata. In conclusion, presence of MHCII, but not Tlr4 or Slc11a1 significantly influences prevalence of naturally acquired infection with S. obvelata. These data justify further comprehensive analyses of the immune components that are involved in pinworm resistance.

  2. Two distinct nuclear factors bind the conserved regulatory sequences of a rabbit major histocompatibility complex class II gene.

    PubMed Central

    Sittisombut, N

    1988-01-01

    The constitutive coexpression of the major histocompatibility complex (MHC) class II genes in B lymphocytes requires positive, trans-acting transcriptional factors. The need for these trans-acting factors has been suggested by the reversion of the MHC class II-negative phenotype of rare B-lymphocyte mutants through somatic cell fusion with B cells or T-cell lines. The mechanism by which the trans-acting factors exert their effect on gene transcription is unknown. The possibility that two highly conserved DNA sequences, located 90 to 100 base pairs (bp) (the A sequence) and 60 to 70 bp (the B sequence) upstream of the transcription start site of the class II genes, are recognized by the trans-acting factors was investigated in this study. By using the gel electrophoresis retardation assay, a minimum of two proteins which specifically bound the conserved A or B sequence of a rabbit DP beta gene were identified in murine nuclear extracts of a B-lymphoma cell line, A20-2J. Fractionation of nuclear extract through a heparin-agarose column allowed the identification of one protein, designated NF-MHCIIB, which bound an oligonucleotide containing the B sequence and protected the entire B sequence in the DNase I protection analysis. Another protein, designated NF-MHCIIA, which bound an oligonucleotide containing the A sequence and partially protected the 3' half of this sequence, was also identified. NF-MHCIIB did not protect a CCAAT sequence located 17 bp downstream of the B sequence. The possible relationship between these DNA-binding factors and the trans-acting factors identified in the cell fusion experiments is discussed. Images PMID:3133552

  3. Genetic Variation on the BAT1-NFKBIL1-LTA Region of Major Histocompatibility Complex Class III Associates with Periodontitis

    PubMed Central

    Marchesani, Marja; Vlachopoulou, Efthymia; Mäntylä, Päivi; Paju, Susanna; Buhlin, Kåre; Suominen, Anna L.; Contreras, Johanna; Knuuttila, Matti; Hernandez, Marcela; Huumonen, Sisko; Nieminen, Markku S.; Perola, Markus; Sinisalo, Juha; Lokki, Marja-Liisa; Pussinen, Pirkko J.

    2014-01-01

    Periodontitis is a chronic inflammatory disease with a multifactorial etiology. We investigated whether human major histocompatibility complex (MHC) polymorphisms (6p21.3) are associated with periodontal parameters. Parogene 1 population samples (n = 169) were analyzed with 13,245 single nucleotide polymorphisms (SNPs) of the MHC region. Eighteen selected SNPs (P ≤ 0.001) were replicated in Parogene 2 population samples (n = 339) and the Health 2000 Survey (n = 1,420). All subjects had a detailed clinical and radiographic oral health examination. Serum lymphotoxin-α (LTA) concentrations were measured in the Parogene populations, and the protein was detected in inflamed periodontal tissue. In the Parogene 1 population, 10 SNPs were associated with periodontal parameters. The strongest associations emerged from the parameters bleeding on probing (BOP) and a probing pocket depth (PPD) of ≥6 mm with the genes BAT1, NFKBIL1, and LTA. Six SNPs, rs11796, rs3130059, rs2239527, rs2071591, rs909253, and rs1041981 (r2, ≥0.92), constituted a risk haplotype. In the Parogene 1 population, the haplotype had the strongest association with the parameter BOP, a PPD of ≥6 mm, and severe periodontitis with odds ratios (95% confidence intervals) of 2.63 (2.21 to 3.20), 2.90 (2.37 to 3.52), and 3.10 (1.63 to 5.98), respectively. These results were replicated in the other two populations. High serum LTA concentrations in the Parogene population were associated with the periodontitis risk alleles of the LTA SNPs (rs909253 and rs1041981) of the haplotype. In addition, the protein was expressed in inflamed gingival connective tissue. We identified a novel BAT1-NFKBIL1-LTA haplotype as a significant contributor to the risk of periodontitis. The genetic polymorphisms in the MHC class III region may be functionally important in periodontitis susceptibility. PMID:24566624

  4. Duplication and population dynamics shape historic patterns of selection and genetic variation at the major histocompatibility complex in rodents

    PubMed Central

    Winternitz, Jamie C; Wares, John P

    2013-01-01

    Genetic variation at the major histocompatibility complex (MHC) is vitally important for wildlife populations to respond to pathogen threats. As natural populations can fluctuate greatly in size, a key issue concerns how population cycles and bottlenecks that could reduce genetic diversity will influence MHC genes. Using 454 sequencing, we characterized genetic diversity at the DRB Class II locus in montane voles (Microtus montanus), a North American rodent that regularly undergoes high-amplitude fluctuations in population size. We tested for evidence of historic balancing selection, recombination, and gene duplication to identify mechanisms maintaining allelic diversity. Counter to our expectations, we found strong evidence of purifying selection acting on the DRB locus in montane voles. We speculate that the interplay between population fluctuations and gene duplication might be responsible for the weak evidence of historic balancing selection and strong evidence of purifying selection detected. To further explore this idea, we conducted a phylogenetically controlled comparative analysis across 16 rodent species with varying demographic histories and MHC duplication events (based on the maximum number of alleles detected per individual). On the basis of phylogenetic generalized linear model-averaging, we found evidence that the estimated number of duplicated loci was positively related to allelic diversity and, surprisingly, to the strength of purifying selection at the DRB locus. Our analyses also revealed that species that had undergone population bottlenecks had lower allelic richness than stable species. This study highlights the need to consider demographic history and genetic structure alongside patterns of natural selection to understand resulting patterns of genetic variation at the MHC. PMID:23789067

  5. Major Histocompatibility Complex Genes Map to Two Chromosomes in an Evolutionarily Ancient Reptile, the Tuatara Sphenodon punctatus.

    PubMed

    Miller, Hilary C; O'Meally, Denis; Ezaz, Tariq; Amemiya, Chris; Marshall-Graves, Jennifer A; Edwards, Scott

    2015-05-07

    Major histocompatibility complex (MHC) genes are a central component of the vertebrate immune system and usually exist in a single genomic region. However, considerable differences in MHC organization and size exist between different vertebrate lineages. Reptiles occupy a key evolutionary position for understanding how variation in MHC structure evolved in vertebrates, but information on the structure of the MHC region in reptiles is limited. In this study, we investigate the organization and cytogenetic location of MHC genes in the tuatara (Sphenodon punctatus), the sole extant representative of the early-diverging reptilian order Rhynchocephalia. Sequencing and mapping of 12 clones containing class I and II MHC genes from a bacterial artificial chromosome library indicated that the core MHC region is located on chromosome 13q. However, duplication and translocation of MHC genes outside of the core region was evident, because additional class I MHC genes were located on chromosome 4p. We found a total of seven class I sequences and 11 class II β sequences, with evidence for duplication and pseudogenization of genes within the tuatara lineage. The tuatara MHC is characterized by high repeat content and low gene density compared with other species and we found no antigen processing or MHC framework genes on the MHC gene-containing clones. Our findings indicate substantial differences in MHC organization in tuatara compared with mammalian and avian MHCs and highlight the dynamic nature of the MHC. Further sequencing and annotation of tuatara and other reptile MHCs will determine if the tuatara MHC is representative of nonavian reptiles in general.

  6. Human-specific evolution of killer cell immunoglobulin-like receptor recognition of major histocompatibility complex class I molecules.

    PubMed

    Parham, Peter; Norman, Paul J; Abi-Rached, Laurent; Guethlein, Lisbeth A

    2012-03-19

    In placental mammals, natural killer (NK) cells are a population of lymphocytes that make unique contributions to immune defence and reproduction, functions essential for survival of individuals, populations and species. Modulating these functions are conserved and variable NK-cell receptors that recognize epitopes of major histocompatibility complex (MHC) class I molecules. In humans, for example, recognition of human leucocyte antigen (HLA)-E by the CD94:NKG2A receptor is conserved, whereas recognition of HLA-A, B and C by the killer cell immunoglobulin-like receptors (KIRs) is diversified. Competing demands of the immune and reproductive systems, and of T-cell and NK-cell immunity-combined with the segregation on different chromosomes of variable NK-cell receptors and their MHC class I ligands-drive an unusually rapid evolution that has resulted in unprecedented levels of species specificity, as first appreciated from comparison of mice and humans. Counterparts to human KIR are present only in simian primates. Observed in these species is the coevolution of KIR and the four MHC class I epitopes to which human KIR recognition is restricted. Unique to hominids is the emergence of the MHC-C locus as a supplier of specialized and superior ligands for KIR. This evolutionary trend is most highly elaborated in the chimpanzee. Unique to the human KIR locus are two groups of KIR haplotypes that are present in all human populations and subject to balancing selection. Group A KIR haplotypes resemble chimpanzee KIR haplotypes and are enriched for genes encoding KIR that bind HLA class I, whereas group B KIR haplotypes are enriched for genes encoding receptors with diminished capacity to bind HLA class I. Correlating with their balance in human populations, B haplotypes favour reproductive success, whereas A haplotypes favour successful immune defence. Evolution of the B KIR haplotypes is thus unique to the human species.

  7. Selection, trans-species polymorphism, and locus identification of major histocompatibility complex class IIβ alleles of New World ranid frogs.

    PubMed

    Kiemnec-Tyburczy, Karen M; Richmond, Jonathan Q; Savage, Anna E; Zamudio, Kelly R

    2010-12-01

    Genes encoded by the major histocompatibility complex (MHC) play key roles in the vertebrate immune system. However, our understanding of the evolutionary processes and underlying genetic mechanisms shaping these genes is limited in many taxa, including amphibians, a group currently impacted by emerging infectious diseases. To further elucidate the evolution of the MHC in frogs (anurans) and develop tools for population genetics, we surveyed allelic diversity of the MHC class II β1 domain in both genomic and complementary DNA of seven New World species in the genus Rana (Lithobates). To assign locus affiliation to our alleles, we used a "gene walking" technique to obtain intron 2 sequences that flanked MHC class IIβ exon 2. Two distinct intron sequences were recovered, suggesting the presence of at least two class IIβ loci in Rana. We designed a primer pair that successfully amplified an orthologous locus from all seven Rana species. In total, we recovered 13 alleles and documented trans-species polymorphism for four of the alleles. We also found quantitative evidence of selection acting on amino acid residues that are putatively involved in peptide binding and structural stability of the β1 domain of anurans. Our results indicated that primer mismatch can result in polymerase chain reaction (PCR) bias, which influences the number of alleles that are recovered. Using a single locus may minimize PCR bias caused by primer mismatch, and the gene walking technique was an effective approach for generating single-copy orthologous markers necessary for future studies of MHC allelic variation in natural amphibian populations.

  8. Selection and trans-species polymorphism of major histocompatibility complex class II genes in the order Crocodylia.

    PubMed

    Jaratlerdsiri, Weerachai; Isberg, Sally R; Higgins, Damien P; Miles, Lee G; Gongora, Jaime

    2014-01-01

    Major Histocompatibility Complex (MHC) class II genes encode for molecules that aid in the presentation of antigens to helper T cells. MHC characterisation within and between major vertebrate taxa has shed light on the evolutionary mechanisms shaping the diversity within this genomic region, though little characterisation has been performed within the Order Crocodylia. Here we investigate the extent and effect of selective pressures and trans-species polymorphism on MHC class II α and β evolution among 20 extant species of Crocodylia. Selection detection analyses showed that diversifying selection influenced MHC class II β diversity, whilst diversity within MHC class II α is the result of strong purifying selection. Comparison of translated sequences between species revealed the presence of twelve trans-species polymorphisms, some of which appear to be specific to the genera Crocodylus and Caiman. Phylogenetic reconstruction clustered MHC class II α sequences into two major clades representing the families Crocodilidae and Alligatoridae. However, no further subdivision within these clades was evident and, based on the observation that most MHC class II α sequences shared the same trans-species polymorphisms, it is possible that they correspond to the same gene lineage across species. In contrast, phylogenetic analyses of MHC class II β sequences showed a mixture of subclades containing sequences from Crocodilidae and/or Alligatoridae, illustrating orthologous relationships among those genes. Interestingly, two of the subclades containing sequences from both Crocodilidae and Alligatoridae shared specific trans-species polymorphisms, suggesting that they may belong to ancient lineages pre-dating the divergence of these two families from the common ancestor 85-90 million years ago. The results presented herein provide an immunogenetic resource that may be used to further assess MHC diversity and functionality in Crocodylia.

  9. Inhibition of glucose trimming by castanospermine results in rapid degradation of unassembled major histocompatibility complex class I molecules.

    PubMed

    Moore, S E; Spiro, R G

    1993-02-25

    The CMT-cKd1 cell line provides a system for studying the initial processing steps of N-linked oligosaccharides as these cells have been shown to produce major histocompatibility complex (MHC) class I molecules which, due to a defect in assembly, recycle between the endoplasmic reticulum and a pre-Golgi compartment, failing to reach the cell surface (Hsu, V.W., Yuan, L. C., Nuchtern, J. G., Lippincott-Schwartz, J., Hämmerling, G. J., and Klausner, R. D. (1991) Nature 352, 441-444). In the present study we observed that when the MHC class I heavy chain of these CMT cells was pulse-radiolabeled with [35S]methionine in the presence of the glucosidase inhibitor, castanospermine (CST), it underwent a rapid degradation during a 60-min chase, in contrast to control cells in which it remained stable during that period. The CST-promoted instability of the MHC molecule appeared to be specific, as it did not occur when 1-deoxymannojirimycin, an inhibitor of mannosidase, was added to the cells. Although endomannosidase was found to be present in the CMT cells, the electrophoretic mobility of the MHC heavy chain produced in the presence of CST indicated that deglucosylation through the alternate route provided by this enzyme did not occur. Furthermore, gamma-interferon did not prevent the rapid disappearance of the MHC molecule, although it brought about entry of this glycoprotein into the secretory pathway in cells incubated without CST. The results of our studies suggest that retention of glucose on N-linked oligosaccharides may under certain circumstances provide a signal for pre-Golgi protein degradation.

  10. Regulation of the in vitro presentation of minor lymphocyte stimulating determinants by major histocompatibility complex-encoded immune response genes

    SciTech Connect

    Ryan, J.J.; Miner, D.W.; Mond, J.J.; Finkelman, F.D.; Woody, J.N.

    1987-04-15

    Activation of murine B lymphocytes in a splenocyte stimulator population with affinity-purified goat anti-mouse IgD (G alpha M delta) antibody was previously shown by this laboratory to enhance the presentation of strongly stimulatory major histocompatibility complex (MHC) and minor lymphocyte-stimulating (Mlsa,d) determinants in a primary mixed lymphocyte reaction. In the present study, the G alpha M delta treatment of murine splenocytes was employed to enhance the detection of the weakly stimulatory non-MHC Mlsc determinant in order to study the role the MHC might play as a restricting element for the recognition of these minor antigens in a primary mixed lymphocyte reaction. Indeed, enhanced T cell proliferation to Mlsc determinants presented on G alpha M delta-treated splenocytes was observed when the responder and activated H-2-compatible stimulator cell shared certain MHC haplotypes. High responsiveness was associated with the H-2a,k,j,p haplotypes, intermediate responsiveness was associated with the H-2f,g haplotypes and low responsiveness was associated with the H-2b,s haplotypes. (Low X high responder)F1 T cells preferentially responded to the Mlsc determinants presented on G alpha M delta-treated stimulator cells of the F1 or parental high responder H-2 haplotype. When mitomycin C instead of irradiation was used to inactivate normal (non-IgD-treated) splenocytes, a similar preferential response of T cells to Mlsc determinants presented on stimulator cells of a high responder H-2 haplotype was also observed. The inability of G alpha M delta-treated splenocytes of the low responder haplotype to elicit substantial levels of T cell proliferation across an Mlsc difference could not be attributed to the failure of these stimulator cells to become activated by the anti-Ig antibody. (Abstract Truncated)

  11. Major Histocompatibility Complex Genes Map to Two Chromosomes in an Evolutionarily Ancient Reptile, the Tuatara Sphenodon punctatus

    PubMed Central

    Miller, Hilary C.; O’Meally, Denis; Ezaz, Tariq; Amemiya, Chris; Marshall-Graves, Jennifer A.; Edwards, Scott

    2015-01-01

    Major histocompatibility complex (MHC) genes are a central component of the vertebrate immune system and usually exist in a single genomic region. However, considerable differences in MHC organization and size exist between different vertebrate lineages. Reptiles occupy a key evolutionary position for understanding how variation in MHC structure evolved in vertebrates, but information on the structure of the MHC region in reptiles is limited. In this study, we investigate the organization and cytogenetic location of MHC genes in the tuatara (Sphenodon punctatus), the sole extant representative of the early-diverging reptilian order Rhynchocephalia. Sequencing and mapping of 12 clones containing class I and II MHC genes from a bacterial artificial chromosome library indicated that the core MHC region is located on chromosome 13q. However, duplication and translocation of MHC genes outside of the core region was evident, because additional class I MHC genes were located on chromosome 4p. We found a total of seven class I sequences and 11 class II β sequences, with evidence for duplication and pseudogenization of genes within the tuatara lineage. The tuatara MHC is characterized by high repeat content and low gene density compared with other species and we found no antigen processing or MHC framework genes on the MHC gene-containing clones. Our findings indicate substantial differences in MHC organization in tuatara compared with mammalian and avian MHCs and highlight the dynamic nature of the MHC. Further sequencing and annotation of tuatara and other reptile MHCs will determine if the tuatara MHC is representative of nonavian reptiles in general. PMID:25953959

  12. Selection and Trans-Species Polymorphism of Major Histocompatibility Complex Class II Genes in the Order Crocodylia

    PubMed Central

    Jaratlerdsiri, Weerachai; Isberg, Sally R.; Higgins, Damien P.; Miles, Lee G.; Gongora, Jaime

    2014-01-01

    Major Histocompatibility Complex (MHC) class II genes encode for molecules that aid in the presentation of antigens to helper T cells. MHC characterisation within and between major vertebrate taxa has shed light on the evolutionary mechanisms shaping the diversity within this genomic region, though little characterisation has been performed within the Order Crocodylia. Here we investigate the extent and effect of selective pressures and trans-species polymorphism on MHC class II α and β evolution among 20 extant species of Crocodylia. Selection detection analyses showed that diversifying selection influenced MHC class II β diversity, whilst diversity within MHC class II α is the result of strong purifying selection. Comparison of translated sequences between species revealed the presence of twelve trans-species polymorphisms, some of which appear to be specific to the genera Crocodylus and Caiman. Phylogenetic reconstruction clustered MHC class II α sequences into two major clades representing the families Crocodilidae and Alligatoridae. However, no further subdivision within these clades was evident and, based on the observation that most MHC class II α sequences shared the same trans-species polymorphisms, it is possible that they correspond to the same gene lineage across species. In contrast, phylogenetic analyses of MHC class II β sequences showed a mixture of subclades containing sequences from Crocodilidae and/or Alligatoridae, illustrating orthologous relationships among those genes. Interestingly, two of the subclades containing sequences from both Crocodilidae and Alligatoridae shared specific trans-species polymorphisms, suggesting that they may belong to ancient lineages pre-dating the divergence of these two families from the common ancestor 85–90 million years ago. The results presented herein provide an immunogenetic resource that may be used to further assess MHC diversity and functionality in Crocodylia. PMID:24503938

  13. Major histocompatibility complex variation in insular populations of the Egyptian vulture: inferences about the roles of genetic drift and selection.

    PubMed

    Agudo, Rosa; Alcaide, Miguel; Rico, Ciro; Lemus, Jesus A; Blanco, Guillermo; Hiraldo, Fernando; Donázar, Jose A

    2011-06-01

    Insular populations have attracted the attention of evolutionary biologists because of their morphological and ecological peculiarities with respect to their mainland counterparts. Founder effects and genetic drift are known to distribute neutral genetic variability in these demes. However, elucidating whether these evolutionary forces have also shaped adaptive variation is crucial to evaluate the real impact of reduced genetic variation in small populations. Genes of the major histocompatibility complex (MHC) are classical examples of evolutionarily relevant loci because of their well-known role in pathogen confrontation and clearance. In this study, we aim to disentangle the partial roles of genetic drift and natural selection in the spatial distribution of MHC variation in insular populations. To this end, we integrate the study of neutral (22 microsatellites and one mtDNA locus) and MHC class II variation in one mainland (Iberia) and two insular populations (Fuerteventura and Menorca) of the endangered Egyptian vulture (Neophron percnopterus). Overall, the distribution of the frequencies of individual MHC alleles (n=17 alleles from two class II B loci) does not significantly depart from neutral expectations, which indicates a prominent role for genetic drift over selection. However, our results point towards an interesting co-evolution of gene duplicates that maintains different pairs of divergent alleles in strong linkage disequilibrium on islands. We hypothesize that the co-evolution of genes may counteract the loss of genetic diversity in insular demes, maximize antigen recognition capabilities when gene diversity is reduced, and promote the co-segregation of the most efficient allele combinations to cope with local pathogen communities.

  14. Major Histocompatibility Complex Based Resistance to a Common Bacterial Pathogen of Amphibians

    PubMed Central

    Barribeau, Seth M.; Villinger, Jandouwe; Waldman, Bruce

    2008-01-01

    Given their well-developed systems of innate and adaptive immunity, global population declines of amphibians are particularly perplexing. To investigate the role of the major histocompatibilty complex (MHC) in conferring pathogen resistance, we challenged Xenopus laevis tadpoles bearing different combinations of four MHC haplotypes (f, g, j, and r) with the bacterial pathogen Aeromonas hydrophila in two experiments. In the first, we exposed ff, fg, gg, gj, and jj tadpoles, obtained from breeding MHC homozygous parents, to one of three doses of A. hydrophila or heat-killed bacteria as a control. In the second, we exposed ff, fg, fr, gg, rg, and rr tadpoles, obtained from breeding MHC heterozygous parents and subsequently genotyped by PCR, to A. hydrophila, heat-killed bacteria or media alone as controls. We thereby determined whether the same patterns of MHC resistance emerged within as among families, independent of non-MHC heritable differences. Tadpoles with r or g MHC haplotypes were more likely to die than were those with f or j haplotypes. Growth rates varied among MHC types, independent of exposure dose. Heterozygous individuals with both susceptible and resistant haplotypes were intermediate to either homozygous genotype in both size and survival. The effect of the MHC on growth and survival was consistent between experiments and across families. MHC alleles differentially confer resistance to, or tolerance of, the bacterial pathogen, which affects tadpoles' growth and survival. PMID:18629002

  15. Effect of temperature on the expression of major histocompatibility complex class-I antigens.

    PubMed

    Aboud, M; Segal, S; Priel, E; Blair, D G; O'Hara, B

    1992-06-01

    In the present study we investigated the effect of temperature on MHC class-I gene expression in BALB/C 3T3 cells incubated for 5 days at 34 degrees C, 37 degrees C and 39 degrees C. FACS analysis revealed no significant difference in the cell surface expression of any of the 3 major class-I antigens at 34 degrees C and 37 degrees C. Strikingly, however, when the level of the respective mRNA was determined, only that of the H-2K was comparable at both temperatures, whereas the levels of the H-2D and H-2L mRNA were profoundly higher at 37 degrees C. These data appear to reflect a differential temperature-related transcriptional control of the different class-I genes or a different temperature effect on the stability of their mRNA. The absence of a parallel increase in surface expression of the corresponding H-2D and H-2L antigens may result from some translational or post-translational limiting factors. At 39 degrees C, however, these limiting factors seem to be overcome since the surface expression of all the 3 antigens was remarkably increased although the level of their encoding mRNA was rather lower than in 37 degrees C. This stimulatory effect might be ascribed to heat shock proteins which are known to arise in cells at heat or other stress conditions. They participate in assembly and disassembly of various protein complexes and in transport of certain proteins across intracellular membranes. Such proteins may have arisen in our cells at 39 degrees C and facilitated the intracellular assembly of the class-I molecules and their transport to the cell surface. The possible implication of such heat shock proteins in the anti-tumor effect of hyperthermia is discussed.

  16. Major histocompatibility complex class I evolution in songbirds: universal primers, rapid evolution and base compositional shifts in exon 3

    PubMed Central

    Alcaide, Miguel; Liu, Mark

    2013-01-01

    Genes of the Major Histocompatibility Complex (MHC) have become an important marker for the investigation of adaptive genetic variation in vertebrates because of their critical role in pathogen resistance. However, despite significant advances in the last few years the characterization of MHC variation in non-model species still remains a challenging task due to the redundancy and high variation of this gene complex. Here we report the utility of a single pair of primers for the cross-amplification of the third exon of MHC class I genes, which encodes the more polymorphic half of the peptide-binding region (PBR), in oscine passerines (songbirds; Aves: Passeriformes), a group especially challenging for MHC characterization due to the presence of large and complex MHC multigene families. In our survey, although the primers failed to amplify exon 3 from two suboscine passerine birds, they amplified exon 3 of multiple MHC class I genes in all 16 species of oscine songbirds tested, yielding a total of 120 sequences. The 16 songbird species belong to 14 different families, primarily within the Passerida, but also in the Corvida. Using a conservative approach based on the analysis of cloned amplicons (n = 16) from each species, we found between 3 and 10 MHC sequences per individual. Each allele repertoire was highly divergent, with the overall number of polymorphic sites per species ranging from 33 to 108 (out of 264 sites) and the average number of nucleotide differences between alleles ranging from 14.67 to 43.67. Our survey in songbirds allowed us to compare macroevolutionary dynamics of exon 3 between songbirds and non-passerine birds. We found compelling evidence of positive selection acting specifically upon peptide-binding codons across birds, and we estimate the strength of diversifying selection in songbirds to be about twice that in non-passerines. Analysis using comparative methods suggest weaker evidence for a higher GC content in the 3rd codon position of

  17. Graft-versus-host resistance induced by class II major histocompatibility complex-specific T cell clones

    PubMed Central

    1991-01-01

    Possible mechanisms of graft-vs.-host (GVH) resistance have been studied using a panel of seven class II major histocompatibility complex-specific T cell clones for elicitation and challenge. One clone recognized I-Ak,d,f, and expressed V beta 8.3 together with J beta 1.5. The remaining six clones were I-Ek specific and expressed V beta 15 rearranged to J beta 1.1 or J beta 1.3. The I-Ek-specific clones were also homologous to each other and different from the I-A-reactive one in the D and N regions. Four of the seven clones exhibited I-Ek- specific cytolytic activity. Each clone, when injected in sublethal numbers into appropriate recipients, could induce resistance to a subsequent lethal dose of any other clone in the panel. The resistance did not require sharing of either T cell receptor beta chains or antigen specificity, or MHC molecules by the eliciting and challenging clone. Cytolytic and noncytolytic clones were equally efficient in inducing GVH resistance. A prerequisite of resistance induction was the activation of eliciting clone subsequent to recognition of class II molecules in the host. Clones preactivated with high concentrations of recombinant interleukin 2, in vitro, could induce GVH resistance also in syngeneic hosts, suggesting that resistance induction was associated with the activated state of clone, rather than antigen recognition per se. In all instances of resistance, the challenging clones failed to induce vascular leakage, which was the cause of death in susceptible recipients (Lehmann, P. V., G. Schumm, D. Moon, U. Hurtenbach, F. Falcioni, S. Muller, and Z. A. Nagy. 1990. J. Exp. Med. 171:1485). Lipopolysaccharide (LPS) induced resistance to vascular leakage did not provide crossresistance to GVH and vice versa, suggesting that interleukin 1 alpha and tumor necrosis factor alpha implicated in LPS resistance are not involved in GVH resistance. Although the mechanism remains unclear, the most likely explanation for GVH resistance in this

  18. Species specificity and augmentation of responses to class II major histocompatibility complex molecules in human CD4 transgenic mice

    PubMed Central

    1992-01-01

    Murine T cell responses to human class II major histocompatibility complex (MHC) molecules were shown to be a minimum of 20-70-fold lower than responses to allogeneic molecules. Transgenic mice expressing slightly below normal (75-95%) or very high (250-380%) cell surface levels of human CD4 were utilized to determine whether this was due to a species-specific interaction between murine CD4 and class II molecules. Human CD4 was shown to function in signal transduction events in murine T cells based on the ability of anti-human CD4 antibody to synergize with suboptimal doses of anti-murine CD3 antibody in stimulating T cell proliferation. In mice expressing lower levels of human CD4, T cell responses to human class II molecules were enhanced up to threefold, whereas allogeneic responses were unaltered. In mice expressing high levels of human CD4, responses to human class II molecules were enhanced at least 10-fold, whereas allogeneic responses were between one and three times the level of normal responses. The relatively greater enhancement of the response to human class II molecules in both lines argues for a preferential interaction between human CD4 and human class II molecules. In mice expressing lower levels of human CD4, responses to human class II molecules were blocked by antibodies to CD4 of either species, indicating participation by both molecules. In mice expressing high levels of human CD4, responses to both human and murine class II molecules were almost completely blocked with anti-human CD4 antibody, whereas anti-murine CD4 antibody had no effect. However, anti-murine CD4 continued to synergize with anti-CD3 in stimulating T cell proliferation in these mice. Thus, overexpression of human CD4 selectively impaired the ability of murine CD4 to assist in the process of antigen recognition. The ability of human CD4 to support a strong allogeneic response under these conditions indicates that this molecule can interact with murine class II molecules to a

  19. Polymorphism in the major histocompatibility complex (MHC class II B) genes of the Rufous-backed Bunting (Emberiza jankowskii)

    PubMed Central

    Li, Dan; Zhao, Yunjiao; Lin, Aiqing; Li, Shi; Feng, Jiang

    2017-01-01

    Genetic diversity is one of the pillars of conservation biology research. High genetic diversity and abundant genetic variation in an organism may be suggestive of capacity to adapt to various environmental changes. The major histocompatibility complex (MHC) is known to be highly polymorphic and plays an important role in immune function. It is also considered an ideal model system to investigate genetic diversity in wildlife populations. The Rufous-backed Bunting (Emberiza jankowskii) is an endangered species that has experienced a sharp decline in both population and habitat size. Many historically significant populations are no longer present in previously populated regions, with only three breeding populations present in Inner Mongolia (i.e., the Aolunhua, Gahaitu and Lubei557 populations). Efforts focused on facilitating the conservation of the Rufous-backed Bunting (Emberiza jankowskii) are becoming increasingly important. However, the genetic diversity of E. jankowskii has not been investigated. In the present study, polymorphism in exon 2 of the MHCIIB of E. jankowskii was investigated. This polymorphism was subsequently compared with a related species, the Meadow Bunting (Emberiza cioides). A total of 1.59 alleles/individual were detected in E. jankowskii and 1.73 alleles/individual were identified in E. cioides. The maximum number of alleles per individual from the three E. jankowskii populations suggest the existence of at least three functional loci, while the maximum number of alleles per individual from the three E. cioides populations suggest the presence of at least four functional loci. Two of the alleles were shared between the E. jankowskii and E. cioides. Among the 12 unique alleles identified in E. jankowskii, 10.17 segregating sites per allele were detected, and the nucleotide diversity was 0.1865. Among the 17 unique alleles identified in E. cioides, eight segregating sites per allele were detected, and the nucleotide diversity was 0

  20. Consequences of cytotoxic T lymphocyte interaction with major histocompatibility complex class I-expressing neurons in vivo

    PubMed Central

    1995-01-01

    Neurons have evolved strategies to evade immune surveillance that include an inability to synthesize the heavy chain of the class I major histocompatibility complex (MHC), proteins that are necessary for cytotoxic T lymphocyte (CTL) recognition of target cells. Multiple viruses have taken advantage of the lack of CTL-mediated recognition and killing of neurons by establishing persistent neuronal infections and thereby escaping attack by antiviral CTL. We have expressed a class I MHC molecule (Db) in neurons of transgenic mice using the neuron- specific enolase (NSE) promoter to determine the pathogenic consequences of CTL recognition of virally infected, MHC-expressing central nervous system (CNS) neurons. The NSE-Db transgene was expressed in H-2b founder mice, and transgene-derived messenger RNA was detected by reverse transcriptase-polymerase chain reaction in transgenic brains from several lines. Purified primary neurons from transgenic but not from nontransgenic mice adhered to coverslips coated with a conformation-dependent monoclonal antibody directed against the Dv molecule and presented viral peptide to CTL in an MHC-restricted manner, indicating that the Db molecule was expressed on transgenic neurons in a functional form. Transgenic mice infected with the neurotropic lymphocytic choriomeningitis virus (LCMV) and given anti- LCMV, MHC-restricted CTL displayed a high morbidity and mortality when compared with controls receiving MHC-mismatched CTL or expressing alternative transgenes. After CTL transfer, transgenic brains showed an increased number of CD8+ cells compared with nontransgenic controls as well as an increased rate of clearance of infectious virus from the CNS. Additionally, an increase in blood-brain barrier permeability was detected during viral clearance in NSE-Db transgenic mice and lasted several months after clearance of virus from neurons. In contrast, LCMV- infected, nontransgenic littermates and mice expressing other gene products from

  1. Localization of eight additional genes in the human major histocompatibility complex, including the gene encoding the casein kinase II {beta} subunit (CSNK2B)

    SciTech Connect

    Albertella, M.R.; Jones, H.; Thomson, W.

    1996-09-01

    A wide range of autoimmune and other diseases are known to be associated with the major histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility complex. Many of these diseases are linked to the genes encoding the polymorphic histocompatibility antigens in the class I and class II regions, but some appear to be more strongly associated with genes in the central 1100-kb class III region, making it important to characterize this region fully for the presence of novel genes. An {approximately}220-kb segment of DNA in the class III region separating the Hsp70 (HSPA1L) and BAT1 (D6S8IE) genes, which was previously known to contain 14 genes. Genomic DNA fragments spanning the gaps between the known genes were used as probes to isolate cDNAs corresponding to five new genes within this region. Evidence from Northern blot analysis and exon trapping experiments that suggested the presence of at least two more new genes was also obtained. Partial cDNA and complete exonic genomic sequencing of one of the new genes has identified it as the casein kinase II{beta} subunit (CSNK2B). Two of the other novel genes lie within a region syntenic to that implicated in susceptibility to experimental allergic orchitis in the mouse, an autoimmune disease of the testis, and represent additional candidates for the Orch-1 locus associated with this disease. In addition, characterization of the 13-kb intergenic gap separating the RD (D6545) and G11 (D6S60E) genes has revealed the presence of a gene encoding a 1246-amino-acid polypeptide that shows significant sequence similarity to the yeast anti-viral Ski2p gene product. 49 refs., 8 figs.

  2. Clozapine-induced agranulocytosis is associated with rare HLA-DQB1 and HLA-B alleles

    PubMed Central

    Goldstein, Jacqueline I; Jarskog, L Fredrik; Hilliard, Chris; Alfirevic, Ana; Duncan, Laramie; Fourches, Denis; Huang, Hailiang; Lek, Monkol; Neale, Benjamin M; Ripke, Stephan; Shianna, Kevin; Szatkiewicz, Jin P; Tropsha, Alexander; van den Oord, Edwin JCG; Cascorbi, Ingolf; Dettling, Michael; Gazit, Ephraim; Goff, Donald C; Holden, Arthur L; Kelly, Deanna L; Malhotra, Anil K; Nielsen, Jimmi; Pirmohamed, Munir; Rujescu, Dan; Werge, Thomas; Levy, Deborah L; Josiassen, Richard C; Kennedy, James L; Lieberman, Jeffrey A; Daly, Mark J; Sullivan, Patrick F

    2014-01-01

    Clozapine is a particularly effective antipsychotic medication but its use is curtailed by the risk of clozapine-induced agranulocytosis/granulocytopenia (CIAG), a severe adverse drug reaction occurring in up to 1% of treated individuals. Identifying genetic risk factors for CIAG could enable safer and more widespread use of clozapine. Here we perform the largest and most comprehensive genetic study of CIAG to date by interrogating 163 cases using genome-wide genotyping and whole-exome sequencing. We find that two loci in the major histocompatibility complex are independently associated with CIAG: a single amino acid in HLA-DQB1 (126Q) (P=4.7×10−14, odds ratio, OR=0.19, 95% CI 0.12–0.29) and an amino acid change in the extracellular binding pocket of HLA-B (158T) (P=6.4×10−10, OR=3.3, 95% CI 2.3–4.9). These associations dovetail with the roles of these genes in immunogenetic phenotypes and adverse drug responses for other medications, and provide insight into the pathophysiology of CIAG. PMID:25187353

  3. Lack of Major Histocompatibility Complex Class I Upregulation and Restrictive Infection by JC Virus Hamper Detection of Neurons by T Lymphocytes in the Central Nervous System.

    PubMed

    Wüthrich, Christian; Batson, Stephanie; Koralnik, Igor J

    2015-08-01

    The human polyomavirus JC (JCV) infects glial cells in immunosuppressed individuals, leading to progressive multifocal leukoencephalopathy. Polyomavirus JC can also infect neurons in patients with JCV granule cell neuronopathy and JCV encephalopathy. CD8-positive T cells play a crucial role in viral containment and outcome in progressive multifocal leukoencephalopathy, but whether CD8-positive T cells can also recognize JCV-infected neurons is unclear. We used immunohistochemistry to determine the prevalence of T cells in neuron-rich areas of archival brain samples from 77 patients with JCV CNS infections and 94 control subjects. Neurons predominantly sustained a restrictive infection with expression of JCV regulatory protein T antigen (T Ag), whereas glial cells were productively infected and expressed both T Ag and the capsid protein VP1. T cells were more prevalent near JCV-infected cells with intact nuclei expressing both T Ag and VP1 compared with those expressing either protein alone. CD8-positive T cells also colocalized more with JCV-infected glial cells than with JCV-infected neurons. Major histocompatibility complex class I expression was upregulated in JCV-infected areas but could only be detected in rare neurons interspersed with infected glial cells. These results suggest that isolated neurons harboring restrictive JCV infection do not upregulate major histocompatibility complex class I and thus may escape recognition by CD8-positive T cells.

  4. Molecular and biological interaction between major histocompatibility complex class I antigens and luteinizing hormone receptors or beta-adrenergic receptors triggers cellular response in mice.

    PubMed Central

    Solano, A R; Cremaschi, G; Sánchez, M L; Borda, E; Sterin-Borda, L; Podestá, E J

    1988-01-01

    Purified IgG from BALB/c mouse anti-C3H serum exerts positive inotropic and chronotropic effects in C3H mouse atria and induces testosterone synthesis in C3H mouse Leydig cells. The effect depends on IgG concentration and can be abolished by beta-adrenergic-receptor and luteinizing hormone-receptor antagonists. IgG interferes with the binding of dihydroalprenolol and luteinizing hormone. Monoclonal antibodies against major histocompatibility complex class I antigens were active on the Leydig cells of C3H and BALB/c mice. There was a parallelism between the effect of each individual monoclonal antibody with specificity for a particular haplotype and the response of the target cell from the strains carrying such haplotypes. These antibodies could precipitate the soluble luteinizing hormone-receptor complex. The results suggested that bound hormone triggers the association of major histocompatibility class I antigen with the receptor, thereby activating the respective target cells. PMID:2839829

  5. Cloning of the major histocompatibility complex class II promoter binding protein affected in a hereditary defect in class II gene regulation.

    PubMed Central

    Reith, W; Barras, E; Satola, S; Kobr, M; Reinhart, D; Sanchez, C H; Mach, B

    1989-01-01

    The regulation of major histocompatibility complex class II gene expression is directly involved in the control of normal and abnormal immune responses. In humans, HLA-DR, -DQ, and -DP class II heterodimers are encoded by a family of alpha- and beta-chain genes clustered in the major histocompatibility complex. Their expression is developmentally controlled and normally restricted to certain cell types. This control is mediated by cis-acting sequences in class II promoters and by trans-acting regulatory factors. Several nuclear proteins bind to class II promoter sequences. In a form of hereditary immunodeficiency characterized by a defect in a trans-acting regulatory factor controlling class II gene transcription, we have observed that one of these nuclear factors (RF-X) does not bind to its target sequence (the class II X box). A cDNA encoding RF-X was isolated by screening a phage expression library with an X-box binding-site probe. The recombinant protein has the binding specificity of RF-X, including a characteristic gradient of affinity for the X boxes of HLA-DR, -DP, and -DQ promoters. RF-X mRNA is present in the regulatory mutants, indicating a defect in the synthesis of a functional form of the RF-X protein. Images PMID:2498880

  6. Human epidermal Langerhans cells cointernalize by receptor-mediated endocytosis "nonclassical" major histocompatibility complex class I molecules (T6 antigens) and class II molecules (HLA-DR antigens).

    PubMed Central

    Hanau, D; Fabre, M; Schmitt, D A; Garaud, J C; Pauly, G; Tongio, M M; Mayer, S; Cazenave, J P

    1987-01-01

    HLA-DR and T6 surface antigens are expressed only by Langerhans cells and indeterminate cells in normal human epidermis. We have previously demonstrated that T6 antigens are internalized in Langerhans cells and indeterminate cells by receptor-mediated endocytosis. This process is induced by the binding of BL6, a monoclonal antibody directed against T6 antigens. In the present study, using a monoclonal antibody directed against HLA-DR antigens, on human epidermal cells in suspension, we show that the surface HLA-DR antigens are also internalized by receptor-mediated endocytosis in Langerhans and indeterminate cells. Moreover, using immunogold double labeling, we demonstrate that T6 and HLA-DR antigens are internalized through common coated regions of the membrane of Langerhans or indeterminate cells. The receptor-mediated endocytosis that is induced involves coated pits and vesicles, receptosomes, lysosomes, and also, in Langerhans cells, the Birbeck granules. Thus, T6 antigens, which are considered to be "unusual" or "nonclassical" major histocompatibility complex class I molecules, and the major histocompatibility complex class II molecules, HLA-DR, are internalized in Langerhans and indeterminate cells through common receptor-mediated endocytosis organelles. Images PMID:3106979

  7. The major histocompatibility complex of the rat,RT 1 : II. biochemical evidence for a complex genetic organization.

    PubMed

    Sporer, R; Black, G; Rigiero, C; Manson, L; Götze, D

    1978-12-01

    Recombinational analysis has shown that the rat MHC,RT1 is divided into two regions:RT1.A, which codes for class I (transplantation) antigens, andRT1.B, which controls the humoral immune response and proliferative response to allogeneic cells as well as the expression of class II (Ia) antigens. Serological and sequence studies suggest that there might be more than one antigen-coding locus within theRT1.A region. Results obtained by sequential immunoprecipitation reveal that both regions code for at least two gene products. By implication, theRT1 complex must therefore harbor at least four loci;RT1.A andD coding for class I glycoproteins (45,000 daltons); andRT1.B andE coding for class II (Ia) glycoproteins (35,000 and 28,000 daltons).

  8. An estimate of the recombination frequency between the B locus and the D locus within the major histocompatibility complex.

    PubMed

    Mickelson, E M; Petersons, J S; Flournoy, N; Clift, R A; Thomas, E D

    1976-10-01

    Mixed leukocyte culture studies on 120 families, including 120 HLA haplo-identical siblings and 210 HLA-identical siblings, were analyzed for unusual patterns of reactivity. Three discrepant reactions were noted in which cells from HLA-identical siblings showed strong mutual stimulation. These data provide an estimate of 0.0065 as the recombination frequency between the HLA-B and HLA-D regions of the major histocompatibility chromosome in man. When combined with the data of Keuning et al. (1975), the value is 0.0068 with a 95% confidence interval of 0.0022 to 0.0158.

