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HLA associations in IDDM. Role of HLA-DR4 subtypes in protection
152
Abstracts
0826
0827
HLA ASSOCIATIONS IN IDDM. ROLE OF HLA-DR4 SUBTYPES IN PROTECTION.
HLA-DQBl GENOTYPES ASSOCIATED WITH IDDM RISK IN HEALTHY SCHOOL CIDLDREN POSITIVE FOR GAD65 AND ISI~ET CELL ANTffiODlES
Undlien Dag E. l , Friede Thomas', Rammensee Hans-Georg", Ranningen Kjcrsti
s.',
Tbcrsby Erik' .
'Institute of Transplantation Immunology, The National Hospital, Oslo, Norway. 'DeutschesKrebsfbrschungszentrum, Heidelberg. Germany.
IDDM susceptibility associated with DQ8 is greatly influenced by which DR4 subtype is carried on the same haplotype. Our data together with those from others suggest the following hierarchy of susceptibility (ranked from the highest): DRBI*0405:::0402:::0401>0404>0403",0406. Based on a comparison of their DRp-chains and peptide motifs. we suggets that the very similar protective DR4 subtypes may preferentially bind a "protective" peptide which are much less accornodated by the susceptible DR4 subtypes. Thus, a peptide which is a strong binder to the DR(a,p 1*0403) and DR(a,pI*0406) subtypes may bind with lower affinity to DR(a.pI*0404) and with an even lower affinity to DR(a.p 1*0402) and DR(a,p 1*0401), and maybe not at all to DR(a.pI*0405). We propose that the susceptibility conferred by DQ8 haplotypes is mainly determined by the DQ8 molecule while a variable degree of protection is conferred by the various DR4 subtypes. This model implies that high risk DR4-DQ8 haplotypes (e.g. which are carrying DRBI*0405, 0402 and 0401) are conferring high risk because these DR4 subtypes are poor binders of a "protective" peptide. We also propose a motif for such a "protective" peptide.
llonen Jorrna, Sjoroos Minna, Rahko Jukka, Kulmala Petri, Vahasalo Paula, Karjalainen Jukka, Knip Mikael Turku Immunology Centre and Department of Virology, University of Turku, and Department of Pediatrics. University of Oulu, Finland HLA-DQBI alleles associated with an increased risk (*0302 and *0201) or protection against (*0602,*0603 and *0301) insulin-dependent diabetes mellitus (IDDM) were analyzed in healthy school children found to be positive for GAD65 or islet cell antibodies (leA). The HLA assay was based on the application of time-resolved fluorometry to measure the hybridization of different lanthanide-labelled, short allele specific probes. Serum samples from 3662 children between ages 7 and 16 yrs were screened and 103 (2.8%) found to be positive for ICA and 19 (0.5%) for GAD65 antibodies. Twelwe (0.3%) were positive for both antibodies. A high proportion, 7/12 (58%) of these twelve children had high (DQB I*020 110302) or moderate risk (DQB I *0302/x. x = a nentral allele or 0302) genotypes which significantly (P
0828
P829
THE HLA AMINO ACIDS INFLUENCING IDDM PREDISPOSmON.
GENETIC HETEROGENEITY BETWEEN TYPE la AND TYPE Ib INSULIN·DEPENDENT DIABETES MEILITUS : HLA CLASS n AND TAP GENE ANALYSIS
Ana- Maria Valdes I, Hugh Salamon 1. Tarhio Jorma-, Kjersti Ronningen-, Glenys Thomson I, IDepartrnent of Integrative Biology, University of California, Berkeley, CA 94720-3140 USA, 2Computer Science Department, Helsinki University, Finland and 31nstitute of Transplantation, Oslo, Norway. The HLA component to insulin dependent diabetes mellitns (IDDM) involves multiple loci, multiple alleles, genetic heterogeneity and interaction effects. We have developed two independent methods to identify the amino acids in the HLA region involved in IDDM. The "unique combinations" method employs an efficient computer algorithm to detect all amino acid combinations (singles, pairs. triplets, etc.) which distinguish a set of sequences from another set of sequences, e.g., haplotypes or genotypes which are common in IDDM patients versus those that are virtually absent from patients yet common in controls. The "haplotype" method is a test of whether all relevant amino acids involved in disease have been identified. For haplotype (chromosome) combinations containing all the amino acid sites involved in the disease process, the relative frequencies of amino acid variants at sites not involved in disease are expected to be the same in patients and controls. Statistical features of tests using this method, including the complication of high correlation between amino acid sites within the HLA genes, have been considered. Our results prove that the combination DQAI 52 - DQB I 57 does not include all the IDDM predisposing elements. Specific amino acids in DRBI, DQAI and DQBI have been identified which account for IDDM predisposition and protection in a number of ethnic groups.