  9. Characterization and 454 pyrosequencing of Major Histocompatibility Complex class I genes in the great tit reveal complexity in a passerine system

    PubMed Central

    2012-01-01

    Background The critical role of Major Histocompatibility Complex (Mhc) genes in disease resistance and their highly polymorphic nature make them exceptional candidates for studies investigating genetic effects on survival, mate choice and conservation. Species that harbor many Mhc loci and high allelic diversity are particularly intriguing as they are potentially under strong selection and studies of such species provide valuable information as to the mechanisms maintaining Mhc diversity. However comprehensive genotyping of complex multilocus systems has been a major challenge to date with the result that little is known about the consequences of this complexity in terms of fitness effects and disease resistance. Results In this study, we genotyped the Mhc class I exon 3 of the great tit (Parus major) from two nest-box breeding populations near Oxford, UK that have been monitored for decades. Characterization of Mhc class I exon 3 was adopted and bidirectional sequencing was carried using the 454 sequencing platform. Full analysis of sequences through a stepwise variant validation procedure allowed reliable typing of more than 800 great tits based on 214,357 reads; from duplicates we estimated the repeatability of typing as 0.94. A total of 862 alleles were detected, and the presence of at least 16 functional loci was shown - the highest number characterized in a wild bird species. Finally, the functional alleles were grouped into 17 supertypes based on their antigen binding affinities. Conclusions We found extreme complexity at the Mhc class I of the great tit both in terms of allelic diversity and gene number. The presence of many functional loci was shown, together with a pseudogene family and putatively non-functional alleles; there was clear evidence that functional alleles were under strong balancing selection. This study is the first step towards an in-depth analysis of this gene complex in this species, which will help understanding how parasite

  10. Effects of Lung Cotransplantation on Cardiac Allograft Tolerance Across a Full Major Histocompatibility Complex Barrier in Miniature Swine

    PubMed Central

    Madariaga, M. L. L.; Spencer, P. J.; Michel, S. G.; La Muraglia, G. M.; O’Neil, M. J.; Mannon, E. C.; Leblang, C.; Rosales, I. A.; Colvin, R. B.; Sachs, D. H.; Allan, J. S.; Madsen, J. C.

    2016-01-01

    A 12-day course of high-dose tacrolimus induces tolerance of major histocompatibility complex– mismatched lung allografts in miniature swine but does not induce tolerance of heart allografts unless a kidney is cotransplanted. To determine whether lungs share with kidneys the ability to induce cardiac allograft tolerance, we investigated heart–lung co-transplantation using the same induction protocol. Hearts (n = 3), heart–kidneys (n=3), lungs (n=6), and hearts–lungs (n=3) were transplanted into fully major histocompatibility complex–mismatched recipients treated with high-dose tacrolimus for 12 days. Serial biopsy samples were used to evaluate rejection, and in vitro assays were used to detect donor responsiveness. All heart–kidney recipients and five of six lung recipients demonstrated long-term graft survival for longer than 272 days, while all heart recipients rejected their allografts within 35 days. Tolerant recipients remained free of alloantibody and showed persistent donor-specific unresponsiveness by cell-mediated lympholysis/mixed-lymphocyte reaction. In contrast, heart–lung recipients demonstrated rejection of both allografts (days 47, 55, and 202) and antidonor responsiveness in vitro. In contrast to kidneys, lung cotransplantation leads to rejection of both heart and lung allografts, indicating that lungs do not have the same tolerogenic capacity as kidneys. We conclude that cells or cell products present in kidney, but not heart or lung allografts, have a unique capacity to confer unresponsiveness on cotransplanted organs, most likely by amplifying host regulatory mechanisms. PMID:26469344

  11. Dominant sequences of human major histocompatibility complex conserved extended haplotypes from HLA-DQA2 to DAXX.

    PubMed

    Larsen, Charles E; Alford, Dennis R; Trautwein, Michael R; Jalloh, Yanoh K; Tarnacki, Jennifer L; Kunnenkeri, Sushruta K; Fici, Dolores A; Yunis, Edmond J; Awdeh, Zuheir L; Alper, Chester A

    2014-10-01

    We resequenced and phased 27 kb of DNA within 580 kb of the MHC class II region in 158 population chromosomes, most of which were conserved extended haplotypes (CEHs) of European descent or contained their centromeric fragments. We determined the single nucleotide polymorphism and deletion-insertion polymorphism alleles of the dominant sequences from HLA-DQA2 to DAXX for these CEHs. Nine of 13 CEHs remained sufficiently intact to possess a dominant sequence extending at least to DAXX, 230 kb centromeric to HLA-DPB1. We identified the regions centromeric to HLA-DQB1 within which single instances of eight "common" European MHC haplotypes previously sequenced by the MHC Haplotype Project (MHP) were representative of those dominant CEH sequences. Only two MHP haplotypes had a dominant CEH sequence throughout the centromeric and extended class II region and one MHP haplotype did not represent a known European CEH anywhere in the region. We identified the centromeric recombination transition points of other MHP sequences from CEH representation to non-representation. Several CEH pairs or groups shared sequence identity in small blocks but had significantly different (although still conserved for each separate CEH) sequences in surrounding regions. These patterns partly explain strong calculated linkage disequilibrium over only short (tens to hundreds of kilobases) distances in the context of a finite number of observed megabase-length CEHs comprising half a population's haplotypes. Our results provide a clearer picture of European CEH class II allelic structure and population haplotype architecture, improved regional CEH markers, and raise questions concerning regional recombination hotspots.

  12. Class II major histocompatibility complex molecules regulate the development of the T4+T8- inducer phenotype of cultured human thymocytes.

    PubMed Central

    Blue, M L; Daley, J F; Levine, H; Schlossman, S F

    1985-01-01

    We demonstrate that a variety of Ia+ cells has the ability to promote the development of human T4+T8- thymocytes in vitro. Prolonged thymocyte culture in the absence of Ia+ accessory cells results in a predominantly T8+T4- cell population. The generation of T4+ cells in the presence of irradiated Ia+ cells could be suppressed up to 70% by a monoclonal antibody directed against a nonpolymorphic epitope on HLA-DR. Using two-color fluorescence sorting techniques, we were able to identify the activated T4+T8+ thymocyte as the cell that interacts with Ia and gives rise to the T4+T8- cell subset. These results directly and specifically implicate class II major histocompatibility complex molecules in the differentiative pathway of the human thymocyte. Images PMID:2933749

  13. Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex.

    PubMed

    Brake, D A; Fedor, C H; Werner, B W; Miller, T J; Taylor, R L; Clare, R A

    1997-04-01

    A model to simulate natural immunity to Eimeria tenella was developed in three chicken lines which differ at the B locus of the major histocompatibility complex. Homozygous, 1-day-old chicks of the B19B19, B24B24, or B30B30 genotype were trickle immunized by being orally fed a small infectious dose of E. tenella oocysts for 5 consecutive days. These naturally exposed birds were then challenged at different times between 5 and 24 days after the final dose, and the level of protection was assessed 6 days after challenge, using body weight gain and intestinal lesion scores. The duration of immunity in naturally exposed birds differed among the major histocompatibility complex lines. Trickle immunization of the B19B19 haplotype afforded the longest and strongest level of protection compared to the other two haplotypes tested. In addition, in vitro splenic and peripheral blood lymphocyte proliferative responses in trickle-immunized birds were measured against sporozoite, merozoite, and tissue culture-derived E. tenella parasite antigens isolated from the recently described SB-CEV-1/F7 established cell line. The lymphocytes obtained from B19B19 birds trickle immunized responded in vitro to the E. tenella-infected SB-CEV-1/F7 tissue culture-derived parasite antigen. Furthermore, antigen-specific immune responses appeared earlier in immune, challenged B19B19 birds than in their naive, challenged counterparts. The development of a model simulating natural immunization will serve as a foundation to further characterize both humoral and cell-mediated responses to E. tenella tissue culture-derived parasite antigens and to better understand host protective immune responses to avian coccidiosis.

  14. A cure for murine sickle cell disease through stable mixed chimerism and tolerance induction after nonmyeloablative conditioning and major histocompatibility complex-mismatched bone marrow transplantation.

    PubMed

    Kean, Leslie S; Durham, Megan M; Adams, Andrew B; Hsu, Lewis L; Perry, Jennifer R; Dillehay, Dirck; Pearson, Thomas C; Waller, Edmund K; Larsen, Christian P; Archer, David R

    2002-03-01

    The morbidity and mortality associated with sickle cell disease (SCD) is caused by hemolytic anemia, vaso-occlusion, and progressive multiorgan damage. Bone marrow transplantation (BMT) is currently the only curative therapy; however, toxic myeloablative preconditioning and barriers to allotransplantation limit this therapy to children with major SCD complications and HLA-matched donors. In trials of myeloablative BMT designed to yield total marrow replacement with donor stem cells, a subset of patients developed mixed chimerism. Importantly, these patients showed resolution of SCD complications. This implies that less toxic preparative regimens, purposefully yielding mixed chimerism after transplantation, may be sufficient to cure SCD without the risks of myeloablation. To rigorously test this hypothesis, we used a murine model for SCD to investigate whether nonmyeloablative preconditioning coupled with tolerance induction could intentionally create mixed chimerism and a clinical cure. We applied a well-tolerated, nonirradiation-based, allogeneic transplantation protocol using nonmyeloablative preconditioning (low-dose busulfan) and costimulation blockade (CTLA4-Ig and anti-CD40L) to produce mixed chimerism and transplantation tolerance to fully major histocompatibility complex-mismatched donor marrow. Chimeric mice were phenotypically cured of SCD and had normal RBC morphology and hematologic indices (hemoglobin, hematocrit, reticulocyte, and white blood cell counts) without evidence of graft versus host disease. Importantly, they also showed normalization of characteristic spleen and kidney pathology. These experiments demonstrate the ability to produce a phenotypic cure for murine SCD using a nonmyeloablative protocol with fully histocompatibility complex-mismatched donors. They suggest a future treatment strategy for human SCD patients that reduces the toxicity of conventional BMT and expands the use of allotransplantation to non-HLA-matched donors.

  15. Narcolepsy: Autoimmunity, Effector T Cell Activation Due to Infection, or T Cell Independent, Major Histocompatibility Complex Class II Induced Neuronal Loss?

    ERIC Educational Resources Information Center

    Fontana, Adriano; Gast, Heidemarie; Reith, Walter; Recher, Mike; Birchler, Thomas; Bassetti, Claudio L.

    2010-01-01

    Human narcolepsy with cataplexy is a neurological disorder, which develops due to a deficiency in hypocretin producing neurons in the hypothalamus. There is a strong association with human leucocyte antigens HLA-DR2 and HLA-DQB1*0602. The disease typically starts in adolescence. Recent developments in narcolepsy research support the hypothesis of…

  16. Major histocompatibility complex class I expression on neurons in subacute sclerosing panencephalitis and experimental subacute measles encephalitis

    SciTech Connect

    Gogate, N.; Yamabe, Toshio; Verma, L.; Dhib-Jalbut, S.

    1996-04-01

    Lack of major histocompatibility class I antigens on neurons has been implicated as a possible mechanism for viral persistence in the brain since these antigens are required for cytotoxic T-lymphocyte recognition of infected cells. In subacute sclerosing panencephalitis (SSPE), measles virus (MV) persists in neurons, resulting in a fatal chronic infection. MHC class I mRNA expression was examined in formalin-fixed brain tissue from 6 SSPE patients by in situ hybridization. In addition MHC class I protein expression in MV-infected neurons was examined in experimental Subacute Measles Encephalitis (SME) by double immunohistochemistry. MHC class I mRNA expression was found to be upregulated in SSPE tissues studied, and in 5 out of 6 cases the expression was definitively seen on neurons. The percentage of neurons expressing MHC class I mRNA ranged between 20 to 84% in infected areas. There was no correlation between the degree of infection and expression of MHC class I molecules on neurons. Importantly, the number of neurons co-expressing MHC class I and MV antigens was markedly low, varying between 2 to 8%. Similar results were obtained in SME where 20 to 30% of the neurons expressed MHC class I but < 8% co-expressed MHC class I and MV antigens. Perivascular infiltrating cells in the infected regions in SME expressed IFN{gamma} immunoreactivity. The results suggest that MV may not be directly involved in the induction of MHC class I on neurons and that cytokines such as IFN{gamma} may play an important role. Furthermore, the paucity of neurons co-expressing MHC class I and MV antigens in SSPE and SME suggests that such cells are either rapidly cleared by cytotoxic T lymphocytes (CTL), or, alternatively, lack of co-expression of MHC class I on MV infected neurons favors MV persistence in these cells by escaping CTL recognition. 33 refs., 3 figs., 3 tabs.

  17. Major histocompatibility complex class II (MHC II) expression during the development of human fetal cerebral occipital lobe, cerebellum, and hematopoietic organs.

    PubMed

    Wierzba-Bobrowicz, T; Kosno-Kruszewska, E; Gwiazda, E; Lechowicz, W

    2000-01-01

    In adults, under physiological conditions proteins of the major histocompatibility complex, class II (MHC II) molecules are synthesized and then presented on the surface of the cells known under a common name as antigen presenting cells (APCs). Dendritic cells (DCs), microglia, macrophages, ameboid microglia and lymphocytes B are qualified as APCs. The aim of present study was to evaluate the expression of MHC II molecules in the central nervous system (CNS) and hematopoietic organs during the fetal development. Observations were made on the cerebral occipital lobe, cerebellum, thymus, spleen and liver of 30 normal human fetuses, between 11 and 22 week of gestation (GW). Histological, histochemical and immunohistochemical techniques were used to identify cells with expression of MHC II molecules. In the brain, MHC II molecules were detected on macrophages/ameboid microglia in meninges, choroid plexus and single cells of ramified microglia in deeper layers of the cortex and white matter. In the other organs besides macrophages and dendritic cells, MHC II molecules were also immunopositive in thymic epithelial cells, and in the spleen and liver also in other cells of stroma and lobule. The expression of MHC II molecules on so extensive population of cells, at an early stage of the fetal development, may evidence their significant involvement in histogenesis and morphogenesis. It seems that in adults the complex of MHC II with protein is originated from the foreign antigen. On the contrary, during normal fetal development the complex of MHC II with protein origins most probably from the fetus own structures.

  18. Structural and Biochemical Analyses of Swine Major Histocompatibility Complex Class I Complexes and Prediction of the Epitope Map of Important Influenza A Virus Strains

    PubMed Central

    Fan, Shuhua; Wu, Yanan; Wang, Song; Wang, Zhenbao; Jiang, Bo; Liu, Yanjie; Liang, Ruiying; Zhou, Wenzhong

    2016-01-01

    ABSTRACT The lack of a peptide-swine leukocyte antigen class I (pSLA I) complex structure presents difficulties for the study of swine cytotoxic T lymphocyte (CTL) immunity and molecule vaccine development to eliminate important swine viral diseases, such as influenza A virus (IAV). Here, after cloning and comparing 28 SLA I allelic genes from Chinese Heishan pigs, pSLA-3*hs0202 was crystalized and solved. SLA-3*hs0202 binding with sβ2m and a KMNTQFTAV (hemagglutinin [HA]-KMN9) peptide from the 2009 pandemic swine H1N1 strain clearly displayed two distinct conformations with HA-KMN9 peptides in the structures, which are believed to be beneficial to stimulate a broad spectrum of CTL immune responses. Notably, we found that different HA-KMN9 conformations are caused, not only by the flexibility of the side chains of residues in the peptide-binding groove (PBG), but also by the skewing of α1 and α2 helixes forming the PBG. In addition, alanine scanning and circular-dichroism (CD) spectra confirmed that the B, D, and F pockets play critical biochemical roles in determining the peptide-binding motif of SLA-3*hs0202. Based on biochemical parameters and comparisons to similar pockets in other known major histocompatibility complex class I (MHC-I) structures, the fundamental motif for SLA-3*hs0202 was determined to be X-(M/A/R)-(N/Q/R/F)-X-X-X-X-X-(V/I) by refolding in vitro and multiple mutant peptides. Finally, 28 SLA-3*hs0202-restricted epitope candidates were identified from important IAV strains, and two of them have been found in humans as HLA-A*0201-specific IAV epitopes. Structural and biochemical illumination of pSLA-3*hs0202 can benefit vaccine development to control IAV in swine. IMPORTANCE We crystalized and solved the first SLA-3 structure, SLA-3*hs0202, and found that it could present the same IAV peptide with two distinct conformations. Unlike previous findings showing that variable peptide conformations are caused only by the flexibility of the side

  19. Definitions of histocompatibility typing terms: Harmonization of Histocompatibility Typing Terms Working Group.

    PubMed

    Nunes, Eduardo; Heslop, Helen; Fernandez-Vina, Marcelo; Taves, Cynthia; Wagenknecht, Dawn R; Eisenbrey, A Bradley; Fischer, Gottfried; Poulton, Kay; Wacker, Kara; Hurley, Carolyn Katovich; Noreen, Harriet; Sacchi, Nicoletta

    2011-12-01

    Histocompatibility testing for stem cell and solid organ transplantation has become increasingly complex as newly discovered human leukocyte antigen (HLA) alleles are described. HLA typing assignments reported by laboratories are used by physicians and donor registries for matching donors and recipients. To communicate effectively, a common language for histocompatibility terms should be established. In early 2010, representatives from clinical, registry, and histocompatibility organizations joined together as the Harmonization of Histocompatibility Typing Terms Working Group to define a consensual language for laboratories, physicians and registries to communicate histocompatibility typing information. The Working Group defined terms for HLA typing resolution, HLA matching and a format for reporting HLA assignments. In addition, definitions of verification typing and extended typing were addressed. The original draft of the Definitions of Histocompatibility Typing Terms was disseminated to colleagues from each organization to gain feedback and create a collaborative document. Commentary gathered during this 90-day review period were discussed and implemented for preparation of this report. Histocompatibility testing continues to evolve thus, the definitions agreed upon today, likely will require refinement and perhaps additional terminology in the future.

  20. Loss of T Cell Antigen Recognition Arising from Changes in Peptide and Major Histocompatibility Complex Protein Flexibility: Implications for Vaccine Design

    SciTech Connect

    Insaidoo, Francis K.; Borbulevych, Oleg Y.; Hossain, Moushumi; Santhanagopolan, Sujatha M.; Baxter, Tiffany K.; Baker, Brian M.

    2012-05-08

    Modification of the primary anchor positions of antigenic peptides to improve binding to major histocompatibility complex (MHC) proteins is a commonly used strategy for engineering peptide-based vaccine candidates. However, such peptide modifications do not always improve antigenicity, complicating efforts to design effective vaccines for cancer and infectious disease. Here we investigated the MART-1{sub 27-35} tumor antigen, for which anchor modification (replacement of the position two alanine with leucine) dramatically reduces or ablates antigenicity with a wide range of T cell clones despite significantly improving peptide binding to MHC. We found that anchor modification in the MART-1{sub 27-35} antigen enhances the flexibility of both the peptide and the HLA-A*0201 molecule. Although the resulting entropic effects contribute to the improved binding of the peptide to MHC, they also negatively impact T cell receptor binding to the peptide {center_dot} MHC complex. These results help explain how the 'anchor-fixing' strategy fails to improve antigenicity in this case, and more generally, may be relevant for understanding the high specificity characteristic of the T cell repertoire. In addition to impacting vaccine design, modulation of peptide and MHC flexibility through changes to antigenic peptides may present an evolutionary strategy for the escape of pathogens from immune destruction.

  1. Isolation of chicken major histocompatibility complex class II (B-L) beta chain sequences: comparison with mammalian beta chains and expression in lymphoid organs.

    PubMed Central

    Bourlet, Y; Béhar, G; Guillemot, F; Fréchin, N; Billault, A; Chaussé, A M; Zoorob, R; Auffray, C

    1988-01-01

    By cross-hybridization in low stringency conditions, using a probe derived from an HLA-DQ beta cDNA clone, we have isolated several chicken genomic DNA clones. These clones were mapped to the major histocompatibility complex (MHC) of the chick (B complex) by virtue of their ability to detect restriction enzyme length polymorphisms between congenic lines of chicken. Evidence was obtained for the presence of at least three B-L beta genes in the chicken genome. The B-L beta genes are transcribed specifically in tissues containing cells of the B lymphocyte and myeloid lineages and expressing the B-L antigens. Exons encoding the beta 1, beta 2 and transmembrane domains of a B-L beta chain have been identified with 63, 66 and 62% similarity with the HLA-DQ beta sequence. This first isolation of an MHC class II gene outside of the mammalian class provides insight into the evolution of MHC genes based on the comparison of avian and mammalian class II beta chain amino acid and nucleotide sequences. Images PMID:2841107

  2. Chicken major histocompatibility complex-encoded B-G antigens are found on many cell types that are important for the immune system.

    PubMed Central

    Salomonsen, J; Dunon, D; Skjødt, K; Thorpe, D; Vainio, O; Kaufman, J

    1991-01-01

    B-G antigens are a polymorphic multigene family of cell surface molecules encoded by the chicken major histocompatibility complex (MHC). They have previously been described only on cells of the erythroid lineage. By using flow cytometry, section staining, and immunoprecipitation with monoclonal antibodies and rabbit antisera to B-G molecules and by using Northern blots with B-G cDNA clones, we demonstrate here that B-G molecules and RNA are present in many other cell types: thrombocytes, peripheral B and T lymphocytes, bursal B cells and thymocytes, and stromal cells in the bursa, thymus, and caecal tonsil of the intestine. The reactions also identify at least one polymorphic B-G determinant encoded by the B-F/B-L region of the chicken MHC. The serology and tissue distribution of B-G molecules are as complex as those of mammalian MHC class I and class II molecules. These facts, taken with certain functional data, lead us to suggest that B-G molecules have an important role in the selection of B cells in the chicken bursa. Images PMID:1996336

  3. The Same Major Histocompatibility Complex Polymorphism Involved in Control of HIV Influences Peptide Binding in the Mouse H-2Ld System*

    PubMed Central

    Narayanan, Samanthi; Kranz, David M.

    2013-01-01

    Single-site polymorphisms in human class I major histocompatibility complex (MHC) products (HLA-B) have recently been shown to correlate with HIV disease progression or control. An identical single-site polymorphism (at residue 97) in the mouse class I product H-2Ld influences stability of the complex. To gain insight into the human polymorphisms, here we examined peptide binding, stability, and structures of the corresponding Ld polymorphisms, Trp97 and Arg97. Expression of LdW97 and LdR97 genes in a cell line that is antigen-processing competent showed that LdR97 was expressed at higher levels than LdW97, consistent with enhanced stability of self-peptide·LdR97 complexes. To further examine peptide-binding capacities of these two allelic variants, we used a high affinity pep-Ld specific probe to quantitatively examine a collection of self- and foreign peptides that bind to Ld. LdR97 bound more effectively than LdW97 to most peptides, although LdW97 bound more effectively to two peptides. The results support the view that many self-peptides in the Ld system (or the HLA-B system) would exhibit enhanced binding to Arg97 alleles compared with Trp97 alleles. Accordingly, the self-peptide·MHC-Arg97 complexes would influence T-cell selection behavior, impacting the T-cell repertoire of these individuals, and could also impact peripheral T cell activity through effects of self-peptide·Ld interacting with TCR and/or CD8. The structures of several peptide·LdR97 and peptide·LdW97 complexes provided a framework of how this single polymorphism could impact peptide binding. PMID:24064213

  4. Molecular modeling of a T-cell receptor bound to a major histocompatibility complex molecule: implications for T-cell recognition.

    PubMed Central

    Almagro, J. C.; Vargas-Madrazo, E.; Lara-Ochoa, F.; Horjales, E.

    1995-01-01

    The main functions of the T-cell receptor (TCR) involve its specific interaction with short and linear antigenic peptides bound to the major histocompatibility complex (MHC) molecules. In the absence of a 3D structure for TCR and for the TCR/peptide/MHC complex, several attempts to characterize the structural components of the TCR/peptide/MHC interaction have been made. However, this subject is still troublesome. In this paper a computer-based 3D model for a TCR/peptide/MHC complex (5C.C7/moth cytochrome c [MCC] peptide 93-103/I-Ek) was obtained. The complex surface shows a high complementarity between the 5C.C7 structure and the peptide/I-Ek molecule. The mapping of residues involved in the TCR/peptide/MHC interaction shows close agreement with mutational experiments (Jorgensen JL, Reay PA, Ehrich EW, Davis MM, 1992b, Annu Rev Immunol 10:835-873). Moreover, the results are consistent with a recent variability analysis of TCR sequences using three variability indexes (Almagro JC, Zenteno-Cuevas R, Vargas-Madrazo E, Lara-Ochoa F, 1995b, Int J Pept Protein Res 45:180-186). Accordingly, the 3D model of the 5C.C7/MCC peptide 93-103/I-Ek complex provides a framework to generate testable hypotheses about TCR recognition. Thus, starting from this model, the role played by each loop that forms the peptide/MHC binding site of the TCR is discussed. PMID:8528069

  5. Molecular modeling of a T-cell receptor bound to a major histocompatibility complex molecule: implications for T-cell recognition.

    PubMed

    Almagro, J C; Vargas-Madrazo, E; Lara-Ochoa, F; Horjales, E

    1995-09-01

    The main functions of the T-cell receptor (TCR) involve its specific interaction with short and linear antigenic peptides bound to the major histocompatibility complex (MHC) molecules. In the absence of a 3D structure for TCR and for the TCR/peptide/MHC complex, several attempts to characterize the structural components of the TCR/peptide/MHC interaction have been made. However, this subject is still troublesome. In this paper a computer-based 3D model for a TCR/peptide/MHC complex (5C.C7/moth cytochrome c [MCC] peptide 93-103/I-Ek) was obtained. The complex surface shows a high complementarity between the 5C.C7 structure and the peptide/I-Ek molecule. The mapping of residues involved in the TCR/peptide/MHC interaction shows close agreement with mutational experiments (Jorgensen JL, Reay PA, Ehrich EW, Davis MM, 1992b, Annu Rev Immunol 10:835-873). Moreover, the results are consistent with a recent variability analysis of TCR sequences using three variability indexes (Almagro JC, Zenteno-Cuevas R, Vargas-Madrazo E, Lara-Ochoa F, 1995b, Int J Pept Protein Res 45:180-186). Accordingly, the 3D model of the 5C.C7/MCC peptide 93-103/I-Ek complex provides a framework to generate testable hypotheses about TCR recognition. Thus, starting from this model, the role played by each loop that forms the peptide/MHC binding site of the TCR is discussed.

  6. HLA DRB1*DQB1* haplotype in HTLV-I-associated familial infective dermatitis may predict development of HTLV-I-associated myelopathy/tropical spastic paraparesis

    SciTech Connect

    LaGrenade, L.; Miller, W.; Pate, E.; Rodgers-Johnson, P.

    1996-01-02

    A possible causal association between infective dermatitis and HTLV-I infection was reported in 1990 and confirmed in 1992. We now report familial infective dermatitis (ID) occurring in a 26-year-old mother and her 9-year-old son. The mother was first diagnosed with ID in 1969 at the age of 2 years in Dermatology Unit at the University Hospital of the West Indies (U.H.W.I.) in Jamacia. The elder of her 2 sons was diagnosed with ID at the age of 3 years, also at U.H.W.I. Both mother and son are HTLV-I-seropositive. A second, younger son, currently age 2 years, is also HTLV-I-seropositive, but without clinical evidence of ID. Major histocompatibility complex (MHC), class II, human leucocyte antigen (HLA) genotyping documented a shared class II haplotype, DRB1*DQB1* (1101-0301), in the mother and her 2 sons. This same haplotype has been described among Japanese patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and has been associated with a possible pathologically heightened immune response to HTLV-I infection. The presence of this haplotype in these familial ID cases with clinical signs of HAM/TSP may have contributed to their risk for development of HAM/TSP. The unaffected, HTLV-I-seropositive, younger son requires close clinical follow-up. 20 refs., 1 fig., 1 tab.

  7. Improved Binding Activity of Antibodies against Major Histocompatibility Complex Class I Chain-Related Gene A by Phage Display Technology for Cancer-Targeted Therapy

    PubMed Central

    Phumyen, Achara; Jumnainsong, Amonrat; Leelayuwat, Chanvit

    2012-01-01

    Major histocompatibility complex class I chain-related gene A (MICA) is an NKG2D ligand that is over-expressed under cellular stress including cancer transformation and viral infection. High expression of MICA in cancer tissues or patients' sera is useful for prognostic or follow-up markers in cancer patients. In this study, phage display technology was employed to improve antigen-binding activities of anti-MICA monoclonal antibodies (WW2G8, WW6B7, and WW9B8). The 12 amino acid residues in the complementarity determining regions (CDRs) on the V domain of the heavy chain CDR3 (HCDR3) of these anti-MICA antibodies were modified by PCR-random mutagenesis, and phages displaying mutated anti-MICA Fab were constructed. After seven rounds of panning, five clones of phages displaying mutant anti-MICA Fab which exhibited 3–7-folds higher antigen-binding activities were isolated. Two clones of the mutants (phage-displayed mutant Fab WW9B8.1 and phage-displayed mutant Fab WW9B8.21) were confirmed to have antigen-binding specificity for cell surface MICA proteins by flow cytometry. These phage clones are able to recognize MICA in a native form according to positive results obtained by indirect ELISA and flow cytometry. Thus, these phage particles could be potentially used for further development of nanomedicine specifically targeting cancer cells expressing MICA proteins. PMID:23226940

  8. The segment of invariant chain that is critical for association with major histocompatibility complex class II molecules contains the sequence of a peptide eluted from class II polypeptides.

    PubMed Central

    Freisewinkel, I M; Schenck, K; Koch, N

    1993-01-01

    Major histocompatibility complex class II molecules present peptides from an extracellular source of antigens to CD4+ T lymphocytes. The class II-associated invariant chain affects this role of alpha and beta polypeptides by restriction of peptide loading to endocytic vesicles. Up to now no specific portion of the invariant chain has been defined as the class II binding site. We constructed recombinant invariant chain genes and inspected association of the mutant invariant chains with class II polypeptides. Here we demonstrate that an extracytoplasmic sequence of the invariant chain (aa 81-109) that is only 23 residues away from the transmembrane region is essential for contact with class II polypeptides, whereas the remaining C-terminal part is dispensable for binding. The sequence of invariant-chain-derived peptides that were eluted from class II molecules is contained in this segment and may define the class II binding site of the invariant chain. The membrane-proximal position of this region suggests that the invariant chain and invariant-chain-derived peptides isolated from class II molecules bind to a domain distinct from the class II pocket. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8415765

  9. Major histocompatibility complex class II dextramers: New tools for the detection of antigen-specific, CD4 T cells in basic and clinical research

    PubMed Central

    Massilamany, Chandirasegaran; Krishnan, Bharathi; Reddy, Jay

    2015-01-01

    The advent of major histocompatibility complex (MHC) tetramer technology has been a major contribution to T cell immunology, because tetramer reagents permit detection of antigen-specific T cells at the single-cell level in heterogeneous populations by flow cytometry. However, unlike MHC class I tetramers, the utility of MHC class II tetramers has been less frequently reported. MHC class II tetramers can be used successfully to enumerate the frequencies of antigen-specific CD4 T cells in cells activated in vitro, but their use for ex vivo analyses continues to be a problem, due in part to their activation dependency for binding with T cells. To circumvent this problem, we recently reported the creation of a new generation of reagents called MHC class II dextramers, which were found to be superior to their counterparts. In this review, we discuss the utility of class II dextramers vis-a-vis tetramers, with respect to their specificity and sensitivity, including potential applications and limitations. PMID:26207337

  10. Spatio-temporal variation in the strength and mode of selection acting on major histocompatibility complex diversity in water vole (Arvicola terrestris) metapopulations.

    PubMed

    Oliver, Matthew K; Lambin, Xavier; Cornulier, Thomas; Piertney, Stuart B

    2009-01-01

    Patterns of spatio-temporal genetic variation at a class II major histocompatibility complex (MHC) locus and multiple microsatellite loci were analysed within and between three water vole metapopulations in Scotland, UK. Comparisons of MHC and microsatellite spatial genetic differentiation, based on standardised tests between two demographically asynchronous zones within a metapopulation, suggested that spatial MHC variation was affected by balancing selection, directional selection and random genetic drift, but that the relative effects of these microevolutionary forces vary temporally. At the metapopulation level, between-year differentiation for MHC loci was significantly correlated with that of microsatellites, signifying that neutral factors such as migration and drift were primarily responsible for overall temporal genetic change at the metapopulation scale. Between metapopulations, patterns of genetic differentiation implied that, at large spatial scales, MHC variation was primarily affected by directional selection and drift. Levels of MHC heterozygosity in excess of Hardy-Weinberg expectations were consistent with overdominant balancing selection operating on MHC variation within metapopulations. However, this effect was not constant among all samples, indicating temporal variation in the strength of selection relative to other factors. The results highlight the benefit of contrasting variation at MHC with neutral markers to separate the effects of stochastic and deterministic microevolutionary forces, and add to a growing body of evidence showing that the mode and relative strength of selection acting on MHC diversity varies both spatially and temporally.

  11. Transloading of tumor cells with foreign major histocompatibility complex class I peptide ligand: a novel general strategy for the generation of potent cancer vaccines.

    PubMed Central

    Schmidt, W; Steinlein, P; Buschle, M; Schweighoffer, T; Herbst, E; Mechtler, K; Kirlappos, H; Birnstiel, M L

    1996-01-01

    The major hurdle to be cleared in active immunotherapy of cancer is the poor immunogenicity of cancer cells. In previous attempts to overcome this problem, whole tumor cells have been used as vaccines, either admixed with adjuvant(s) or genetically engineered to express nonself proteins or immunomodulatory factors before application. We have developed a novel approach to generate an immunogeneic, highly effective vaccine: major histocompatibility complex (MHC) class I-positive cancer cells are administered together with MHC class I-matched peptide ligands of foreign, nonself origin, generated by a procedure we term transloading. Murine tumor lines of the H2-Kd or the H2-Db haplotype, melanoma M-3 and B16-F10, respectively, as well as colon carcinoma CT-26 (H2-Kd), were transloaded with MHC-matched influenza virus-derived peptides and applied as irradiated vaccines. Mice bearing a deposit of live M-3 melanoma cells were efficiently cured by this treatment. In the CT-26 colon carcinoma and the B16-F10 melanoma, high efficacies were obtained against tumor challenge, suggesting the universal applicability of this new type of vaccine. With foreign peptide ligands adapted to the requirements of a desired MHC class I haplotype, this concept may be used for the treatment of human cancers. Images Fig. 1 PMID:8790404

  12. Evidence that transporters associated with antigen processing translocate a major histocompatibility complex class I-binding peptide into the endoplasmic reticulum in an ATP-dependent manner.

    PubMed Central

    Androlewicz, M J; Anderson, K S; Cresswell, P

    1993-01-01

    We have investigated the role of the putative peptide transporters associated with antigen processing (TAP) by using a permeabilized-cell system. The main objective was to determine whether these molecules, which bear homology to the ATP-binding cassette family of transporters, translocate antigenic peptides across the endoplasmic reticulum membrane for assembly with major histocompatibility complex (MHC) class I molecules and beta 2-microglobulin light chain. The pore-forming toxin streptolysin O was used to generate permeabilized cells, and peptide translocation was determined by measuring the amount of added radiolabeled peptide bound to endogenous class I molecules. No radiolabeled peptide was associated with MHC class I glycoproteins from unpermeabilized cells. We found that efficient peptide binding to MHC class I molecules in permeabilized cells is both transporter dependent and ATP dependent. In antigen-processing mutant cells lacking a functional transporter, uptake occurs only through a less-efficient transporter and ATP-independent pathway. In addition, short peptides (8-10 amino acids) known to bind MHC class I molecules compete efficiently with a radiolabeled peptide for TAP-dependent translocation, whereas longer peptides and a peptide derived from an endoplasmic reticulum signal sequence do not compete efficiently. This result indicates that the optimal substrates for TAP possess the characteristics of MHC-binding peptides. Images Fig. 2 Fig. 3 Fig. 4 PMID:8415666

  13. Applicability of major histocompatibility complex DRB1 alleles as markers to detect vertebrate hybridization: a case study from Iberian ibex × domestic goat in southern Spain

    PubMed Central

    2012-01-01

    Background Hybridization between closely related wild and domestic species is of great concern because it can alter the evolutionary integrity of the affected populations. The high allelic variability of Major Histocompatibility Complex (MHC) loci usually excludes them from being used in studies to detect hybridization events. However, if a) the parental species don’t share alleles, and b) one of the parental species possesses an exceptionally low number of alleles (to facilitate analysis), then even MHC loci have the potential to detect hybrids. Results By genotyping the exon2 of the MHC class II DRB1 locus, we were able to detect hybridization between domestic goats (Capra hircus) and free-ranging Iberian ibex (Capra pyrenaica hispanica) by molecular means. Conclusions This is the first documentation of a Capra pyrenaica × Capra hircus hybridization, which presented us the opportunity to test the applicability of MHC loci as new, simple, cost-effective, and time-saving approach to detect hybridization between wild species and their domesticated relatives, thus adding value to MHC genes role in animal conservation and management. PMID:23006678

  14. Gene Conversion in the Evolution of Both the H-2 and Qa Class I Genes of the Murine Major Histocompatibility Complex

    PubMed Central

    Kuhner, M.; Watts, S.; Klitz, W.; Thomson, G.; Goodenow, R. S.

    1990-01-01

    In order to better understand the role of gene conversion in the evolution of the class I gene family of the major histocompatibility complex (MHC), we have used a computer algorithm to detect clustered sequence similarities among 24 class I DNA sequences from the H-2, Qa, and Tla regions of the murine MHC. Thirty-four statistically significant clusters were detected; individual analysis of the clusters suggested at least 25 past gene conversion or recombination events. These clusters are comparable in size to the conversions observed in the spontaneously occurring H-2K(bm) and H-2K(km2) mutations, and are distributed throughout all exons of the class I gene. Thus, gene conversion does not appear to be restricted to the regions of the class I gene encoding their antigen-presentation function. Moreover, both the highly polymorphic H-2 loci and the relatively monomorphic Qa and Tla loci appear to have participated as donors and recipients in conversion events. If gene conversion is not limited to the highly polymorphic loci of the MHC, then another factor, presumably natural selection, must be responsible for maintaining the observed differences in level of variation. PMID:2076814

  15. Characterization and genotyping of the DRB1 gene of the major histocompatibility complex (MHC) in the Marmota monax, animal model of hepatitis B.

    PubMed

    Moreno-Cugnon, Leire; Esparza-Baquer, Aitor; Larruskain, Amaia; García-Etxebarria, Koldo; Menne, Stephan; González-Aseguinolaza, Gloria; Jugo, Begoña M

    2015-02-01

    The major histocompatibility complex (MHC)-containing genes are among the most polymorphic in vertebrates. MHC genes code for proteins that are critical in the immune system response. In this study, the polymorphism of the second exon of the MHC class II DRB gene was characterized in the Eastern woodchuck (Marmota monax). Woodchucks chronically infected with the woodchuck hepatitis virus (WHV) represent the best available animal model for the study of chronic hepatitis B infection in humans. In the genotyped animals we found fifteen alleles, which were expressed in two independent loci and that were named DRB1A and DRB1B in this work. The 15 alleles investigated showed an elevated divergence. A significant excess of non-synonymous substitutions was detected, which could indicate that a historical positive selection is acting in the woodchuck DRB1 genes. This hypothesis was confirmed in our study by the high variability in or near the antigen binding sites (ABS) and by the results obtained in sequence variability analyses. This analysis identified the presence of a microsatellite sequence that is located at the start of the second intron, which could further allow the development of a fast and cheap semiautomatic sequencing method.

  16. Intermediate number of major histocompatibility complex class IIB length variants relates to enlarged perivisceral fat deposits in the blunt-head cichlid Tropheus moorii.

    PubMed

    Hablützel, P I; Vanhove, M P M; Grégoir, A F; Hellemans, B; Volckaert, F A M; Raeymaekers, J A M

    2014-10-01

    Studying the genetic basis of host-parasite interactions represents an outstanding opportunity to observe eco-evolutionary processes. Established candidates for such studies in vertebrates are immunogenes of the major histocompatibility complex (MHC). The MHC has been reported to reach high intra- and interindividual diversity, and a diverse MHC might be advantageous when facing infections from multiple parasites. However, other studies indicated that individuals with an intermediate number of MHC alleles are less infected with parasites or have other fitness advantages. In this study, we assessed the optimal number of MHC alleles in the blunt-head cichlid Tropheus moorii from Lake Tanganyika. We investigated the influence of the interindividual variation in number of MHC length variants on parasite infection and body condition, measured by the amount of perivisceral fat reserves. Surprisingly, there was no correlation between parasite infection and number of MHC length variants or perivisceral fat deposits. However, the individual number of MHC length variants significantly correlated with the amount of perivisceral fat deposits in males, suggesting that male individuals with an intermediate number of alleles might be able to use their fat reserves more efficiently.

  17. Transcription of non-classic major histocompatibility complex (MHC) class I in the bovine placenta throughout gestation and after Brucella abortus infection.

    PubMed

    Dos Santos, Larissa Sarmento; da Silva Mol, Juliana Pinto; de Macedo, Auricélio Alves; Silva, Ana Patrícia Carvalho; Dos Santos Ribeiro, Diego Luiz; Santos, Renato Lima; da Paixão, Tatiane Alves; de Carvalho Neta, Alcina Vieira

    2015-10-15

    Transcription of non-classical major histocompatibility complex class I (MHC-I) was assessed in the bovine placenta throughout gestation. Additionally, the effect of Brucella abortus infection on expression of non-classical MHC-I was also evaluated using a chorioallantoic membrane explant model of infection. The non-classical MHC-I genes MICB and NC3 had higher levels of transcription in the intercotyledonary region when compared to the placentome, which had higher levels of transcription at the second trimester of gestation. NC1 and classical MHC-I had very low levels of transcription throughout gestation. Trophoblastic cells of B. abortus-infected chorioallantoic membrane explants had an increase in transcription of non-classical MHC-I at 4h post infection. Therefore, this study provides an analysis of non-classical MHC-I transcription at different stages of gestation and different placental tissues, and during B. abortus infection. These findings provide additional knowledge on immune regulation in placental tissues, a known immune-privileged site.

  18. Specific Capture of Peptide-Receptive Major Histocompatibility Complex Class I Molecules by Antibody Micropatterns Allows for a Novel Peptide-Binding Assay in Live Cells.

    PubMed

    Dirscherl, Cindy; Palankar, Raghavendra; Delcea, Mihaela; Kolesnikova, Tatiana A; Springer, Sebastian

    2017-02-02

    Binding assays with fluorescently labeled ligands and recombinant receptor proteins are commonly performed in 2D arrays. But many cell surface receptors only function in their native membrane environment and/or in a specific conformation, such as they appear on the surface of live cells. Thus, receptors on live cells should be used for ligand binding assays. Here, it is shown that antibodies preprinted on a glass surface can be used to specifically array a peptide receptor of the immune system, i.e., the major histocompatibility complex class I molecule H-2K(b) , into a defined pattern on the surface of live cells. Monoclonal antibodies make it feasible to capture a distinct subpopulation of H-2K(b) and hold it at the cell surface. This patterned receptor enables a novel peptide-binding assay, in which the specific binding of a fluorescently labeled index peptide is visualized by microscopy. Measurements of ligand binding to captured cell surface receptors in defined confirmations apply to many problems in cell biology and thus represent a promising tool in the field of biosensors.

  19. A large protein containing zinc finger domains binds to related sequence elements in the enhancers of the class I major histocompatibility complex and kappa immunoglobulin genes.

    PubMed Central

    Baldwin, A S; LeClair, K P; Singh, H; Sharp, P A

    1990-01-01

    A cDNA from a B-cell library was previously isolated that encodes a sequence-specific DNA-binding protein with affinities for related sites in a class I major histocompatibility complex (MHC) and kappa immunoglobulin gene enhancers. We report here approximately 6.5 kilobases of sequence of the MBP-1 (MHC enhancer binding protein 1) cDNA. MBP-1 protein has a molecular weight predicted to be greater than 200,000. A DNA-binding domain with high affinity for the MHC enhancer sequence TGGGGATTCCCCA was localized to an 118-amino-acid protein fragment containing two zinc fingers of the class Cys2-X12-His2. Analysis of expression of MBP-1 mRNA revealed relatively high expression in HeLa cells and in a human retinal cell line, with lower levels in Jurkat T cells and in two B-cell lines. Interestingly, expression of MBP-1 mRNA was inducible by mitogen and phorbol ester treatment of Jurkat T cells and by serum treatment of confluent serum-deprived human fibroblasts. Images PMID:2108316

  20. The CLIP region of invariant chain plays a critical role in regulating major histocompatibility complex class II folding, transport, and peptide occupancy.

    PubMed

    Romagnoli, P; Germain, R N

    1994-09-01

    Invariant chain (Ii) contributes in a number of distinct ways to the proper functioning of major histocompatibility complex (MHC) class II molecules. These include promoting effective association and folding of newly synthesized MHC class II alpha and beta subunits, increasing transit of assembled heterodimers out of the endoplasmic reticulum (ER), inhibiting class II peptide binding, and facilitating class II movement to or accumulation in endosomes/lysosomes. Although the cytoplasmic tail of Ii makes a key contribution to the endocytic localization of class II, the relationship between the structure of Ii and its other diverse functions remains unknown. We show here that two thirds of the lumenal segment of Ii can be eliminated without affecting its contributions to the secretory pathway events of class II folding, ER to Golgi transport, or inhibition of peptide binding. These same experiments reveal that a short (25 residue) contiguous internal segment of Ii (the CLIP region), frequently found associated with purified MHC class II molecules, is critical for all three functions. Together with other recent findings, these results raise the possibility that the contributions of Ii to the early postsynthetic behavior of class II may depend on its interaction with the class II binding site. This would be consistent with the intracellular behavior of unoccupied MHC class I and class II molecules as incompletely folded proteins and imply a related structural basis for the similar contributions of Ii to class II and of short peptides to class I assembly and transport.

  1. High-frequency stimulation of the subthalamic nucleus counteracts cortical expression of major histocompatibility complex genes in a rat model of Parkinson's disease.

    PubMed

    Grieb, Benjamin; Engler, Gerhard; Sharott, Andrew; von Nicolai, Constantin; Streichert, Thomas; Papageorgiou, Ismini; Schulte, Alexander; Westphal, Manfred; Lamszus, Katrin; Engel, Andreas K; Moll, Christian K E; Hamel, Wolfgang

    2014-01-01

    High-frequency stimulation of the subthalamic nucleus (STN-HFS) is widely used as therapeutic intervention in patients suffering from advanced Parkinson's disease. STN-HFS exerts a powerful modulatory effect on cortical motor control by orthodromic modulation of basal ganglia outflow and via antidromic activation of corticofugal fibers. However, STN-HFS-induced changes of the sensorimotor cortex are hitherto unexplored. To address this question at a genomic level, we performed mRNA expression analyses using Affymetrix microarray gene chips and real-time RT-PCR in sensorimotor cortex of parkinsonian and control rats following STN-HFS. Experimental parkinsonism was induced in Brown Norway rats by bilateral nigral injections of 6-hydroxydopamine and was assessed histologically, behaviorally, and electrophysiologically. We applied prolonged (23h) unilateral STN-HFS in awake and freely moving animals, with the non-stimulated hemisphere serving as an internal control for gene expression analyses. Gene enrichment analysis revealed strongest regulation in major histocompatibility complex (MHC) related genes. STN-HFS led to a cortical downregulation of several MHC class II (RT1-Da, Db1, Ba, and Cd74) and MHC class I (RT1CE) encoding genes. The same set of genes showed increased expression levels in a comparison addressing the effect of 6-hydroxydopamine lesioning. Hence, our data suggest the possible association of altered microglial activity and synaptic transmission by STN-HFS within the sensorimotor cortex of 6-hydroxydopamine treated rats.

  2. Evidence of gene orthology and trans-species polymorphism, but not of parallel evolution, despite high levels of concerted evolution in the major histocompatibility complex of flamingo species.

    PubMed

    Gillingham, M A F; Courtiol, A; Teixeira, M; Galan, M; Bechet, A; Cezilly, F

    2016-02-01

    The major histocompatibility complex (MHC) is a cornerstone in the study of adaptive genetic diversity. Intriguingly, highly polymorphic MHC sequences are often not more similar within species than between closely related species. Divergent selection of gene duplicates, balancing selection maintaining trans-species polymorphism (TSP) that predate speciation and parallel evolution of species sharing similar selection pressures can all lead to higher sequence similarity between species. In contrast, high rates of concerted evolution increase sequence similarity of duplicated loci within species. Assessing these evolutionary models remains difficult as relatedness and ecological similarities are often confounded. As sympatric species of flamingos are more distantly related than allopatric species, flamingos represent an ideal model to disentangle these evolutionary models. We characterized MHC Class I exon 3, Class IIB exon 2 and exon 3 of the six extant flamingo species. We found up to six MHC Class I loci and two MHC Class IIB loci. As all six species shared the same number of MHC Class IIB loci, duplication appears to predate flamingo speciation. However, the high rate of concerted evolution has prevented the divergence of duplicated loci. We found high sequence similarity between all species regardless of codon position. The latter is consistent with balancing selection maintaining TSP, as under this mechanism amino acid sites under pathogen-mediated selection should be characterized by fewer synonymous codons (due to their common ancestry) than under parallel evolution. Overall, balancing selection maintaining TSP appears to result in high MHC similarity between species regardless of species relatedness and geographical distribution.

  3. Physical map of human 6p21.2-6p21.3: region flanking the centromeric end of the major histocompatibility complex.

    PubMed

    Tripodis, N; Mason, R; Humphray, S J; Davies, A F; Herberg, J A; Trowsdale, J; Nizetic, D; Senger, G; Ragoussis, J

    1998-06-01

    We have physically mapped and cloned a 2.5-Mb chromosomal segment flanking the centromeric end of the major histocompatibility complex (MHC). We characterized in detail 27 YACs, 144 cosmids, 51 PACs, and 5 BACs, which will facilitate the complete genomic sequencing of this region of chromosome 6. The contig contains the genes encoding CSBP, p21, HSU09564 serine kinase, ZNF76, TCP-11, RPS10, HMGI(Y), BAK, and the human homolog of Tctex-7 (HSET). The GLO1 gene was mapped further centromeric in the 6p21.2-6p21.1 region toward TCTE-1. The gene order of the GLO1-HMGI(Y) segment in respect to the centromere is similar to the gene order in the mouse t-chromosome distal inversion, indicating that there is conservation in gene content but not gene order between humans and mice in this region. The close linkage of the BAK and CSBP genes to the MHC is of interest because of their possible involvement in autoimmune disease.

  4. Impact of lipid rafts on the T -cell-receptor and peptide-major-histocompatibility-complex interactions under different measurement conditions

    NASA Astrophysics Data System (ADS)

    Li, Long; Xu, Guang-Kui; Song, Fan

    2017-01-01

    The interactions between T-cell receptor (TCR) and peptide-major-histocompatibility complex (pMHC), which enable T-cell development and initiate adaptive immune responses, have been intensively studied. However, a central issue of how lipid rafts affect the TCR-pMHC interactions remains unclear. Here, by using a statistical-mechanical membrane model, we show that the binding affinity of TCR and pMHC anchored on two apposing cell membranes is significantly enhanced because of the lipid raft-induced signaling protein aggregation. This finding may provide an alternative insight into the mechanism of T-cell activation triggered by very low densities of pMHC. In the case of cell-substrate adhesion, our results indicate that the loss of lateral mobility of the proteins on the solid substrate leads to the inhibitory effect of lipid rafts on TCR-pMHC interactions. Our findings help to understand why different experimental methods for measuring the impact of lipid rafts on the receptor-ligand interactions have led to contradictory conclusions.

  5. Allospecific cytotoxic T lymphocytes recognize an H-2 peptide in the context of a murine major histocompatibility complex class I molecule.

    PubMed Central

    Song, E S; Linsk, R; Olson, C A; McMillan, M; Goodenow, R S

    1988-01-01

    We have isolated cytotoxic T lymphocytes (CTL) preferentially reactive with the alpha 1 external domain of the H-2Ld antigen by selecting for T cells capable of recognizing a variant major histocompatibility complex (MHC) class I antigen sharing alpha 1 sequences with H-2Ld. Using these CTL, we demonstrate that a synthetic alpha 1 peptide corresponding to one of the helices derived from the H-2Ld molecule can be presented by a class I restriction element to reconstitute a CTL determinant borne by intact H-2Ld. Moreover, several other H-2L-reactive CTL generated independently were also able to recognize H-2Ld either as an intact alloantigen or as a peptide in conjunction with appropriate class I restriction elements. These data demonstrate that an H-2 peptide can reconstitute a CTL target structure and suggest that some alloreactive T cells in fact might be directed against allogeneic class I peptides in the context of a class I framework. PMID:3258067

  6. Immune response genes controlling responsiveness to major transplantation antigens. Specific major histocompatibility complex-linked defect for antibody responses to class I alloantigens

    SciTech Connect

    Butcher, G.W.; Corvalan, J.R.; Licence, D.R.; Howard, J.C.

    1982-01-01

    We have identified two major histocompatibility complex (MHC)-linked Ir genes that control the antibody response made by rats against class I major alloantigens. We have named these genes Ir-RT1Aa and Ir-RT1Ac. These Ir genes determine responsiveness of the immunized animal in a typical codominant fashion. There is no evidence so far for trans-complementation between low-responder haplotypes. Detailed studies of Ir-RT1Aa indicate that it controls the antibody response to at least two distinct alloantigenic determinants on RT1Aa molecules. These class I molecules thus behave like hapten-carrier conjugates when the response against the carrier is under Ir gene control. Analysis of the origin of alloantibody-forming cells in tetraparental radiation chimeras indicates that Ir-RT1Aa must control the provision of effective help to B cells. In many respects therefore, the properties of Ir-RT1Aa are broadly similar to those described for Ir genes controlling antibody responses to conventional antigens. The existence of apparently conventional Ir genes controlling the antibody response to major alloantigens strongly suggest that the processing of these transmembrane molecules by host antigen-presenting cells is a prerequisite for immune induction, and that it is the MHC of the responder rather than that of the allograft to which T helper cells are restricted in alloimmune responses in vivo.

  7. Impact of lipid rafts on the T-cell-receptor and peptide-major-histocompatibility-complex interactions under different measurement conditions.

    PubMed

    Li, Long; Xu, Guang-Kui; Song, Fan

    2017-01-01

    The interactions between T-cell receptor (TCR) and peptide-major-histocompatibility complex (pMHC), which enable T-cell development and initiate adaptive immune responses, have been intensively studied. However, a central issue of how lipid rafts affect the TCR-pMHC interactions remains unclear. Here, by using a statistical-mechanical membrane model, we show that the binding affinity of TCR and pMHC anchored on two apposing cell membranes is significantly enhanced because of the lipid raft-induced signaling protein aggregation. This finding may provide an alternative insight into the mechanism of T-cell activation triggered by very low densities of pMHC. In the case of cell-substrate adhesion, our results indicate that the loss of lateral mobility of the proteins on the solid substrate leads to the inhibitory effect of lipid rafts on TCR-pMHC interactions. Our findings help to understand why different experimental methods for measuring the impact of lipid rafts on the receptor-ligand interactions have led to contradictory conclusions.

  8. Techniques to improve the direct ex vivo detection of low frequency antigen-specific CD8+ T cells with peptide-major histocompatibility complex class I tetramers.

    PubMed

    Chattopadhyay, Pratip K; Melenhorst, J Joseph; Ladell, Kristin; Gostick, Emma; Scheinberg, Phillip; Barrett, A John; Wooldridge, Linda; Roederer, Mario; Sewell, Andrew K; Price, David A

    2008-11-01

    The ability to quantify and characterize antigen-specific CD8+ T cells irrespective of functional readouts using fluorochrome-conjugated peptide-major histocompatibility complex class I (pMHCI) tetramers in conjunction with flow cytometry has transformed our understanding of cellular immune responses over the past decade. In the case of prevalent CD8+ T cell populations that engage cognate pMHCI tetramers with high avidities, direct ex vivo identification and subsequent data interpretation is relatively straightforward. However, the accurate identification of low frequency antigen-specific CD8+ T cell populations can be complicated, especially in situations where T cell receptor-mediated tetramer binding occurs at low avidities. Here, we highlight a few simple techniques that can be employed to improve the visual resolution, and hence the accurate quantification, of tetramer binding CD8+ T cell populations by flow cytometry. These methodological modifications enhance signal intensity, especially in the case of specific CD8+ T cell populations that bind cognate antigen with low avidities, minimize background noise, and enable improved discrimination of true pMHCI tetramer binding events from nonspecific uptake.

  9. Structural analysis of the human interferon gamma receptor: a small segment of the intracellular domain is specifically required for class I major histocompatibility complex antigen induction and antiviral activity.

    PubMed

    Cook, J R; Jung, V; Schwartz, B; Wang, P; Pestka, S

    1992-12-01

    Mutations of the human interferon gamma (IFN-gamma) receptor intracellular domain have permitted us to define a restricted region of that domain as necessary for both induction of class I major histocompatibility complex antigen by IFN-gamma and protection against encephalomyocarditis virus. This region consists of five amino acids (YDKPH), all of which are conserved in the human and murine receptors. Tyr-457 and His-461 are essential for activity. Approximately 80% of the amino acids of the intracellular domain of the receptor is not required for major histocompatibility complex class I antigen induction or for antiviral protection against encephalomyocarditis virus. The observation that there was no protection by IFN-gamma against vesiculostomatitis virus indicates that other factors, in addition to chromosome 21 accessory factor(s), are required to generate the full complement of transduction signals from the human IFN-gamma receptor.

  10. Altered Expression of Raet1e, a Major Histocompatibility Complex Class 1–Like Molecule, Underlies the Atherosclerosis Modifier Locus Ath11 10b

    PubMed Central

    Rodríguez, José M.; Wolfrum, Susanne; Robblee, Megan; Chen, Kwan Y.; Gilbert, Zachary N.; Choi, Jae-Hoon; Teupser, Daniel; Breslow, Jan L.

    2014-01-01

    Rationale Quantitative trait locus mapping of an intercross between C57.Apoe−/− and FVB.Apoe−/− mice revealed an atherosclerosis locus controlling aortic root lesion area on proximal chromosome 10, Ath11. In a previous work, subcongenic analysis showed Ath11 to be complex with proximal (10a) and distal (10b) regions. Objective To identify the causative genetic variation underlying the atherosclerosis modifier locus Ath11 10b. Methods and Results We now report subcongenic J, which narrows the 10b region to 5 genes, Myb, Hbs1L, Aldh8a1, Sgk1, and Raet1e. Sequence analysis of these genes revealed no amino acid coding differences between the parental strains. However, comparing aortic expression of these genes between F1.Apoe−/− Chr10SubJ(B/F) and F1.Apoe−/− Chr10SubJ(F/F) uncovered a consistent difference only for Raet1e, with decreased, virtually background, expression associated with increased atherosclerosis in the latter. The key role of Raet1e was confirmed by showing that transgene-induced aortic overexpression of Raet1e in F1.Apoe−/− Chr10SubJ(F/F) mice decreased atherosclerosis. Promoter reporter constructs comparing C57 and FVB sequences identified an FVB mutation in the core of the major aortic transcription start site abrogating activity. Conclusions This nonbiased approach has revealed Raet1e, a major histocompatibility complex class 1–like molecule expressed in lesional aortic endothelial cells and macrophage-rich regions, as a novel atherosclerosis gene and represents one of the few successes of the quantitative trait locus strategy in complex diseases. PMID:23948654

  11. Histocompatible chicken inbred lines: homogeneities in the major histocompatibility complex antigens of the GSP, GSN/1, PNP/DO and BM-C inbred lines assessed by hemagglutination, mixed lymphocyte reaction and skin transplantation.

    PubMed

    Valdez, Marcos B; Mizutani, Makoto; Fujiwara, Akira; Yazawa, Hajime; Yamagata, Takahiro; Shimada, Kiyoshi; Namikawa, Takao

    2007-10-01

    Chicken inbred lines of the GSP, GSN/1, PNP/DO and BM-C have been established by selection of a specific allele at the B blood group locus (MHC B-G region) and other polymorphic loci through pedigree mating. To extend the potential of these inbred lines as experimental animals in Aves, we assessed the antigenic homogeneities of the MHC antigens by three immunological methods. Antigenic variations of red blood cells (RBCs) were surveyed in the inbred lines and a random-bred line (NG) derived from the Nagoya breed by using ten kinds of intact antisera produced in the inbred line of chickens against RBCs of a red junglefowl and hybrids. In the hemagglutination test, no individual variations were found within the inbred line at all, while all the ten antisera detected highly heterogeneous reactions in individuals of the NG. The reciprocal one-way mixed lymphocyte reactions gave constantly higher stimulation responses (P<0.01) between individual pairs from the inbred lines having different B alleles compared to pairs within the inbred line, while lower stimulation was observed between pairs of the GSP and GSN/1 inbred lines both having the B(21) allele. In reciprocal skin transplantation, the transplanted skingrafts within the inbred line and between individuals from the GSP and GSN/1 inbred lines survived more than 100 days, while all the skingrafts showed signs of rejection within 7 days among the inbred lines having different B alleles. The results obtained by the three practical methods coincidentally indicated that the individuals in the respective four inbred lines were histocompatible, and further, that the GSP and GSN/1 individuals were histocompatible.

  12. Membrane Ia expression and antigen-presenting accessory cell function of L cells transfected with class II major histocompatibility complex genes

    PubMed Central

    1984-01-01

    To study the relationship between the structure and function of Ia antigens, as well as the physiologic requirements for antigen presentation to major histocompatibility complex-restricted T cells, class II A alpha and A beta genes from the k and d haplotypes were transfected into Ltk- fibroblasts using the calcium phosphate coprecipitation technique. Individually transfected genes were actively transcribed in the L cells without covalent linkage to, or cotransformation with, viral enhancer sequences. However, cell surface expression of detectable I-A required the presence of transfected A alpha dA beta d or A alpha kA beta k pairs in a single cell. The level of I-A expression under these conditions was 1/5-1/10 that of Ia+ B lymphoma cells, or B lymphoma cells expressing transfected class II genes. These I-A-expressing transfectants were tested for accessory cell function and shown to present polypeptide and complex protein antigens to T cell clones and hybridomas in the context of the transfected gene products. One T cell clone, restricted to I-Ak plus GAT (L-glutamic acid60-L-alanine30-L-tyrosine10), had a profound cytotoxic effect on I-Ak- but not I-Ad-expressing transfectants in the presence of specific antigen. Assays of unprimed T cells showed that both Ia+ and Ia- L cells could serve as accessory cells for concanavalin A-induced proliferative responses. These data indicate that L cells can transcribe, translate, and express transfected class II genes and that such I-A-bearing L cells possess the necessary metabolic mechanisms for presenting these antigens to T lymphocytes in the context of their I-A molecules. PMID:6436430

  13. Proteasome-independent major histocompatibility complex class I cross-presentation mediated by papaya mosaic virus-like particles leads to expansion of specific human T cells.

    PubMed

    Leclerc, Denis; Beauseigle, Diane; Denis, Jérome; Morin, Hélène; Paré, Christine; Lamarre, Alain; Lapointe, Réjean

    2007-02-01

    The development of versatile vaccine platforms is a priority that is recognized by health authorities worldwide; such platforms should induce both arms of the immune system, the humoral and cytotoxic-T-lymphocyte responses. In this study, we have established that a vaccine platform based on the coat protein of papaya mosaic virus (PapMV CP), previously shown to induce a humoral response, can induce major histocompatibility complex (MHC) class I cross-presentation of HLA-A*0201 epitopes from gp100, a melanoma antigen, and from influenza virus M1 matrix protein. PapMV proteins were able to assemble into stable virus-like particles (VLPs) in a crystalline and repetitive structure. When we pulsed HLA-A*0201+ antigen-presenting cells (APCs) with the recombinant PapMV FLU or gp100, we noted that antigen-specific CD8+ T cells were highly reactive to these APCs, demonstrating that the epitope from the VLPs were processed and loaded on the MHC class I complex. APCs were preincubated with two different proteasome inhibitors, which did not affect the efficiency of peptide presentation on MHC class I. Classical presentation from an endogenous antigen was abolished in the same conditions. Clearly, antigen presentation mediated by the PapMV system was proteasome independent. Finally, PapMV-pulsed APCs had the capacity to expand highly avid antigen-specific T cells against the influenza virus M1 HLA-A*0201 epitope when cocultured with autologous peripheral blood mononuclear cells. This study demonstrates the potential of PapMV for MHC class I cross-presentation and for the expansion of human antigen-specific T cells. It makes VLPs from PapMV CP a very attractive platform to trigger cellular responses for vaccine development against chronic infectious diseases and cancers.

  14. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection

    PubMed Central

    Nishi, Manami; El-Hage, Sandy; Fox, Barbara A.; Bzik, David J.

    2015-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4+ T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, namely, the MHC-II-associated invariant chain (Ii or CD74) and the peptide editor H2-DM, in professional antigen-presenting cells (pAPCs). Genetic deletion of CD74 restored the ability of infected dendritic cells to present a parasite antigen in the context of MHC-II in vitro. CD74 mRNA and protein levels were, surprisingly, elevated in infected cells, whereas MHC-II and H2-DM expression was inhibited. CD74 accumulated mainly in the endoplasmic reticulum (ER), and this phenotype required live parasites, but not active replication. Finally, we compared the impacts of genetic deletion of CD74 and H2-DM genes on parasite dissemination toward lymphoid organs in mice, as well as activation of CD4+ T cells and interferon gamma (IFN-γ) levels during acute infection. Cyst burdens and survival during the chronic phase of infection were also evaluated in wild-type and knockout mice. These results highlight the fact that the infection is influenced by multiple levels of parasite manipulation of the MHC-II antigen presentation pathway. PMID:26195549

  15. Equine herpesvirus type 4 UL56 and UL49.5 proteins downregulate cell surface major histocompatibility complex class I expression independently of each other.

    PubMed

    Said, Abdelrahman; Azab, Walid; Damiani, Armando; Osterrieder, Nikolaus

    2012-08-01

    Major histocompatibility complex class I (MHC-I) molecules are critically important in the host defense against various pathogens through presentation of viral peptides to cytotoxic T lymphocytes (CTLs), a process resulting in the destruction of virus-infected cells. Herpesviruses interfere with CTL-mediated elimination of infected cells by various mechanisms, including inhibition of peptide transport and loading, perturbation of MHC-I trafficking, and rerouting and proteolysis of cell surface MHC-I. In this study, we show that equine herpesvirus type 4 (EHV-4) modulates MHC-I cell surface expression through two different mechanisms. First, EHV-4 can lead to a significant downregulation of MHC-I expression at the cell surface through the product of ORF1, a protein expressed with early kinetics from a gene that is homologous to herpes simplex virus 1 UL56. The EHV-4 UL56 protein reduces cell surface MHC-I as early as 4 h after infection. Second, EHV-4 can interfere with MHC-I antigen presentation, starting at 6 h after infection, by inhibition of the transporter associated with antigen processing (TAP) through its UL49.5 protein. Although pUL49.5 has no immediate effect on overall surface MHC-I levels in infected cells, it blocks the supply of antigenic peptides to the endoplasmic reticulum (ER) and transport of peptide-loaded MHC-I to the cell surface. Taken together, our results show that EHV-4 encodes at least two viral immune evasion proteins: pUL56 reduces MHC-I molecules on the cell surface at early times after infection, and pUL49.5 interferes with MHC-I antigen presentation by blocking peptide transport in the ER.

  16. Brief review of the chicken Major Histocompatibility Complex: the genes, their distribution on chromosome 16, and their contributions to disease resistance

    PubMed Central

    Miller, Marcia M.; Taylor, Robert L.

    2016-01-01

    Nearly all genes presently mapped to chicken chromosome 16 (GGA 16) have either a demonstrated role in immune responses or are considered to serve in immunity by reason of sequence homology with immune system genes defined in other species. The genes are best described in regional units. Among these, the best known is the polymorphic major histocompatibility complex-B (MHC-B) region containing genes for classical peptide antigen presentation. Nearby MHC-B is a small region containing two CD1 genes, which encode molecules known to bind lipid antigens and which will likely be found in chickens to present lipids to specialized T cells, as occurs with CD1 molecules in other species. Another region is the MHC-Y region, separated from MHC-B by an intervening region of tandem repeats. Like MHC-B, MHC-Y is polymorphic. It contains specialized class I and class II genes and c-type lectin-like genes. Yet another region, separated from MHC-Y by the single nucleolar organizing region (NOR) in the chicken genome, contains olfactory receptor genes and scavenger receptor genes, which are also thought to contribute to immunity. The structure, distribution, linkages and patterns of polymorphism in these regions, suggest GGA 16 evolves as a microchromosome devoted to immune defense. Many GGA 16 genes are polymorphic and polygenic. At the moment most disease associations are at the haplotype level. Roles of individual MHC genes in disease resistance are documented in only a very few instances. Provided suitable experimental stocks persist, the availability of increasingly detailed maps of GGA 16 genes combined with new means for detecting genetic variability will lead to investigations defining the contributions of individual loci and more applications for immunogenetics in breeding healthy poultry. PMID:26740135

  17. Association between major histocompatibility complex microsatellites, fecal egg count, blood packed cell volume and blood eosinophilia in Pelibuey sheep infected with Haemonchus contortus.

    PubMed

    Castillo, Juan Antonio Figueroa; Medina, Rubén Danilo Méndez; Villalobos, José Manuel Berruecos; Gayosso-Vázquez, Amanda; Ulloa-Arvízu, Raúl; Rodríguez, Rebeca Acosta; Ramírez, Hugo Pérez; Morales, Rogelio A Alonso

    2011-05-11

    The objective of this study was to assess the correlation among traits associated with resistance or susceptibility to Haemonchus contortus infestation and to evaluate the participation of the ovine major histocompatibility complex (MHC) in Pelibuey sheep, a prevalent breed in tropical and sub-tropical regions in Mexico and elsewhere. Association among the fecal egg count (FEC), blood packed cell volume (PCV), antibody (AB) levels, serum proteins (SP) and blood eosinophil count (EOS) was assessed in 52 lambs experimentally infected with H. contortus, and the participation of the MHC was evaluated using polymorphisms in three microsatellites, located at the class I (OMHC1) and class II (OLADRB1, OLADRB2) regions of the MHC. Spearman correlation analysis among the traits showed a negative association (P<0.01) between FEC and PCV (-0.35), EOS (-0.50), SP (-0.30) and AB (-0.57), and a positive correlation of antibodies with EOS (0.50). The homozygotes for the OMHC1-188 and OLADRB2-282 alleles were associated with a reduction in FEC (-813 and -551, respectively). Conversely, the OMHC1-200 and OMHC1-206 alleles were associated with an increase in FEC (1704 and 1008, respectively). Furthermore, the OLADRB1-482 allele was associated with an increase of 163 EOS by allele copy, while the OMHC1-200 allele showed a reduction of 95 EOS in homozygotes. The associations among microsatellite MHC loci and the remaining variables were not significant. These results reinforce the evidence that MHC polymorphisms have an important role in parasite resistance or susceptibility in Pelibuey sheep and could be used as genetic markers to assist selection and improve parasite resistance to H. contortus.

  18. Assessment of biodiversity in Chilean cattle using the distribution of major histocompatibility complex class II BoLA-DRB3 allele.

    PubMed

    Takeshima, S-N; Miyasaka, T; Matsumoto, Y; Xue, G; Diaz, V de la Barra; Rogberg-Muñoz, A; Giovambattista, G; Ortiz, M; Oltra, J; Kanemaki, M; Onuma, M; Aida, Y

    2015-01-01

    Bovine leukocyte antigens (BoLAs) are used extensively as markers for bovine disease and immunological traits. In this study, we estimated BoLA-DRB3 allele frequencies using 888 cattle from 10 groups, including seven cattle breeds and three crossbreeds: 99 Red Angus, 100 Black Angus, 81 Chilean Wagyu, 49 Hereford, 95 Hereford × Angus, 71 Hereford × Jersey, 20 Hereford × Overo Colorado, 113 Holstein, 136 Overo Colorado, and 124 Overo Negro cattle. Forty-six BoLA-DRB3 alleles were identified, and each group had between 12 and 29 different BoLA-DRB3 alleles. Overo Negro had the highest number of alleles (29); this breed is considered in Chile to be an 'Old type' European Holstein Friesian descendant. By contrast, we detected 21 alleles in Holstein cattle, which are considered to be a 'Present type' Holstein Friesian cattle. Chilean cattle groups and four Japanese breeds were compared by neighbor-joining trees and a principal component analysis (PCA). The phylogenetic tree showed that Red Angus and Black Angus cattle were in the same clade, crossbreeds were closely related to their parent breeds, and Holstein cattle from Chile were closely related to Holstein cattle in Japan. Overall, the tree provided a thorough description of breed history. It also showed that the Overo Negro breed was closely related to the Holstein breed, consistent with historical data indicating that Overo Negro is an 'Old type' Holstein Friesian cattle. This allelic information will be important for investigating the relationship between major histocompatibility complex (MHC) and disease.

  19. Short communication: Establishment of a new polymerase chain reaction-sequence-based typing method for genotyping cattle major histocompatibility complex class II DRB3.

    PubMed

    Takeshima, S-N; Matsumoto, Y; Aida, Y

    2009-06-01

    Sequence-based typing (SBT) is the most comprehensive method for characterizing major histocompatibility complex (MHC) gene polymorphisms. We report here a new PCR-SBT method for genotyping cattle MHC (BoLA) class II DRB3 using the Assign 400ATF ver. 1.0.2.41 software (Conexio Genomics, Fremantle, Australia), which detects alleles in a semiautomated manner. We examined 12 sets of PCR reactions for their ability to amplify BoLA-DRB3 exon 2 and selected an optimal primer set, which used ERB3N-HL031 for first-round PCR and ALL-DRB3B for second-round PCR. Next, we constructed a BoLA-DRB3 allele database using the reference sequences of the Assign 400ATF software and successfully assigned heterozygous samples (including those with deletion alleles) using bidirectional sequencing, unlike our previously described method, which used unidirectional sequencing for detecting of deletion alleles. Next, blood samples of 128 Holstein cattle were used to correlate the results of our modified PCR-SBT method with those of our previously described PCR-SBT method. Each new PCR-SBT result corresponded completely with the DRB3 allele that was genotyped by our previously described PCR-SBT method. Moreover, we confirmed the accuracy of our modified PCR-SBT method by genotyping 7 sire cattle and their 22 calves using Japanese Black cattle. This new method will contribute to high-throughput genotyping of BoLA-DRB3 by sequence-based typing.

  20. The major histocompatibility complex in monotremes: an analysis of the evolution of Mhc class I genes across all three mammalian subclasses.

    PubMed

    Miska, Katarzyna B; Harrison, Gavan A; Hellman, Lars; Miller, Robert D

    2002-09-01

    We report the isolation and characterization of cDNA clones of expressed, functional major histocompatibility complex class-I ( Mhc-I) genes from two species of monotremes: the duck-billed platypus and the short-beaked echidna. The cDNA clones were isolated from libraries constructed from spleen RNA, clearly establishing their expression in at least this one peripheral lymphoid organ. From the presence of conserved amino acid residues, it appears the expressed sequences encode molecules that likely function as classical Mhc-I. These clones were isolated using monotreme Mhc-I processed pseudogenes as probes. These processed pseudogenes were isolated from genomic DNA and, based on their structure, are likely independently derived in the platypus and echidna. When all the monotreme sequences were included in phylogenetic analyses, we found no apparent orthologous relationships between the platypus and echidna Mhc-I. Analyses that included a large number of Mhc-I sequences from other taxa support a separate monotreme Mhc-I clade, basal to a therian Mhc-I clade that is comprised of sequences from marsupial and placental mammals. The phylogenies also support the hypothesis that Mhc-I genes of placental mammals, marsupials, and monotremes are derived from three separate lineages of Mhc-I genes, best explained by two rounds of duplications and deletions. The first round would have occurred prior to the divergence of monotremes and therians, and the second prior to the divergence of marsupials and placental mammals. The sequences described here represent the first reported functional monotreme Mhc-I, as well as the first processed pseudogenes of any type from monotremes.

  1. Cost effective and time efficient measurement of CD4, CD8, major histocompatibility complex Class II, and macrophage antigen expression in the lungs of chickens.

    PubMed

    Fletcher, Oscar J; Tan, Xun; Cortes, Lucia; Gimeno, Isabel

    2012-05-15

    Cells expressing CD4, CD8, major histocompatibility complex (MHC) Class II, and macrophage biomarkers in lungs of chickens were quantified by measuring total area of antigen expressed using imageJ, a software program developed at the National Institutes of Health and available at no cost. The procedures reported here were rapid, and reproducible. Total area of antigen expressed had positive correlation with manual counts of cells expressing CD4 and CD8 biomarkers after inoculation with serotype 1 Marek's disease virus (MDV) vaccines. Visual inspection and overlays prepared from outlines of cells counted by imageJ confirmed agreement between antigen expression and area measured. Total area measured was not dependent on time of image acquisition from randomly selected fields from the same slides. Total area values were not computer specific, but acquisition of the original images required standardization of microscope used and camera setup. All steps in the process from sample collection through sectioning, staining, and image acquisition must be standardized as much as possible. Chickens infected with a very virulent+ (vv(+)) isolate of MDV (648A) had increased CD4, CD8, MHC Class II, and macrophage biomarker expression compared to noninfected control chickens at 10 days post infection, but variable responses depending on the specific biomarker measured at 3 and 5 days post infection. The procedure described here is faster and more reproducible than manual counting in cases (CD4 and CD8) where the number of positive cells is low enough for manual counts. Manual counting is not possible with MHC Class II and macrophage antigens nor when CD4(+) cells are present in large numbers following proliferation to tumors, thus subjective systems are used for scoring in these conditions. Using imageJ as described eliminates the need for subjective and less reproducible methods for measuring expression of these antigens.

  2. Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

    2017-05-01

    Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm-egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm-egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm-egg interactions.

  3. Comparative genome analysis of the major histocompatibility complex (MHC) class I B/C segments in primates elucidated by genomic sequencing in common marmoset (Callithrix jacchus).

    PubMed

    Shiina, Takashi; Kono, Azumi; Westphal, Nico; Suzuki, Shingo; Hosomichi, Kazuyoshi; Kita, Yuki F; Roos, Christian; Inoko, Hidetoshi; Walter, Lutz

    2011-08-01

    Common marmoset monkeys (Callithrix jacchus) have emerged as important animal models for biomedical research, necessitating a more extensive characterization of their major histocompatibility complex (MHC) region. However, the genomic information of the marmoset MHC (Caja) is still lacking. The MHC-B/C segment represents the most diverse MHC region among primates. Therefore, in this paper, to elucidate the detailed gene organization and evolutionary processes of the Caja class I B (Caja-B) segment, we determined two parts of the Caja-B sequences with 1,079 kb in total, ranging from H6orf15 to BAT1 and compared the structure and phylogeny with that of other primates. This segment contains 54 genes in total, nine Caja-B genes (Caja-B1 to Caja-B9), two MIC genes (MIC1 and MIC2), eight non-MHC genes, two non-coding genes, and 33 non-MHC pseudogenes that have not been observed in other primate MHC-B/C segments. Caja-B3, Caja-B4, and Caja-B7 encode proper MHC class I proteins according to amino acid structural characteristics. Phylogenetic relationships based on 48 MHC-I nucleotide sequences in primates suggested (1) species-specific divergence for Caja, Mamu, and HLA/Patr/Gogo lineages, (2) independent generation of the "seven coding exon" type MHC-B genes in Mamu and HLA/Patr/Gogo lineages from an ancestral "eight coding exon" type MHC-I gene, (3) parallel correlation with the long and short segmental duplication unit length in Caja and Mamu lineages. These findings indicate that the MHC-B/C segment has been under permanent selective pressure in the evolution of primates.

  4. Characterization of major histocompatibility complex (MHC) DRB exon 2 and DRA exon 3 fragments in a primary terrestrial rabies vector (Procyon lotor).

    PubMed

    Castillo, Sarrah; Srithayakumar, Vythegi; Meunier, Vanessa; Kyle, Christopher J

    2010-08-10

    The major histocompatibility complex (MHC) presents a unique system to explore links between genetic diversity and pathogens, as diversity within MHC is maintained in part by pathogen driven selection. While the majority of wildlife MHC studies have investigated species that are of conservation concern, here we characterize MHC variation in a common and broadly distributed species, the North American raccoon (Procyon lotor). Raccoons host an array of broadly distributed wildlife diseases (e.g., canine distemper, parvovirus and raccoon rabies virus) and present important human health risks as they persist in high densities and in close proximity to humans and livestock. To further explore how genetic variation influences the spread and maintenance of disease in raccoons we characterized a fragment of MHC class II DRA exon 3 (250 bp) and DRB exon 2 (228 bp). MHC DRA was found to be functionally monomorphic in the 32 individuals screened; whereas DRB exon 2 revealed 66 unique alleles among the 246 individuals screened. Between two and four alleles were observed in each individual suggesting we were amplifying a duplicated DRB locus. Nucleotide differences between DRB alleles ranged from 1 to 36 bp (0.4-15.8% divergence) and translated into 1 to 21 (1.3-27.6% divergence) amino acid differences. We detected a significant excess of nonsynonymous substitutions at the peptide binding region (P = 0.005), indicating that DRB exon 2 in raccoons has been influenced by positive selection. These data will form the basis of continued analyses into the spatial and temporal relationship of the raccoon rabies virus and the immunogenetic response in its primary host.

  5. Brucella abortus inhibits major histocompatibility complex class II expression and antigen processing through interleukin-6 secretion via Toll-like receptor 2.

    PubMed

    Barrionuevo, Paula; Cassataro, Juliana; Delpino, M Victoria; Zwerdling, Astrid; Pasquevich, Karina A; García Samartino, Clara; Wallach, Jorge C; Fossati, Carlos A; Giambartolomei, Guillermo H

    2008-01-01

    The strategies that allow Brucella abortus to survive inside macrophages for prolonged periods and to avoid the immunological surveillance of major histocompatibility complex class II (MHC-II)-restricted gamma interferon (IFN-gamma)-producing CD4+ T lymphocytes are poorly understood. We report here that infection of THP-1 cells with B. abortus inhibited expression of MHC-II molecules and antigen (Ag) processing. Heat-killed B. abortus (HKBA) also induced both these phenomena, indicating the independence of bacterial viability and involvement of a structural component of the bacterium. Accordingly, outer membrane protein 19 (Omp19), a prototypical B. abortus lipoprotein, inhibited both MHC-II expression and Ag processing to the same extent as HKBA. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited MHC-II expression, indicating that any Brucella lipoprotein could down-modulate MHC-II expression and Ag processing. Inhibition of MHC-II expression and Ag processing by either HKBA or lipidated Omp19 (L-Omp19) depended on Toll-like receptor 2 and was mediated by interleukin-6. HKBA or L-Omp19 also inhibited MHC-II expression and Ag processing of human monocytes. In addition, exposure to the synthetic lipohexapeptide inhibited Ag-specific T-cell proliferation and IFN-gamma production of peripheral blood mononuclear cells from Brucella-infected patients. Together, these results indicate that there is a mechanism by which B. abortus may prevent recognition by T cells to evade host immunity and establish a chronic infection.

  6. Key role of Toll-like receptor 2 in the inflammatory response and major histocompatibility complex class ii downregulation in Brucella abortus-infected alveolar macrophages.

    PubMed

    Ferrero, Mariana C; Hielpos, M Soledad; Carvalho, Natalia B; Barrionuevo, Paula; Corsetti, Patricia P; Giambartolomei, Guillermo H; Oliveira, Sergio C; Baldi, Pablo C

    2014-02-01

    Alveolar macrophages (AM) seem to constitute the main cellular target of inhaled brucellae. Here, we show that Brucella abortus invades and replicates in murine AM without inducing cytotoxicity. B. abortus infection induced a statistically significant increase of tumor necrosis factor alpha (TNF-α), CXCL1 or keratinocyte chemoattractant (KC), interleukin-1β (IL-1β), IL-6, and IL-12 in AM from C57BL/6 mice and BALB/c mice, but these responses were generally weaker and/or delayed compared to those elicited in peritoneal macrophages. Studies using knockout mice for TLR2, TLR4, and TLR9 revealed that TNF-α and KC responses were mediated by TLR2 recognition. Brucella infection reduced in a multiplicity of infection-dependent manner the expression of major histocompatibility complex class II (MHC-II) molecules induced by gamma interferon (IFN-γ) in AM. The same phenomenon was induced by incubation with heat-killed B. abortus (HKBA) or the lipidated form of the 19-kDa outer membrane protein of Brucella (L-Omp19), and it was shown to be mediated by TLR2 recognition. In contrast, no significant downregulation of MHC-II was induced by either unlipidated Omp19 or Brucella LPS. In a functional assay, treatment of AM with either L-Omp19 or HKBA reduced the MHC-II-restricted presentation of OVA peptides to specific T cells. One week after intratracheal infection, viable B. abortus was detected in AM from both wild-type and TLR2 KO mice, but CFU counts were higher in the latter. These results suggest that B. abortus survives in AM after inhalatory infection in spite of a certain degree of immune control exerted by the TLR2-mediated inflammatory response. Both the modest nature of the latter and the modulation of MHC-II expression by the bacterium may contribute to such survival.