P830
wrrn
ASSOCIATION MAPPING A POOLED DNA GENOMIC SCREEN OF THE NON-HLA GENES IN IDDM, RA AND MS Glenys Thomson I, Lisa Barcellos, I, William Klitz I , Leigh Field 2, Rose Tobias 2, Anne Bowcockc, Ross Wilson 3, lDepartrnent of Integrative Biology, University of California, Berkeley, CA USA, 2Department of Medical Genetics, University of Calgary, Canada and 3Department of Pediatrics, University of Texas, Dallas, USA. A number of HLA associated diseases, e.g., insulin dependent diabetes (IDDM), rheumatoid arthritis (RA), and multiple sclerosis (MS), involve a large non-HLA genetic component, Affected sib pair linkage studies have been the main method used to date to detect these non-HLA genes. Sufficient marker density is now available for microsatellite genomic screens to also detect disease loci by association. Several aspects of marker association screening using automation and pooled DNA have been investigated. We have demonstrated that pooled control and patient DNA samples (hemochromatosis and MS), and family based samples (affected sib pairs with IDDM), gave accurate determination of microsatellite allele frequencies, and allowed detection of marker-disease associations including disease heterogeneity and interaction effects. Combined with theoretical and empirical studies, statistical power and experimental design considerations. we have shown that association genomic screening with pooled DNA is appropriate and feasible, both in case-control and family based (simplex and affected sib pair) samples. Our results are relevant to all disease studies, but in particular to the non-HLA components of the complex HLA associated diseases. as well as study of the non-Hl.A genetic components ofinfectious diseases, e.g., AIDS and tuberculosis.
2
Maugendre Didier', Alizadeh Mehdi , Gauthier Anisia', Guilhem Isabelle', 2 Pouillaud Charles'', Genetet Bernard', Allannic Hubert', Semana Gilbert 1 : Endocrologie, CHRU - 2 : Laboratoire Universitaire d'Immunologie, ETS Bretagne Est, Rennes, France. The aim of tbis study was to compare the genetic susceptibility linked to the HLA Class II region genes in isolated insulin-dependent diabetes mellitus (la-IDOM) (n=179) and insulin-dependent diabetes mellitus associated with another autoimmune endocrinopathy (lb-IDDM)(n=83). HLA genes DRBl, DQAl and DQBl were studied at the genomic level, as well as genes TAPI and TAP2. While it appeared that common genetic traits characterize diabetes regardless of the subtype (la or Ib), certain features differentiate the two forms of IDOM. Extending the analysis of risk haplotypes DRBl*03 and ORBl*04 to TAP genes elicited a difference between IaIDDM and Ib-IDDM patients. Haplotype DRBl*03 was thus characterized in la-IDDM patients by a lower frequency of alleles TAPl-B (13.5 %) and TAP2-B (16.2 %), not found in Ib-lDDM patients (3 3.3 % for each allele). Likewise, haplotype DRBl*04 is characterized in Ib-IDDM patients by a lower frequency of alleles TAPI-C (4.0 %) and TAP2-B (8.0 %) than in IaIDDM patients (22.2 % and 25.9 %, respectively).
P831
COMBINATION OF POLYMORPffiC RESIDUES IN HLA-DQu AND LQp CHAINS FORM A DOMAIN STRUCfURE PATIERN AND ARE ASSOCIATED WITH INSUUN-DEPENDENT DIABETES (IDOl\ot). Sanjeevi CB, Landin-Olsson M, Kockum I, Dahlquist G, Lernmark A. Karolinska Hospital, Stockholm, Lund University Hospital, Lund, Umea University Hospital, Urnea, Sweden. HLA-DQ8 (A*0301-B*0302) and DQ2 (A*0501-B*020l) are positively associated with IDDM in Swedish Caucasians. Together they account for 89% patients and 47% controls. The aim of the present study was to analze the importance of several polymorphic residues in DQ" and DQfl chain in susceptiblity to IDDM in Swedish children (0-15 years). For this, HlA-DQ genotyping was done by PeR-SSO in 425 patients and 367 matched controls. Polymorphic residues identical to DQu and DQjl in DQ8 and DQ2 «A*0301 and A*0501 and B*0302 and B*0201) were aligned and compared. Residues RFTlL at positions 52, 61, 64, 66, 69 of DQ" chain accounted for 4051425 (95%) patients and 254/367 (69%) controls (Odds ratio 9.01. Pc
Abstracts
0826
0827
HLA ASSOCIATIONS IN IDDM. ROLE OF HLA-DR4 SUBTYPES IN PROTECTION.