  7. Serum soluble major histocompatibility complex class I-related chain A/B expression in patients with alcoholic liver disease in Hainan Li community

    PubMed Central

    Wei, Xiaobin; Ren, Biqiong; Lin, Danqin; Luo, Bin; Fu, Xianxian; Li, Chunyun; Xia, Huan; Xiao, Xi; Yu, Ping

    2015-01-01

    Background/Aims: To study the expression and clinical significance of serum soluble major histocompatibility complex class I-related chain A/B (sMICA/B), and its correlation with percentage of CD4+, CD8+, and NK cells, Liver fibrosis screening test, and liver enzymes in alcoholic liver disease (ALD). Methods: Hainan Li ALD patients (n = 141) and healthy Li subjects (n = 100) were enrolled for the study. Liver enzymes were measured using automatic biochemical analyzer and Liver fibrosis screening test was used to study the correlation. In addition, sMICA/B expression in serum and percentage of CD4+, CD8+, and NK cells were determined using ELISA and flow cytometry respectively. Results: Liver fibrosis screening test results and liver enzymes concentration were significantly higher (both P < 0.01), whereas the expression of sMICA and sMICB was significantly indifferent (P > 0.01) between ALD patients and healthy controls. However, percentage of CD4+, CD8+, and NK cells were statistically lower in ALD patients than in healthy controls. The Kendall’s tau-b correlation coefficient for sMICA and sMICB/sMICA and LV was 0.561 and 0.120 respectively (P < 0.01). Pearson correlation coefficient of sMICA with the percentage of CD4+, CD8+%, and NK cells was -0.587, -0.525, and -0.232 respectively, whereas the coefficient of sMICB was -0.590, -0.554, and -0.292 respectively (P < 0.01). Conclusion: 1. Liver fibrosis screening test is an excellent non-invasive approach for the diagnosis of hepatic fibrosis and shows significant correlation with liver enzymes. 2. sMICA and sMICB failed to assess the degree of hepatic fibrosis. 3. Decreased percentage of CD4+, CD8+, and NK cells were attributed as one of the risk factors for ALD. PMID:26550349

  8. Gastric mucosal hyperplasia via upregulation of gastrin induced by persistent activation of gastric innate immunity in major histocompatibility complex class II deficient mice

    PubMed Central

    Fukui, T; Nishio, A; Okazaki, K; Uza, N; Ueno, S; Kido, M; Inoue, S; Kitamura, H; Kiriya, K; Ohashi, S; Asada, M; Tamaki, H; Matsuura, M; Kawasaki, K; Suzuki, K; Uchida, K; Fukui, H; Nakase, H; Watanabe, N; Chiba, T

    2006-01-01

    Background and aim Major histocompatibility complex class II deficient (Aα0/0) mice have decreased CD4+ T cells, making them immunologically similar to patients with acquired immunodeficiency syndrome (AIDS). Both patients with AIDS and Aα0/0 mice have hypertrophic gastric folds. To clarify the mechanism of gastric mucosal hyperplasia, we investigated the pathophysiology and the role of the innate immunity in the stomach of Aα0/0 mice. Methods Stomachs from 1–6 month old Aα0/0 mice, kept under specific pathogen free conditions, were examined at 1 month intervals histologically and immunohistochemically. Gene expression of proinflammatory cytokines, Toll‐like receptors (TLRs), cyclooxygenase (COX)‐2, and myeloperoxidase (MPO) activity in the gastric mucosa was investigated. Serum gastrin levels and gastric acidity were measured. Bacterial culture of the stomach was performed. To clarify the roles of hypergastrinaemia in the gastric mucosa, a gastrin receptor antagonist (AG041R) was administered. Results Aα0/0 mice had a diffusely thick corpus mucosa with infiltration of CD11b+ granulocytes and macrophages. Anti‐Ki67 staining demonstrated expansion of the proliferating neck zone. Gene expression of interleukin 1β, interferon γ, TLR‐2, TLR‐4, and COX‐2 were upregulated, and MPO activity was increased. Only a small amount of non‐pathogenic bacteria was detected in the stomach. Serum gastrin levels and Reg‐Iα positive cells in the gastric mucosa increased, despite normal gastric acidity. After treatment with AG041R, gastric mucosal thickness was significantly reduced. Conclusion Persistent activation of innate immunity in the stomach induced gastric mucosal hyperplasia through upregulation of gastrin synthesis in Aα0/0 mice, suggesting a pathophysiology similar to the gastric changes in patients with AIDS. PMID:16322110

  9. B Cell-Activating Transcription Factor Plays a Critical Role in the Pathogenesis of Anti-Major Histocompatibility Complex-Induced Obliterative Airway Disease.

    PubMed

    Xu, Z; Ramachandran, S; Gunasekaran, M; Nayak, D; Benshoff, N; Hachem, R; Gelman, A; Mohanakumar, T

    2016-04-01

    Antibodies (Abs) against major histocompatibility complex (MHC) results in T helper-17 (Th17)-mediated immunity against lung self-antigens (SAgs), K-α1 tubulin and collagen V and obliterative airway disease (OAD). Because B cell-activating transcription factor (BATF) controls Th17 and autoimmunity, we proposed that BATF may play a critical role in OAD. Anti-H2K(b) was administered intrabronchially into Batf (-/-) and C57BL/6 mice. Histopathology of the lungs on days 30 and 45 after Ab administration to Batf (-/-) mice resulted in decreased cellular infiltration, epithelial metaplasia, fibrosis, and obstruction. There was lack of Abs to SAgs, reduction of Sag-specific interleukin (IL)-17 T cells, IL-6, IL-23, IL-17, IL-1β, fibroblast growth factor-6, and CXCL12 and decreased Janus kinase 2, signal transducer and activator of transcription 3 (STAT3), and retinoid-related orphan receptor γT. Further, micro-RNA (miR)-301a, a regulator of Th17, was reduced in Batf (-/-) mice in contrast to upregulation of miR-301a and downregulation of protein inhibitor of activated STAT3 (PIAS3) in anti-MHC-induced OAD animals. We also demonstrate an increase in miR-301a in the bronchoalveolar lavage cells from lung transplant recipients with Abs to human leukocyte antigen. This was accompanied by reduction in PIAS3 mRNA. Therefore, we conclude that BATF plays a critical role in the immune responses to SAgs and pathogenesis of anti-MHC-induced rejection. Targeting BATF should be considered for preventing chronic rejection after human lung transplantation.

  10. Autoantibody Profiles in Collagen Disease Patients with Interstitial Lung Disease (ILD): Antibodies to Major Histocompatibility Complex Class I-Related Chain A (MICA) as Markers of ILD.

    PubMed

    Furukawa, Hiroshi; Oka, Shomi; Shimada, Kota; Masuo, Kiyoe; Nakajima, Fumiaki; Funano, Shunichi; Tanaka, Yuki; Komiya, Akiko; Fukui, Naoshi; Sawasaki, Tatsuya; Tadokoro, Kenji; Nose, Masato; Tsuchiya, Naoyuki; Tohma, Shigeto

    2015-01-01

    Interstitial lung disease (ILD) is frequently associated with collagen disease. It is then designated as collagen vascular disease-associated ILD (CVD-ILD), and influences patients' prognosis. The prognosis of acute-onset diffuse ILD (AoDILD) occurring in patients with collagen disease is quite poor. Here, we report our investigation of auto-antibody (Ab) profiles to determine whether they may be useful in diagnosing CVD-ILD or AoDILD in collagen disease. Auto-Ab profiles were analyzed using the Lambda Array Beads Multi-Analyte System, granulocyte immunofluorescence test, Proto-Array Human Protein Microarray, AlphaScreen assay, and glutathione S-transferase capture enzyme-linked immunosorbent assay in 34 patients with rheumatoid arthritis (RA) with or without CVD-ILD and in 15 patients with collagen disease with AoDILD. The average anti-major histocompatibility complex class I-related chain A (MICA) Ab levels were higher in RA patients with CVD-ILD than in those without (P = 0.0013). The ratio of the average anti-MICA Ab level to the average anti-human leukocyte antigen class I Ab level (ie, MICA/Class I) was significantly higher in RA patients with CVD-ILD compared with those without (P = 4.47 × 10(-5)). To the best of our knowledge, this is the first report of auto-Ab profiles in CVD-ILD. The MICA/Class I ratio could be a better marker for diagnosing CVD-ILD than KL-6 (Krebs von den lungen-6).

  11. Autoantibody Profiles in Collagen Disease Patients with Interstitial Lung Disease (ILD): Antibodies to Major Histocompatibility Complex Class I-Related Chain A (MICA) as Markers of ILD

    PubMed Central

    Furukawa, Hiroshi; Oka, Shomi; Shimada, Kota; Masuo, Kiyoe; Nakajima, Fumiaki; Funano, Shunichi; Tanaka, Yuki; Komiya, Akiko; Fukui, Naoshi; Sawasaki, Tatsuya; Tadokoro, Kenji; Nose, Masato; Tsuchiya, Naoyuki; Tohma, Shigeto

    2015-01-01

    Interstitial lung disease (ILD) is frequently associated with collagen disease. It is then designated as collagen vascular disease-associated ILD (CVD-ILD), and influences patients’ prognosis. The prognosis of acute-onset diffuse ILD (AoDILD) occurring in patients with collagen disease is quite poor. Here, we report our investigation of auto-antibody (Ab) profiles to determine whether they may be useful in diagnosing CVD-ILD or AoDILD in collagen disease. Auto-Ab profiles were analyzed using the Lambda Array Beads Multi-Analyte System, granulocyte immunofluorescence test, Proto-Array Human Protein Microarray, AlphaScreen assay, and glutathione S-transferase capture enzyme-linked immunosorbent assay in 34 patients with rheumatoid arthritis (RA) with or without CVD-ILD and in 15 patients with collagen disease with AoDILD. The average anti-major histocompatibility complex class I-related chain A (MICA) Ab levels were higher in RA patients with CVD-ILD than in those without (P = 0.0013). The ratio of the average anti-MICA Ab level to the average anti-human leukocyte antigen class I Ab level (ie, MICA/Class I) was significantly higher in RA patients with CVD-ILD compared with those without (P = 4.47 × 10−5). To the best of our knowledge, this is the first report of auto-Ab profiles in CVD-ILD. The MICA/Class I ratio could be a better marker for diagnosing CVD-ILD than KL-6 (Krebs von den lungen-6). PMID:26327779

  12. Determinant selection of major histocompatibility complex class I- restricted antigenic peptides is explained by class I-peptide affinity and is strongly influenced by nondominant anchor residues

    PubMed Central

    1994-01-01

    The contribution of major histocompatibility complex (MHC) class I- peptide affinity to immunodominance of particular peptide antigens (Ags) in the class I-restricted cytotoxic T lymphocyte (CTL) response is not clearly established. Therefore, we have compared the H-2Kb- restricted binding and presentation of the immunodominant ovalbumin (OVA)257-264 (SIINFEKL) determinant to that of a subdominant OVA determinant OVA55-62 (KVVRFDKL). Immunodominance of OVA257-264 was not attributable to the specific T cell repertoire but correlated instead with more efficient Ag presentation. This enhanced Ag presentation could be accounted for by the higher affinity of Kb/OVA257-264 compared with Kb/OVA55-62 despite the presence of a conserved Kb-binding motif in both peptides. Kinetic binding studies using purified soluble H-2Kb molecules (Kbs) and biosensor techniques indicated that the Kon for association of OVA257-264-C6 and Kbs at 25 degrees C was integral of 10- fold faster (5.9 x 10(3) M-1 s-1 versus 6.5 x 10(2) M-1 s-1), and the Koff approximately twofold slower (9.1 x 10(-6) s-1 versus 1.6 x 10(-5) s-1), than the rate constants for interaction of OVA55-62-C6 and Kbs. The association of these peptides with Kb was significantly influenced by multiple residues at presumed nonanchor sites within the peptide sequence. The contribution of each peptide residue to Kb-binding was dependent upon the sequence context and the summed contributions were not additive. Thus the affinity of MHC class I-peptide binding is a critical factor controlling presentation of peptide Ag and immunodominance in the class I-restricted CTL response. PMID:7523572

  13. Identification of a cis-acting element in the class I major histocompatibility complex gene promoter responsive to activation by retroviral sequences.

    PubMed Central

    Choi, S Y; van de Mark, K; Faller, D V

    1997-01-01

    The infection of cells with Moloney murine leukemia virus (M-MuLV) causes an increase in specific cellular gene products, including the major histocompatibility complex (MHC) class I antigens. This upregulation occurs through a transactivation process mediated by the long terminal repeat (LTR) of M-MuLV, and we show here that the gene activation response to the LTR requires at least one specific cis element within the MHC proximal promoter region. Nested deletions of MHC class I H-2Kb gene promoter sequence were subcloned into a chloramphenicol acetyltransferase (CAT) reporter vector and then transiently introduced into BALB/c-3T3 cells expressing M-MuLV or cotransfected into BALB/c-3T3 cells with a vector containing subgenomic portions of the virus, including the LTR. CAT activity assays demonstrated that a minimal H-2Kb gene promoter (-64 to +12) contained elements sufficient for this transactivation. DNase I footprinting assays located a protein-binding site in the region of -64 to -34 bp from the transcriptional start site, and point mutation analysis confirmed the location of this cis-acting element, designated the let response element (LRE), and defined a binding motif. This LRE is distinct from binding sites for currently known transcription factors in the class I MHC gene promoter and is conserved in the promoters of human and murine MHC class I genes. Mutation of the LRE resulted in dramatic reduction in both DNA-protein binding activity in electrophoretic mobility shift assay and in the ability of the mutated promoter to respond to retroviral transactivation. Addition of the LRE to a heterologous promoter conferred the ability to respond to retroviral transactivation. PMID:8995614

  14. Brief review of the chicken Major Histocompatibility Complex: the genes, their distribution on chromosome 16, and their contributions to disease resistance.

    PubMed

    Miller, Marcia M; Taylor, Robert L

    2016-02-01

    Nearly all genes presently mapped to chicken chromosome 16 (GGA 16) have either a demonstrated role in immune responses or are considered to serve in immunity by reason of sequence homology with immune system genes defined in other species. The genes are best described in regional units. Among these, the best known is the polymorphic major histocompatibility complex-B (MHC-B) region containing genes for classical peptide antigen presentation. Nearby MHC-B is a small region containing two CD1 genes, which encode molecules known to bind lipid antigens and which will likely be found in chickens to present lipids to specialized T cells, as occurs with CD1 molecules in other species. Another region is the MHC-Y region, separated from MHC-B by an intervening region of tandem repeats. Like MHC-B, MHC-Y is polymorphic. It contains specialized class I and class II genes and c-type lectin-like genes. Yet another region, separated from MHC-Y by the single nucleolar organizing region (NOR) in the chicken genome, contains olfactory receptor genes and scavenger receptor genes, which are also thought to contribute to immunity. The structure, distribution, linkages and patterns of polymorphism in these regions, suggest GGA 16 evolves as a microchromosome devoted to immune defense. Many GGA 16 genes are polymorphic and polygenic. At the moment most disease associations are at the haplotype level. Roles of individual MHC genes in disease resistance are documented in only a very few instances. Provided suitable experimental stocks persist, the availability of increasingly detailed maps of GGA 16 genes combined with new means for detecting genetic variability will lead to investigations defining the contributions of individual loci and more applications for immunogenetics in breeding healthy poultry.

  15. Up-regulation of major histocompatibility complex class II antigen expression in the central nervous system of dogs with spontaneous canine distemper virus encephalitis.

    PubMed

    Alldinger, S; Wünschmann, A; Baumgärtner, W; Voss, C; Kremmer, E

    1996-09-01

    Major histocompatibility complex class II (MHC II) and canine distemper virus (CDV) antigen expression were compared by immunohistochemistry in the cerebellar white matter of ten dogs with naturally occurring canine distemper encephalitis. In addition, infiltrating mononuclear cells were characterized by employing poly- and monoclonal antibodies directed against human CD3, canine MHC II, CD5, B cell antigen and CDV-specific nucleoprotein. Positive antigen-antibody reaction was visualized by the avidin-biotin-peroxidase complex method on frozen sections. Histologically, neuropathological changes were categorized into acute, subacute, and chronic. In control brains, MHC II expression was weak and predominantly detected on resident microglia of the white matter and on endothelial, perivascular and intravascular cells. In CDV antigen-positive brains, MHC II was mainly found on microglia and to a lesser extent on endothelial, meningeal, choroid plexus epithelial, ependymal and intravascular cells. In addition, virtually all of the perivascular cells expressed MHC II antigen. CDV antigen was demonstrated most frequently in astrocytes. Of the perivascular lymphocytes, the majority were CD3-positive cells, followed by B cells. Only a small proportion of perivascular cells expressed the CD5 antigen. In addition, B cells and CD3 and CD5 antigen-positive cells were found occasionally in subacute and frequently in chronic demyelinating plaques. In acute encephalitis, CDV antigen exhibited a multifocal or diffuse distribution, and MHC II was moderately up-regulated throughout the white matter and accentuated in CDV antigen-positive plaques. In subacute encephalitis, moderate multifocal CDV antigen and moderate to strong diffuse MHC II-specific staining, especially prominent in CDV antigen-positive lesions, were observed. In chronic encephalitis, CDV antigen expression was restricted to single astrocytes at the edge of the lesions or was absent, while MHC II expression

  16. Recognition of the Major Histocompatibility Complex (MHC) Class Ib Molecule H2-Q10 by the Natural Killer Cell Receptor Ly49C.

    PubMed

    Sullivan, Lucy C; Berry, Richard; Sosnin, Natasha; Widjaja, Jacqueline M L; Deuss, Felix A; Balaji, Gautham R; LaGruta, Nicole L; Mirams, Michiko; Trapani, Joseph A; Rossjohn, Jamie; Brooks, Andrew G; Andrews, Daniel M

    2016-09-02

    Murine natural killer (NK) cells are regulated by the interaction of Ly49 receptors with major histocompatibility complex class I molecules (MHC-I). Although the ligands for inhibitory Ly49 were considered to be restricted to classical MHC (MHC-Ia), we have shown that the non-classical MHC molecule (MHC-Ib) H2-M3 was a ligand for the inhibitory Ly49A. Here we establish that another MHC-Ib, H2-Q10, is a bona fide ligand for the inhibitory Ly49C receptor. H2-Q10 bound to Ly49C with a marginally lower affinity (∼5 μm) than that observed between Ly49C and MHC-Ia (H-2K(b)/H-2D(d), both ∼1 μm), and this recognition could be prevented by cis interactions with H-2K in situ To understand the molecular details underpinning Ly49·MHC-Ib recognition, we determined the crystal structures of H2-Q10 and Ly49C bound H2-Q10. Unliganded H2-Q10 adopted a classical MHC-I fold and possessed a peptide-binding groove that exhibited features similar to those found in MHC-Ia, explaining the diverse peptide binding repertoire of H2-Q10. Ly49C bound to H2-Q10 underneath the peptide binding platform to a region that encompassed residues from the α1, α2, and α3 domains, as well as the associated β2-microglobulin subunit. This docking mode was conserved with that previously observed for Ly49C·H-2K(b) Indeed, structure-guided mutation of Ly49C indicated that Ly49C·H2-Q10 and Ly49C·H-2K(b) possess similar energetic footprints focused around residues located within the Ly49C β4-stand and L5 loop, which contact the underside of the peptide-binding platform floor. Our data provide a structural basis for Ly49·MHC-Ib recognition and demonstrate that MHC-Ib represent an extended family of ligands for Ly49 molecules.

  17. Analysis of Major Histocompatibility Complex-Bound HIV Peptides Identified from Various Cell Types Reveals Common Nested Peptides and Novel T Cell Responses

    PubMed Central

    Rucevic, Marijana; Kourjian, Georgio; Boucau, Julie; Blatnik, Renata; Garcia Bertran, Wilfredo; Berberich, Matthew J.; Walker, Bruce D.; Riemer, Angelika B.

    2016-01-01

    ABSTRACT Despite the critical role of epitope presentation for immune recognition, we still lack a comprehensive definition of HIV peptides presented by HIV-infected cells. Here we identified 107 major histocompatibility complex (MHC)-bound HIV peptides directly from the surface of live HIV-transfected 293T cells, HIV-infected B cells, and primary CD4 T cells expressing a variety of HLAs. The majority of peptides were 8 to 12 amino acids (aa) long and mostly derived from Gag and Pol. The analysis of the total MHC-peptidome and of HLA-A02-bound peptides identified new noncanonical HIV peptides of up to 16 aa that could not be predicted by HLA anchor scanning and revealed an heterogeneous surface peptidome. Nested sets of surface HIV peptides included optimal and extended HIV epitopes and peptides partly overlapping or distinct from known epitopes, revealing new immune responses in HIV-infected persons. Surprisingly, in all three cell types, a majority of Gag peptides derived from p15 rather than from the most immunogenic p24. The cytosolic degradation of peptide precursors in corresponding cells confirmed the generation of identified surface-nested peptides. Cytosolic degradation revealed peptides commonly produced in all cell types and displayed by various HLAs, peptides commonly produced in all cell types and selectively displayed by specific HLAs, and peptides produced in only one cell type. Importantly, we identified areas of proteins leading to common presentations of noncanonical peptides by several cell types with distinct HLAs. These peptides may benefit the design of immunogens, focusing T cell responses on relevant markers of HIV infection in the context of HLA diversity. IMPORTANCE The recognition of HIV-infected cells by immune T cells relies on the presentation of HIV-derived peptides by diverse HLA molecules at the surface of cells. The landscape of HIV peptides displayed by HIV-infected cells is not well defined. Considering the diversity of HLA

  18. Heterogenous graft rejection pathways in class I major histocompatibility complex-disparate combinations and their differential susceptibility to immunomodulation induced by intravenous presensitization with relevant alloantigens

    PubMed Central

    1991-01-01

    The present study investigates the heterogeneity of graft rejection pathways in class I major histocompatibility complex (MHC)-disparate combinations and the susceptibility of each pathway to immunomodulation induced by intravenous presensitization with alloantigens. Depletion of CD8+ T cells was induced by repeated administration of anti-CD8 monoclonal antibody. CD8+ T cell-depleted mice failed to generate anti- allo class I MHC cytotoxic T cell (CTL) responses but exhibited anti- allo class I MHC T cell responses, such as mixed lymphocyte reaction (MLR)/IL-2 production, that were induced by CD4+ T cells. In contrast, donor-specific intravenous presensitization (DSP), as a model of donor- specific transfusion, induced almost complete elimination of CD4+ and CD8+ T cell-mediated MLR/IL-2 production, whereas this regimen did not affect the generation of CTL responses induced by DSP-resistant elements (CD8+ CTL precursors and CD4+ CTL helpers). Prolongation of skin graft survival was not induced by either of the above two regimens alone, but by the combination of these. Prolonged graft survival was obtained irrespective of whether the administration of anti-CD8 antibody capable of eliminating CTL was started before or after DSP. The combination of DSP with injection of anti-CD4 antibody also effectively prolonged graft survival. However, this was the case only when the injection of antibody was started before DSP, because such antibody administration was capable of inhibiting the generation of CTL responses by eliminating DSP-resistant CD4+ CTL helpers. These results indicate that (a) the graft rejection in class I-disparate combinations is induced by CD8+ CTL-involved and -independent pathways that are resistant and susceptible to DSP, respectively; (b) DSP contributes to, but is not sufficient for, the prolongation of graft survival; and (c) the suppression of graft rejection requires an additional treatment for reducing DSP-resistant CTL responses. The results are

  19. Major Histocompatibility Complex Class II HLA-DRα Is Downregulated by Kaposi's Sarcoma-Associated Herpesvirus-Encoded Lytic Transactivator RTA and MARCH8

    PubMed Central

    Sun, Zhiguo; Jha, Hem Chandra; Pei, Yong-gang

    2016-01-01

    ABSTRACT Kaposi's sarcoma-associated herpesvirus (KSHV) maintains two modes of life cycle, the latent and lytic phases. To evade the attack of the cell host's immune system, KSHV switches from the lytic to the latent phase, a phase in which only a few of viral proteins are expressed. The mechanism by which KSHV evades the attack of the immune system and establishes latency has not been fully understood. Major histocompatibility complex class II (MHC-II) molecules are key components of the immune system defense mechanism against viral infections. Here we report that HLA-DRα, a member of the MHC-II molecules, was downregulated by the replication and transcription activator (RTA) protein encoded by KSHV ORF50, an important regulator of the viral life cycle. RTA not only downregulated HLA-DRα at the protein level through direct binding and degradation through the proteasome pathway but also indirectly downregulated the protein level of HLA-DRα by enhancing the expression of MARCH8, a member of the membrane-associated RING-CH (MARCH) proteins. Our findings indicate that KSHV RTA facilitates evasion of the virus from the immune system through manipulation of HLA-DRα. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) has a causal role in a number of human cancers, and its persistence in infected cells is controlled by the host's immune system. The mechanism by which KSHV evades an attack by the immune system has not been well understood. This work represents studies which identify a novel mechanism by which the virus can facilitate evasion of an immune system. We now show that RTA, the replication and transcription activator encoded by KSHV (ORF50), can function as an E3 ligase to degrade HLA-DRα. It can directly bind and induce degradation of HLA-DRα through the ubiquitin-proteasome degradation pathway. In addition to the direct regulation of HLA-DRα, RTA can also indirectly downregulate the level of HLA-DRα protein by upregulating transcription of MARCH8

  20. Affinity-purified CCAAT-box-binding protein (YEBP) functionally regulates expression of a human class II major histocompatibility complex gene and the herpes simplex virus thymidine kinase gene

    SciTech Connect

    Zeleznik-Le, N.J.; Azizkhan, J.C.; Ting, J.P.Y. )

    1991-03-01

    Efficient major histocompatibility complex class II gene expression requires conseved protein-binding promoter elements, including X and Y elements. The authors affinity purified an HLA-DRA Y-element (CCAAT)-binding protein (YEBP) and used it to reconstitute Y-depleted HLA-DRA in vitro transcription. This directly demonstrates a positive functional role for YEBP in HLA-DRA transcription. The ability of YEBP to regulate divergent CCAAT elements was also assessed; YEBP was found to partially activate the thymidine kinase promoter. This functional analysis of YEBP shows that this protein plays an important role in the regulation of multiple genes.

  1. Linking Pig-Tailed Macaque Major Histocompatibility Complex Class I Haplotypes and Cytotoxic T Lymphocyte Escape Mutations in Simian Immunodeficiency Virus Infection

    PubMed Central

    Gooneratne, Shayarana L.; Alinejad-Rokny, Hamid; Ebrahimi, Diako; Bohn, Patrick S.; Wiseman, Roger W.; O'Connor, David H.; Davenport, Miles P.

    2014-01-01

    ABSTRACT The influence of major histocompatibility complex class I (MHC-I) alleles on human immunodeficiency virus (HIV) diversity in humans has been well characterized at the population level. MHC-I alleles likely affect viral diversity in the simian immunodeficiency virus (SIV)-infected pig-tailed macaque (Macaca nemestrina) model, but this is poorly characterized. We studied the evolution of SIV in pig-tailed macaques with a range of MHC-I haplotypes. SIVmac251 genomes were amplified from the plasma of 44 pig-tailed macaques infected with SIVmac251 at 4 to 10 months after infection and characterized by Illumina deep sequencing. MHC-I typing was performed on cellular RNA using Roche/454 pyrosequencing. MHC-I haplotypes and viral sequence polymorphisms at both individual mutations and groups of mutations spanning 10-amino-acid segments were linked using in-house bioinformatics pipelines, since cytotoxic T lymphocyte (CTL) escape can occur at different amino acids within the same epitope in different animals. The approach successfully identified 6 known CTL escape mutations within 3 Mane-A1*084-restricted epitopes. The approach also identified over 70 new SIV polymorphisms linked to a variety of MHC-I haplotypes. Using functional CD8 T cell assays, we confirmed that one of these associations, a Mane-B028 haplotype-linked mutation in Nef, corresponded to a CTL epitope. We also identified mutations associated with the Mane-B017 haplotype that were previously described to be CTL epitopes restricted by Mamu-B*017:01 in rhesus macaques. This detailed study of pig-tailed macaque MHC-I genetics and SIV polymorphisms will enable a refined level of analysis for future vaccine design and strategies for treatment of HIV infection. IMPORTANCE Cytotoxic T lymphocytes select for virus escape mutants of HIV and SIV, and this limits the effectiveness of vaccines and immunotherapies against these viruses. Patterns of immune escape variants are similar in HIV type 1-infected human

  2. Diverse peptide presentation of rhesus macaque major histocompatibility complex class I Mamu-A 02 revealed by two peptide complex structures and insights into immune escape of simian immunodeficiency virus.

    PubMed

    Liu, Jun; Dai, Lianpan; Qi, Jianxun; Gao, Feng; Feng, Youjun; Liu, Wenjun; Yan, Jinghua; Gao, George F

    2011-07-01

    Major histocompatibility complex class I (MHC I)-restricted CD8(+) T-cell responses play a pivotal role in anti-human immunodeficiency virus (HIV) immunity and the control of viremia. The rhesus macaque is an important animal model for HIV-related research. Among the MHC I alleles of the rhesus macaque, Mamu-A 02 is prevalent, presenting in ≥20% of macaques. In this study, we determined the crystal structure of Mamu-A 02, the second structure-determined MHC I from the rhesus macaque after Mamu-A 01. The peptide presentation characteristics of Mamu-A 02 are exhibited in complex structures with two typical Mamu-A 02-restricted CD8(+) T-cell epitopes, YY9 (Nef159 to -167; YTSGPGIRY) and GY9 (Gag71 to -79; GSENLKSLY), derived from simian immunodeficiency virus (SIV). These two peptides utilize similar primary anchor residues (Ser or Thr) at position 2 and Tyr at position 9. However, the central region of YY9 is different from that of GY9, a difference that may correlate with the immunogenic variance of these peptides. Further analysis indicated that the distinct conformations of these two peptides are modulated by four flexible residues in the Mamu-A 02 peptide-binding groove. The rare combination of these four residues in Mamu-A 02 leads to a variant presentation for peptides with different residues in their central regions. Additionally, in the two structures of the Mamu-A 02 complex, we compared the binding of rhesus and human β(2) microglobulin (β(2)m) to Mamu-A 02. We found that the peptide presentation of Mamu-A 02 is not affected by the interspecies interaction with human β(2)m. Our work broadens the understanding of CD8(+) T-cell-specific immunity against SIV in the rhesus macaque.

  3. Diverse Peptide Presentation of Rhesus Macaque Major Histocompatibility Complex Class I Mamu-A*02 Revealed by Two Peptide Complex Structures and Insights into Immune Escape of Simian Immunodeficiency Virus ▿

    PubMed Central

    Liu, Jun; Dai, Lianpan; Qi, Jianxun; Gao, Feng; Feng, Youjun; Liu, Wenjun; Yan, Jinghua; Gao, George F.

    2011-01-01

    Major histocompatibility complex class I (MHC I)-restricted CD8+ T-cell responses play a pivotal role in anti-human immunodeficiency virus (HIV) immunity and the control of viremia. The rhesus macaque is an important animal model for HIV-related research. Among the MHC I alleles of the rhesus macaque, Mamu-A*02 is prevalent, presenting in ≥20% of macaques. In this study, we determined the crystal structure of Mamu-A*02, the second structure-determined MHC I from the rhesus macaque after Mamu-A*01. The peptide presentation characteristics of Mamu-A*02 are exhibited in complex structures with two typical Mamu-A*02-restricted CD8+ T-cell epitopes, YY9 (Nef159 to -167; YTSGPGIRY) and GY9 (Gag71 to -79; GSENLKSLY), derived from simian immunodeficiency virus (SIV). These two peptides utilize similar primary anchor residues (Ser or Thr) at position 2 and Tyr at position 9. However, the central region of YY9 is different from that of GY9, a difference that may correlate with the immunogenic variance of these peptides. Further analysis indicated that the distinct conformations of these two peptides are modulated by four flexible residues in the Mamu-A*02 peptide-binding groove. The rare combination of these four residues in Mamu-A*02 leads to a variant presentation for peptides with different residues in their central regions. Additionally, in the two structures of the Mamu-A*02 complex, we compared the binding of rhesus and human β2 microglobulin (β2m) to Mamu-A*02. We found that the peptide presentation of Mamu-A*02 is not affected by the interspecies interaction with human β2m. Our work broadens the understanding of CD8+ T-cell-specific immunity against SIV in the rhesus macaque. PMID:21561910

  4. HLA-DRB1-DQB1 Haplotypes Confer Susceptibility and Resistance to Multiple Sclerosis in Sardinia

    PubMed Central

    Cocco, Eleonora; Sardu, Claudia; Pieroni, Enrico; Valentini, Maria; Murru, Raffaele; Costa, Gianna; Tranquilli, Stefania; Frau, Jessica; Coghe, Giancarlo; Carboni, Nicola; Floris, Matteo; Contu, Paolo; Marrosu, Maria Giovanna

    2012-01-01

    Introduction Genetic predisposition to multiple sclerosis (MS) in Sardinia (Italy) has been associated with five DRB1*-DQB1* haplotypes of the human leukocyte antigen (HLA). Given the complexity of these associations, an in-depth re-analysis was performed with the specific aims of confirming the haplotype associations; establishing the independence of the associated haplotypes; and assessing patients' genotypic risk of developing MS. Methods and Results A transmission disequilibrium test (TDT) of the DRB1*-DQB1* haplotypes in 943 trio families, confirmed a higher than expected transmission rate (over-transmission) of the *13:03-*03:01 (OR = 2.9, P = 7.6×10−3), *04:05-*03:01 (OR = 2.4, P = 4.4×10−6) and *03:01-*02:01 (OR = 2.1, P = 1.0×10−15) haplotype. In contrast, the *16:01-*05:02 (OR = 0.5, P = 5.4×10−11) and the *15:02-*06:01 (OR = 0.3, P = 1.5×10−3) haplotypes exhibited a lower than expected transmission rate (under-transmission). The independence of the transmission of each positively and negatively associated haplotype was confirmed relative to all positively associated haplotypes, and to the negatively associated *16:01-*05:02 haplotype. In patients, carriage of two predisposing haplotypes, or of protective haplotypes, respectively increased or decreased the patient's risk of developing MS. The risk of MS followed a multiplicative model of genotypes, which was, in order of decreasing ORs: *04:05-*0301/*03:01-*02:01 (OR = 4.5); *03:01-*02:01/*03:01-*02:01 (OR = 4.1); and the *16:01-*05:02/*16:01-*0502 (OR = 0.2) genotypes. Analysis of DRB1 and DQB1 protein chain residues showed that the Val/Gly residue at position 86 of the DRB1 chain was the only difference between the protective *16:01- *15:02 alleles and the predisposing *15:01 one. Similarly, the Ala/Val residue at position 38 of the DQB1 chain differentiated the positively associated *06:02 allele and the negatively associated *05

  5. Bovine leukocyte antigen major histocompatibility complex class II DRB3*2703 and DRB3*1501 alleles are associated with variation in levels of protection against Theileria parva challenge following immunization with the sporozoite p67 antigen.

    PubMed

    Ballingall, Keith T; Luyai, Anthony; Rowlands, G John; Sales, Jill; Musoke, Anthony J; Morzaria, Subash P; McKeever, Declan J

    2004-05-01

    Initial laboratory trials of an experimental subunit vaccine against Theileria parva based on the 67-kDa major sporozoite surface antigen revealed a range of responses to challenge. We have analyzed convergence in seven sets of monozygotic twins which suggests that genetic factors may have an influence in determining the degree of protection provided by p67 immunization. In addition, we have examined whether allelic diversity at major histocompatibility complex class II loci influences protection. Analysis of bovine leukocyte antigen DRB3 diversity in 201 animals identified significant associations with vaccine success (DRB3*2703; P = 0.027) and vaccine failure (DRB3*1501; P = 0.013). Furthermore, DRB3*2703 was associated with the likelihood of immunized animals showing little to no clinical signs of disease following challenge. We discuss the acquired and innate immune mechanisms that may be behind the associations described here.

  6. The life span of major histocompatibility complex-peptide complexes influences the efficiency of presentation and immunogenicity of two class I-restricted cytotoxic T lymphocyte epitopes in the Epstein-Barr virus nuclear antigen 4

    PubMed Central

    1996-01-01

    We have investigated the reactivity to two human histocompatibility leukocyte antigen (HLA) A11-restricted cytotoxic T lymphocyte (CTL) epitopes derived from amino acids 416-424 (IVTDFSVIK, designated IVT) and 399-408 (AVFDRKSVAK, designated AVF) of the Epstein-Barr virus (EBV) nuclear antigen (EBNA) 4. A strong predominance of CTL clones specific for the IVT epitope was demonstrated in polyclonal cultures generated by stimulation of lymphocytes from the EBV-seropositive donor BK with the autologous B95.8 virus-transformed lymphoblastoid cell line (LCL). This was not due to intrinsic differences of CTL efficiency since clones specific for the two epitopes lysed equally well A11- positive phytohemagglutinin blasts and LCLs pulsed with the relevant synthetic peptide. Irrespective of the endogenous levels of EBNA4 expression, untreated LCLs were lysed more efficiently by the IVT- specific effectors, suggesting that a higher density of A11-IVT complexes is presented at the cell surface. In accordance, 10-50-fold higher amounts of IVT peptides were found in high-performance liquid chromatography fractions of acid extracts corresponding to an abundance of about 350-12,800 IVT and 8-760 AVF molecules per cell. Peptide- mediated competition of CTL sensitization, transport assays in streptolysin-O permeabilized cells, and induction of A11 expression in the transporter associated with antigen presentation-deficient T2/A11 transfectant demonstrated that the IVT and AVF peptides bind with similar affinities to A11, are translocated with equal efficiency to the endoplasmic reticulum, and form complexes of comparable stability over a wide range of temperature and pH conditions. A rapid surface turnover of A11 molecules containing the AVF peptide was demonstrated in metabolically active T2/A11 cells corresponding to a half-life of approximately 3.5 as compared to approximately 2 h for molecules induced at 26 degrees C in the absence of exogenous peptides and >12 h for IVT

  7. Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen Inhibits Major Histocompatibility Complex Class II Expression by Disrupting Enhanceosome Assembly through Binding with the Regulatory Factor X Complex

    PubMed Central

    Thakker, Suhani; Purushothaman, Pravinkumar; Gupta, Namrata; Challa, Shanthan; Cai, Qiliang

    2015-01-01

    ABSTRACT Major histocompatibility complex class II (MHC-II) molecules play a central role in adaptive antiviral immunity by presenting viral peptides to CD4+ T cells. Due to their key role in adaptive immunity, many viruses, including Kaposi's sarcoma-associated herpesvirus (KSHV), have evolved multiple strategies to inhibit the MHC-II antigen presentation pathway. The expression of MHC-II, which is controlled mainly at the level of transcription, is strictly dependent upon the binding of the class II transactivator (CIITA) to the highly conserved promoters of all MHC-II genes. The recruitment of CIITA to MHC-II promoters requires its direct interactions with a preassembled MHC-II enhanceosome consisting of cyclic AMP response element-binding protein (CREB) and nuclear factor Y (NF-Y) complex and regulatory factor X (RFX) complex proteins. Here, we show that KSHV-encoded latency-associated nuclear antigen (LANA) disrupts the association of CIITA with the MHC-II enhanceosome by binding to the components of the RFX complex. Our data show that LANA is capable of binding to all three components of the RFX complex, RFX-associated protein (RFXAP), RFX5, and RFX-associated ankyrin-containing protein (RFXANK), in vivo but binds more strongly with the RFXAP component in in vitro binding assays. Levels of MHC-II proteins were significantly reduced in KSHV-infected as well as LANA-expressing B cells. Additionally, the expression of LANA in a luciferase promoter reporter assay showed reduced HLA-DRA promoter activity in a dose-dependent manner. Chromatin immunoprecipitation assays showed that LANA binds to the MHC-II promoter along with RFX proteins and that the overexpression of LANA disrupts the association of CIITA with the MHC-II promoter. These assays led to the conclusion that the interaction of LANA with RFX proteins interferes with the recruitment of CIITA to MHC-II promoters, resulting in an inhibition of MHC-II gene expression. Thus, the data presented here identify

  8. T cell receptor genes in a series of class I major histocompatibility complex-restricted cytotoxic T lymphocyte clones specific for a Plasmodium berghei nonapeptide: implications for T cell allelic exclusion and antigen-specific repertoire

    PubMed Central

    1991-01-01

    We report here the first extensive study of a T cell repertoire for a class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) response. We have found that the T cell receptors (TCRs) carried by 28 H-2Kd-restricted CTL clones specific for a single Plasmodium berghei circumsporozoite nonapeptide are highly diverse in terms of V alpha, J alpha, and J beta segments and aminoacid composition of the junctional regions. However, despite this extensive diversity, a high proportion of the TCRs contain the same V beta segment. These results are in contrast to most previously reported T cell responses towards class II MHC-peptide complexes, where the TCR repertoires appeared to be much more limited. In our study, the finding of a dominant V beta in the midst of otherwise highly diverse TCRs suggests the importance of the V beta segment in shaping the T cell repertoire specific for a given MHC-peptide complex. As an additional finding, we observed that nearly all clones have rearranged both TCR alpha loci. Moreover, as many as one-third of the CTL clones that we analyzed apparently display two productive alpha rearrangements. This argues against a regulated model of sequential recombination at the alpha locus and consequently raises the question of whether allelic exclusion of the TCR alpha chain is achieved at all. PMID:1836010

  9. HLA-DRB and -DQB1 polymorphism in the Macedonian population.

    PubMed

    Hristova-Dimceva, A; Verduijn, W; Schipper, R F; Schreuder, G M

    2000-01-01

    HLA-DRB1, DRB3/4/5 and DQB1 polymorphism has been studied in a population of 80 unrelated healthy Macedonians using molecular methods. Twenty-five different DRB1 alleles were identified of which DRB1*1104, *1501, *1601, and *1101 were found most frequently. Among the 15 identified DQB1 alleles, two were predominant: DQB1*0301 and *0502. The most frequent three-locus haplotypes were DRB1*1104-DRB3*02-DQB1*0301 (18%/), DRB1*1101-DRB3*02-DQB1*0301 (9%) and DRB1*1601-DRB5*02-DQB1*0502 (10%). Polymorphism for DRB1*04, *13 and *15 haplotypes was extensive. Eleven different DR2-related haplotypes were found, some of which were unusual for European populations: DRB1*1501-DRB5*0102-DQB1*0502, DRB1*1501-DRB5*02-DQB1*0502, DRB1*1501-DRB5*0102-DQB1*0601.

  10. Characterization and evolution of ovine MHC class II DQB sequence polymorphism.

    PubMed

    van Oorschot, R A; Maddox, J F; Adams, L J; Fabb, S A

    1994-12-01

    The second exons of OLA-DQB genes from 13 merino sheep were sequenced following amplification by the polymerase chain reaction or isolation from a cDNA library. Ten distinct exon 2 sequences, coding for 10 novel amino acid sequences, were characterized in these sheep. The single-strand conformation polymorphism technique was shown to be capable of discriminating between all sequences. This brings the total number of different OLA-DQB exon 2 sequences (nucleotide and amino acid) which have been characterized to 12, and demonstrates that the OLA-DQB region is highly polymorphic with 29% of nucleotide and 46% of amino acid sites showing variation. Evidence is presented that the OLA-DQB sequences belong to at least two lineages of DQB genes. Some ovine DQB sequences are more like bovine DQB counterparts than other ovine DQB sequences suggesting that the artiodactyl DQB gene and allele lineages predate the separation of the ovine and bovine species 20 million years ago.

  11. T cell receptor repertoire for a viral epitope in humans is diversified by tolerance to a background major histocompatibility complex antigen

    PubMed Central

    1995-01-01

    that mimics a structure presented on HLA B*4402. Thus, tolerance to a background major histocompatibility antigen can effectively diversify the TCR repertoire for a foreign epitope by deflecting the response away from an immunodominant combination of TCR-binding residues. PMID:7500015

  12. Transfer and expression of three cloned human non-HLA-A,B,C class I major histocompatibility complex genes in mutant lymphoblastoid cells.

    PubMed Central

    Shimizu, Y; Geraghty, D E; Koller, B H; Orr, H T; DeMars, R

    1988-01-01

    The HLA-A, -B, and -C class I human histocompatibility antigens and the genes that encode them have been isolated and characterized. Apparently complete class I non-HLA-A, B, C genes have been identified on HindIII-generated 5.4-kilobase (kb), 6.0-kb, and 6.2-kb DNA fragments derived from lymphoblastoid cell line (LCL) 721. We studied the expressibility of these genes by subcloning them into the nonintegrating pHeBo vector and transferring the chimeric plasmids into mutant LCL 721.221. This mutant was derived from LCL 721 by means of immunoselections following gamma-ray mutagenesis that eliminated expressions of the HLA-A, -B, and -C alpha chains. The HLA-A, B, C-null phenotype of mutant 721.221 made it possible to monitor the expression of class I genes transferred into it by assaying cell surface binding of monoclonal antibodies BBM.1 and W6/32, which recognize beta 2-microglobulin and HLA class I alpha-chain epitopes, respectively. Increased binding of BBM.1 and W6/32 was clearly observed in transferents containing the class I gene of the 6.0-kb DNA fragment but not in transferents containing the class I genes of the 5.4- and 6.2-kb DNA fragments. However, one-dimensional gel electrophoresis of BBM.1 and W6/32 immunoprecipitates made with [35S]methionine-labeled cell lysates showed that transfer of each non-HLA-A, B, C class I gene into 721.221 resulted in the appearance of an alpha chain that coprecipitated with beta 2-microglobulin. The three previously unreported alpha chains differed from each other in size and were smaller than HLA-A, -B, and -C alpha chains. These observations clearly show that these three cloned, nonallelic, non-HLA-A, B, C class I genes encode alpha chains that can be expressed in human cells. Images PMID:3257565

  13. Expression, purification and preliminary X-ray crystallographic analysis of the human major histocompatibility antigen HLA-B*1402 in complex with a viral peptide and with a self-peptide

    SciTech Connect

    Kumar, Pravin; Vahedi-Faridi, Ardeschir; Volz, Armin; Ziegler, Andreas; Saenger, Wolfram

    2007-07-01

    The crystallization of HLA-B*1402 in complex with two peptides is reported. The product of the human major histocompatibility (HLA) class I allele HLA-B*1402 only differs from that of allele HLA-B*1403 at amino-acid position 156 of the heavy chain (Leu in HLA-B*1402 and Arg in HLA-B*1403). However, both subtypes are known to be differentially associated with the inflammatory rheumatic disease ankylosing spondylitis (AS) in black populations in Cameroon and Togo. HLA-B*1402 is not associated with AS, in contrast to HLA-B*1403, which is associated with this disease in the Togolese population. The products of these alleles can present peptides with Arg at position 2, a feature shared by a small group of other HLA-B antigens, including HLA-B*2705, the prototypical AS-associated subtype. Complexes of HLA-B*1402 with a viral peptide (RRRWRRLTV, termed pLMP2) and a self-peptide (IRAAPPPLF, termed pCatA) were prepared and were crystallized using polyethylene glycol as precipitant. The complexes crystallized in space groups P2{sub 1} (pLMP2) and P2{sub 1}2{sub 1}2{sub 1} (pCatA) and diffracted synchrotron radiation to 2.55 and 1.86 Å resolution, respectively. Unambiguous solutions for both data sets were obtained by molecular replacement using a peptide-complexed HLA-B*2705 molecule (PDB code) as a search model.

  14. Human peripheral blood leucocyte non-obese diabetic-severe combined immunodeficiency interleukin-2 receptor gamma chain gene mouse model of xenogeneic graft-versus-host-like disease and the role of host major histocompatibility complex

    PubMed Central

    King, M A; Covassin, L; Brehm, M A; Racki, W; Pearson, T; Leif, J; Laning, J; Fodor, W; Foreman, O; Burzenski, L; Chase, T H; Gott, B; Rossini, A A; Bortell, R; Shultz, L D; Greiner, D L

    2009-01-01

    Immunodeficient non-obese diabetic (NOD)-severe combined immune-deficient (scid) mice bearing a targeted mutation in the gene encoding the interleukin (IL)-2 receptor gamma chain gene (IL2rγnull) engraft readily with human peripheral blood mononuclear cells (PBMC). Here, we report a robust model of xenogeneic graft-versus-host-like disease (GVHD) based on intravenous injection of human PBMC into 2 Gy conditioned NOD-scid IL2rγnull mice. These mice develop xenogeneic GVHD consistently (100%) following injection of as few as 5 × 106 PBMC, regardless of the PBMC donor used. As in human disease, the development of xenogeneic GVHD is highly dependent on expression of host major histocompatibility complex class I and class II molecules and is associated with severely depressed haematopoiesis. Interrupting the tumour necrosis factor-α signalling cascade with etanercept, a therapeutic drug in clinical trials for the treatment of human GVHD, delays the onset and progression of disease. This model now provides the opportunity to investigate in vivo mechanisms of xenogeneic GVHD as well as to assess the efficacy of therapeutic agents rapidly. PMID:19659776

  15. Detection of aberrant transcription of major histocompatibility complex class II antigen presentation genes in chronic lymphocytic leukaemia identifies HLA-DOA mRNA as a prognostic factor for survival.

    PubMed

    Souwer, Yuri; Chamuleau, Martine E D; van de Loosdrecht, Arjan A; Tolosa, Eva; Jorritsma, Tineke; Muris, Jettie J F; Dinnissen-van Poppel, Marion J; Snel, Sander N; van de Corput, Lisette; Ossenkoppele, Gert J; Meijer, Chris J L M; Neefjes, Jacques J; Marieke van Ham, S

    2009-05-01

    In human B cells, effective major histocompatibility complex (MHC) class II-antigen presentation depends not only on MHC class II, but also on the invariant chain (CD74 or Ii), HLA-DM (DM) and HLA-DO (DO), the chaperones regulating the antigen loading process of MHC class II molecules. We analysed immediate ex vivo expression of HLA-DR (DR), CD74, DM and DO in B cell chronic lymphocytic leukaemia (B-CLL). Real-time reverse transcription polymerase chain reaction demonstrated a highly significant upregulation of DRA, CD74, DMB, DOA and DOB mRNA in purified malignant cells compared to B cells from healthy donors. The increased mRNA levels were not translated into enhanced protein levels but could reflect aberrant transcriptional regulation. Indeed, upregulation of DRA, DMB, DOA and DOB mRNA correlated with enhanced expression of class II transactivator (CIITA). In-depth analysis of the various CIITA transcripts demonstrated a significant increased activity of the interferon-gamma-inducible promoter CIITA-PIV in B-CLL. Comparison of the aberrant mRNA levels with clinical outcome identified DOA mRNA as a prognostic indicator for survival. Multivariate analysis revealed that the prognostic value of DOA mRNA was independent of the mutational status of the IGHV genes. Thus, aberrant transcription of DOA forms a novel and additional prognostic indicator for survival in B-CLL.

  16. The chicken beta 2-microglobulin gene is located on a non-major histocompatibility complex microchromosome: a small, G+C-rich gene with X and Y boxes in the promoter.

    PubMed Central

    Riegert, P; Andersen, R; Bumstead, N; Döhring, C; Dominguez-Steglich, M; Engberg, J; Salomonsen, J; Schmid, M; Schwager, J; Skjødt, K; Kaufman, J

    1996-01-01

    beta 2-Microglobulin is an essential subunit of major histocompatibility complex (Mhc) class I molecules, which present antigenic peptides to T lymphocytes. We sequenced a number of cDNAs and two genomic clones corresponding to chicken beta 2-microglobulin. The chicken beta 2-microglobulin gene has a similar genomic organization but smaller introns and higher G+C content than mammalian beta 2-microglobulin genes. The promoter region is particularly G+C-rich and contains, in addition to interferon regulatory elements, potential S/W, X, and Y boxes that were originally described for mammalian class II but not class I alpha or beta 2-microglobulin genes. There is a single chicken beta 2-microglobulin gene that has little polymorphism in the coding region. Restriction fragment length polymorphisms from Mhc homozygous lines, Mhc congenic lines, and backcross families, as well as in situ hybridization, show that the beta 2-microglobulin gene is located on a microchromosome different from the one that contains the chicken Mhc. We propose that the structural similarities between the beta 2-microglobulin and Mhc genes in the chicken are due to their presence on microchromosomes and suggest that these features and the microchromosomes appeared by deletion of DNA in the lineage leading to the birds. Images Fig. 4 Fig. 5 PMID:8577748

  17. Upregulation of class I major histocompatibility complex gene expression in primary sensory neurons, satellite cells, and Schwann cells of mice in response to acute but not latent herpes simplex virus infection in vivo

    PubMed Central

    1994-01-01

    Major histocompatibility complex (MHC) deficiency is typical of almost all resident cells in normal neural tissue. However, CD8+ T cells, which recognize antigenic peptides in the context of class I MHC molecules, are known to mediate clearance of herpes simplex virus (HSV) from spinal ganglia of experimentally infected mice, leading to the hypothesis that class I expression in the peripheral nervous system must be upregulated in response to HSV infection. In addressing this hypothesis it is shown, in BALB/c (H-2d) mice, that normally deficient class I transcripts transiently accumulate in peripheral nerve Schwann cells, ganglionic satellite cells, and primary sensory neurons, indicating that in each of these cell types class I expression is regulated at the transcriptional level in vivo. Furthermore, for 3-4 wk after infection, H-2Kd/Dd antigens are expressed by satellite and Schwann cells but not neurons, suggesting additional posttranscriptional regulation of class I synthesis in neurons. Alternatively, the class I RNAs induced in neurons may not be derived from classical class I genes. Factors regulating H-2 class I expression emanate from within infected ganglia, probably from infected neurons themselves. However, induction of class I molecules was not maintained during latency, when viral gene expression in neurons is restricted to a single region within the virus repeats. These data have implications for the long-term survival of cells in HSV-infected neural tissue. PMID:8064236

  18. Major histocompatibility complex class-II molecules promote targeting of human immunodeficiency virus type 1 virions in late endosomes by enhancing internalization of nascent particles from the plasma membrane

    PubMed Central

    Finzi, Andrés; Perlman, Mira; Bourgeois-Daigneault, Marie-Claude; Thibodeau, Jacques; Cohen, Éric A.

    2014-01-01

    Summary Productive assembly of human immunodeficiency virus type 1 (HIV-1) takes place, primarily, at the plasma membrane. However, depending on the cell types, a significant proportion of nascent virus particles are internalized and routed to late endosomes. We previously reported that expression of human leucocyte antigen (HLA)-DR promoted a redistribution of Gag in late endosomes and an increased detection of mature virions in these compartments in HeLa and human embryonic kidney 293T model cell lines. Although this redistribution of Gag resulted in a marked decrease of HIV-1 release, the underlying mechanism remained undefined. Here, we provide evidence that expression of HLA-DR at the cell surface induces a redistribution of mature Gag products into late endosomes by enhancing nascent HIV-1 particle internalization from the plasma membrane through a process that relies on the presence of intact HLA-DR α and β-chain cytosolic tails. These findings raise the possibility that major histocompatibility complex class-II molecules might influence endocytic events at the plasma membrane and as a result promote endocytosis of progeny HIV-1 particles. PMID:23170932

  19. FUNCTIONAL IMPLICATION OF MAJOR HISTOCOMPATIBILITY (MH) VARIATION USING AN ESTUARINE FISH POPULATION

    EPA Science Inventory

    Recently, there has been a dramatic expansion of studies of major histocompatibility complex (MHC) variation aimed at discovering functional differences in immunity across wild populations of diverse vertebrate species. Some species with relatively low genetic diversity or under ...

  20. Dissection of the interaction of the human cytomegalovirus-derived US2 protein with major histocompatibility complex class I molecules: prominent role of a single arginine residue in human leukocyte antigen-A2.

    PubMed

    Thilo, Claudia; Berglund, Peter; Applequist, Steven E; Yewdell, Jonathan W; Ljunggren, Hans-Gustaf; Achour, Adnane

    2006-03-31

    Human cytomegalovirus encodes several proteins that interfere with expression of major histocompatibility complex (MHC) class I molecules on the surface of infected cells. The unique short protein 2 (US2) binds to many MHC class I allomorphs in the endoplasmic reticulum, preventing cell surface expression of the class I molecule in question. The molecular interactions underlying US2 binding to MHC class I molecules and its allele specificity have not been fully clarified. In the present study, we first compared the sequences and the structures of US2 retained versus non-retained human leukocyte antigen (HLA) class I allomorphs to identify MHC residues of potential importance for US2 binding. On the basis of this analysis, 18 individual HLA-A2 mutants were generated and the ability of full-length US2 to bind wild-type and mutated HLA-A2 complexes was assessed. We demonstrate that Arg181 plays a critical role in US2-mediated inhibition of HLA-A2 cell surface expression. The structural comparison of all known crystal structures of HLA-A2 either alone, or in complex with T cell receptor or the CD8 co-receptor, indicates that binding of US2 to HLA-A2 results in a unique, large conformational change of the side chain of Arg181. However, although the presence of Arg181 seems to be a prerequisite for US2 binding to HLA-A2, it is not sufficient for binding to all MHC class I alleles.

  1. Crystal structure of swine major histocompatibility complex class I SLA-1 0401 and identification of 2009 pandemic swine-origin influenza A H1N1 virus cytotoxic T lymphocyte epitope peptides.

    PubMed

    Zhang, Nianzhi; Qi, Jianxun; Feng, Sijia; Gao, Feng; Liu, Jun; Pan, Xiaocheng; Chen, Rong; Li, Qirun; Chen, Zhaosan; Li, Xiaoying; Xia, Chun; Gao, George F

    2011-11-01

    The presentation of viral epitopes to cytotoxic T lymphocytes (CTLs) by swine leukocyte antigen class I (SLA I) is crucial for swine immunity. To illustrate the structural basis of swine CTL epitope presentation, the first SLA crystal structures, SLA-1 0401, complexed with peptides derived from either 2009 pandemic H1N1 (pH1N1) swine-origin influenza A virus (S-OIV(NW9); NSDTVGWSW) or Ebola virus (Ebola(AY9); ATAAATEAY) were determined in this study. The overall peptide-SLA-1 0401 structures resemble, as expected, the general conformations of other structure-solved peptide major histocompatibility complexes (pMHC). The major distinction of SLA-1 0401 is that Arg(156) has a "one-ballot veto" function in peptide binding, due to its flexible side chain. S-OIV(NW9) and Ebola(AY9) bind SLA-1 0401 with similar conformations but employ different water molecules to stabilize their binding. The side chain of P7 residues in both peptides is exposed, indicating that the epitopes are "featured" peptides presented by this SLA. Further analyses showed that SLA-1 0401 and human leukocyte antigen (HLA) class I HLA-A 0101 can present the same peptides, but in different conformations, demonstrating cross-species epitope presentation. CTL epitope peptides derived from 2009 pandemic S-OIV were screened and evaluated by the in vitro refolding method. Three peptides were identified as potential cross-species influenza virus (IV) CTL epitopes. The binding motif of SLA-1 0401 was proposed, and thermostabilities of key peptide-SLA-1 0401 complexes were analyzed by circular dichroism spectra. Our results not only provide the structural basis of peptide presentation by SLA I but also identify some IV CTL epitope peptides. These results will benefit both vaccine development and swine organ-based xenotransplantation.

  2. Crystal Structure of Swine Major Histocompatibility Complex Class I SLA-1*0401 and Identification of 2009 Pandemic Swine-Origin Influenza A H1N1 Virus Cytotoxic T Lymphocyte Epitope Peptides ▿

    PubMed Central

    Zhang, Nianzhi; Qi, Jianxun; Feng, Sijia; Gao, Feng; Liu, Jun; Pan, Xiaocheng; Chen, Rong; Li, Qirun; Chen, Zhaosan; Li, Xiaoying; Xia, Chun; Gao, George F.

    2011-01-01

    The presentation of viral epitopes to cytotoxic T lymphocytes (CTLs) by swine leukocyte antigen class I (SLA I) is crucial for swine immunity. To illustrate the structural basis of swine CTL epitope presentation, the first SLA crystal structures, SLA-1*0401, complexed with peptides derived from either 2009 pandemic H1N1 (pH1N1) swine-origin influenza A virus (S-OIVNW9; NSDTVGWSW) or Ebola virus (EbolaAY9; ATAAATEAY) were determined in this study. The overall peptide–SLA-1*0401 structures resemble, as expected, the general conformations of other structure-solved peptide major histocompatibility complexes (pMHC). The major distinction of SLA-1*0401 is that Arg156 has a “one-ballot veto” function in peptide binding, due to its flexible side chain. S-OIVNW9 and EbolaAY9 bind SLA-1*0401 with similar conformations but employ different water molecules to stabilize their binding. The side chain of P7 residues in both peptides is exposed, indicating that the epitopes are “featured” peptides presented by this SLA. Further analyses showed that SLA-1*0401 and human leukocyte antigen (HLA) class I HLA-A*0101 can present the same peptides, but in different conformations, demonstrating cross-species epitope presentation. CTL epitope peptides derived from 2009 pandemic S-OIV were screened and evaluated by the in vitro refolding method. Three peptides were identified as potential cross-species influenza virus (IV) CTL epitopes. The binding motif of SLA-1*0401 was proposed, and thermostabilities of key peptide–SLA-1*0401 complexes were analyzed by circular dichroism spectra. Our results not only provide the structural basis of peptide presentation by SLA I but also identify some IV CTL epitope peptides. These results will benefit both vaccine development and swine organ-based xenotransplantation. PMID:21900158

  3. Genetic linkage of IgA deficiency to the major histocompatibility complex: evidence for allele segregation distortion, parent-of-origin penetrance differences, and the role of anti-IgA antibodies in disease predisposition.

    PubMed Central

    Vorechovský, I; Webster, A D; Plebani, A; Hammarström, L

    1999-01-01

    Immunoglobulin A (IgA) deficiency (IgAD) is characterized by a defect of terminal lymphocyte differentiation, leading to a lack of IgA in serum and mucosal secretions. Familial clustering, variable population prevalence in different ethnic groups, and a predominant inheritance pattern suggest a strong genetic predisposition to IgAD. The genetic susceptibility to IgAD is shared with a less prevalent, but more profound, defect called "common variable immunodeficiency" (CVID). Here we show an increased allele sharing at 6p21 in affected members of 83 multiplex IgAD/CVID pedigrees and demonstrate, using transmission/diseqilibrium tests, family-based associations indicating the presence of a predisposing locus, designated "IGAD1," in the proximal part of the major histocompatibility complex (MHC). The recurrence risk of IgAD was found to depend on the sex of parents transmitting the defect: affected mothers were more likely to produce offspring with IgAD than were affected fathers. Carrier mothers but not carrier fathers transmitted IGAD1 alleles more frequently to the affected offspring than would be expected under random segregation. The differential parent-of-origin penetrance is proposed to reflect a maternal effect mediated by the production of anti-IgA antibodies tentatively linked to IGAD1. This is supported by higher frequency of anti-IgA-positive females transmitting the disorder to children, in comparison with female IgAD nontransmitters, and by linkage data in the former group. Such pathogenic mechanisms may be shared by other MHC-linked complex traits associated with the production of specific autoantibodies, parental effects, and a particular MHC haplotype. PMID:10090895

  4. Human major histocompatibility complex class I antigens: residues 61-83 of the HLA-B7 heavy chain specify an alloreactive site.

    PubMed Central

    Walker, L E; Ketler, T A; Houghten, R A; Schulz, G; Chersi, A; Reisfeld, R A

    1985-01-01

    A chemically synthesized peptide (sequence in text) homologous to residues 61-83 of the HLA-B7 heavy chain, induced antibodies that specifically recognized the HLA heavy chain-beta 2-microglobulin complex and the free heavy chain of the HLA-B7 antigen. These antibodies specifically immunoprecipitated the HLA-B7 beta 2-microglobulin complex solubilized from human lymphoblastoid cells by nonionic detergents and reacted with free HLA-B7 heavy chains in blots on nitrocellulose. These observations suggest that the antigenic conformation of this region of the HLA-B7 molecule is independent of the presence of beta 2-microglobulin and that amino acid residues 61-83 mimic an alloreactive site expressed by the HLA-B7 antigen. Images PMID:3881768

  5. Association of the bovine leukocyte antigen major histocompatibility complex class II DRB3*4401 allele with host resistance to the Lone Star tick, Amblyomma americanum.

    PubMed

    Untalan, Pia M; Pruett, John H; Steelman, C Dayton

    2007-04-10

    The MHC of cattle, known as the bovine leukocyte antigen (BoLA) complex, plays an integral role in disease and parasite susceptibility, and immune responsiveness of the host. While susceptibility to tick infestation in cattle is believed to be heritable, genes that may be responsible for the manifestation of this phenotype remain elusive. In an effort to analyze the role that genes within the BoLA complex may play in host resistance to ticks, we have evaluated components of this system within a herd of cattle established at our laboratory that has been phenotyped for ectoparasite susceptibility. Of three microsatellite loci within the BoLA complex analyzed, alleles of two microsatellite loci within the BoLA class IIa cluster (DRB1-118 and DRB3-174) associated with the tick-resistant phenotype, prompting further investigation of gene sequences within the DRB3 region. DRB3 is a class IIa gene, the second exon of which is highly polymorphic since it encodes the antigen recognition site of the DR class II molecule. Analysis of the second exon of the DRB3 gene from the phenotyped calves in our herd revealed a significant association between the DRB3*4401 allele and the tick-resistant phenotype. To our knowledge, this is the first report of a putative association between a class IIa DRB3 sequence and host resistance to the Lone Star tick. Elucidation of the mechanism involved in tick resistance will contribute to improving breeding schemes for parasite resistance, which will be beneficial to the cattle industry.

  6. Development of a rapid in vitro protein refolding assay which discriminates between peptide-bound and peptide-free forms of recombinant porcine major histocompatibility class I complex (SLA-I).

    PubMed

    Oleksiewicz, M B; Kristensen, B; Ladekjaer-Mikkelsen, A-S; Nielsen, J

    2002-05-01

    The extracellular domains of swine leukocyte antigen class I (SLA-I, major histocompatibility complex protein class I) were cloned and sequenced for two haplotypes (H4 and H7) which do not share any alleles based on serological typing, and which are the most important in Danish farmed pigs. The extracellular domain of SLA-I was connected to porcine beta2 microglobulin by glycine-rich linkers. The engineered single-chain proteins, consisting of fused SLA-I and beta2 microglobulin, were overexpressed as inclusion bodies in Escherichia coli. Also, variants were made of the single-chain proteins, by linking them through glycine-rich linkers to peptides representing T-cell epitopes from classical swine fever virus (CSFV) and foot-and-mouth disease virus (FMDV). An in vitro refold assay was developed, using a monoclonal anti-SLA antibody (PT85A) to gauge refolding. The single best-defined, SLA-I restricted porcine CD8(+) T-cell epitope currently known is a 9-residue peptide from the polyprotein of CSFV (J. Gen. Virol. 76 (1995) 3039). Based on results with the CSFV epitope and two porcine haplotypes (H4 and H7), the in vitro refold assay appeared able to discriminate between peptide-free and peptide-occupied forms of SLA-I. It remains to be seen whether the rapid and technically very simple in vitro refold assay described here will prove generally applicable for the screening of virus-derived peptides for SLA-I binding.

  7. Conservation of Babesia bovis small heat shock protein (Hsp20) among strains and definition of T helper cell epitopes recognized by cattle with diverse major histocompatibility complex class II haplotypes.

    PubMed

    Norimine, Junzo; Mosqueda, Juan; Palmer, Guy H; Lewin, Harris A; Brown, Wendy C

    2004-02-01

    Babesia bovis small heat shock protein (Hsp20) is recognized by CD4+ T lymphocytes from cattle that have recovered from infection and are immune to challenge. This candidate vaccine antigen is related to a protective antigen of Toxoplasma gondii, Hsp30/bag1, and both are members of the alpha-crystallin family of proteins that can serve as molecular chaperones. In the present study, immunofluorescence microscopy determined that Hsp20 is expressed intracellularly in all merozoites. Importantly, Hsp20 is also expressed by tick larval stages, including sporozoites, so that natural tick-transmitted infection could boost a vaccine-induced response. The predicted amino acid sequence of Hsp20 from merozoites is completely conserved among different B. bovis strains. To define the location of CD4+ T-cell epitopes for inclusion in a multiepitope peptide or minigene vaccine construct, truncated recombinant Hsp20 proteins and overlapping peptides were tested for their ability to stimulate T cells from immune cattle. Both amino-terminal (amino acids [aa] 1 to 105) and carboxy-terminal (aa 48 to 177) regions were immunogenic for the majority of cattle in the study, stimulating strong proliferation and IFN-gamma production. T-cell lines from all individuals with distinct DRB3 haplotypes responded to aa 11 to 62 of Hsp20, which contained one or more immunodominant epitopes for each animal. One epitope, DEQTGLPIKS (aa 17 to 26), was identified by T-cell clones. The presence of strain-conserved T helper cell epitopes in aa 11 to 62 of the ubiquitously expressed Hsp20 that are presented by major histocompatibility complex class II molecules represented broadly in the Holstein breed supports the inclusion of this region in vaccine constructs to be tested in cattle.

  8. Efficient targeting of protein antigen to the dendritic cell receptor DEC-205 in the steady state leads to antigen presentation on major histocompatibility complex class I products and peripheral CD8+ T cell tolerance.

    PubMed

    Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Rivera, Miguel; Nussenzweig, Michel C; Steinman, Ralph M

    2002-12-16

    To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal alphaDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c- cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When alphaDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4-48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of alphaDEC-205:OVA to DCs in the steady state initially induced 4-7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with alphaDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic alphaCD40 antibody produced large amounts of interleukin 2 and interferon gamma, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation.

  9. A factor that regulates the class II major histocompatibility complex gene DPA is a member of a subfamily of zinc finger proteins that includes a Drosophila developmental control protein.

    PubMed Central

    Sugawara, M; Scholl, T; Ponath, P D; Strominger, J L

    1994-01-01

    A novel DNA sequence element termed the J element involved in the regulated expression of class II major histocompatibility complex genes was recently described. To study this element and its role in class II gene regulation further, a cDNA library was screened with oligonucleotide probes containing both the S element and the nearby J element of the human DPA gene. Several DNA clones were obtained by this procedure, one of which, clone 18, is reported and characterized here. It encodes a protein predicted to contain 688 amino acid residues, including 11 zinc finger motifs of the C2H2 type in the C-terminal region, that are Krüppel-like in the conservation of the H/C link sequence connecting them. The 160 N-terminal amino acids in the nonfinger region of clone 18 are highly homologous with similar regions of several other human, mouse, and Drosophila sequences, defining a subfamily of Krüppel-like zinc finger proteins termed TAB (tramtrack [ttk]-associated box) here. One of the Drosophila sequences, ttk, is a developmental control gene, while a second does not contain a zinc finger region but encodes a structure important in oocyte development. An acidic activation domain is located between the N-terminal conserved region of clone 18 and its zinc fingers. This protein appears to require both the S and J elements, which are separated by 10 bp for optimal binding. Antisense cDNA to clone 18 inhibited the expression of a reporter construct containing the DPA promoter, indicating its functional importance in the expression of this class II gene. Images PMID:7969177

  10. Survival of Salmonella enterica serovar Typhimurium within late endosomal-lysosomal compartments of B lymphocytes is associated with the inability to use the vacuolar alternative major histocompatibility complex class I antigen-processing pathway.

    PubMed

    Rosales-Reyes, Roberto; Alpuche-Aranda, Celia; Ramírez-Aguilar, María de la Luz; Castro-Eguiluz, Angel Denisse; Ortiz-Navarrete, Vianney

    2005-07-01

    Gamma interferon (IFN-gamma)-activated macrophages use an alternative processing mechanism to present Salmonella antigens to CD8(+) T lymphocytes. This pathway involves processing of antigen in a vacuolar compartment followed by secretion and loading of antigenic peptides to major histocompatibility complex class I (MHC-I) molecules on macrophage cell surface and bystander cells. In this study, we have shown that B lymphocytes are not able to process Salmonella antigens using this alternative pathway. This is due to differences in Salmonella enterica serovar Typhimurium-containing vacuoles (SCV) when comparing late endosomal-lysosomal processing compartments in B lymphocytes to those in macrophages. The IFN-gamma-activated IC21 macrophage cell line and A-20 B-cell line were infected with live or dead Salmonella enterica serovar Typhimurium. The SCV in B cells were in a late endosomal-lysosomal compartment, whereas SCV in macrophages were remodeled to a non-characteristic late endosomal-lysosomal compartment over time. Despite the difference in SCV within macrophages and B lymphocytes, S. enterica serovar Typhimurium survives more efficiently within the IFN-gamma-activated B cells than in activated macrophage cell lines. Similar results were found during in vivo acute infection. We determined that a lack of remodeling of late endosomal-lysosomal compartments by live Salmonella infection in B lymphocytes is associated with the inability to use the alternative MHC-I antigen-processing pathway, providing a survival advantage to the bacterium. Our data also suggest that the B lymphocyte late endosome-lysosome environment allows the expression of Salmonella virulence mechanisms favoring B lymphocytes in addition to macrophages and dendritic cells as a reservoir during in vivo infection.

  11. Efficient Targeting of Protein Antigen to the Dendritic Cell Receptor DEC-205 in the Steady State Leads to Antigen Presentation on Major Histocompatibility Complex Class I Products and Peripheral CD8+ T Cell Tolerance

    PubMed Central

    Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Rivera, Miguel; Nussenzweig, Michel C.; Steinman, Ralph M.

    2002-01-01

    To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal αDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c− cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When αDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4–48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of αDEC-205:OVA to DCs in the steady state initially induced 4–7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with αDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic αCD40 antibody produced large amounts of interleukin 2 and interferon γ, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation. PMID:12486105

  12. An Important Role for Major Histocompatibility Complex Class I-Restricted T Cells, and a Limited Role for Gamma Interferon, in Protection of Mice against Lethal Herpes Simplex Virus Infection

    PubMed Central

    Holterman, Ai-Xuan; Rogers, Kathleen; Edelmann, Kurt; Koelle, David M.; Corey, Lawrence; Wilson, Christopher B.

    1999-01-01

    Herpes simplex virus (HSV) inhibits major histocompatibility complex (MHC) class I expression in infected cells and does so much more efficiently in human cells than in murine cells. Given this difference, if MHC class I-restricted T cells do not play an important role in protection of mice from HSV, an important role for these cells in humans would be unlikely. However, the contribution of MHC class I-restricted T cells to the control of HSV infection in mice remains unclear. Further, the mechanisms by which these cells may act to control infection, particularly in the nervous system, are not well understood, though a role for gamma interferon (IFN-γ) has been proposed. To address the roles of MHC class I and of IFN-γ, C57BL/6 mice deficient in MHC class I expression (β2 microglobulin knockout [β2KO] mice), in IFN-γ expression (IFN-γKO mice), or in both (IFN-γKO/β2KO mice) were infected with HSV by footpad inoculation. β2KO mice were markedly compromised in their ability to control infection, as indicated by increased lethality and higher concentrations of virus in the feet and spinal ganglia. In contrast, IFN-γ appeared to play at most a limited role in viral clearance. The results suggest that MHC class I-restricted T cells play an important role in protection of mice against neuroinvasive HSV infection and do so largely by mechanisms other than the production of IFN-γ. PMID:9971787

  13. Major-histocompatibility-complex gene markers and restriction-fragment analysis of steroid 21-hydroxylase (CYP21) and complement C4 genes in classical congenital adrenal hyperplasia patients in a single population.

    PubMed Central

    Partanen, J; Koskimies, S; Sipilä, I; Lipsanen, V

    1989-01-01

    The gene CYP21B, encoding the steroid 21-hydroxylase enzyme of adrenal steroid biosynthesis, has been mapped to the human major histocompatibility complex (MHC). Deficiency of this enzyme leads to congenital adrenal hyperplasia (CAH). We report the phenotypes of the HLA and complement C4 and Bf genes, which are closely linked to the CYP21B gene, together with a detailed analysis of the CYP21 and C4 RFLP, in 17 Finnish families with CAH. The RFLP analysis with six restriction enzymes suggested that, altogether, 35% of the affected chromosomes had a CYP21B + C4B gene deletion, 9% an obvious gene conversion of the CYP21B gene to a CYP21A-like gene, and 3% a CYP21A + C4B duplication. The remaining 53% gave the RFLP patterns also found in nonaffected chromosomes. We also found that a 14.0-kb EcoRI RFLP marker of the CYP21 genes was strongly associated with the presence of a short C4B gene, suggesting that some of the RFLP markers found with the CYP21 probe may actually derive from C4B gene polymorphism. Three particular MHC haplotypes, each with a characteristic RFLP pattern, were found in many unrelated families. These three haplotypes accounted for 59% of the affected chromosomes in our study group, the rest (41%) of the affected chromosomes being distributed among various subtypes. The results suggest that, within a single, well-defined population such as in Finland, only a few CYP21B gene defects may constitute a substantial part of the affected chromosomes. This finding will help in genetic studies of CAH in such populations. Images Figure 2 PMID:2565078

  14. Retinoic acid induction of major histocompatibility complex class I genes in NTera-2 embryonal carcinoma cells involves induction of NF-kappa B (p50-p65) and retinoic acid receptor beta-retinoid X receptor beta heterodimers.

    PubMed Central

    Segars, J H; Nagata, T; Bours, V; Medin, J A; Franzoso, G; Blanco, J C; Drew, P D; Becker, K G; An, J; Tang, T

    1993-01-01

    Retinoic acid (RA) treatment of human embryonal carcinoma (EC) NTera-2 (NT2) cells induces expression of major histocompatibility complex (MHC) class I and beta-2 microglobulin surface molecules. We found that this induction was accompanied by increased levels of MHC class I mRNA, which was attributable to the activation of the two conserved upstream enhancers, region I (NF-kappa B like) and region II. This activation coincided with the induction of nuclear factor binding activities specific for the two enhancers. Region I binding activity was not present in undifferentiated NT2 cells, but binding of an NF-kappa B heterodimer, p50-p65, was induced following RA treatment. The p50-p65 heterodimer was produced as a result of de novo induction of p50 and p65 mRNAs. Region II binding activity was present in undifferentiated cells at low levels but was greatly augmented by RA treatment because of activation of a nuclear hormone receptor heterodimer composed of the retinoid X receptor (RXR beta) and the RA receptor (RAR beta). The RXR beta-RAR beta heterodimer also bound RA responsive elements present in other genes which are likely to be involved in RA triggering of EC cell differentiation. Furthermore, transfection of p50 and p65 into undifferentiated NT2 cells synergistically activated region I-dependent MHC class I reporter activity. A similar increase in MHC class I reporter activity was demonstrated by cotransfection of RXR beta and RAR beta. These data show that following RA treatment, heterodimers of two transcription factor families are induced to bind to the MHC enhancers, which at least partly accounts for RA induction of MHC class I expression in NT2 EC cells. Images PMID:8413217

  15. Combination of the histone deacetylase inhibitor depsipeptide and 5-fluorouracil upregulates major histocompatibility complex class II and p21 genes and activates caspase-3/7 in human colon cancer HCT-116 cells

    PubMed Central

    Okada, Kouji; Hakata, Shuko; Terashima, Jun; Gamou, Toshie; Habano, Wataru; Ozawa, Shogo

    2016-01-01

    Epigenetic anticancer drugs such as histone deacetylase (HDAC) inhibitors have been combined with existing anticancer drugs for synergistic or additive effects. In the present study, we found that a very low concentration of depsipeptide, an HDAC inhibitor, potentiated the antitumor activity of 5-fluorouracil (5-FU) in a human colon cancer cell model using HCT-116, HT29, and SW48 cells via the inhibition of colony formation ability or cellular viability. Exposure to a combination of 5-FU (1.75 µM) and 1 nM depsipeptide for 24 and 48 h resulted in a 3- to 4-fold increase in activated caspase-3/7, while 5-FU alone failed to activate caspase-3/7. Microarray and subsequent gene ontology analyses revealed that compared to 5-FU or depsipeptide alone, the combination treatment of 5-FU and depsipeptide upregulated genes related to cell death and the apoptotic process consistent with the inhibition of colony formation and caspase-3/7 activation. These analyses indicated marked upregulation of antigen processing and presentation of peptide or polysaccharide antigen via major histocompatibility complex (MHC) class (GO:0002504) and MHC protein complex (GO:0042611). Compared with vehicle controls, the cells treated with the combination of 5-FU and depsipeptide showed marked induction (3- to 8.5-fold) of expression of MHC class II genes, but not of MHC class I genes. Furthermore, our global analysis of gene expression, which was focused on genes involved in the molecular regulation of MHC class II genes, showed enhancement of pro-apoptotic PCAF and CIITA after the combination of 5-FU and depsipeptide. These results may indicate a closer relationship between elevation of MHC class II expression and cellular apoptosis induced by the combination of depsipeptide and 5-FU. To the best of our knowledge, this is the first study to report that the combination of 5-FU and depsipeptide induces human colon cancer cell apoptosis in a concerted manner with the induction of MHC class II gene

  16. HLA: The Major Histocompatibility Complex of Man

    DTIC Science & Technology

    1991-01-01

    REPORT (Year, Month Day) iS. PAGE COUNT Book chapter I FROM TO 1991 34 16. SUPPLEMENTARY NOTATION In: Clinical diagnosis and management by laboratory...multiparous women. During human system. This assay represented a tremendous pregnancy , the woman mounts an immune response to technical advance because...fixation, which can introduce a potential source 29 W" of error and m ajor variability in laboratory diagnosis . 25 ..-.-. ........... ............ The

  17. Immune-privileged embryonic Swiss mouse STO and STO cell-derived progenitor cells: major histocompatibility complex and cell differentiation antigen expression patterns resemble those of human embryonic stem cell lines.

    PubMed

    Koch, Katherine S; Son, Kyung-Hwa; Maehr, Rene; Pellicciotta, Illenia; Ploegh, Hidde L; Zanetti, Maurizio; Sell, Stewart; Leffert, Hyam L

    2006-09-01

    Embryonic mouse STO (S, SIM; T, 6-thioguanine resistant; O, ouabain resistant) and 3(8)21-enhanced green fluorescent protein (EGFP) cell lines exhibit long-term survival and hepatic progenitor cell behaviour after xenogeneic engraftment in non-immunosuppressed inbred rats, and were previously designated major histocompatibility complex (MHC) class I- and class II-negative lines. To determine the molecular basis for undetectable MHC determinants, the expression and haplotype of H-2K, H-2D, H-2L and I-A proteins were reassessed by reverse transcriptase-polymerase chain reaction (RT-PCR), cDNA sequencing, RNA hybridization, immunoblotting, quantitative RT-PCR (QPCR), immunocytochemistry and flow cytometry. To detect cell differentiation (CD) surface antigens characteristic of stem cells, apoptotic regulation or adaptive immunity that might facilitate progenitor cell status or immune privilege, flow cytometry was also used to screen untreated and cytokine [interferon (IFN)-gamma]-treated cultures. Despite prior PCR genotyping analyses suggestive of H-2q haplotypes in STO, 3(8)21-EGFP and parental 3(8)21 cells, all three lines expressed H-2K cDNA sequences identical to those of d-haplotype BALB/c mice, as well as constitutive and cytokine-inducible H-2K(d) determinants. In contrast, apart from H-2L(d[LOW]) display in 3(8)21 cells, H-2Dd, H-2Ld and I-Ad determinants were undetectable. All three lines expressed constitutive and cytokine-inducible CD34; however, except for inducible CD117([LOW]) expression in 3(8)21 cells, no expression of CD45, CD117, CD62L, CD80, CD86, CD90.1 or CD95L/CD178 was observed. Constitutive and cytokine-inducible CD95([LOW]) expression was detected in STO and 3(8)21 cells, but not in 3(8)21-EGFP cells. MHC (class I(+[LOW])/class II-) and CD (CD34+/CD80-/CD86-/CD95L-) expression patterns in STO and STO cell-derived progenitor cells resemble patterns reported for human embryonic stem cell lines. Whether these patterns reflect associations with

  18. HLA DQB1*06:02 Negative Narcolepsy with Hypocretin/Orexin Deficiency

    PubMed Central

    Han, Fang; Lin, Ling; Schormair, Barbara; Pizza, Fabio; Plazzi, Giuseppe; Ollila, Hanna M.; Nevsimalova, Sona; Jennum, Poul; Knudsen, Stine; Winkelmann, Juliane; Coquillard, Cristin; Babrzadeh, Farbod; Strom, Tim M.; Wang, Chunlin; Mindrinos, Michael; Vina, Marcelo Fernandez; Mignot, Emmanuel

    2014-01-01

    Study Objectives: To identify rare allelic variants and HLA alleles in narcolepsy patients with hypocretin (orexin, HCRT) deficiency but lacking DQB1*06:02. Settings: China (Peking University People's Hospital), Czech Republic (Charles University), Denmark (Golstrup Hospital), Italy (University of Bologna), Korea (Catholic University), and USA (Stanford University). Design: CSF hypocretin-1, DQB1*06:02, clinical and polysomnographic data were collected in narcolepsy patients (552 with and 144 without cataplexy) from 6 sites. Numbers of cases with and without DQB1*06:02 and low CSF hypocretin-1 were compiled. HLA class I (A, B, C), class II (DRBs, DQA1, DQB1, DPA1, and DPB1), and whole exome sequencing were conducted in 9 DQB1*06:02 negative cases with low CSF hypocretin-1. Sanger sequencing of selected exons in DNMT1, HCRT, and MOG was performed to exclude mutations in known narcolepsy-associated genes. Measurements and Results: Classic narcolepsy markers DQB1*06:02 and low CSF hypocretin-1 were found in 87.4% of cases with cataplexy, and in 20.0% without cataplexy. Nine cases (all with cataplexy) were DQB1*06:02 negative with low CSF hypocretin-1, constituting 1.7% [0.8%-3.4%] of all cases with cataplexy and 1.8% [0.8%-3.4%] of cases with low CSF hypocretin independent of cataplexy across sites. Five HLA negative subjects had severe cataplexy, often occurring without clear triggers. Subjects had diverse ethnic backgrounds and HLA alleles at all loci, suggesting no single secondary HLA association. The rare subtype DPB1*0901, and homologous DPB1*10:01 subtype, were present in 5 subjects, suggesting a secondary association with HLA-DP. Preprohypocretin sequencing revealed no mutations beyond one previously reported in a very early onset case. No new MOG or DNMT1 mutations were found, nor were suspicious or private variants in novel genes identified through exome sequencing. Conclusions: Hypocretin, MOG, or DNMT1 mutations are exceptional findings in DQB1

  19. Identification of a Colonial Chordate Histocompatibility Gene

    PubMed Central

    Voskoboynik, Ayelet; Newman, Aaron M.; Corey, Daniel M.; Sahoo, Debashis; Pushkarev, Dmitry; Neff, Norma F.; Passarelli, Benedetto; Koh, Winston; Ishizuka, Katherine J.; Palmeri, Karla J.; Dimov, Ivan K.; Keasar, Chen; Fan, H. Christina; Mantalas, Gary L.; Sinha, Rahul; Penland, Lolita; Quake, Stephen R.; Weissman, Irving L.