HLA-DQBl GENOTYPES ASSOCIATED WITH IDDM RISK IN HEALTHY SCHOOL CIDLDREN POSITIVE FOR GAD65 AND ISI~ET CELL ANTffiODlES
Undlien Dag E. l , Friede Thomas', Rammensee Hans-Georg", Ranningen Kjcrsti
s.',
Tbcrsby Erik' .
'Institute of Transplantation Immunology, The National Hospital, Oslo, Norway. 'DeutschesKrebsfbrschungszentrum, Heidelberg. Germany.
IDDM susceptibility associated with DQ8 is greatly influenced by which DR4 subtype is carried on the same haplotype. Our data together with those from others suggest the following hierarchy of susceptibility (ranked from the highest): DRBI*0405:::0402:::0401>0404>0403",0406. Based on a comparison of their DRp-chains and peptide motifs. we suggets that the very similar protective DR4 subtypes may preferentially bind a "protective" peptide which are much less accornodated by the susceptible DR4 subtypes. Thus, a peptide which is a strong binder to the DR(a,p 1*0403) and DR(a,pI*0406) subtypes may bind with lower affinity to DR(a.pI*0404) and with an even lower affinity to DR(a.p 1*0402) and DR(a,p 1*0401), and maybe not at all to DR(a.pI*0405). We propose that the susceptibility conferred by DQ8 haplotypes is mainly determined by the DQ8 molecule while a variable degree of protection is conferred by the various DR4 subtypes. This model implies that high risk DR4-DQ8 haplotypes (e.g. which are carrying DRBI*0405, 0402 and 0401) are conferring high risk because these DR4 subtypes are poor binders of a "protective" peptide. We also propose a motif for such a "protective" peptide.
llonen Jorrna, Sjoroos Minna, Rahko Jukka, Kulmala Petri, Vahasalo Paula, Karjalainen Jukka, Knip Mikael Turku Immunology Centre and Department of Virology, University of Turku, and Department of Pediatrics. University of Oulu, Finland HLA-DQBI alleles associated with an increased risk (*0302 and *0201) or protection against (*0602,*0603 and *0301) insulin-dependent diabetes mellitus (IDDM) were analyzed in healthy school children found to be positive for GAD65 or islet cell antibodies (leA). The HLA assay was based on the application of time-resolved fluorometry to measure the hybridization of different lanthanide-labelled, short allele specific probes. Serum samples from 3662 children between ages 7 and 16 yrs were screened and 103 (2.8%) found to be positive for ICA and 19 (0.5%) for GAD65 antibodies. Twelwe (0.3%) were positive for both antibodies. A high proportion, 7/12 (58%) of these twelve children had high (DQB I*020 110302) or moderate risk (DQB I *0302/x. x = a nentral allele or 0302) genotypes which significantly (P
0828
P829
THE HLA AMINO ACIDS INFLUENCING IDDM PREDISPOSmON.
GENETIC HETEROGENEITY BETWEEN TYPE la AND TYPE Ib INSULIN·DEPENDENT DIABETES MEILITUS : HLA CLASS n AND TAP GENE ANALYSIS
Ana- Maria Valdes I, Hugh Salamon 1. Tarhio Jorma-, Kjersti Ronningen-, Glenys Thomson I, IDepartrnent of Integrative Biology, University of California, Berkeley, CA 94720-3140 USA, 2Computer Science Department, Helsinki University, Finland and 31nstitute of Transplantation, Oslo, Norway. The HLA component to insulin dependent diabetes mellitns (IDDM) involves multiple loci, multiple alleles, genetic heterogeneity and interaction effects. We have developed two independent methods to identify the amino acids in the HLA region involved in IDDM. The "unique combinations" method employs an efficient computer algorithm to detect all amino acid combinations (singles, pairs. triplets, etc.) which distinguish a set of sequences from another set of sequences, e.g., haplotypes or genotypes which are common in IDDM patients versus those that are virtually absent from patients yet common in controls. The "haplotype" method is a test of whether all relevant amino acids involved in disease have been identified. For haplotype (chromosome) combinations containing all the amino acid sites involved in the disease process, the relative frequencies of amino acid variants at sites not involved in disease are expected to be the same in patients and controls. Statistical features of tests using this method, including the complication of high correlation between amino acid sites within the HLA genes, have been considered. Our results prove that the combination DQAI 52 - DQB I 57 does not include all the IDDM predisposing elements. Specific amino acids in DRBI, DQAI and DQBI have been identified which account for IDDM predisposition and protection in a number of ethnic groups.