    2013-01-01

    Histocompatibility is the basis by which multicellular organisms of the same species distinguish self from non-self. Relatively little is known about the mechanisms underlying histocompatibility reactions in lower organisms. Botryllus schlosseri is a colonial urochordate, a sister group of vertebrates, that exhibits a genetically determined natural transplantation reaction, whereby self-recognition between colonies leads to formation of parabionts with a common vasculature, whereas rejection occurs between incompatible colonies. Using genetically defined lines, whole-transcriptome sequencing, and genomics, we identified a single gene that encodes self/non-self and determines “graft” outcomes in this organism. This gene is significantly upregulated in colonies poised to undergo fusion or rejection, is highly expressed in the vasculature, and is functionally linked to histocompatibility outcomes. These findings establish a platform for advancing the science of allorecognition. PMID:23888037

  20. Sequencing of two new HLA class II alleles: DRB3*0218 and DQB1*030202.

    PubMed

    Balas, A; Aviles, M J; Lillo, R; Alonso-Nieto, M; Zarapuz, L; García-Villaescusa, R; García-Sánchez, F; Vicario, J L

    2004-06-01

    Two novel human leukocyte antigen (HLA) class II alleles for DRB3 and DQB1 genes detected in Caucasoid Spanish individuals are described: DRB3*0218 and DQB1*030202. Both alleles have been found during routine high-resolution typing by sequencing. DRB3*0218 shows a novel DRB3 gene polymorphic position, located at amino acid residue 58, alanine to glutamic acid. This residue is shared by several DRB1 alleles, including all described DRB1*11 subtypes. DQB1*030202 differs from DQB1*030201 by a point mutation at position 319 (T to C). This nucleotide change generates a new codon at amino acid position 75 that is not shared by any other DQB1 allele.

  1. The HLA DQB1 gene locus: Further evidence for an association with schizophrenia

    SciTech Connect

    Zhang, X.R.; Rudert, W.A.; Nimgaonkar, L.

    1994-09-01

    A genetic predisposition to schizophrenia is well-established. Immunological abnormalities suggestive of an auto-immune disorder have also been noted. However, no consistent associations with HLA have been detected. A negative association between schizophrenia and HLA DQB1*0602 among African-Americans, but not among Caucasian individuals, was reported recently. The association is plausible, because (i) an association of insulin dependent diabetes mellitus (IDDM) with the HLA DQB1 gene locus is known, and (ii) an inverse relationship between the prevalence of schizophrenia and IDDM has been suggested. In view of the ethnic differences in the above association, a cohort of Chinese ethnicity from Singapore was examined in the present study. Consenting male inpatients with schizophrenia (n=102, ICD-9 criteria) participated. The controls were male adults undergoing pre-employment checkup (n=111). HLA DQB1 gene polymorphisms were analyzed using a PCR-based reverse dot-blot assay. In case of ambiguity, samples were checked using PCR amplification with sequence-specific primers. In support of the earlier report, a negative association with HLA DQB1*0602 was noted (odds ratio 0.22, C.I. 0.18, 0.83; {chi}{sup 2}=8.0, p<0.005; both analyses uncorrected for multiple comparisons).

  2. HLA-DRB and HLA-DQB Allele and Haplotype Frequencies in Iranian Patients with Recurrent Aphthous Stomatitis.

    PubMed

    Najafi, Shamsolmoulouk; Mohammadzadeh, Mahsa; Zare Bidoki, Alireza; Meighani, Ghasem; Aslani, Saeed; Mahmoudi, Mahdi; Rezaei, Nima

    Recurrent aphthous stomatitis (RAS) is known as the most common chronic disease of the oral cavity, which affects a range of 5-25% of the population. RAS appears to be associated with some human leukocyte antigen (HLA) class II alleles and haplotypes. This study attempts to survey the distribution of HLA-DRB and -DQB alleles among Iranian RAS patients and healthy controls. In order to evaluate the association of HLA-DR and DQ alleles and haplotypes, 54 patients with RAS and 100 unrelated healthy subjects as control group were investigated. Our data indicated that DRB1*13:17, DRB1*15:01, and DRB5*01 were significantly more frequent in RAS patients in comparison to controls. However, DRB3:01allele frequency was higher in the controls compared to the patients. The significantly frequent allele in the patients compared with the healthy subjects was HLA-DQB1*03:02. However, both HLA-DQB1*02:01 and HLA-DQB1*03:01 alleles were most frequent in the healthy individuals rather than the patients. The DRB*04/DQB1*03:01 and DRB*01:01/DQB1*02:01 haplotypes were significantly distributed in healthy subjects compared with patients. However, DRB*07:01/DQB1*03:02 haplotype was found to be significantly frequent in patients than controls. In respect of HLA genes, factors are involved in the incidence of RAS; various HLA-DRB and HLA-DQB1 alleles and the related haplotypes are suggested to be the three main RAS susceptibility factors in our population study.

  3. Role of CD4 molecule in the induction of interleukin 2 and interleukin 2 receptor in class II major histocompatibility complex-restricted antigen-specific T helper clones. T cell receptor/CD3 complex transmits CD4-dependent and CD4-independent signals.

    PubMed Central

    Oyaizu, N; Chirmule, N; Pahwa, S

    1992-01-01

    The CD4 molecule plays an essential role in antigen-induced activation of T helper (Th) cells, but its contribution to signal transduction events resulting in physiologic T cell function is ill defined. By utilizing anti-CD4 monoclonal antibodies (MAbs) that recognize distinct epitopes of CD4, we have investigated the role of CD4 molecule in antigen-induced interleukin 2 (IL-2) and IL-2 receptor (IL-2R) alpha chain expression in class II major histocompatibility complex-restricted antigen-specific human Th clones. Pretreatment of the Th clones with Leu3a resulted in a dose-dependent suppression of antigen-induced proliferative responses, inositol phosphate accumulation, increase in free cytoplasmic calcium ions ([Ca2+]i), IL-2 mRNA accumulation, IL-2 secretion, and membrane IL-2R expression. IL-2R mRNA accumulation, however, was unaffected even at highest Leu3a concentrations. Leu3a treatment did not affect bypass activation of T cells with PMA plus ionomycin or activation via CD2 molecule. The MAb OKT4, which binds another domain of CD4, was not inhibitory. These results suggest that after T cell antigen receptor-CD3 activation, IL-2 gene induction, IL-2 secretion, and membrane IL-2R expression are absolutely dependent upon participation of CD4 molecules, phosphatidylinositol (PI) hydrolysis, and increase in [Ca2+]i. The requirement for IL-2R gene induction, however, occurs independently of CD4 molecule participation and PI hydrolysis. Images PMID:1534818

  4. DQA1 and DQB1 promoter diversity and linkage disequilibrium with class II haplotypes in Mexican Mestizo population.

    PubMed

    Alaez, C; Vázquez-García, M N; Gorodezky, C

    2001-06-01

    The upstream sequences in the 5' flanking region of HLA class II genes, regulate their expression and contribute to the development of immunological diseases. We analyzed 105 healthy unrelated Mexican Mestizos for QAP and QBP polymorphism. DNA typing for DRB1, DQA1, DQB1, QAP1 and QBP1 was done using a standardized PCR-SSOP. Although all QAP alleles previously described were found in Mexicans, the distribution differed as compared to other populations. QAP-3.1, 4.1 and 4.2 were the most frequent alleles and were associated with DQA1*03, *0501 and *0402 respectively. The prevalent QBP alleles were 3.21, 3.1 and 4.1 found mainly associated with DQB1*0302, *0301 and *0501. Linkage disequilibria between the promoter and the corresponding DQA1 and DQB1 allele, are in general the same as described by others. A total of 61 different haplotypes were defined, only six of them with a frequency above 4%. The haplotypes DRB1*0407-QAP-3.1-DQA1*03-QBP-3.21-DQB1*0302 (HF = 14.37%) and DRB1*0802-QAP-4.2-DQA1*0401-QBP-4.1-DQB1*0402 (HF = 14.22%), which have an Amerindian ancestry, are the most frequent in Mexicans. Some rare combinations were detected such as DRB1*0405-QAP-1.3-DQA1*0101/4-QBP-5.11/5.12-DQB1*0501 and DRB1*0403-QAP-3.2-DQA1*03-QBP-3.21-DQB1*0302, probably due to ancient recombination events. This knowledge is relevant as a basis to evaluate functional implications and to explore the role of promoter diversity in disease expression.

  5. Polymorphisms of HLA-DRB1, -DQA1 and -DQB1 in Inhabitants of Astana, the Capital City of Kazakhstan

    PubMed Central

    Kuranov, Alexandr B.; Vavilov, Mikhail N.; Abildinova, Gulshara Zh.; Akilzhanova, Ainur R.; Iskakova, Aisha N.; Zholdybayeva, Elena V.; Boldyreva, Margarita N.; Müller, Claudia A.; Momynaliev, Kuvat T.

    2014-01-01

    Background Kazakhstan has been inhabited by different populations, such as the Kazakh, Kyrgyz, Uzbek and others. Here we investigate allelic and haplotypic polymorphisms of human leukocyte antigen (HLA) genes at DRB1, DQA1 and DQB1 loci in the Kazakh ethnic group, and their genetic relationship between world populations. Methodology/Principal Findings A total of 157 unrelated Kazakh ethnic individuals from Astana were genotyped using sequence based typing (SBT-Method) for HLA-DRB1, -DQA1 and -DQB1 loci. Allele frequencies, neighbor-joining method, and multidimensional scaling analysis have been obtained for comparison with other world populations. Statistical analyses were performed using Arlequin v3.11. Applying the software PAST v. 2.17 the resulting genetic distance matrix was used for a multidimensional scaling analysis (MDS). Respectively 37, 17 and 19 alleles were observed at HLA-DRB1, -DQA1 and -DQB1 loci. The most frequent alleles were HLA-DRB1*07:01 (13.1%), HLA-DQA1*03:01 (13.1%) and HLA-DQB1*03:01 (17.6%). In the observed group of Kazakhs DRB1*07:01-DQA1*02:01-DQB1*02:01 (8.0%) was the most common three loci haplotype. DRB1*10:01-DQB1*05:01 showed the strongest linkage disequilibrium. The Kazakh population shows genetic kinship with the Kazakhs from China, Uyghurs, Mongolians, Todzhinians, Tuvinians and as well as with other Siberians and Asians. Conclusions/Significance The HLA-DRB1, -DQA1and -DQB1 loci are highly polymorphic in the Kazakh population, and this population has the closest relationship with other Asian and Siberian populations. PMID:25531278

  6. MHC-DRB1/DQB1 Gene Polymorphism and Its Association with Resistance/Susceptibility to Cystic Echinococcosis in Chinese Merino Sheep

    PubMed Central

    Jia, Bin; Jiang, Song; Du, Yingchun

    2014-01-01

    The aim of this study was to analyze the relationship between polymorphism of the MHC-DRB1/DQB1 gene and its resistance to Cystic Echinococcosis (C.E), as well as to screen out the molecular genetic marker of antiechinococcosis in Chinese Merino sheep. The MHCII-DRB1/DQB1 exon 2 was amplified by polymerase chain reaction (PCR) from DNA samples of healthy and hydatidosis sheep. PCR products were characterized by restriction fragment length polymorphism (RFLP) technique. Five restriction enzymes (Mval, HaeIII, SacI, SacII, and Hin1I) were employed to cut DRB1, while seven restriction enzymes (MroxI, ScaI, SacII, NciI, TaqI, Mval, and HaeIII) were employed to cut DQB1.Results showed that frequencies of patterns Mvalbb (P < 0.01), SacIab in DRB1 exon 2 (P < 0.05), and TaqIaa, HaeIIInn (P < 0.01) in DQB1 exon 2 were significantly higher in the healthy group compared with the C.E individuals, which implied that there was a strong association between these genotypes and hydatidosis resistance or susceptibility. Chi-square test showed that individuals with the genic haplotype DRB1-SacIab/DRB1-Mvalbb/DQB1-TaqIaa/DQB1-HaeIIInn (P < 0.01) were relatively resistant to C.E, while individuals with the genic haplotypes DRB1-Mvalbc/DQB1-Mvalyy/DQB1-TaqIab/DQB1-HaeIIImn (P < 0.01) and DRB1-Mvalbb/DQB1-Mvalcc/DQB1-TaqIab/DQB1-HaeIIImn (P < 0.01) were more susceptible to C.E. In addition, to confirm these results, a fielding experiment was performed with Chinese Merino sheep which were artificially infected with E.g. The result was in accordance with the results of the first study. In conclusion, MHC-DRB1/DQB1 exon 2 plays an important role as resistant to C.E in Chinese Merino sheep. In addition, the molecular genetic marker of antiechinococcosis (DRB1-SacIab/DRB1-Mvalbb/DQB1-TaqIaa/DQB1-HaeIIInn) was screened out in Chinese Merino sheep. PMID:24782918

  7. Class I major histocompatibility proteins as cell surface receptors for simian virus 40.

    PubMed

    Atwood, W J; Norkin, L C

    1989-10-01

    Class I major histocompatibility complex proteins appear to be the major cell surface receptors for simian virus 40 (SV40), as implied by the following observations. Adsorption of SV40 to LLC-MK2 rhesus monkey kidney cells specifically inhibited binding of a monoclonal antibody (MAb) against class I human lymphocyte antigen (HLA) proteins. Conversely, pretreatment of LLC-MK2 cells with anti-HLA MAbs inhibited infection by SV40. The ability of anti-HLA to inhibit infection was greatly reduced when the order of addition of the anti-HLA and the virus was reversed. Infection was also inhibited by preincubating SV40 with purified soluble class I protein. Finally, human lymphoblastoid cells of the Daudi line, which do not express class I major histocompatibility complex proteins, were infected at relatively low levels with SV40 virions. In a control experiment, we found that pretreatment of cells with a MAb specific for the leukocytic-function-associated antigen LFA-3 actually enhanced infection. This finding may also support the premise that class I major histocompatibility complex proteins are receptors for SV40.

  8. Adaptive major histocompatibility complex (MHC) and neutral genetic variation in two native Baltic Sea fishes (perch Perca fluviatilis and zander Sander lucioperca) with comparisons to an introduced and disease susceptible population in Australia (P. fluviatilis): assessing the risk of disease epidemics.

    PubMed

    Faulks, L K; Östman, Ö

    2016-04-01

    This study assessed the major histocompatibility complex (MHC) and neutral genetic variation and structure in two percid species, perch Perca fluviatilis and zander Sander lucioperca, in a unique brackish ecosystem, the Baltic Sea. In addition, to assess the importance of MHC diversity to disease susceptibility in these populations, comparisons were made to an introduced, disease susceptible, P. fluviatilis population in Australia. Eighty-three MHC class II B exon 2 variants were amplified: 71 variants from 92 P. fluviatilis samples, and 12 variants from 82 S. lucioperca samples. Microsatellite and MHC data revealed strong spatial genetic structure in S. lucioperca, but not P. fluviatilis, across the Baltic Sea. Both microsatellite and MHC data showed higher levels of genetic diversity in P. fluviatilis from the Baltic Sea compared to Australia, which may have facilitated the spread of an endemic virus, EHNV in the Australian population. The relatively high levels of genetic variation in the Baltic Sea populations, together with spatial genetic structure, however, suggest that there currently seems to be little risk of disease epidemics in this system. To ensure this remains the case in the face of ongoing environmental changes, fisheries and habitat disturbance, the conservation of local-scale genetic variation is recommended.

  9. DQB1 Locus Alone Explains Most of the Risk and Protection in Narcolepsy with Cataplexy in Europe

    PubMed Central

    Tafti, Mehdi; Hor, Hyun; Dauvilliers, Yves; Lammers, Gert J.; Overeem, Sebastiaan; Mayer, Geert; Javidi, Sirous; Iranzo, Alex; Santamaria, Joan; Peraita-Adrados, Rosa; Vicario, José L.; Arnulf, Isabelle; Plazzi, Giuseppe; Bayard, Sophie; Poli, Francesca; Pizza, Fabio; Geisler, Peter; Wierzbicka, Aleksandra; Bassetti, Claudio L.; Mathis, Johannes; Lecendreux, Michel; Donjacour, Claire E.H.M.; van der Heide, Astrid; Heinzer, Raphaël; Haba-Rubio, José; Feketeova, Eva; Högl, Birgit; Frauscher, Birgit; Benetó, Antonio; Khatami, Ramin; Cañellas, Francesca; Pfister, Corinne; Scholz, Sabine; Billiard, Michel; Baumann, Christian R.; Ercilla, Guadalupe; Verduijn, Willem; Claas, Frans H.J.; Dubois, Valérie; Nowak, Jacek; Eberhard, Hans-Peter; Pradervand, Sylvain; Hor, Charlotte N.; Testi, Manuela; Tiercy, Jean-Marie; Kutalik, Zoltán

    2014-01-01

    Study Objective: Prior research has identified five common genetic variants associated with narcolepsy with cataplexy in Caucasian patients. To replicate and/or extend these findings, we have tested HLA-DQB1, the previously identified 5 variants, and 10 other potential variants in a large European sample of narcolepsy with cataplexy subjects. Design: Retrospective case-control study. Setting: A recent study showed that over 76% of significant genome-wide association variants lie within DNase I hypersensitive sites (DHSs). From our previous GWAS, we identified 30 single nucleotide polymorphisms (SNPs) with P < 10-4 mapping to DHSs. Ten SNPs tagging these sites, HLADQB1, and all previously reported SNPs significantly associated with narcolepsy were tested for replication. Patients and Participants: For GWAS, 1,261 narcolepsy patients and 1,422 HLA-DQB1*06:02-matched controls were included. For HLA study, 1,218 patients and 3,541 controls were included. Measurements and Results: None of the top variants within DHSs were replicated. Out of the five previously reported SNPs, only rs2858884 within the HLA region (P < 2x10-9) and rs1154155 within the TRA locus (P < 2x10-8) replicated. DQB1 typing confirmed that DQB1*06:02 confers an extraordinary risk (odds ratio 251). Four protective alleles (DQB1*06:03, odds ratio 0.17, DQB1*05:01, odds ratio 0.56, DQB1*06:09 odds ratio 0.21, DQB1*02 odds ratio 0.76) were also identified. Conclusion: An overwhelming portion of genetic risk for narcolepsy with cataplexy is found at DQB1 locus. Since DQB1*06:02 positive subjects are at 251-fold increase in risk for narcolepsy, and all recent cases of narcolepsy after H1N1 vaccination are positive for this allele, DQB1 genotyping may be relevant to public health policy. Citation: Tafti M; Hor H; Dauvilliers Y; Lammers GJ; Overeem S; Mayer G; Javidi S; Iranzo A; Santamaria J; Peraita-Adrados R; Vicario JL; Arnulf I; Plazzi G; Bayard S; Poli F; Pizza F; Geisler P; Wierzbicka A; Bassetti CL

  10. Distribution of HLA-DRB1 and HLA-DQB1 alleles in Lak population of Iran.

    PubMed

    Varzi, Ali Mohammad; Shahsavar, Farhad; Tarrahi, Mohammad Javad

    2016-07-01

    Human leukocyte antigen (HLA) genes are the most polymorphic loci in the human genome and encode the highly polymorphic molecules critically involved in immune responses. Anthropological studies based on highly polymorphic HLA genes provide useful information for bone marrow donor registry, forensic medicine, disease association studies, as well as designing peptide vaccines against tumors, and infectious or autoimmune diseases. The aim of this study was to determine the HLA-DRB1 and HLA-DQB1 allele frequencies in 100 unrelated Lak individuals from Lorestan province of Iran. Finally, we compared the results with those previously described in four other Iranian populations. Commercial HLA-Type kits were used for determination of the HLA-DRB1 and HLA-DQB1 allele frequencies. Differences between populations in the distribution of HLA-DRB1 and HLA-DQB1 alleles were estimated by χ2 test with Yate's correction and Fisher's exact test. The most frequent HLA-DRB1 alleles were (*)1103=4 (23%), (*)1502 (9.5%), (*)0701 (9%), (*)0301 (8.5%), (*)1101 (7.5%) and (*)1501 (6%) while HLA-DQB1(*)0301 (40%), (*)0201 (15%), (*)0502 (10.5%), (*)0303 (10%), (*)0602=3 (9.5%), and (*)0501 (7.5%) were the most frequent alleles in Lak population. HLA-DRB1(*)0409, (*)0804, (*)1102, (*)1112, (*)1405, and HLA-DQB1(*)0503, (*)0604 were the least observed frequencies in Lak population. Our results based on HLA-DRB1 and HLA-DQB1 allele frequencies showed that the Lak population possesses the previously reported general features of the Lur and Kurd populations but still with unique, decreased or increased frequencies of several alleles. In other words, the Lak population is close to Lurs Khorramabadi and Kurd but far from Lurs Kohkiloyeh/Boyerahmad and Bakhtiari.

  11. HLA-DRB1 and HLA-DQB1 methylation changes promote the occurrence and progression of Kazakh ESCC.

    PubMed

    Hu, Jian Ming; Li, Ling; Chen, Yun Zhao; Liu, Chunxia; Cui, Xiaobin; Yin, Liang; Yang, Lan; Zou, Hong; Pang, Lijuan; Zhao, Jin; Qi, Yan; Cao, Yuwen; Jiang, Jinfang; Liang, Weihua; Li, Feng

    2014-10-01

    Human leukocyte antigen II (HLA-II) plays an important role in host immune responses to cancer cells. Changes in gene methylation may result in aberrant expression of HLA-II, serving a key role in the pathogenesis of Kazakh esophageal squamous cell carcinoma (ESCC). We analyzed the expression level of HLA-II (HLA-DP, -DQ, and -DR) by immunohistochemistry, as well as the methylation status of HLA-DRB1 and HLA-DQB1 by MassARRAY spectrometry in Xinjiang Kazakh ESCC. Expression of HLA-II in ESCC was significantly higher than that in cancer adjacent normal (ACN) samples (P < 0.05). Decreased HLA-II expression was closely associated with later clinical stages of ESCC (P < 0.05). Hypomethylation of HLA-DRB1 and hypermethylation of HLA-DQB1 was significantly correlated with occurrence of Kazakh ESCC (P < 0.01), and mainly manifested as hypomethylation of CpG9, CpG10-11, and CpG16 in HLA-DRB1 and hypermethylation of CpG6-7 and CpG16-17 in HLA-DQB1 (P < 0.01). Moreover, hypomethylation of HLA-DQB1 CpG6-7 correlated with poor differentiation in ESCCs, whereas hypermethylation of HLA-DRB1 CpG16 and hypomethylation of HLA-DQB1 CpG16-17 were significantly associated with later stages of ESCC (P < 0.05). A significant inverse association between HLA-DRB1 CpG9 methylation and HLA-II expression was found in ESCC (P < 0.05). These findings suggest aberrant HLA-DRB1 and HLA-DQB1 methylation contributes to the aberrant expression of HLA-II. These molecular changes may influence the immune response to specific tumor epitopes, promoting the occurrence and progression of Kazakh ESCC.

  12. Fluorescent directed heteroduplex analysis enhances PCR-based DQA1 and DQB1 genotyping

    SciTech Connect

    Zimmerman, P.A.; Mansfield, E.S.; Miyasaki, T.

    1994-09-01

    We previously showed how directed heteroduplex analysis (DHDA) simplifies DQA1 and DQB1 genotyping and have used the technique to identify a new DQA1 allele (DQA{sup *}0502, which has a single nucleotide difference from DQA1{sup *}0501). In DHDA, labeled probes are mixed with unlabeled PCR products amplified from patient genomic DNA. After controlled re-annealing, allelic heteroduplexes are resolved on polyacrylamide gels (5%, 2.7 M urea). To utilize fluorescence imaging for detecting the heteroduplexes in HLA-typing, probes are labeled by PCR amplification using locus-specific generic primers and gels scanned using the Fluorimager{trademark} 575 (Molecular Dynamics, Inc.). We generate 2-color DHDA probes using locus-specific PCR primers 5{prime}-end labeled with the fluorochromes FAM (positive-strand primer) and JOE (negative-strand primer) (Perkin-Elmer). Genotypic analysis within families obtained from the CEPH repository have been performed by fluorescence-based DHDA. Results to date show 100% concordance between DHDA and sequence-specific oligonucleotide probe (SSOP) genotyping. Fluorescence-based DHDA is performed with fewer probes than SSOP (1 set of locus-specific probes for DHDA and 10 SSOP probes for DQA1 typing or 13 SSOP probes for DQB1 typing). In addition, fluorescent DHDA allows rapid assessment of genotype, aproximately four hours from receipt of sample to typing result. These results suggest that fluorescent DHDA may facilitate DNA-based HLA-typing within the time constraints required for solid organ transplantation.

  13. X-ray diffraction analysis of crystals from the human major histocompatibility antigen HLA-B*2706 in complex with a viral peptide and with a self-peptide.

    PubMed

    Zawacka, Anna; Loll, Bernhard; Biesiadka, Jacek; Saenger, Wolfram; Uchanska-Ziegler, Barbara; Ziegler, Andreas

    2005-12-01

    The human leukocyte antigen (HLA) alleles HLA-B*2704 and HLA-B*2706 show an ethnically restricted distribution and are differentially associated with ankylosing spondylitis, with HLA-B*2706 lacking association with this autoimmune disease. However, the products of the two alleles differ by only two amino acids, at heavy-chain residues 114 (His in HLA-B*2704; Asp in HLA-B*2706) and 116 (Asp in HLA-B*2704; Tyr in HLA-B*2706). Both residues could be involved in contacting amino acids of a bound peptide, suggesting that peptides presented by these subtypes play a role in disease pathogenesis. Two HLA-B*2706-peptide complexes were crystallized using the hanging-drop vapour-diffusion method with PEG as precipitant. Data sets were collected to resolutions of 2.70 A (viral peptide pLMP2, RRRWRRLTV; space group P2(1)2(1)2(1)) and 1.83 A (self-peptide pVIPR, RRKWRRWHL; space group P2(1)). Using HLA-B*2705 complexed with the pGR peptide (RRRWHRWRL) as a search model, unambiguous molecular-replacement solutions were found for both HLA-B*2706 complexes.

  14. Tannerella forsythia and the HLA-DQB1 allele are associated with susceptibility to periodontal disease in Japanese adolescents.

    PubMed

    Shimomura-Kuroki, Junko; Yamashita, Kie; Shimooka, Shohachi

    2009-01-01

    Periodontal disease is a multiple factor disease caused by genetic factors, environmental factors, and periodontal bacteria (periodontal pathogens). The present study aimed to elucidate the risk factors for periodontal disease in Japanese adolescents. Subjects (11-16 years old) were classified into three groups: localized aggressive periodontitis (LAP), periodontal attachment loss (PAL), and periodontally healthy (PH) groups. Genomic DNA isolated from the buccal mucosa was used for single-nucleotide polymorphism analyses of the candidate genes (interleukin-1alpha-889; interleukin-1alpha +4845; interleukin-1beta +3954; an immunoglobulin G Fc gamma receptor, FcgammaRIIa-R/H131; and a human leukocyte antigen class II allele, HLA-DQB1) of aggressive periodontitis. Subgingival plaque samples obtained from the same subjects were used for 16S rRNAbased polymerase chain reaction analysis of five important periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia). Tannerella forsythia was detected in the deepest periodontal pockets in all subjects in the LAP and PAL groups. The prevalence of an atypical BamHI restriction site in HLA-DQB1 of the LAP group was significantly higher than that in the PH and PAL groups. Furthermore, all subjects who had the atypical BamHI restriction site in HLA-DQB1 had T. forsythia infection. These results suggested that T. forsythia is associated with periodontal disease in Japanese adolescents and also suggested that HLA-DQB1 is related to LAP and is associated with T. forsythia infection.

  15. A novel cysteine-rich sequence-specific DNA-binding protein interacts with the conserved X-box motif of the human major histocompatibility complex class II genes via a repeated Cys-His domain and functions as a transcriptional repressor

    PubMed Central

    1994-01-01

    The class II major histocompatibility complex (MHC) molecules function in the presentation of processed peptides to helper T cells. As most mammalian cells can endocytose and process foreign antigen, the critical determinant of an antigen-presenting cell is its ability to express class II MHC molecules. Expression of these molecules is usually restricted to cells of the immune system and dysregulated expression is hypothesized to contribute to the pathogenesis of a severe combined immunodeficiency syndrome and certain autoimmune diseases. Human complementary DNA clones encoding a newly identified, cysteine-rich transcription factor, NF-X1, which binds to the conserved X-box motif of class II MHC genes, were obtained, and the primary amino acid sequence deduced. The major open reading frame encodes a polypeptide of 1,104 amino acids with a symmetrical organization. A central cysteine-rich portion encodes the DNA-binding domain, and is subdivided into seven repeated motifs. This motif is similar to but distinct from the LIM domain and the RING finger family, and is reminiscent of known metal-binding regions. The unique arrangement of cysteines indicates that the consensus sequence CX3CXL-XCGX1- 5HXCX3CHXGXC represents a novel cysteine-rich motif. Two lines of evidence indicate that the polypeptide encodes a potent and biologically relevant repressor of HLA-DRA transcription: (a) overexpression of NF-X1 from a retroviral construct strongly decreases transcription from the HLA-DRA promoter; and (b) the NF-X1 transcript is markedly induced late after induction with interferon gamma (IFN- gamma), coinciding with postinduction attenuation of HLA-DRA transcription. The NF-X1 protein may therefore play an important role in regulating the duration of an inflammatory response by limiting the period in which class II MHC molecules are induced by IFN-gamma. PMID:7964459

  16. An association analysis of HLA-DQB1 with narcolepsy without cataplexy and idiopathic hypersomnia with/without long sleep time in a Japanese population

    PubMed Central

    Miyagawa, Taku; Toyoda, Hiromi; Kanbayashi, Takashi; Imanishi, Aya; Sagawa, Yohei; Kotorii, Nozomu; Kotorii, Tatayu; Hashizume, Yuji; Ogi, Kimihiro; Hiejima, Hiroshi; Kamei, Yuichi; Hida, Akiko; Miyamoto, Masayuki; Ikegami, Azusa; Wada, Yamato; Takami, Masanori; Fujimura, Yota; Tamura, Yoshiyuki; Omata, Naoto; Masuya, Yasuhiro; Kondo, Hideaki; Moriya, Shunpei; Furuya, Hirokazu; Kato, Mitsuhiro; Kojima, Hiroto; Kashiwase, Koichi; Saji, Hiroh; Khor, Seik-Soon; Yamasaki, Maria; Ishigooka, Jun; Wada, Yuji; Chiba, Shigeru; Yamada, Naoto; Okawa, Masako; Kuroda, Kenji; Kume, Kazuhiko; Hirata, Koichi; Uchimura, Naohisa; Shimizu, Tetsuo; Inoue, Yuichi; Honda, Yutaka; Mishima, Kazuo; Honda, Makoto; Tokunaga, Katsushi

    2015-01-01

    Narcolepsy without cataplexy (NA w/o CA) (narcolepsy type 2) is a lifelong disorder characterized by excessive daytime sleepiness and rapid eye movement (REM) sleep abnormalities, but no cataplexy. In the present study, we examined the human leukocyte antigen HLA-DQB1 in 160 Japanese patients with NA w/o CA and 1,418 control subjects. Frequencies of DQB1*06:02 were significantly higher in patients with NA w/o CA compared with controls (allele frequency: 16.6 vs. 7.8%, P=1.1×10−7, odds ratio (OR)=2.36; carrier frequency: 31.3 vs. 14.7%, P=7.6×10−8, OR=2.64). Distributions of HLA-DQB1 alleles other than DQB1*06:02 were compared between NA w/o CA and narcolepsy with cataplexy (NA-CA) to assess whether the genetic backgrounds of the two diseases have similarities. The distribution of the HLA-DQB1 alleles in DQB1*06:02-negative NA w/o CA was significantly different from that in NA-CA (P=5.8×10−7). On the other hand, the patterns of the HLA-DQB1 alleles were similar between DQB1*06:02-positive NA w/o CA and NA-CA. HLA-DQB1 analysis was also performed in 186 Japanese patients with idiopathic hypersomnia (IHS) with/without long sleep time, but no significant associations were observed. PMID:27081540

  17. HLA-DQA1 and HLA-DQB1 alleles and haplotypes in two Brazilian Indian tribes: evidence of conservative evolution of HLA-DQ.

    PubMed

    Sotomaior, V S; Faucz, F R; Schafhauser, C; Janzen-Dück, M; Boldt, A B; Petzl-Erler, M L

    1998-08-01

    Nucleotide sequence polymorphism of the HLA-DQA1 and HLA-DQB1 class II genes was analyzed in the Kaingang and Guarani Amerindians from southern Brazil using PCR sequence-specific oligonucleotide typing methods. Four different DQA1-DQB1 haplotypes were found: DQA1*0401-DQB1*0402 (associated with DRB1*0802, DRB1*08041, and DRB1*0807), DQA1*0501-DQB1*0301 (associated with DRB1*1602, DRB1*1413, and DRB1*1402), DQA1*03-DQB1*0302 (associated with DRB1*0404 and DRB1*0411), and DQA1*03-DQB1*03032 (associated with DRB1*09012). These HLA-DQA1 and HLA-DQB1 alleles and haplotypes are common in many other populations of all major ethnic groups. Alleles and haplotypes introduced into the populations by post-Columbian admixture were seen at low frequency both in the Kaingang (3.2%) and in the Guarani (3.8%). No novel HLA-DQA1 and HLA-DQB1 alleles have thus far been identified in Amerindians. This differs from previous results for HLA-DRB1, another class II locus presenting novel alleles (i.e., alleles not found in other ethnic groups and probably generated after migration of paleo-Indians to the Americas) in the Guarani and in other South American Indian populations. The distribution of the HLA-DQ alleles and haplotypes in Amerindians indicates a weaker diversifying selective pressure on the HLA-DQ genes compared with HLA-DRB1 and HLA-B. The more conservative evolution of HLA-DQA1 and HLA-DQB1 compared with HLA-DRB1 is strong evidence of (still not well-defined) functional differences of these class II genes.

  18. An association analysis of HLA-DQB1 with narcolepsy without cataplexy and idiopathic hypersomnia with/without long sleep time in a Japanese population.

    PubMed

    Miyagawa, Taku; Toyoda, Hiromi; Kanbayashi, Takashi; Imanishi, Aya; Sagawa, Yohei; Kotorii, Nozomu; Kotorii, Tatayu; Hashizume, Yuji; Ogi, Kimihiro; Hiejima, Hiroshi; Kamei, Yuichi; Hida, Akiko; Miyamoto, Masayuki; Ikegami, Azusa; Wada, Yamato; Takami, Masanori; Fujimura, Yota; Tamura, Yoshiyuki; Omata, Naoto; Masuya, Yasuhiro; Kondo, Hideaki; Moriya, Shunpei; Furuya, Hirokazu; Kato, Mitsuhiro; Kojima, Hiroto; Kashiwase, Koichi; Saji, Hiroh; Khor, Seik-Soon; Yamasaki, Maria; Ishigooka, Jun; Wada, Yuji; Chiba, Shigeru; Yamada, Naoto; Okawa, Masako; Kuroda, Kenji; Kume, Kazuhiko; Hirata, Koichi; Uchimura, Naohisa; Shimizu, Tetsuo; Inoue, Yuichi; Honda, Yutaka; Mishima, Kazuo; Honda, Makoto; Tokunaga, Katsushi

    2015-01-01

    Narcolepsy without cataplexy (NA w/o CA) (narcolepsy type 2) is a lifelong disorder characterized by excessive daytime sleepiness and rapid eye movement (REM) sleep abnormalities, but no cataplexy. In the present study, we examined the human leukocyte antigen HLA-DQB1 in 160 Japanese patients with NA w/o CA and 1,418 control subjects. Frequencies of DQB1*06:02 were significantly higher in patients with NA w/o CA compared with controls (allele frequency: 16.6 vs. 7.8%, P=1.1×10(-7), odds ratio (OR)=2.36; carrier frequency: 31.3 vs. 14.7%, P=7.6×10(-8), OR=2.64). Distributions of HLA-DQB1 alleles other than DQB1*06:02 were compared between NA w/o CA and narcolepsy with cataplexy (NA-CA) to assess whether the genetic backgrounds of the two diseases have similarities. The distribution of the HLA-DQB1 alleles in DQB1*06:02-negative NA w/o CA was significantly different from that in NA-CA (P=5.8×10(-7)). On the other hand, the patterns of the HLA-DQB1 alleles were similar between DQB1*06:02-positive NA w/o CA and NA-CA. HLA-DQB1 analysis was also performed in 186 Japanese patients with idiopathic hypersomnia (IHS) with/without long sleep time, but no significant associations were observed.

  19. Protective Effect of HLA-DQB1 Alleles Against Alloimmunization in Patients with Sickle Cell Disease

    PubMed Central

    Tatari-Calderone, Zohreh; Gordish-Dressman, Heather; Fasano, Ross; Riggs, Michael; Fortier, Catherine; Andrew; Campbell, D.; Charron, Dominique; Gordeuk, Victor R.; Luban, Naomi L.C.; Vukmanovic, Stanislav; Tamouza, Ryad

    2015-01-01

    Background Alloimmunization or the development of alloantibodies to Red Blood Cell (RBC) antigens is considered one of the major complications after RBC transfusions in patients with sickle cell disease (SCD) and can lead to both acute and delayed hemolytic reactions. It has been suggested that polymorphisms in HLA genes, may play a role in alloimmunization. We conducted a retrospective study analyzing the influence of HLA-DRB1 and DQB1 genetic diversity on RBC-alloimmunization. Study design Two-hundred four multi-transfused SCD patients with and without RBC-alloimmunization were typed at low/medium resolution by PCR-SSO, using IMGT-HLA Database. HLA-DRB1 and DQB1 allele frequencies were analyzed using logistic regression models, and global p-value was calculated using multiple logistic regression. Results While only trends towards associations between HLA-DR diversity and alloimmunization were observed, analysis of HLA-DQ showed that HLA-DQ2 (p=0.02), -DQ3 (p=0.02) and -DQ5 (p=0.01) alleles were significantly higher in non-alloimmunized patients, likely behaving as protective alleles. In addition, multiple logistic regression analysis showed both HLA-DQ2/6 (p=0.01) and HLA-DQ5/5 (p=0.03) combinations constitute additional predictor of protective status. Conclusion Our data suggest that particular HLA-DQ alleles influence the clinical course of RBC transfusion in patients with SCD, which could pave the way towards predictive strategies. PMID:26476208

  20. Pituitary transplantation: cyclosporine enables transplantation across a minor histocompatibility barrier.

    PubMed

    Tulipan, N B; Huang, S; Allen, G S

    1986-03-01

    Pituitary glands from neonatal donors were transplanted to the median eminence of hypophysectomized adult rats. Rats with transplants were then treated for 2 weeks with the immunosuppressive drug cyclosporine. For 5 weeks thereafter, blood was drawn at regular intervals for determination of serum thyroxine, prolactin, and luteinizing hormone. Cyclosporine-treated recipients of grafts with minor histocompatibility differences had normal levels of thyroxine and prolactin, whereas untreated animals did not. In addition, the treated animals responded to oophorectomy with a marked elevation in serum luteinizing hormone. This evidence indicates that cyclosporine enables successful transplantation across a minor histocompatibility barrier. It also suggests that these grafts interact with the hypothalamus. Transplantation across a major histocompatibility barrier was unsuccessful even in the presence of cyclosporine.

  1. Interaction between HLA-DRB1-DQB1 Haplotypes in Sardinian Multiple Sclerosis Population

    PubMed Central

    Cocco, Eleonora; Murru, Raffaele; Costa, Gianna; Kumar, Amit; Pieroni, Enrico; Melis, Cristina; Barberini, Luigi; Sardu, Claudia; Lorefice, Lorena; Fenu, Giuseppe; Frau, Jessica; Coghe, Giancarlo; Carboni, Nicola; Marrosu, Maria Giovanna

    2013-01-01

    We performed a case-control study in 2,555 multiple sclerosis (MS) Sardinian patients and 1,365 healthy ethnically matched controls, analyzing the interactions between HLA-DRB1-DQB1 haplotypes and defining a rank of genotypes conferring a variable degree of risk to the disease. Four haplotypes were found to confer susceptibility (*13∶03-*03∶01 OR = 3.3, Pc 5.1×10−5, *04∶05-*03∶01 OR = 2.1, Pc 9.7×10−8, *15∶01-*06∶02 OR = 2.0, Pc = 9.1×10−3, *03∶01-*02∶01 OR = 1.7 Pc = 7.9×10−22) and protection (*11, OR = 0.8, Pc = 2.7×10−2, *16∶01-*05∶02 OR = 0.6, Pc = 4.8×10−16, *14∶01-4-*05∶031 = OR = 0.5, Pc = 9.8×10−4 and *15∶02-*06∶01 OR = 0.4, Pc = 5.1×10−4). The relative predispositional effect method confirms all the positively associated haplotypes and showed that also *08 and *04 haplotypes confers susceptibility, while the *11 was excluded as protective haplotype. Genotypic ORs highlighted two typologies of interaction between haplotypes: i) a neutral interaction, in which the global risk is coherent with the sum of the single haplotype risks; ii) a negative interaction, in which the genotypic OR observed is lower than the sum of the OR of the two haplotypes. The phylogenic tree of the MS-associated DRB1 alleles found in Sardinian patients revealed a cluster represented by *14∶01, *04∶05, *13∶03, *08∶01 and *03∶01 alleles. Sequence alignment analysis showed that amino acids near pocket P4 and pocket P9 differentiated protective from predisposing alleles under investigation. Furthermore, molecular dynamics simulation performed on alleles revealed that position 70 is crucial in binding of MBP 85–99 peptide. All together, these data suggest that propensity to MS observed in Sardinian population carried by the various HLA-DRB1-DQB1 molecules can be due to functional peculiarity in the antigen presentation mechanisms. PMID:23593151

  2. Class I and class II major histocompatibility molecules play a role in bone marrow-derived macrophage development

    NASA Technical Reports Server (NTRS)

    Armstrong, J. W.; Simske, S. J.; Beharka, A. A.; Balch, S.; Luttges, M. W.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Class I and class II major histocompatibility complex (MHC) molecules play significant roles in T cell development and immune function. We show that MHCI- and MHCII-deficient mice have low numbers of macrophage precursors and circulating monocytes, as well as abnormal bone marrow cell colony-stimulating factor type 1 secretion and bone composition. We suggest that MHCI and MHCII molecules play a significant role in macrophage development.

  3. Human leukocyte antigen class II (DRB1 and DQB1) alleles and haplotypes frequencies in patients with pemphigus vulgaris among the Serbian population.

    PubMed

    Zivanovic, D; Bojic, S; Medenica, L; Andric, Z; Popadic, D

    2016-05-01

    The etiology of pemphigus vulgaris (PV) is multifactorial and includes genetic, environmental, hormonal, and immunological factors. Inheritance of certain Human class II leukocyte antigen (HLA) alleles is by far the best-established predisposing factor for the development of PV. Class II HLA alleles vary among racial/ethnic backgrounds. We have determined an association between HLA class II alleles and PV among the Serbian population. A total of 72 patients with confirmed diagnosis of PV were genotyped for HLA class II alleles. HLA frequencies were compared with unrelated healthy bone marrow donors. The statistical significance of differences between patients and controls was evaluated using Fisher's exact test. The DRB1*04 and DRB1*14 allelic groups were associated with PV (P adj = 4.45 × 10(-13) and 4.06 × 10(-19) respectively), while HLA-DRB1*11 was negatively associated with PV (P adj = 0.0067) suggesting a protective role. DRB1*04:02, DRB1*14:04, DQB1*03:02 and DQB1*05:03 alleles were shown to be strongly associated with PV (P adj = 1.63 × 10(-12), 5.20 × 10(-7), 1.28 × 10(-6), and 4.44 × 10(-5), respectively). The frequency of HLA DRB1*04-DQB1*03 and HLA DRB1*14-DQB1*05 haplotypes in PV patients was significantly higher than in controls (31.3% vs 8.8%, P adj =7.66 × 10(-8) and 30.6% vs 6.3%, P adj = 3.22 × 10(-10), respectively). At high-resolution level, statistical significance was observed in HLA-DRB1*04:02-DQB1*03:02 and HLA-DRB1*14:04-DQB1*05:03 haplotypes (P adj = 5.55 × 10(-12), and P adj = 3.91 × 10(-6), respectively). Our findings suggest that HLA-DRB1*04:02, DRB1*14:04, HLA-DQB1* 03:02 and DQB1*05:03 alleles and HLA-DRB1*04:02-DQB1*03:02 and HLA-DRB1*14:04-DQB1*05:03 haplotypes are genetic markers for susceptibility for PV, while DRB1*11 allelic group appears protective in Serbian population.

  4. A new DRB1*1202 allele (DRB1*12022) found in association with DQA1*0102 and DQB1*0602 in two Black narcoleptic subjects

    SciTech Connect

    Behar, E.; Grumet, F.C.; Lin, X.; Mignot, E.

    1995-01-01

    DQB1*0602 is a better genetic marker than DR2 for narcolepsy susceptibility across all ethnic groups; for instance, only 75% of African American narcoleptics are DR2+ compared with 96% DQB1*0602+. We studied DRB1 genes of DR2- but DQB1*0602+ African American patients with cataplexy and observed two with an unusual DR12, DQA1*0102, DQB1*0602 haplotype; a new allelic variant of DRB1*1202 has been designated DRB*12022. 8 refs.

  5. Not Only Sleepwalking But NREM Parasomnia Irrespective of the Type Is Associated with HLA DQB1*05:01

    PubMed Central

    Heidbreder, Anna; Frauscher, Birgit; Mitterling, Thomas; Boentert, Matthias; Schirmacher, Anja; Hörtnagl, Paul; Schennach, Harald; Massoth, Christina; Happe, Svenja; Mayer, Geert; Young, Peter; Högl, Birgit

    2016-01-01

    Study Objectives: Despite the high prevalence and clinical relevance of NREM parasomnias, data on supportive genetic markers are scarce, and mainly refer to sleepwalking only. Methods: We retrospectively analyzed clinical, polysomnographic, and HLA findings of 74 adults (37 men) with NREM parasomnia gathered from four neurological sleep centers. Parasomniac events were classified according to ICSD-2 criteria. HLA DQB1 genotyping was compared to regional-matched reference allele-frequencies. Results: Fifty-six patients had more than 2 different parasomnia type: 11 sleepwalking, 4 sleep terrors, 3 confusional arousals only. Parasomniac events were documented during video-polysomnography (V-PSG) in 70% (49/70) of subjects (71.4% confusional arousals, 8.2% sleep terrors, 4.1% sleepwalking, 16.3% ≥ 2 NREM parasomnia types). Violent behavior during V-PSG occurred in 8.5% (6/71). NREM parasomnia onset was reported after the age of 30 years in 6.8% (5/74). The HLA DQB1*05:01 allele was present in 41% (29/71) compared to 24.2% in the regional-matched reference allele group (p < 0.05). This haplotype prevalence did not differ within the NREM parasomnia type. Epworth Sleepiness Score was 10 or higher in 28.6%. Conclusions: This is a large polysomnography-based case series of patients with NREM parasomnia. In patients with suspected sleepwalking or sleep terrors, polysomnography is highly useful in detecting arousals from NREM sleep as a marker of NREM parasomnia. We confirmed previous findings by demonstrating a high prevalence of the HLA DQB1*05:01 genotype for different types of NREM parasomnias. Our findings therefore support a common genetic background, and corroborate the importance of video-polysomnography in the work-up of parasomnia. Citation: Heidbreder A, Frauscher B, Mitterling T, Boentert M, Schirmacher A, Hörtnagl P, Schennach H, Massoth C, Happe S, Mayer G, Young P. Not only sleepwalking but NREM parasomnia irrespective of the type is associated with HLA DQB1

  6. Histocompatibility Typing for the Prediction of Susceptibility to Infectious Disease.

    DTIC Science & Technology

    1980-06-01

    population chosen for the index study comprises individuals who as infants suffered respiratory syncytial virus ( RSV ) infection, where a small number... RSV ) during the newborn period. This virus causes an upper respiratory infection and in some infants causes a serious complication with dyspnea and...HLA Genotyping 11 5.1 HLA-A,B,C typing 11 5.2 HLA-DR 12 F. PROPOSAL FOR CONTINUATION OF CONTRACT - WORK PLAN 12 1. Histocompatibility Typing for RSV

  7. T-cell responses to minor histocompatibility antigens.

    PubMed Central

    Lai, P K; Waterfield, J D; Gascoigne, N R; Sharrock, C E; Mitchison, N A

    1982-01-01

    We have investigated the helper and cytotoxic T-cell response to minor histocompatibility antigens and generated long term antigen-specific cell lines to them. Antigen-specific activity was selected for by regular restimulation with irradiated cells bearing the antigens in the presence of interleukin 2, so that alloreactivity to other cell surface antigens was gradually lost. Helper T cells cultured over several months were active in vivo and in vitro, but the culturing method eventually selected for cytotoxic T cells at the expense of helper T cells, with concomitant changes in the proportions of cells expressing the Lyt phenotypes. Individual long term cultures of cytotoxic T cells specific for minor histocompatibility antigens were restricted by either H2K or D but not both. Helper T cells to minor histocompatibility antigens derived directly from primed F1 mice did not show restriction to the priming parental haplotype. This is consistent with antigen reprocessing by the F1 antigen presenting cells such that populations of helper T cells restricted by both parental H-2 haplotypes were primed. F1 cytotoxic T cells were restricted to the parental H-2 haplotype used for in vitro boosting, irrespective of which H-2 was used for in vivo priming. PMID:6214502

  8. HLA DRB1*130101-DQB1*060101 haplotype is associated with acute chest syndrome in sickle cell anemia patients.

    PubMed

    Mahdi, N; Al-Subaie, A M; Al-Ola, K; Al-Irhayim, A Q; Ali, M E; Al-Irhayim, Z; Almawi, W Y

    2009-03-01

    We investigated the association of human leukocyte antigens (HLA) class II alleles and haplotypes with the pathogenesis of acute chest syndrome (ACS) in 186 sickle cell anemia (SCA) patients, of whom 58 had documented ACS (new pulmonary infiltrate, fever, and other associated clinical events) and 128 with a negative history of ACS, serving as controls. HLA DRB1* and -DQB1* genotyping was performed by polymerase chain reaction-sequence-specific priming. Of the DRB1* and DQB1* alleles analyzed, only DRB1*130101 (Pc < 0.001) was positively associated with ACS. DRB1*130101-DQB1*060101 haplotype was more prevalent among ACS patients (P = 0.018), thus conferring disease susceptibility. Specific HLA alleles and haplotypes may influence ACS risk in SCA patients, and specific HLA genotypes may be useful markers for identifying high-risk SCA ACS patients.

  9. Association of HLA-A, B, DRB1* and DQB1* alleles and haplotypes in south Indian T2DM patients.

    PubMed

    Chinniah, Rathika; Vijayan, Murali; Sivanadham, Ramgopal; Ravi, Padma Malini; Panneerselvam, Dharmarajan; Karuppiah, Balakrishnan

    2016-10-30

    The genes of Human Leukocyte Antigen (HLA) system are implicated in the susceptibility of several diseases including Type 2 diabetes (T2DM). Therefore, we aimed to investigate the association of HLA alleles with T2DM in south India. A total of 344 patients (195 males; 149 females) and 309 controls (186 males; 123 females) were genotyped for HLA-DR/-DQ alleles. Based on predominant DR/DQ haplotypes, 222 patients and 222 age/sex matched controls were HLA-A/-B genotyped. HLA alleles were typed by PCR-SSP methods. Susceptible association was observed for the alleles A*33 (OR=13.8), A*01 (OR=3.69), A*02 (OR=2.91), B*07 (OR=4.12), DRB1*11 (OR=2.23), DRB1*04 (OR=1.51), DRB1*03 (OR=1.90) and DQB1*02 (OR=1.49). Protective association was observed for the alleles A*11 (OR=0.59), A*68 (OR=0.68), B*40 (OR=0.50), B*54 (OR=0.42), B*57 (OR=0.31), B*51 (OR=0.29) and DRB1*10 (OR=0.45). Gender stratified analysis too confirmed many of these associations. Predominant susceptible haplotypes were A*33-B*40 (OR=10.27), A*01-B*07 (OR=4.97), A*02-B*07 (OR=6.50), DRB1*03-DQB1*05 (OR=1.88), DRB1*03-DQB1*06 (OR=3.01), DRB1*04-DQB1*05 (2.63), A*01-B*07-DRB1*10 (OR=8.26) and A*11-B*35-DRB1*07 (OR=9.338). Haplotypes A*03-B*07 (OR=0.57; p<0.034) and DRB1*10-DQB1*05 (OR=0.57; p<0.033) were protectively associated. Further, a very strong susceptible association was documented for four-locus haplotypes such as A*11-B*40-DRB1*15-DQB1*06 (n=15; OR=16.01; p<0.001); A*01-B*07-DRB1*10-DQB1*05 (n=8; OR=8.26; p<0.043) and A*11-B*07-DRB1*07-DQB1*05 (n=8; OR=8.26; p<0.043). Thus, a number of HLA alleles and haplotypes showed susceptible and protective association(s) in T2DM patients from south India.

  10. Polymorphism in the upstream regulatory region of DQA1 genes and DRB1, QAP, DQA1, and DQB1 haplotypes in the German population.

    PubMed

    Haas, J P; Kimura, A; Andreas, A; Hochberger, M; Keller, E; Brünnler, G; Bettinotti, M P; Nevinny-Stickel, C; Hildebrandt, B; Sierp, G

    1994-01-01

    Polymorphism in the URR of the MHC class II DQA1 gene defines ten different alleles named QAP. Oligotyping for the alleles of DRB1, QAP, DQA1, and DQB1 have been performed in 210 unrelated healthy controls from Germany. Moreover, 83 HTCs from the Tenth IHWS have been tested. Four point loci haplotypes (DRB1, QAP, DQA1, and DQB1) have been analyzed in the unrelated healthy population sample. Computer analysis of the linkage disequilibria leads to the conclusion that QAP alleles are in strong linkage disequilibrium with alleles either the DQA1 or the DRB1 locus. One typical ("common") haplotype was found to be associated with each DRB1 allele in the majority (86%) of the tested persons. Apart from that, 25 other less frequent ("unusual") haplotypes, with an overall frequency of 14% have been defined. Some of these "unusual" MHC class II haplotypes were found to differ only in the regulatory alleles of DQA1 (QAP alleles) while they are identical for the alleles coding for structural elements (DRB1, DQA1, and DQB1). Most of the "unusual" haplotypes were found to carry HLA-DQ6. Assuming that "unusual" (= rare) haplotypes have arisen from "common" (= frequent) haplotypes by point mutation and recombination, we propose the existence of three recombination sites in the MHC DR-DQ region: one between DRB1 and QAP, the second between QAP and DQA1, and the third between DQA1 and DQB1.

  11. Beyond the MHC: A canine model of dermatomyositis shows a complex pattern of genetic risk involving novel loci

    PubMed Central

    Evans, Jacquelyn M.; Hill, Cody M.; Anderson, Kendall J.

    2017-01-01

    Juvenile dermatomyositis (JDM) is a chronic inflammatory myopathy and vasculopathy driven by genetic and environmental influences. Here, we investigated the genetic underpinnings of an analogous, spontaneous disease of dogs also termed dermatomyositis (DMS). As in JDM, we observed a significant association with a haplotype of the major histocompatibility complex (MHC) (DLA-DRB1*002:01/-DQA1*009:01/-DQB1*001:01), particularly in homozygosity (P-val = 0.0001). However, the high incidence of the haplotype among healthy dogs indicated that additional genetic risk factors are likely involved in disease progression. We conducted genome-wide association studies in two modern breeds having common ancestry and detected strong associations with novel loci on canine chromosomes 10 (P-val = 2.3X10-12) and 31 (P-val = 3.95X10-8). Through whole genome resequencing, we identified primary candidate polymorphisms in conserved regions of PAN2 (encoding p.Arg492Cys) and MAP3K7CL (c.383_392ACTCCACAAA>GACT) on chromosomes 10 and 31, respectively. Analyses of these polymorphisms and the MHC haplotypes revealed that nine of 27 genotypic combinations confer high or moderate probability of disease and explain 93% of cases studied. The pattern of disease risk across PAN2 and MAP3K7CL genotypes provided clear evidence for a significant epistatic foundation for this disease, a risk further impacted by MHC haplotypes. We also observed a genotype-phenotype correlation wherein an earlier age of onset is correlated with an increased number of risk alleles at PAN2 and MAP3K7CL. High frequencies of multiple genetic risk factors are unique to affected breeds and likely arose coincident with artificial selection for desirable phenotypes. Described herein is the first three-locus association with a complex canine disease and two novel loci that provide targets for exploration in JDM and related immunological dysfunction. PMID:28158183

  12. Beyond the MHC: A canine model of dermatomyositis shows a complex pattern of genetic risk involving novel loci.

    PubMed

    Evans, Jacquelyn M; Noorai, Rooksana E; Tsai, Kate L; Starr-Moss, Alison N; Hill, Cody M; Anderson, Kendall J; Famula, Thomas R; Clark, Leigh Anne

    2017-02-01

    Juvenile dermatomyositis (JDM) is a chronic inflammatory myopathy and vasculopathy driven by genetic and environmental influences. Here, we investigated the genetic underpinnings of an analogous, spontaneous disease of dogs also termed dermatomyositis (DMS). As in JDM, we observed a significant association with a haplotype of the major histocompatibility complex (MHC) (DLA-DRB1*002:01/-DQA1*009:01/-DQB1*001:01), particularly in homozygosity (P-val = 0.0001). However, the high incidence of the haplotype among healthy dogs indicated that additional genetic risk factors are likely involved in disease progression. We conducted genome-wide association studies in two modern breeds having common ancestry and detected strong associations with novel loci on canine chromosomes 10 (P-val = 2.3X10-12) and 31 (P-val = 3.95X10-8). Through whole genome resequencing, we identified primary candidate polymorphisms in conserved regions of PAN2 (encoding p.Arg492Cys) and MAP3K7CL (c.383_392ACTCCACAAA>GACT) on chromosomes 10 and 31, respectively. Analyses of these polymorphisms and the MHC haplotypes revealed that nine of 27 genotypic combinations confer high or moderate probability of disease and explain 93% of cases studied. The pattern of disease risk across PAN2 and MAP3K7CL genotypes provided clear evidence for a significant epistatic foundation for this disease, a risk further impacted by MHC haplotypes. We also observed a genotype-phenotype correlation wherein an earlier age of onset is correlated with an increased number of risk alleles at PAN2 and MAP3K7CL. High frequencies of multiple genetic risk factors are unique to affected breeds and likely arose coincident with artificial selection for desirable phenotypes. Described herein is the first three-locus association with a complex canine disease and two novel loci that provide targets for exploration in JDM and related immunological dysfunction.

  13. Association of narcolepsy-cataplexy with HLA-DRB1 and DQB1 in Mexican patients: A relationship between HLA and gender is suggested

    PubMed Central

    Alaez, Carmen; Lin, Ling; Flores-A, Hilario; Vazquez, Miriam; Munguia, Andrea; Mignot, Emmanuel; Haro, Reyes; Baker, Harry; Gorodezky, Clara

    2008-01-01

    Background Narcolepsy-cataplexy is characterized by excessive daytime sleepiness with recurrent episodes of irresistible sleep, cataplexy, hallucinations and sleep paralysis. Its aetiology is unknown, but it is positively associated with the human leukocyte antigens (HLA) in all studied populations. The purpose of the present study was to investigate the association of HLA class II DRB1/DQB1 alleles with narcolepsy-cataplexy in Mexican Mestizo patients. Methods This is a case-control study of consecutive patients and ethnically matched controls. We included 32 patients diagnosed with typical narcolepsy-cataplexy, of the National Institute of Neurology, of the Institute of Psychiatry and at the Center of Narcolepsy at Stanford University. As healthy controls, 203 Mexican Mestizos were included. DRB1 alleles were identified using sequence based typing. A PCR-SSOP reverse dot blot was used for DQB1 typing. Allele frequency was calculated by direct counting and the significance of the differences was assessed using the Yates Chi square. Odds ratio and confidence intervals were evaluated. Results HLA-DRB1*1501 (OR = 8.2; pc < 0.0001) and DQB1*0602 (OR = 8.4; pc < 0.0001) were found positively associated with narcolepsy. When deleting DQB1*0602+ patients from the analysis, DQB1*0301 was also found increased (OR = 2.7; p = 0.035; pc = NS). DQB1*0602/DQB1*0301 genotype was present in 15.6% of the cases (OR = 11.5; p = 0.00035), conferring a high risk. DRB1*0407 (OR = 0.2; p = 0.016 pc = NS) and DQB1*0302(OR = 0.4; p = 0.017, pc = NS) were found decreased in the patients. The gender stratification analysis showed a higher risk in females carrying DRB1*1501 (OR = 15.8, pc < 0.0001) and DQB1*0602 (OR = 19.8, pc < 0.0001) than in males (OR = 5.0 for both alleles; p = 0.012, pc = NS for DRB1 & p = 0.0012, pc = 0.017 for DQB1). The susceptibility alleles found in Mexicans with narcolepsy are also present in Japanese and Caucasians; DRB1*04 linked protection has also been shown

  14. A Simple and Rapid Method for Quality Control of Major Histocompatibility Complex–Peptide Monomers by Flow Cytometry

    PubMed Central

    Chandran, P. Anoop; Heidu, Sonja; Zelba, Henning; Schmid-Horch, Barbara; Rammensee, Hans-Georg; Pascolo, Steve; Gouttefangeas, Cécile

    2017-01-01

    Major histocompatibility complex (MHC) multimers are essential tools in T cell immunomonitoring, which are employed both in basic and clinical research, as well as for assessing clinical samples during therapy. The generation of MHC monomers loaded with synthetic peptides is an elaborate and time-consuming process. It would be beneficial to assess the quality of these monomers prior to downstream applications. In this technical note, we describe a novel flow cytometry-based, cell-free, quick, and robust assay to check the quality of MHC monomers directly after refolding or after long-term storage. PMID:28228758

  15. HISTOCOMPATIBILITY STUDIES IN A CLOSELY BRED COLONY OF DOGS

    PubMed Central

    Rapaport, Felix T.; Boyd, Arthur D.; Spencer, Frank C.; Lower, Richard R.; Dausset, Jean; Cannon, Florence D.; Ferrebee, Joseph W.

    1971-01-01

    The DL-A system of histocompatibility plays an important role in conditioning the survival of cardiac allografts in the unmodified canine host. The mean survival time of six cardiac allografts performed in DL-A-compatible littermate dogs obtained from a closely bred colony of beagles was 53.2 days, while the MST of transplants performed in seven DL-A-incompatible animals was 7.3 days. The MST of cardiac allografts performed in nine DL-A-compatible nonlittermate beagles was 26.3 days, as compared with 6.3 days in six DL-A-incompatible nonlittermate transplants. The results did not appear to be affected by Swisher erythrocyte-group incompatibilities. The MST of 28 cardiac allografts performed in randomly selected mongrel dogs was 10.0 days. Incompatibilities for DL-A antigens e, f, g, l, and m may constitute major barriers to transplantation, but antigens b, c, d, and k appeared to act as weak histocompatibility antigens. Under controlled conditions of donor-recipient DL-A compatibility, cardiac allografts may be less immunogenic than renal transplants. Heart transplants performed across major donor-recipient DL-A incompatibilities appeared, however, to be more vulnerable to the events of allograft rejection than renal allografts performed under similar conditions. The selection of optimally compatible donor-recipient combinations for organ transplantation may be aided materially by genetic studies of the transmission of DL-A antigens to the animals under consideration. PMID:4943931

  16. Abnormal distribution of the histocompatibility antigens (HLA) in lousy patients.

    PubMed

    Morsy, T A; Alalfy, M S; Sabry, A H; Fikry, A A; El Sharkawy, I M

    1996-04-01

    The histocompatibility antigens have important functions in the development of the immune response, in the development of immunologic tolerance and in the resistance and susceptibility to diseases. In the present study, the frequency of the human leucocytic antigens (HLA) were studied in 31 lousy children with Pediculus h. capitis (head lice) and 14 adults with Phthirus pubis (pubic lice) to evaluate the immune response in their pathogenesis. The patients (children and adults) were parasite-free as indicated by urine, stool and blood analysis and clinical examination. A significant increase was found between HLA-A11 and, -B5 and lousy children with P. h. capitis and between HLA,-A11, -B5 and -B27 and lousy adults with P. pubis. The association between HLA antigens and parasitic infection was discussed.

  17. Polymorphism of the DQA1 promoter region (QAP) and DRB1, QAP, DQA1, DQB1 haplotypes in systemic lupus erythematosus. SLE Study Group members.

    PubMed

    Yao, Z; Kimura, A; Hartung, K; Haas, P J; Volgger, A; Brünnler, G; Bönisch, J; Albert, E D

    1993-01-01

    We have investigated the DNA polymorphism for the DQA1 promoter region (QAP) and HLA-class II DRB1, DQA1, and DQB1 genes in 178 central European patients with Systemic lupus erythematosus (SLE) using polymerase chain reaction and Dig-ddUTP labeled oligonucleotides. Increased frequencies of DRB1*02 and *03 are confirmed by DNA typing. In addition, the frequencies of DQA1*0501, *0102 and DQB1*0201, *0602 alleles are increased in the patients as compared to controls. The strongest association to SLE is found with DRB1*03 and DOB1*0201 alleles (p < 10(-7), p corr. < 10(-5) and p < 10(-6), p corr. < 10(-4), respectively). By investigating the DQA1 promoter region in the SLE patients we have detected nine different QAP variants. Increased frequencies of QAP1.2 and QAP4.1 are observed in patients as compared to controls (p < 0.05, p corr. = n.s.). Analysis of linkage disequilibria demonstrates a very strong association between QAP variants and DQA1, DRB1 alleles. Certain QAP variants are completely associated with DQA1 and DRB1 alleles, whereas others can combine with different DQA1 and DRB1 alleles. All DRB1*02-positive patients and controls carry QAP1.2, and all DRB1*03-positive patients and controls carry QAP4.1. Conversely, the QAP1.2 variant appears only in DRB1*02 haplotypes, while the QAP4.1 variant can be observed in DRB1*03, *11, and *1303 haplotypes. Based on the strong linkage disequilibria between DRB1-DQA1-DQB1 genes and between DRB1-QAP-DQA1, we have deduced the four-point haplotypes for DRB1-QAP-DQA1-DQB1 in patients and controls. Two haplotypes DRB1*02-QAP1.2-DQA1*0102-DQB1*0602 and DRB1*03-QAP4.1-DQA1*0501-DQB1*0201 are significantly increased in patients as compared to controls (p < 0.01, p corr. = n.s., RR = 1.8 and p < 10(-7), p corr. < 10(-5), RR = 3.1, respectively). The analysis of relative risks attributed to the various alleles of QAP, DQA1, and DQB1 as well as the investigation of the deduced DRB1-QAP-DQA1-DQB1 haplotypes leads to the conclusion

  18. Human leukocyte antigen class II DQB1*0301, DRB1*1101 alleles and spontaneous clearance of hepatitis C virus infection: A meta-analysis

    PubMed Central

    Hong, Xin; Yu, Rong-Bin; Sun, Nan-Xiong; Wang, Bin; Xu, Yao-Chu; Wu, Guan-Ling

    2005-01-01

    AIM: To assess the associations of human leukocyte antigen (HLA) class II DQB1*0301 and/or DRB1*1101 allele with spontaneous hepatitis C virus (HCV) clearance by meta-analysis of individual dataset from all studies published till date. METHODS: To clarify the impact of HLA class II polymorphisms on viral clearance, we performed a meta-analysis of the published data from 11 studies comparing the frequencies of DQB1*0301 and DRB1*1101 alleles in individuals with spontaneous resolution to those with persistent infection. As we identified the heterogeneity between studies, summary statistical data were calculated based on a random-effect model. RESULTS: Meta-analyses yielded summary estimates-odds ratio (OR) of 2.36 [95%CI (1.62, 3.43), P<0.00001] and 2.02 [95%CI (1.56, 2.62), P<0.00001] for the effects of DQB1*0301 and DRB1*1101 alleles on spontaneous clearance of HCV, respectively. CONCLUSION: These results support the hypothesis that specific HLA class II alleles might influence the susceptibility or resistance to persistent HCV infection. Both DQB1*0301 and DRB1*1101 are protective alleles and present HCV epitopes more effectively to CD4+T lymphocytes than others, and subjects with these two alleles are at a lower risk of developing chronic HCV infection. Large, multi-ethnic confirmatory and well-designed studies are needed to determine the host genetic determinants of HCV infection. PMID:16437632

  19. A strong association between thyrotropin receptor-blocking antibody-positive atrophic autoimmune thyroiditis and HLA-DR8 and HLA-DQB1 0302 in Koreans

    SciTech Connect

    Cho, Bo Youn; Chung, Jae Hoon; Lee, Hong Kyu; Koh, Chang-Soon; Lee, Jung-Bin ); Shong, Young Kee ); Han, Hoon ); Chang, Youn Bok )

    1993-09-01

    The authors investigated whether the associations between HLA alleles of patients with autoimmune hypothyroidism varied according to the presence or absence of TSH receptor-blocking antibody (TRBab). They analyzed the HLA-A, -B, -C, and -DR antigens by serotyping and the DQA1 and DQB1 genes using both enzymatic DNA amplification and sequence-specific oligonucleotide hybridizations. The patient population consisted of 47 Korean patients with atrophic autoimmune thyroiditis and 62 patients with goitrous autoimmune thyroiditis. The antigen frequency of HLA-DR8 was significantly increased in 23 atrophic autoimmune thyroiditis patients that were positive for TSH binding inhibitor immunoglobulin (TBII) compared to 136 controls [52% vs. 16%; x[sup 2] = 13.1; Pc (corrected P value) = 0.003]. This relative risk was 5.7; the etiological fraction was 0.43. HLA-DQB1*0302 was also increased in patients with TBII-positive atrophic autoimmune thyroiditis (24% vs. 7%; x[sup 2] = 11.2; Pc = 0.012; relative risk = 4.4; etiological fraction = 0.19). No specific DR antigens or DQB1 alleles were increased in either TBII-negative atrophic autoimmune thyroidities or goitrous autoimmune thyroiditis. A significant decrease in the frequency of HLA-DR6 antigen was observed in both TBII-positive atrophic antoimmune thyroiditis (0% vs. 32%; x[sup 2] = 8.4; Pc = 0.03) and goitrous autoimmune thyroiditis (0% vs. 32%; x[sup 2] = 23.2; Pc < 0.001) patients. The frequency of the HLC-Cwl antigen was significantly increased in all patient groups. The authors conclude that TRBab-positive atrophic autoimmune thyroiditis is immunogenetically different from both goitrous autoimmune thyroiditis and TRBab-negative atrophic autoimmune thyroiditis. It is possible that HLA-DR8 and/or DQB1*0302 may be related to the susceptibility genes involved in the production of TRBab in Koreans. 32 refs., 5 tabs.

  20. Class I major histocompatibility proteins are an essential component of the simian virus 40 receptor.

    PubMed

    Breau, W C; Atwood, W J; Norkin, L C

    1992-04-01

    The class I molecules encoded by the major histocompatibility complex (MHC) present endogenously synthesized antigenic peptide fragments to cytotoxic T lymphocytes. We show here that these proteins are an essential component of the cell surface receptor for simian virus 40 (SV40). First, SV40 binding to cells can be blocked by two monoclonal antibodies against class I human lymphocyte antigen (HLA) proteins but not by monoclonal antibodies specific for other cell surface proteins. Second, SV40 does not bind to cells of two different human lymphoblastoid cell lines which do not express surface class I MHC proteins because of genetic defects in the beta 2-microglobulin gene in one line and in the HLA complex in the other. Transfection of these cell lines with cloned genes for beta 2-microglobulin and HLA-B8, respectively, restored expression of their surface class I MHC proteins and resulted in concomitant SV40 binding. Finally, SV40 binds to purified HLA proteins in vitro and selectively binds to class I MHC proteins in a cell surface extract.

  1. Minor histocompatibility antigens on transfused leukoreduced units of red blood cells induce bone marrow transplant rejection in a mouse model.

    PubMed

    Desmarets, Maxime; Cadwell, Chantel M; Peterson, Kenneth R; Neades, Renee; Zimring, James C

    2009-09-10

    When successful, human leukocyte antigen (HLA)-matched bone marrow transplantation with reduced-intensity conditioning is a cure for several nonmalignant hematologic disorders that require chronic transfusion, such as sickle cell disease and aplastic anemia. However, there are unusually high bone marrow transplant (BMT) rejection rates in these patients. Rejection correlates with the number of transfusions before bone marrow transplantation, and it has been hypothesized that preimmunization to antigens on transfused blood may prime BMT rejection. Using a novel mouse model of red blood cell (RBC) transfusion and major histocompatibility complex-matched bone marrow transplantation, we report that transfusion of RBC products induced BMT rejection across minor histocompatibility antigen (mHA) barriers. It has been proposed that contaminating leukocytes are responsible for transfusion-induced BMT rejection; however, filter leukoreduction did not prevent rejection in the current studies. Moreover, we generated a novel transgenic mouse with RBC-specific expression of a model mHA and demonstrated that transfusion of RBCs induced a CD8(+) T-cell response. Together, these data suggest that mHAs on RBCs themselves are capable of inducing BMT rejection. Cellular immunization to mHAs is neither monitored nor managed by current transfusion medicine practice; however, the current data suggest that mHAs on RBCs may represent an unappreciated and significant consequence of RBC transfusion.

  2. Therapy of relapsed leukemia after allogeneic hematopoietic cell transplantation with T cells specific for minor histocompatibility antigens

    PubMed Central

    Fujii, Nobuharu; Akatsuka, Yoshiki; Chaney, Colette N.; Mito, Jeffrey K.; Loeb, Keith R.; Gooley, Ted A.; Brown, Michele L.; Koo, Kevin K. W.; Rosinski, Kellie V.; Ogawa, Seishi; Matsubara, Aiko; Appelbaum, Frederick R.; Riddell, Stanley R.

    2010-01-01

    The adoptive transfer of donor T cells that recognize recipient minor histocompatibility antigens (mHAgs) is a potential strategy for preventing or treating leukemic relapse after allogeneic hematopoietic cell transplantation (HCT). A total of 7 patients with recurrent leukemia after major histocompatibility complex (MHC)–matched allogeneic HCT were treated with infusions of donor-derived, ex vivo–expanded CD8+ cytotoxic T lymphocyte (CTL) clones specific for tissue-restricted recipient mHAgs. The safety of T-cell therapy, in vivo persistence of transferred CTLs, and disease response were assessed. Molecular characterization of the mHAgs recognized by CTL clones administered to 3 patients was performed to provide insight into the antileukemic activity and safety of T-cell therapy. Pulmonary toxicity of CTL infusion was seen in 3 patients, was severe in 1 patient, and correlated with the level of expression of the mHAg-encoding genes in lung tissue. Adoptively transferred CTLs persisted in the blood up to 21 days after infusion, and 5 patients achieved complete but transient remissions after therapy. The results of these studies illustrate the potential to selectively enhance graft-versus-leukemia activity by the adoptive transfer of mHAg-specific T-cell clones and the challenges for the broad application of this approach in allogeneic HCT. This study has been registered at http://clinicaltrials.gov as NCT00107354. PMID:20071660

  3. [HLA DRB1*, DQB1*, DPA1*, and DPB1* and their association with the pathogenesis of leukemia in the population of Venezuela].

    PubMed

    Rivera-Pirela, Sergio E; Echeverría, Miriam; Salcedo, Pedro; Márquez, Georgina; Carrillo, Zuhey; Parra, Yennis; Cipriani, Ana María; Núñez, José R; Álvarez de Mon, Melchor

    2016-01-01

    Antecedentes: La presencia de HLA es un factor que influye en la patogénesis de las leucemias. Objetivos: Se evaluó la presencia de alelos HLA clase II DRB1*, DQB1*, DPA1* y DPB1* en 47 pacientes con leucemia linfoide aguda (LLA) y 48 con leucemia mieloide crónica (LMC), para compararlos con 48 voluntarios sanos de Zulia, Venezuela, y determinar las posibles asociaciones de HLA con las leucemias. Métodos: Se utilizó la técnica de PCR-SSP de baja y alta resolución para las regiones HLA clase II DRB1*, DQB1*, DPA1* y DPB1* conforme las instrucciones del KIT Olerup SSP Genovision. Resultados: Los alelos HLA-DRB1*14, especialmente DRB1*14:21, -DPA1*1:06, -DPA1*01:03,-DPA1*02:01, y los haplotipos HLA-DPA1*01:03-DPB1*04:01, DPA1*01:03-DPB1*02:01, DPA1*01:03-DPB1*99:01, -DRB1*14-DPA1*01:03, -DRB1*15-DPA1*01:03 tuvieron asociación con LMC (RR > 3); los alelos HLA-DRB1*13, -DQB1*02, -DPA1*01:05, -DPA1*01:09 y los haplotipos HLA-DPA1*01:09-DPB1*02:01, DPA1*01:09-DPB1*04:01 resultaron protectores (RR < 1). Los alelos HLA-DQB1*04, -DQB1*05, -DPA1*1:06, -DPA1*01:07, -DPA1*1:08 tuvieron asociación positiva con LLA. Los alelos HLA-DPA1*01:09, -DPA1*02:01, -DPB1*02:01, -DPB1*03:01 y los haplotipos HLA-DPA1*01:03-DPB1*04:02, -DPA1*01:09-DPB1*02:01, -DPA1*01:09-DPB1*04:01, -DPA1*02:01-DPB1*04:02 resultaron asociados negativamente. Conclusiones: La fuerte asociación de HLA DRB1*14 con la LMC y la ausencia de asociaciones DRB1* con LLA y los otros patrones de asociación identificados sugieren marcadas diferencias en las patogénesis de las leucemias, lo que orienta hacia posibles deficiencias en la presentación antigénica para LLA o posibles efectos de mimetismo molecular en LMC.

  4. Atlantic salmon eggs favour sperm in competition that have similar major histocompatibility alleles

    PubMed Central

    Yeates, Sarah E.; Einum, Sigurd; Fleming, Ian A.; Megens, Hendrik-Jan; Stet, René J.M.; Hindar, Kjetil; Holt, William V.; Van Look, Katrien J.W.; Gage, Matthew J.G.

    2008-01-01

    Polyandry and post-copulatory sexual selection provide opportunities for the evolution of female differential sperm selection. Here, we examined the influence of variation in major histocompatibility (MH) class I allelic composition upon sperm competition dynamics in Atlantic salmon. We ran in vitro fertilization competitions that mimicked the gametic microenvironment, and replicated a paired-male experimental design that allowed us to compare differences in sperm competition success among males when their sperm compete for eggs from females that were genetically either similar or dissimilar at the MH class I locus. Concurrently, we measured variation in spermatozoal traits that are known to influence relative fertilization success under these conditions. Contrary to the findings demonstrating mechanisms that promote MH complex heterozygosity, our results showed that males won significantly greater relative fertilization success when competing for eggs from genetically similar females at the MH class I. This result also showed covariation with the known influences of sperm velocity on relative fertilization success. We discuss these unexpected findings in relation to sperm–egg recognition and hybridization avoidance mechanisms based upon immunogenetic variation. PMID:18854296

  5. Three novel NY-ESO-1 epitopes bound to DRB1*0803, DQB1*0401 and DRB1*0901 recognized by CD4 T cells from CHP-NY-ESO-1-vaccinated patients.

    PubMed

    Mizote, Yu; Taniguchi, Taku; Tanaka, Kei; Isobe, Midori; Wada, Hisashi; Saika, Takashi; Kita, Shoichi; Koide, Yukari; Uenaka, Akiko; Nakayama, Eiichi

    2010-07-19

    Three novel NY-ESO-1 CD4 T cell epitopes were identified using PBMC obtained from patients who were vaccinated with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein (CHP-NY-ESO-1). The restriction molecules were determined by antibody blocking and using various EBV-B cells with different HLA alleles as APC to present peptides to CD4 T cells. The minimal epitope peptides were determined using various N- and C-termini truncated peptides deduced from 18-mer overlapping peptides originally identified for recognition. Those epitopes were DRB1*0901-restricted NY-ESO-1 87-100, DQB1*0401-restricted NY-ESO-1 95-107 and DRB1*0803-restricted NY-ESO-1 124-134. CD4 T cells used to determine those epitope peptides recognized EBV-B cells or DC that were treated with recombinant NY-ESO-1 protein or NY-ESO-1-expressing tumor cell lysate, suggesting that the epitope peptides are naturally processed. These CD4 T cells showed a cytokine profile with Th1 characteristics. Furthermore, NY-ESO-1 87-100 peptide/HLA-DRB1*0901 tetramer staining was observed. Multiple Th1-type CD4 T cell responses are beneficial for inducing effective anti-tumor responses after NY-ESO-1 protein vaccination.

  6. 76 FR 22711 - Announcement of the Re-Approval of the American Society of Histocompatibility and Immunogenetics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Society of Histocompatibility and Immunogenetics (ASHI) as an Accreditation Organization Under the...), HHS. ACTION: Notice. SUMMARY: This notice announces the application of the American Society...

  7. [Histocompatibility HLA system of man. Considerations in the light of current concepts. VII. Nonclassical HLA- E, F, and H loci].

    PubMed

    Kedzierska, A; Turowski, G

    2001-01-01

    Current opinions connected with HLA-E and HLA-F genes determining "nonclassical" (HLA-Ib) class I antigens of the Main Histocompatibility Complex MHC, and formed in the consequence of mutation or partial deletion of HLA-H pseudogene loci were presented. The expression of protein products of HLA-E and -F genes on some cells and tissues, their polymorphism, and also their biological functions in organisms were qualified by the use of molecular technics. The kind and frequency of occurrence of mutations 845 A (C282Y) and 187 G (H63D) in gene HLA-H were analysed, and in this context some genetic aspects of hereditary hemochromatozy (HH) were discussed.

  8. Autosomal Minor Histocompatibility Antigens: How Genetic Variants Create Diversity in Immune Targets

    PubMed Central

    Griffioen, Marieke; van Bergen, Cornelis A. M.; Falkenburg, J. H. Frederik

    2016-01-01

    Allogeneic stem cell transplantation (alloSCT) can be a curative treatment for hematological malignancies. Unfortunately, the desired anti-tumor or graft-versus-leukemia (GvL) effect is often accompanied with undesired side effects against healthy tissues known as graft-versus-host disease (GvHD). After HLA-matched alloSCT, GvL and GvHD are both mediated by donor-derived T-cells recognizing polymorphic peptides presented by HLA surface molecules on patient cells. These polymorphic peptides or minor histocompatibility antigens (MiHA) are produced by genetic differences between patient and donor. Since polymorphic peptides may be useful targets to manipulate the balance between GvL and GvHD, the dominant repertoire of MiHA needs to be discovered. In this review, the diversity of autosomal MiHA characterized thus far as well as the various molecular mechanisms by which genetic variants create immune targets and the role of cryptic transcripts and proteins as antigen sources are described. The tissue distribution of MiHA as important factor in GvL and GvHD is considered as well as possibilities how hematopoietic MiHA can be used for immunotherapy to augment GvL after alloSCT. Although more MiHA are still needed for comprehensive understanding of the biology of GvL and GvHD and manipulation by immunotherapy, this review shows insight into the composition and kinetics of in vivo immune responses with respect to specificity, diversity, and frequency of specific T-cells and surface expression of HLA–peptide complexes and other (accessory) molecules on the target cell. A complex interplay between these factors and their environment ultimately determines the spectrum of clinical manifestations caused by immune responses after alloSCT. PMID:27014279

  9. Genetic Variation in the IL-6 and HLA-DQB1 Genes Is Associated with Spontaneous Clearance of Hepatitis C Virus Infection

    PubMed Central

    Waldron, Paul Ravi; Belitskaya-Lévy, Ilana; Chary, Aarthi; Won, Johann; Winters, Mark; Monto, Alexander; Ryan, James; Lazzeroni, Laura C.; Holodniy, Mark

    2016-01-01

    Background. Millions of people are infected with hepatitis C virus (HCV) worldwide and 30% spontaneously clear the infection. Reasons for HCV clearance without antiviral treatment are not well understood. Methods. Blood was collected for DNA analysis from patients with chronic HCV infection or evidence of spontaneous clearance. To overcome anticipated limitations of small sample size, primary analyses consisted of a candidate gene analysis of 12 preselected genes based on known association with host immunologic response to HCV infection. To further reduce the impact of multiple testing on power, a single likelihood ratio test was conducted for each gene using all associated SNPs assayed on the Illumina Quad 610/660W chip. Step-down permutation methods were used to adjust for multiple testing in all analyses. Results. Ninety-five and 62 patients with HCV chronic infection or spontaneous clearance, respectively, were included for analysis. HLA-DQB1 (p = 1.76⁎10−5) and IL-6 (p = 0.0007) genes were significantly associated with spontaneous HCV clearance. IL-28B was not significantly associated with spontaneous clearance (p = 0.17). Conclusion. Our whole-gene analytic strategy identified a previously unreported association of IL-6 with spontaneous clearance of HCV infection. We also confirmed the finding that HLA-DQB1 is associated with spontaneous resolution of HCV infection. PMID:27340680

  10. Genetic Variation in the IL-6 and HLA-DQB1 Genes Is Associated with Spontaneous Clearance of Hepatitis C Virus Infection.

    PubMed

    Waldron, Paul Ravi; Belitskaya-Lévy, Ilana; Chary, Aarthi; Won, Johann; Winters, Mark; Monto, Alexander; Ryan, James; Lazzeroni, Laura C; Holodniy, Mark

    2016-01-01

    Background. Millions of people are infected with hepatitis C virus (HCV) worldwide and 30% spontaneously clear the infection. Reasons for HCV clearance without antiviral treatment are not well understood. Methods. Blood was collected for DNA analysis from patients with chronic HCV infection or evidence of spontaneous clearance. To overcome anticipated limitations of small sample size, primary analyses consisted of a candidate gene analysis of 12 preselected genes based on known association with host immunologic response to HCV infection. To further reduce the impact of multiple testing on power, a single likelihood ratio test was conducted for each gene using all associated SNPs assayed on the Illumina Quad 610/660W chip. Step-down permutation methods were used to adjust for multiple testing in all analyses. Results. Ninety-five and 62 patients with HCV chronic infection or spontaneous clearance, respectively, were included for analysis. HLA-DQB1 (p = 1.76⁎10(-5)) and IL-6 (p = 0.0007) genes were significantly associated with spontaneous HCV clearance. IL-28B was not significantly associated with spontaneous clearance (p = 0.17). Conclusion. Our whole-gene analytic strategy identified a previously unreported association of IL-6 with spontaneous clearance of HCV infection. We also confirmed the finding that HLA-DQB1 is associated with spontaneous resolution of HCV infection.