P830
wrrn
ASSOCIATION MAPPING A POOLED DNA GENOMIC SCREEN OF THE NON-HLA GENES IN IDDM, RA AND MS Glenys Thomson I, Lisa Barcellos, I, William Klitz I , Leigh Field 2, Rose Tobias 2, Anne Bowcockc, Ross Wilson 3, lDepartrnent of Integrative Biology, University of California, Berkeley, CA USA, 2Department of Medical Genetics, University of Calgary, Canada and 3Department of Pediatrics, University of Texas, Dallas, USA. A number of HLA associated diseases, e.g., insulin dependent diabetes (IDDM), rheumatoid arthritis (RA), and multiple sclerosis (MS), involve a large non-HLA genetic component, Affected sib pair linkage studies have been the main method used to date to detect these non-HLA genes. Sufficient marker density is now available for microsatellite genomic screens to also detect disease loci by association. Several aspects of marker association screening using automation and pooled DNA have been investigated. We have demonstrated that pooled control and patient DNA samples (hemochromatosis and MS), and family based samples (affected sib pairs with IDDM), gave accurate determination of microsatellite allele frequencies, and allowed detection of marker-disease associations including disease heterogeneity and interaction effects. Combined with theoretical and empirical studies, statistical power and experimental design considerations. we have shown that association genomic screening with pooled DNA is appropriate and feasible, both in case-control and family based (simplex and affected sib pair) samples. Our results are relevant to all disease studies, but in particular to the non-HLA components of the complex HLA associated diseases. as well as study of the non-Hl.A genetic components ofinfectious diseases, e.g., AIDS and tuberculosis.
2
Maugendre Didier', Alizadeh Mehdi , Gauthier Anisia', Guilhem Isabelle', 2 Pouillaud Charles'', Genetet Bernard', Allannic Hubert', Semana Gilbert 1 : Endocrologie, CHRU - 2 : Laboratoire Universitaire d'Immunologie, ETS Bretagne Est, Rennes, France. The aim of tbis study was to compare the genetic susceptibility linked to the HLA Class II region genes in isolated insulin-dependent diabetes mellitus (la-IDOM) (n=179) and insulin-dependent diabetes mellitus associated with another autoimmune endocrinopathy (lb-IDDM)(n=83). HLA genes DRBl, DQAl and DQBl were studied at the genomic level, as well as genes TAPI and TAP2. While it appeared that common genetic traits characterize diabetes regardless of the subtype (la or Ib), certain features differentiate the two forms of IDOM. Extending the analysis of risk haplotypes DRBl*03 and ORBl*04 to TAP genes elicited a difference between IaIDDM and Ib-IDDM patients. Haplotype DRBl*03 was thus characterized in la-IDDM patients by a lower frequency of alleles TAPl-B (13.5 %) and TAP2-B (16.2 %), not found in Ib-lDDM patients (3 3.3 % for each allele). Likewise, haplotype DRBl*04 is characterized in Ib-IDDM patients by a lower frequency of alleles TAPI-C (4.0 %) and TAP2-B (8.0 %) than in IaIDDM patients (22.2 % and 25.9 %, respectively).
P831
COMBINATION OF POLYMORPffiC RESIDUES IN HLA-DQu AND LQp CHAINS FORM A DOMAIN STRUCfURE PATIERN AND ARE ASSOCIATED WITH INSUUN-DEPENDENT DIABETES (IDOl\ot). Sanjeevi CB, Landin-Olsson M, Kockum I, Dahlquist G, Lernmark A. Karolinska Hospital, Stockholm, Lund University Hospital, Lund, Umea University Hospital, Urnea, Sweden. HLA-DQ8 (A*0301-B*0302) and DQ2 (A*0501-B*020l) are positively associated with IDDM in Swedish Caucasians. Together they account for 89% patients and 47% controls. The aim of the present study was to analze the importance of several polymorphic residues in DQ" and DQfl chain in susceptiblity to IDDM in Swedish children (0-15 years). For this, HlA-DQ genotyping was done by PeR-SSO in 425 patients and 367 matched controls. Polymorphic residues identical to DQu and DQjl in DQ8 and DQ2 «A*0301 and A*0501 and B*0302 and B*0201) were aligned and compared. Residues RFTlL at positions 52, 61, 64, 66, 69 of DQ" chain accounted for 4051425 (95%) patients and 254/367 (69%) controls (Odds ratio 9.01. Pc