  11. A measure of limited joint motion and deformity correlates with HLA-DRB1 and DQB1 alleles in patients with rheumatoid arthritis

    PubMed Central

    Cranney, A.; Goldstein, R.; Pham, B.; Newkirk, M.; Karsh, J.

    1999-01-01

    OBJECTIVE—To assess factors associated with a poor outcome in rheumatoid arthritis (RA), a measure was developed of limited joint motion and deformity, a deformity index (DI), and correlated biochemical and genetic variables with the magnitude of the DI.
METHODS—Forty patients were evaluated in a cross sectional study. Clinical measures included the DI and Health Assessment Questionnaire, and disease variables included the erythrocyte sedimentation rate, C reactive protein, rheumatoid factor, and HLA-DRB1 and DQB1 alleles.
RESULTS—Significant correlations were noted between increasing DI and duration of RA and concentration of C reactive protein. Patients with a DQB1*301 allele or DR4 allele had a higher DI than those without, and a positive trend was noted between increasing DI and dose of DRB1 RA susceptibility alleles. The trend was lost when a non-linear regression technique was used to remove the effect attributable to C reactive protein, suggesting an interrelation between persistent inflammation and genetics in determining total joint damage.
CONCLUSIONS—The DI may be useful to study interactions between genetic and inflammatory processes in rheumatoid disease progression.

 PMID:10531075

  12. A real-time PCR assay for the rapid identification of the autoimmune disease-associated allele HLA-DQB1*0602

    PubMed Central

    Gersuk, Vivian H.; Nepom, Gerald T.

    2011-01-01

    Many autoimmune diseases share a genetic association with the presence or absence of HLA-DQB1*0602, including type I diabetes, multiple sclerosis, and narcolepsy. High resolution HLA typing to determine the presence of this allele is cumbersome and expensive by currently available techniques. We present a real-time PCR assay for the identification of HLA-DQB1*0602, using sequence-specific primers and probes, that provides rapid and sensitive identification of this allele, involves minimal hands-on time, and provides a major cost savings compared to existing methods. The assay allows the simultaneous determination of both the presence and the number of copies of this allele. Since there is no post-PCR handling, the risk of contamination is avoided. We have validated the assay using 44 blinded and 32 unblinded samples, previously typed by standard techniques, which were identified with 100% accuracy, sensitivity, and specificity. Further, using a narcolepsy cohort of 734 subjects, we demonstrated the robustness of the assay to analyze DNA isolated from buccal swabs, demonstrating the applicability of this assay as an alternative approach to traditional HLA typing methods. PMID:19317743

  13. Leukosialin (CD43)-major histocompatibility class I molecule interactions involved in spontaneous T cell conjugate formation

    PubMed Central

    1996-01-01

    Resting T cells spontaneously adhere in a selective manner to potent accessory cells, such as dendritic cells (DC) and lymphoblastoid B blasts (LCL). Here we demonstrate that leukosialin (CD43) and major histocompatibility complex class I molecules (MHC-I) might play a critical role in this process. T cell conjugate formation with monocyte- derived DC (md-DC) and LCL could be strongly inhibited by either preincubating T cells with Fab fragments of CD43 monoclonal antibody (mAb) 6F5 or by preincubating md-DC or LCL with MHC-I mAb W6/32. Intact CD43 mAb 6F5, in contrast to monovalent Fab fragments, enhanced T cell adhesiveness by transactivating CD2 binding to CD58 molecules. Interestingly, induction of this proadhesive signal via CD43 with intact 6F5 mAb was found to revert mAb W6/32-mediated inhibition of T cell conjugate formation. These observations indicated that CD43 cross- linkage mimics and monovalent mAb 6F5 inhibits interaction of T cell CD43 with a stimulatory ligand on opposing cells, presumably MHC-I. For the demonstration of direct physical interaction between CD43 on T cells and MHC-I-coated beads it was necessary, however, to ligate CD2 on T cells with a stimulatory pair of CD2 mAbs (VIT13 plus TS2/18). This suggests that CD2 ligation crosswise upregulates CD43 binding avidity for MHC-I and that both adhesion molecule pairs (CD43/MHC-I and CD2/CD58) act in concert to induce and mediate T cell conjugate formation with certain cell types. PMID:8920865

  14. 42 CFR 413.200 - Payment of independent organ procurement organizations and histocompatibility laboratories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... histocompatibility laboratories in connection with kidney acquisition and transplantation will be reimbursed under... standards and providing the services for kidneys or other organs set forth in § 413.2171(d) of this chapter... an OPO or laboratory, during its previous fiscal year, associated with procuring a kidney...

  15. MH(2)c: Characterization of major histocompatibility α-helices - an information criterion approach.

    PubMed

    Hischenhuber, B; Frommlet, F; Schreiner, W; Knapp, B

    2012-07-01

    Major histocompatibility proteins share a common overall structure or peptide binding groove. Two binding groove domains, on the same chain for major histocompatibility class I or on two different chains for major histocompatibility class II, contribute to that structure that consists of two α-helices ("wall") and a sheet of eight anti-parallel beta strands ("floor"). Apart from the peptide presented in the groove, the major histocompatibility α-helices play a central role for the interaction with the T cell receptor. This study presents a generalized mathematical approach for the characterization of these helices. We employed polynomials of degree 1 to 7 and splines with 1 to 2 nodes based on polynomials of degree 1 to 7 on the α-helices projected on their principal components. We evaluated all models with a corrected Akaike Information Criterion to determine which model represents the α-helices in the best way without overfitting the data. This method is applicable for both the stationary and the dynamic characterization of α-helices. By deriving differential geometric parameters from these models one obtains a reliable method to characterize and compare α-helices for a broad range of applications.

  16. Participation of a novel 88-kD protein in the biogenesis of murine class I histocompatibility molecules

    PubMed Central

    1991-01-01

    Chemical cross-linking and gel permeation chromatography were used to examine early events in the biogenesis of class I histocompatibility molecules. We show that newly synthesized class I heavy chains associate rapidly and quantitatively with an 88-kD protein in three murine tumor cell lines. This protein (p88) does not appear to possess Asn-linked glycans and it is not the abundant ER protein, GRP94. The class I-p88 complex exists transiently (t1/2 = 20-45 min depending on the specific class I heavy chain) and several lines of evidence suggest that p88 dissociates from the complex while still in the ER. Dissociation is not triggered upon binding of beta 2-microglobulin to the heavy chain (t1/2 = 2-5 min). However, the rate of dissociation does correlate with the characteristic rate of ER to Golgi transport for the particular class I molecule studied. Consequently, dissociation of p88 may be rate limiting for ER to Golgi transport. Class I molecules bind antigenic peptides, apparently in the ER, for subsequent presentation to cytotoxic T lymphocytes at the cell surface. p88 could promote peptide binding or it may retain class I molecules in the ER during formation of the ternary complex of heavy chain, beta 2- microglobulin, and peptide. PMID:1999467

  17. Bone marrow transplantation with unrelated donors: what is the probability of identifying an HLA-A/B/Cw/DRB1/B3/B5/DQB1-matched donor?

    PubMed

    Tiercy, J M; Bujan-Lose, M; Chapuis, B; Gratwohl, A; Gmür, J; Seger, R; Kern, M; Morell, A; Roosnek, E

    2000-08-01

    Patients transplanted with marrow from an HLA-ABDR serologically matched unrelated donor suffer from more post-transplant complications than those who are transplanted with marrow from an HLA-identical sibling. This is most likely due to either HLA-ABDR incompatibilities not resolved by standard techniques and/or HLA polymorphisms not tested for by routine tissue typing (HLA-Cw,-DQ). By resolving these incompatibilities by molecular techniques combined with the in vitro cytotoxic T lymphocyte precursor frequency (CTLpf) test, we have shown that a high degree of HLA compatibility is associated with increased patient survival. However, higher requirements for HLA matching decrease the number of available donors. We have estimated the probability of finding an HLA-A/B/Cw/DRB1/DRB3/DRB5/DQB1 compatible donor based on 104 consecutive unrelated bone marrow donor searches initiated between January 1995 and December 1997, with December 1998 as the endpoint. For 96 patients (92.3%), one or more ABDR-identical donors were listed in the Bone Marrow Donor Worldwide Registry (BMDW). After contacting the registries, we obtained at least one (mean, 5.36; range, 1-20; total, 461) blood sample for 86 patients. A highly compatible donor was identified for 33/86 patients (38.4%), after testing an average number of 4.5 donors/patients (range, 1-13). However, by accepting an HLA-DRB3 or -DQB1 or -Cw incompatibility, this number would be as high as 68.6%. Approximately half of the patients (n = 40) for whom a search had been initiated have been transplanted: 22 patients with a perfectly matched donor, 15 patients with an HLA-DRB3 or -DQB1 or -Cw mismatch and three with other mismatches. The average time needed to identify the most compatible donor was 4 months. Extremely long searches seemed to be less useful, because after testing the first seven, a more compatible donor was seldom found. These results show that even when requirements for compatibility are high, the chances of finding

  18. Complexity.

    PubMed

    Gómez-Hernández, J Jaime

    2006-01-01

    It is difficult to define complexity in modeling. Complexity is often associated with uncertainty since modeling uncertainty is an intrinsically difficult task. However, modeling uncertainty does not require, necessarily, complex models, in the sense of a model requiring an unmanageable number of degrees of freedom to characterize the aquifer. The relationship between complexity, uncertainty, heterogeneity, and stochastic modeling is not simple. Aquifer models should be able to quantify the uncertainty of their predictions, which can be done using stochastic models that produce heterogeneous realizations of aquifer parameters. This is the type of complexity addressed in this article.

  19. Tumour necrosis factor microsatellites and HLA-DRB1*, HLA-DQA1*, and HLA-DQB1* alleles in Peruvian patients with rheumatoid arthritis

    PubMed Central

    Castro, F; Acevedo, E; Ciusani, E; Angulo, J; Wollheim, F; Sandberg-Wollheim, M

    2001-01-01

    OBJECTIVE—To study the association between rheumatoid arthritis (RA) and HLA and tumour necrosis factor (TNF) polymorphism in Peruvian mestizo patients in comparison with ethnically similar controls.
METHODS—Seventy nine patients with RA and 65 ethnically matched healthy controls were genotyped for HLA-DRB1, HLA-DQA1, HLA-DQB1, and TNFα and TNFβ alleles using PCR amplification. Clinical severity was assessed as mild, moderate, or severe in 35 of the patients.
RESULTS—TNFα6 showed the strongest association with disease susceptibility. The TNFα6 allele was more common in patients than in controls (p<0.0076) and the proportion of patients with at least one copy of this allele was greater (p<0.015, relative risk 2.35). Among the HLA-DRB1* alleles with the shared epitope sequence, only the DRB1*1402 allele was significantly increased in patients compared with controls (p<0.0311), as was the proportion of patients with at least one copy of this allele (p<0.0232, relative risk 2.74). In contrast, the overall frequency of alleles with the shared epitope was not different in patients and controls. The haplotype HLA-DRB1*1402-DQB1*0301-DQA1*0401 was significantly more common in patients. TNFα6 was more common in patients whether or not they had this haplotype. None of the 11 patients lacking the TNFα6 allele had severe disease.
CONCLUSIONS—This study shows for the first time that TNF gene polymorphism is associated with susceptibility to RA in a non-white population. TNFα6 and HLA-DRB1*1402 independently conferred significantly increased risk in Peruvian mestizo patients.

 PMID:11454644

  20. The PANE1 gene encodes a novel human minor histocompatibility antigen that is selectively expressed in B-lymphoid cells and B-CLL

    PubMed Central

    Brickner, Anthony G.; Evans, Anne M.; Mito, Jeffrey K.; Xuereb, Suzanne M.; Feng, Xin; Nishida, Tetsuya; Fairfull, Liane; Ferrell, Robert E.; Foon, Kenneth A.; Hunt, Donald F.; Shabanowitz, Jeffrey; Engelhard, Victor H.; Riddell, Stanley R.; Warren, Edus H.

    2006-01-01

    Minor histocompatibility antigens (mHAg's) are peptides encoded by polymorphic genes that are presented by major histocompatibility complex (MHC) molecules and recognized by T cells in recipients of allogeneic hematopoietic cell transplants. Here we report that an alternative transcript of the proliferation-associated nuclear element 1 (PANE1) gene encodes a novel human leukocyte antigen (HLA)-A*0301-restricted mHAg that is selectively expressed in B-lymphoid cells. The antigenic peptide is entirely encoded within a unique exon not present in other PANE1 transcripts. Sequencing of PANE1 alleles in mHAg-positive and mHAg-negative cells demonstrates that differential T-cell recognition is due to a single nucleotide polymorphism within the variant exon that replaces an arginine codon with a translation termination codon. The PANE1 transcript that encodes the mHAg is expressed at high levels in resting CD19+ B cells and B-lineage chronic lymphocytic leukemia (B-CLL) cells, and at significantly lower levels in activated B cells. Activation of B-CLL cells through CD40 ligand (CD40L) stimulation decreases expression of the mHAg-encoding PANE1 transcript and reciprocally increases expression of PANE1 transcripts lacking the mHAg-encoding exon. These studies suggest distinct roles for different PANE1 isoforms in resting compared with activated CD19+ cells, and identify PANE1 as a potential therapeutic target in B-CLL. PMID:16391015

  1. Isotypic and allotypic variation of human class II histocompatibility antigen alpha-chain genes.

    PubMed

    Auffray, C; Lillie, J W; Arnot, D; Grossberger, D; Kappes, D; Strominger, J L

    DNA sequences of four human class II histocompatibility antigen alpha chain DNA sequences (derived from cDNA and genomic clones representing DC1 alpha, DC4 alpha, DX alpha and SB alpha) are presented and compared to DR alpha and to mouse I-A alpha and I-E alpha sequences. These data suggest possible mechanisms for the generation of polymorphism and the evolution of the DR, DC and SB families.

  2. Interferon treatment of mice: enhanced expression of histocompatibility antigens on lymphoid cells.

    PubMed Central

    Lindahl, P; Gresser, I; Leary, P; Tovey, M

    1976-01-01

    Treatment of young and mature mice with potent mouse interferon preparations results in a marked enhancement of the expression of histocompatibility antigens on the surface of thymocytes and splenic lymphocytes as measured by an enhanced absorption of alloantiserum. We postulate that such modifications of the cell surface may reflect an effect of interferon on lymphocyte maturation and may be relevant to the effect of interferon on lymphocyte function. PMID:1063409

  3. Natural selection of the major histocompatibility complex (Mhc) in Hawaiian honeycreepers (Drepanidinae)

    USGS Publications Warehouse

    Jarvi, S.I.; Tarr, C.L.; Mcintosh, C.E.; Atkinson, C.T.; Fleischer, R.C.

    2004-01-01

    The native Hawaiian honeycreepers represent a classic example of adaptive radiation and speciation, but currently face one the highest extinction rates in the world. Although multiple factors have likely influenced the fate of Hawaiian birds, the relatively recent introduction of avian malaria is thought to be a major factor limiting honeycreeper distribution and abundance. We have initiated genetic analyses of class II ?? chain Mhc genes in four species of honeycreepers using methods that eliminate the possibility of sequencing mosaic variants formed by cloning heteroduplexed polymerase chain reaction products. Phylogenetic analyses group the honeycreeper Mhc sequences into two distinct clusters. Variation within one cluster is high, with dN > d S and levels of diversity similar to other studies of Mhc (B system) genes in birds. The second cluster is nearly invariant and includes sequences from honeycreepers (Fringillidae), a sparrow (Emberizidae) and a blackbird (Emberizidae). This highly conserved cluster appears reminiscent of the independently segregating Rfp-Y system of genes defined in chickens. The notion that balancing selection operates at the Mhc in the honeycreepers is supported by transpecies polymorphism and strikingly high dN/dS ratios at codons putatively involved in peptide interaction. Mitochondrial DNA control region sequences were invariant in the i'iwi, but were highly variable in the 'amakihi. By contrast, levels of variability of class II ?? chain Mhc sequence codons that are hypothesized to be directly involved in peptide interactions appear comparable between i'iwi and 'amakihi. In the i'iwi, natural selection may have maintained variation within the Mhc, even in the face of what appears to a genetic bottleneck.

  4. Serum proteases alter the antigenicity of peptides presented by class I major histocompatibility complex molecules.

    PubMed Central

    Falo, L D; Colarusso, L J; Benacerraf, B; Rock, K L

    1992-01-01

    Any effect of serum on the antigenicity of peptides is potentially relevant to their use as immunogens in vivo. Here we demonstrate that serum contains distinct proteases that can increase or decrease the antigenicity of peptides. By using a functional assay, we show that a serum component other than beta 2-microglobulin enhances the presentation of ovalbumin peptides produced by cyanogen bromide cleavage. Three features of this serum activity implicate proteolysis: it is temperature dependent, it results in increased antigenicity in a low molecular weight peptide fraction, and it is inhibited by the protease inhibitor leupeptin. Conversely, presentation of the synthetic peptide OVA-(257-264) is inhibited by serum. This inhibition is unaffected by leupeptin but is blocked by bestatin, a protease inhibitor with distinct substrate specificities. Implications for peptide-based vaccine design and immunotherapy are discussed. PMID:1518868

  5. Attenuation of transplant arteriosclerosis by oral feeding of major histocompatibility complex encoding chitosan-DNA nanoparticles.

    PubMed

    Goldmann, Katja; Hoffmann, Julia; Eckl, Sebastian; Spriewald, Bernd M; Ensminger, Stephan M

    2013-01-01

    One promising approach for the induction of transplant tolerance is the pre-treatment of transplant recipients with donor MHC-alloantigen. Our study focuses on the oral delivery of MHC-antigen encoding genes via chitosan-DNA nanoparticles to modulate the alloimmune response in order to reduce the development of transplant arteriosclerosis, the hallmark feature of chronic rejection after heart transplantation. Therefore, we performed fully allogeneic mouse abdominal aortic transplants using C57BL/6 (H2(b)) mice as donors and CBA.J (H2(k)) mice as recipients. Aortic grafts were analyzed by histology and morphometry on day 30 after transplantation, levels of circulating alloantibodies were detected by FACS analysis. Pre-treatment of recipient mice with chitosan-DNA nanoparticles encoding for K(b), one of the MHC-I molecules of the donor, resulted in a significant reduction of intimal proliferation compared to untreated controls. When Ovalbumin was fed instead of K(b) encoding nanoparticles (K(b)-NP) or Balb/c (H2(d)) grafts were used instead of C57BL/6 (H2(b)) grafts as antigen controls, both groups showed no reduction of intimal thickness indicating an antigen-specific mechanism. In addition, analysis of peripheral blood of the transplanted mice showed significant suppression of alloantibody formation in the K(b)-NP fed group compared to all other allogeneic transplanted groups suggesting modulation of the humoral immune response. These results demonstrate the potential of chitosan-DNA nanoparticles to induce K(b)-specific tolerance and to reduce the development of transplant arteriosclerosis.

  6. The great diversity of major histocompatibility complex class II genes in Philippine native cattle

    PubMed Central

    Takeshima, S.N.; Miyasaka, T.; Polat, M.; Kikuya, M.; Matsumoto, Y.; Mingala, C.N.; Villanueva, M.A.; Salces, A.J.; Onuma, M.; Aida, Y.

    2014-01-01

    Bovine leukocyte antigens (BoLA) are extensively used as markers for bovine disease and immunological traits. However, none of the BoLA genes in Southeast Asian breeds have been characterized by polymerase chain reaction (PCR)-sequence-based typing (SBT). Therefore, we sequenced exon 2 of the BoLA class II DRB3 gene from 1120 individual cows belonging to the Holstein, Sahiwal, Simbrah, Jersey, Brahman, and Philippine native breeds using PCR-SBT. Several cross-breeds were also examined. BoLA-DRB3 PCR-SBT identified 78 previously reported alleles and five novel alleles. The number of BoLA-DRB3 alleles identified in each breed from the Philippines was higher (71 in Philippine native cattle, 58 in Brahman, 46 in Holstein × Sahiwal, and 57 in Philippine native × Brahman) than that identified in breeds from other countries (e.g., 23 alleles in Japanese Black and 35 in Bolivian Yacumeño cattle). A phylogenetic tree based on the DA distance calculated from the BoLA-DRB3 allele frequency showed that Philippine native cattle from different Philippine islands are closely related, and all of them are closely similar to Philippine Brahman cattle but not to native Japanese and Latin American breeds. Furthermore, the BoLA-DRB3 allele frequency in Philippine native cattle from Luzon Island, located in the Northern Philippines was different from that in cattle from Iloilo, Bohol, and Leyte Islands, which are located in the Southern Philippines. Therefore, we conclude that Philippine native cattle can be divided into two populations, North and South areas. Moreover, a neutrality test revealed that Philippine native cattle from Leyte showed significantly greater genetic diversity, which may be maintained by balancing selection. This study shows that Asian breeds have high levels of BoLA-DRB3 polymorphism. This finding, especially the identification of five novel BoLA-DRB3 alleles, will be helpful for future SBT studies of BoLA-DRB3 alleles in East Asian cattle. PMID:25606401

  7. A high recombination frequency within the chicken major histocompatibility (B) complex.

    PubMed

    Hepkema, B G; Tilanus, M G; Blankert, H J; Albers, G A; Grosfeld-Stulemeyer, M C; Hensen, E J

    1993-10-01

    Chickens of a commercial pure White Leghorn line were typed for B-F and B-G by serological, biochemical and molecular biological methods. Amongst 287 typed animals of one particular line, three animals with recombinant haplotypes were identified. Compared to earlier reports this revealed a statistically significant (P < 0.05), tenfold higher recombination frequency in this chicken line.

  8. Expression of rat class I major histocompatibility complex (MHC) alloantigens and hepatocytes and hepatoma cells

    SciTech Connect

    Hunt, J.M.; Desai, P.A.; Chakraborty, S.

    1986-03-05

    Altered expression of Class I MHC alloantigens has been reported for murine tumors, and may be associated with the tumorigenic phenotype of tumor cells. To characterize MHC Class I alloantigen expression on a chemically-induced transplantable rat hepatoma cell line, 17X, derived from a (WF x F344) F/sub 1/ rat, polyvalent anti-F344 and anti-WF rat alloantisera were first used to immunoprecipitate the rat RT1.A Class I MHC alloantigens expressed on primary (WF x F344) F/sub 1/ hepatocyptes in short-term monolayer cultures. Two-dimensional isoelectric focusing and SDS-PAGE of immunoprecipitates from /sup 35/S-methionine-labeled (WF x F344) F/sub 1/ hepatocytes clearly resolved the RT1.A/sup u/ (WF) and RT1.A/sup LvI/ (F344) parental alloantigens. Identical radiolabeling and immunoprecipitation failed to detect either parental alloantigen on the 17X hepatoma cells. However, indirect immunofluorescence and immunoblot analyses demonstrated the presence of parental alloantigens on the 17X cells. Immunization of F344 rats but not of WF rats with 17X cells resulted in antibodies cytotoxic for normal (WF X F344) F/sub 1/ spleen cells in the presence of complement. These findings indicate that a combination of detection techniques will be necessary to characterize altered alloantigen expression on rat hepatoma cells.

  9. Evaluation of the major histocompatibility complex (Mhc) in cranes: applications to conservation efforts

    USGS Publications Warehouse

    Jarvi, S.I.; Miller, M.M.; Goto, R.M.; Gee, G.F.; Briles, W.E.

    2001-01-01

    Although there have been heated discussions concerning the relative importance of using Mhc diversity as a basis for selecting breeders in conservation projects, most parties agree that the genetic variability residual in an endangered species should be maintained through genetic management, if at all possible. Substantial evidence exists (particularly in birds) documenting the influences of specific Mhc haplotypes on disease outcome and also that those individuals which are heterozygous for Mhc alleles appear to have an advantage for survival over those that are homozygous. Thus, conservation of genetic variability of the Mhc is likely important for the preservation of fitness, especially in small breeding populations. More than half of the world's crane species are listed as endangered. Members of all 15 known species are represented among breeding animals for captive propagation at the International Crane Foundation (Wisconsin) and the USGS Patuxent Wildlife Research Center (Maryland). Collaborative multi-organization efforts and the availability of extensive pedigree records have allowed the study of Mhc variability in several species of cranes. We have found, for example, that Mhc diversity in the captive Florida sandhill crane (Grus canadensis pratensis) population appears high, whereas in the captive whooping crane (Grus americana), which has undergone a severe 'genetic bottleneck,? both the number of alleles and the levels of heterozygosity appear to be substantially reduced.

  10. Polymorphisms of the equine major histocompatibility complex class II DRA locus.

    PubMed

    Brown, J J; Thomson, W; Clegg, P; Eyre, S; Kennedy, L J; Matthews, J; Carter, S; Ollier, W E R

    2004-08-01

    The full extent of the polymorphism of ELA-DRA in Equidae is not yet known. Given the apparent differences in DRA polymorphisms between Equidae and other species, the aims of this study were to more fully characterize ELA-DRA, determine the extent of gene polymorphism and establish the allele-frequency distribution. An allele reference panel for the second exon of ELA-DRA was established by sequence-based typing of 69 equine DNA samples consisting of various breeds of domestic horse (Equus caballus), together with donkeys (Equus asinus), Grant's zebras (Equus boehmi) and one onager (Equus hemionus). Five of the six previously reported alleles detected using single-strand conformation polymorphism were found: ELA-DRA*0101, ELA-DRA*0201, ELA-DRA*0301, ELA-DRA*0501 (Albright-Fraser DG et al. Polymorphism of DRA among equids. Immunogenetics 1996: 43: 315-7) and ELA-DRA*0601 (GenBank accession number AF5419361). In addition to the previously reported alleles, five novel ELA-DRA alleles were detected within the ELA-DRA allele reference panel. One of these was identified in E. caballus (ELA-DRA*JBH11), one in E. boehmi and E. hemionus (ELA-DRA*JBZ185) and three in E. asinus (ELA-DRA*JBD3, ELA-DRA*JBD17 and ELA-DRA*JBH45). A total of 565 equine DNA samples were screened using reference-strand-mediated conformation analysis, a double-stranded conformation-based mutation detection system that can be used to type existing ELA-DRA alleles and identify new variants. Based on our findings, at least 11 ELA-DRA alleles are now known to exist, and this level of polymorphism at the DRA locus appears to be unique to the genus Equus. Both the previously reported alleles and the new alleles displayed a species-specific distribution.

  11. Trafficking of major histocompatibility complex class II molecules through intracellular compartments containing HLA-DM.

    PubMed

    Robbins, N F; Hammond, C; Denzin, L K; Pan, M; Cresswell, P

    1996-01-01

    The endosomal site(s) where MHC class II molecules become competent to bind antigenic peptide has not been completely characterized. We identified endocytic compartments through which newly synthesized MHC class II molecules move prior to their expression on the plasma membrane. The compartments co-sediment with lysosomes in the most dense regions of Percoll gradients. The appearance of proteolytic fragments of the invariant chain (I chain), namely leupeptin-induced proteins (LIPs) and class-II-associated invariant chain peptides (CLIP), in this region of the gradient suggests that the release of MHC class II molecules from I chain association occurs within these vesicles. The formation of SDS-stable alpha beta dimers indicated that MHC class II molecules contained within these compartments are receptive to peptide binding. A majority of the HLA-DM protein was found in the same region of the Percoll gradient, consistent with its established function in MHC class-II-restricted antigen presentation. Immunoelectron micrographs of dense-sedimenting compartments indicated that I chain, MHC class II, and DM molecules are contained within both multivesicular and multilamellar vesicles. The final stages of I chain dissociation from MHC class II molecules and DM-mediated peptide loading probably occur in these compartments.

  12. Geometry Dynamics of α-Helices in Different Class I Major Histocompatibility Complexes

    PubMed Central

    Ribarics, Reiner; Kenn, Michael; Karch, Rudolf; Ilieva, Nevena; Schreiner, Wolfgang

    2015-01-01

    MHC α-helices form the antigen-binding cleft and are of particular interest for immunological reactions. To monitor these helices in molecular dynamics simulations, we applied a parsimonious fragment-fitting method to trace the axes of the α-helices. Each resulting axis was fitted by polynomials in a least-squares sense and the curvature integral was computed. To find the appropriate polynomial degree, the method was tested on two artificially modelled helices, one performing a bending movement and another a hinge movement. We found that second-order polynomials retrieve predefined parameters of helical motion with minimal relative error. From MD simulations we selected those parts of α-helices that were stable and also close to the TCR/MHC interface. We monitored the curvature integral, generated a ruled surface between the two MHC α-helices, and computed interhelical area and surface torsion, as they changed over time. We found that MHC α-helices undergo rapid but small changes in conformation. The curvature integral of helices proved to be a sensitive measure, which was closely related to changes in shape over time as confirmed by RMSD analysis. We speculate that small changes in the conformation of individual MHC α-helices are part of the intrinsic dynamics induced by engagement with the TCR. PMID:26649324

  13. Salmonella infections in the absence of the major histocompatibility complex II

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Beharka, A. A.; Spooner, B. S. (Principal Investigator)

    1998-01-01

    We examined the pathogenesis of the facultative intracellular bacterium, Salmonella typhimurium in MHCII-/-, C2D knock-out mice, and wild-type C57BL/6J mice. The MHCII knock-out shortened the kinetics of animal death and reduced the dose of S. typhimurium needed to kill mice. We measured the physiological and cytokine responses of both mouse strains after S. typhimurium injection. Animal weight loss, spleen weights, liver weights, thymus weights, and serum corticosterone concentrations were comparable after injection with several doses of bacteria. The only physiological differences observed between the two strains were observed 3 days after injection of the highest dose of bacteria tested. Serum concentrations of tumor necrosis factor alpha, interleukin-2, and interleukin-6 increased in a dose-dependent fashion irrespective of mouse MHCII expression. Therefore, even in the absence of MHCII, mice are able to mount relatively normal physiological and immunological responses. Consistent with these normal responses, an increased percentage of MHCII-/- mice, primed with a low dose of bacteria 13 days earlier, were able to survive a lethal challenge of Salmonella compared with unprimed controls. Lastly, C2D mice had significantly higher serum interleukin-10 concentrations than C57BL/6J mice 48 h after infection with all doses of S. typhimurium. C2D macrophages also secreted significantly more IL-10 and less NO and O2- after lipopolysaccharide or phorbol ester stimulation in vitro than wild-type macrophages.

  14. Recovery from Friend disease in mice with reduced major histocompatibility complex class I expression.

    PubMed Central

    Hasenkrug, K J; Sprangrude, G J; Nishio, J; Brooks, D M; Chesebro, B

    1994-01-01

    Mice homozygous for the b allele of the MHC gene, H-2D, have a high incidence of recovery from Friend virus infections, while mice heterozygous for the b allele at H-2D have a very low incidence of recovery. Previous experiments indicated that the low recovery rates associated with heterozygosity at H-2D might be related to a gene dosage effect requiring the expression of two H-2Db alleles for high recovery. We investigated the effects of reduced H-2Db expression on recovery from Friend disease by using H-2b homozygous mice carrying a single beta 2-microglobulin gene disruption. These mice had reductions in cell surface H-2Db expression comparable to those of H-2Da/b heterozygotes. Numerous cell types with various levels of H-2Db expression were examined, and in each case, the expression levels in the beta 2-microglobulin mutants closely reflected those observed in the H-2Da/b heterozygotes. We found, however, that reduced expression did not affect recovery from Friend disease, indicating that heterozygous levels of H-2Db expression are sufficient for the high-recovery phenotype previously associated only with H-2Db homozygotes. PMID:8138991

  15. Comparative genomics of the human, macaque and mouse major histocompatibility complex.

    PubMed

    Shiina, Takashi; Blancher, Antoine; Inoko, Hidetoshi; Kulski, Jerzy K

    2017-02-01

    The MHC is a highly polymorphic genomic region that encodes the transplantation and immune regulatory molecules. It receives special attention for genetic investigation because of its important role in the regulation of innate and adaptive immune responses and its strong association with numerous infectious and/or autoimmune diseases. The MHC locus was first discovered in the mouse and for the past 50 years it has been studied most intensively in both mice and humans. However, in recent years the macaque species have emerged as some of the more important and advanced experimental animal models for biomedical research into MHC with important human immunodeficiency virus/simian immunodeficiency virus and transplantation studies undertaken in association with precise MHC genotyping and haplotyping methods using Sanger sequencing and next-generation sequencing. Here, in this special issue on 'Macaque Immunology' we provide a short review of the genomic similarities and differences among the human, macaque and mouse MHC class I and class II regions, with an emphasis on the association of the macaque class I region with MHC polymorphism, haplotype structure and function.

  16. Restriction fragment length polymorphism within the class I gene loci of the equine major histocompatibility complex

    SciTech Connect

    Alexander, A.J.; Bailey, E.; Woodward, J.G.

    1986-03-05

    Fourteen standard bred horses were serotyped as homozygous for 1 of 6 Equine Leukocyte Antigen (ELA) specificities. DNA was purified from peripheral leukocytes and digested with Hind III or Pvu II. Southern blot hybridization analysis was carried out using a /sup 32/P-labeled mouse cDNA probe (PH2IIa) specific for class I MHC genes. Both enzymes generated blots that contained a large number of bands (23 to 30) per horse. Significant polymorphism existed among most fragment sizes, while a dozen highly conserved band sizes suggested the presence of Qa/tla - like genes. Only 2 animals (both W6's) showed identical band patterns. Polymorphism was greatest between horses of different serotypes and was significantly decreased within serotypes. Unique bands were present on both blots for both W1's and W6's and may account for the serologic specificity seen in ELA W1 and W6 horses. This study is consistent with the findings in other higher vertebrates and implies that the MHC of the horse includes a highly polymorphic class I multigene family.

  17. Varying expression of major histocompatibility complex antigens on human renal endothelium and epithelium.

    PubMed Central

    Evans, P. R.; Trickett, L. P.; Smith, J. L.; MacIver, A. G.; Tate, D.; Slapak, M.

    1985-01-01

    Pre-anastomosis wedge biopsies from 14 cadaveric donor kidneys were examined for the expression of class I (HLA-ABC) and class II (HLA-DR) antigens in renal tissue. Two monoclonal antibodies to class I antigens and four to class II antigens were used in an indirect immunoperoxidase technique. Consistent expression of both antigens was demonstrated on the surface of glomerular, peritubular capillary and venous endothelial cells. Renal arteries contained only class I antigens. Proximal tubules contained varying amounts of each antigen in their cytoplasm. Sixteen human lymphocytotoxic allo-antisera showed marked variation in their ability to detect HLA antigens on the kidney. The selection of donors for recipients of renal allografts involves the complement-dependent cytotoxicity test and the failure of some lymphocytotoxic antisera to bind to the kidney indicates that some suitable patients may be incorrectly excluded. The use of a binding assay using an immunoperoxidase technique should be included in cross-match techniques particularly for patients who have high levels of circulating cytotoxic antibodies. Images Fig. 1 Fig. 2 Fig. 3 PMID:3855644

  18. Immune Responses to Tissue-Restricted Nonmajor Histocompatibility Complex Antigens in Allograft Rejection

    PubMed Central

    Bharat, Ankit

    2017-01-01

    Chronic diseases that result in end-stage organ damage cause inflammation, which can reveal sequestered self-antigens (SAgs) in that organ and trigger autoimmunity. The thymus gland deletes self-reactive T-cells against ubiquitously expressed SAgs, while regulatory mechanisms in the periphery control immune responses to tissue-restricted SAgs. It is now established that T-cells reactive to SAgs present in certain organs (e.g., lungs, pancreas, and intestine) are incompletely eliminated, and the dysregulation of peripheral immuneregulation can generate immune responses to SAgs. Therefore, chronic diseases can activate self-reactive lymphocytes, inducing tissue-restricted autoimmunity. During organ transplantation, donor lymphocytes are tested against recipient serum (i.e., cross-matching) to detect antibodies (Abs) against donor human leukocyte antigens, which has been shown to reduce Ab-mediated hyperacute rejection. However, primary allograft dysfunction and rejection still occur frequently. Because donor lymphocytes do not express tissue-restricted SAgs, preexisting Abs against SAgs are undetectable during conventional cross-matching. Preexisting and de novo immune responses to tissue-restricted SAgs (i.e., autoimmunity) play a major role in rejection. In this review, we discuss the evidence that supports autoimmunity as a contributor to rejection. Testing for preexisting and de novo immune responses to tissue-restricted SAgs and treatment based on immune responses after organ transplantation may improve short- and long-term outcomes after transplantation. PMID:28164137

  19. Contrasting responses to selection in class I and class IIα major histocompatibility-linked markers in salmon

    PubMed Central

    Consuegra, S; de Eyto, E; McGinnity, P; Stet, R J M; Jordan, W C

    2011-01-01

    Comparison of levels and patterns of genetic variation in natural populations either across loci or against neutral expectation can yield insight into locus-specific differences in the strength and direction of evolutionary forces. We used both approaches to test the hypotheses on patterns of selection on major histocompatibility (MH)-linked markers. We performed temporal analyses of class I and class IIα MH-linked markers and eight microsatellite loci in two Atlantic salmon populations in Ireland on two temporal scales: over six decades and 9 years in the rivers Burrishoole and Delphi, respectively. We also compared contemporary Burrishoole and Delphi samples with nearby populations for the same loci. On comparing patterns of temporal and spatial differentiation among classes of loci, the class IIα MH-linked marker was consistently identified as an outlier compared with patterns at the other microsatellite loci or neutral expectation. We found higher levels of temporal and spatial heterogeneity in heterozygosity (but not in allelic richness) for the class IIα MH-linked marker compared with microsatellites. Tests on both within- and among-population differentiation are consistent with directional selection acting on the class IIα-linked marker in both temporal and spatial comparisons, but only in temporal comparisons for the class I-linked marker. Our results indicate a complex pattern of selection on MH-linked markers in natural populations of Atlantic salmon. These findings highlight the importance of considering selection on MH-linked markers when using these markers for management and conservation purposes. PMID:21266985

  20. Peripheral T Cell Survival Requires Continual Ligation of the T Cell Receptor to Major Histocompatibility Complex–Encoded Molecules

    PubMed Central

    Kirberg, Jörg; Berns, Anton; Boehmer, Harald von

    1997-01-01

    In the thymus, T cells are selected according to their T cell receptor (TCR) specificity. After positive selection, mature cells are exported from primary lymphoid organs to seed the secondary lymphoid tissue. An important question is whether survival of mature T cells is an intrinsic property or requires continuous survival signals, i.e., engagement of the TCR by major histocompatibility complex (MHC) molecules in the periphery, perhaps in a similar way as occurring during thymic positive selection. To address this issue we used recombination-activating gene (Rag)-deficient H-2b mice expressing a transgenic TCR restricted by I-Ed class II MHC molecules. After engraftment with Rag−/− H-2d fetal thymi, CD4+8− peripheral T cells emerged. These cells were isolated and transferred into immunodeficient hosts of H-2b or H-2d haplotype, some of the latter being common cytokine receptor γ chain deficient to exclude rejection of H-2b donor cells by host natural killer cells. Our results show that in the absence, but not in the presence, of selecting MHC molecules, peripheral mature T cells are short lived and disappear within 7 wk, indicating that continuous contact of the TCR with selecting MHC molecules is required for survival of T cells. PMID:9334366

  1. Identification by sequencing based typing and complete coding region analysis of three new HLA class II alleles: DRB3*0210, DRB3*0211 and DQB1*0310.

    PubMed

    Balas, A; Santos, S; Aviles, M J; Garcia-Sanchez, F; Lillo, R; Vicario, J L

    2000-10-01

    The study of HLA class II polymorphism by direct exon 2 DNA sequencing analysis has been established to be a reliable and accurate high-resolution typing procedure. This approach shows some advantages in relation to previous methods, polymerase chain reaction using sequence-specific oligonucleotides (PCR-SSO) and sequence-specific primers (PCR-SSP), basically due to the capability of analysis for the complete sequenced genomic region, including non-polymorphic motifs. DRB3 and DQB1 sequencing based typing (SBT) in unrelated bone marrow donor searching allowed us to detect three new alleles. The complete coding region sequences were characterised from cDNA. Two new DRB3 alleles, DRB3*0210 and DRB3*0211, were described in two Caucasian bone marrow donors. Both sequences showed single point mutations regarding DRB3*0202, producing amino acid replacements at positions 51 (Asp to Thr) and 67 (Leu to Ile), respectively. These two point mutations can be found in other DRB alleles, and suggest that gene conversion would be involved in the origin of both alleles. A new DQB1 sequence was found in a Spanish patient that showed two nucleotide differences, positions 134 and 141, with regard to its close similar DQB1*03011 allele. Only substitution at position 134 provoked amino acid replacement at residue 45, Glu to Gly. This single amino acid change would be involved in the lack of serologic recognition of this new molecule by DQ7-specific reagents.

  2. Minor histocompatibility antigens--targets of graft versus leukemia responses.

    PubMed

    Riddell, Stanley R; Murata, M; Bryant, S; Warren, E H

    2002-08-01

    Immune-mediated elimination of tumor cells by donor T cells recognizing recipient minor H antigens contributes to the curative potential of allogeneic HCT. The importance of the allogeneic response to a successful outcome is clearly illustrated by the results of stem cell transplant for malignancy after nonmyeloablative conditioning. Remarkably little is understood about the molecular nature of minor H antigens and this has impeded efforts to determine the role of specific disparities in graft versus tumor reactions or to manipulate T cell responses to augment antitumor activity without exacerbating GVHD. The isolation of minor H antigen-specific CD8+ and CD4+ T cell clones from recipients of allogeneic HCT has provided the reagents to characterize their expression on leukemic progenitors and to identify the genes encoding these antigens. Using cDNA expression cloning, genetic polymorphisms in the human IFI-75, Uty, KIAA0020, and UGT2B17 genes have been identified to encode new minor H antigens presented by HLA A3, B8, A2, and A29 respectively. Two of these genes are preferentially expressed in hematopoietic cells including leukemic progenitors suggesting it may be possible to augment T cell responses to promote a selective graft versus leukemia effect. A third gene, UGT2B17 is highly expressed in liver and GI tract and may be a target for GVHD in these organs. The studies to identify the molecular nature of minor H antigens have provided insights into the complexities of the graft versus host response associated with allogeneic HCT, but the challenge for the future will be to develop strategies that can selectively induce durable graft versus tumor effects without GVHD. A critical issue in developing specific immunotherapy to augment GVL responses is to determine which minor H antigens are expressed on leukemic stem cells. Studies using transplantation of human AML into SCID mice have identified a putative leukemic stem cell which is contained in the CD34+ CD38

  3. Histocompatibility Typing.

    DTIC Science & Technology

    1980-03-28

    Oslo, New York, NY Norway Maryline Sasportes, Institute de Recherches Susan Hsu, Johns Hopkins University, sur Les Maladies du iang, Paris, France...from PLT cells primed initially series of critical values obtained from with lymphoblastoid cells were highly Harter’s tables ( Harter 1960). Critical...M. L., Wink. Harter , H. L (1960) Critical tables for Duncan’s R. & Bach, F. H. (1975) HLA-LD Typing: new multiple range test. Biometrics 16. A rapid