PubMed HealthSearch

Biomedical subjects

O Olerup

Publications and source records attributed to O Olerup.

At least 19 recordsLinked to original sources

Shared HLA class II-associated genetic susceptibility and resistance, related to the HLA-DQB1 gene, in IgA deficiency and common variable immunodeficiency.

Most cases of selective IgA deficiency (IgA-D) and common variable immunodeficiency (CVID) occur sporadically. However, familial clustering is not uncommon, and the two disorders can occur within the same family. We have previously described positive associations with three DR-DQ haplotypes as well as a strong negative association with DRw15,DQw6,Dw2 in IgA-D. Different amino acids at position 57 of the HLA-DQ beta chain were found to be related to susceptibility and resistance to IgA-D. Now we have found identical, although somewhat weaker, positive and negative DR-DQ associations in a large group of CVID patients (n = 86), as well as the same associations with codon 57 of the DQB1 gene. In addition, we have confirmed our earlier observations in an independent group of IgA-D individuals (n = 69), and in sib-pair analysis we have found linkage of the genetic susceptibility to IgA-D to the HLA class II region. In IgA-D individuals not carrying the three overrepresented DR-DQ haplotypes, the same positive association with a non-aspartic acid residue at position 57 of the HLA-DQ beta chain was seen. The previously reported associations with deletions of the HLA class III genes C4A (fourth component of complement) and CYP21P (steroid 21-hydroxylase pseudogene) were, in our groups of immunodeficient individuals, statistically secondary to the association with the DQB1 allele 0201. The shared HLA class II associations in the two humoral immunodeficiencies support the hypothesis that IgA-D and CVID are related disorders. Disease susceptibility and resistance are most closely associated with a gene(s) within the DR-DQ region, alleles of the DQB1 locus being candidate genes.

Alleles

Genetic regulation of human anti-malarial antibodies in twins.

Immune responses to defined antigens may differ between individuals in a population as the reflection of differences in genetic regulation. In experimental animals, variation in responsiveness to a given epitope may be due to major histocompatibility complex (HLA, in humans) class II restrictions, implying serious limitations for the development of subunit vaccines. For human populations, knowledge of the relative importance of genetic as opposed to environmental factors affecting the immune response is scarce. We have compared antibody levels after immunization through repeated infections to a major malarial antigen (Pf155/RESA) in monozygotic twins with those in dizygotic twins, siblings, or unrelated controls. Antibody responses to the intact antigen and to some of its immunodominant epitopes were found to be more concordant within monozygotic twin pairs than in dizygotic pairs or age- and sex-matched siblings living under similar environmental conditions. The results support the conclusion that the antibody responses were genetically regulated. When the responses were assessed for possible associations with different HLA class II DRB, DQA, and DQB alleles had haplotypes, no associations were found. This suggests that the regulation of the Pf155/RESA antibody responses seen in this study reflects the impact of factors encoded by genes outside the HLA class II regions.

Adolescent

Restricted V alpha 2.3 gene usage by CD4+ T lymphocytes in bronchoalveolar lavage fluid from sarcoidosis patients correlates with HLA-DR3.

The alpha/beta T cell receptor (TcR) V gene usage of bronchoalveolar lavage (BAL) lymphocytes and peripheral blood lymphocytes (PBL) from 11 sarcoidosis patients and 4 healthy controls was investigated, using eight alpha/beta TcR V gene product-specific monoclonal antibodies (mAb). Twenty-seven percent (3/11) of the sarcoidosis patients had a highly significant increase in V alpha 2.3+CD4+ T lymphocytes in the bronchoalveolar space, while displaying normal frequencies of these T cells in peripheral blood. The reactivities with the remaining seven TcR mAb were normal. In the control group, no compartmentalization of any T cells was seen. Four of the patients expressed the HLA-DR3 (w17), DQw2 haplotype. Interestingly, the three patients with distinct signs of compartmentalized V alpha 2.3+CD4+ T cells all expressed this HLA haplotype. Additionally, a fourth patient with pronounced, although less significant, accumulation of V alpha 2.3+CD4+ T cells in the lung, was also HLA-DR3(w17), DQw2+. Expression of V alpha 2.3+CD4+ T cells in BAL of these patients correlated with clinical disease, as revealed on re-analyzing the four patients after 6 months or longer. Predominant TcR V alpha 2.3 gene usage in compartmentalized CD4+ BAL T lymphocytes, linked to HLA-DR3(w17), DQw2 haplotype, may thus indicate presence of a specific antigen localized to the lungs of sarcoidosis patients.

Adult

Increased numbers of T cells recognizing multiple myelin basic protein epitopes in multiple sclerosis.

Myelin basic protein (MBP)-autoreactive T cells have a crucial pathogenetic role in experimental allergic encephalomyelitis (EAE) and certain MBP epitopes may be immunodominantly recognized. The heterogeneity and quantity of the T cell response to different epitopes of MBP in multiple sclerosis (MS) and non-MS controls is not so clearly defined. We now study T cell reactivity to six different peptides of MBP in MS compared to controls in short-term cultures of blood mononuclear cells by measuring numbers of T cells that secrete interferon-gamma in response to antigen. In comparison with controls, MS patients showed dramatically increased numbers of MBP peptide-reactive T cells with mean values varying between 10.4 and 22.5 per 10(5) blood mononuclear cells. Among those MBP peptides examined (amino acid 1-20, 63-88, 89-101, 96-118, 110-128 and 148-165), no single peptide is preferentially recognized. Neither is any preferential response apparent after subdivision of the MS patients according to their HLA-DR genotype. Our findings suggest that a quantitative increase of a broad repertoire of myelin-autoreactive T cells with capacity to secrete IFN-gamma can be important for the pathogenesis of MS.

Adult

Different genetic backgrounds for malnutrition-related diabetes and type 1 (insulin-dependent) diabetes mellitus in south Indians.

HLA-DRB, -DQA and -DQB genes were studied in ten South Indian malnutrition-related diabetic patients, ten Type 1 (insulin-dependent) diabetic patients and 45 control subjects, by TaqI restriction fragment length polymorphism analysis. The DR7,DQw9 haplotype was found to be frequent in patients with malnutrition-related diabetes (p less than 0.01). The DRw17,DQw2 haplotype was overrepresented in the patients with Type 1 diabetes compared to control subjects (p less than 0.05). In vitro amplification of the polymorphic second exon of DQB genes by the polymerase chain reaction technique was performed on DNA from 10 malnutrition-related diabetic patients, 10 Type 1 diabetic patients and 13 control subjects, as they belong to a new population. Hybridization with sequence-specific oligonucleotide probes for DQB1 alleles showed homozygosity of aspartic acid at position 57 in 7 of 10 malnutrition-related diabetic patients compared to 2 of 10 Type 1 diabetic (p less than 0.05) and 15 of 45 control subjects (p less than 0.05). Homozygosity of non-aspartic acid at position 57 was present in 7 of 10 Type 1 diabetic compared to 0 of 10 malnutrition-related diabetic patients (p less than 0.005) and 3 of 45 control subjects (p less than 0.05). This study has confirmed the association of DQB1 57 non-asp in South Indians with Type 1 diabetes. In addition, our data clearly show that the genetic background of malnutrition-related diabetes mellitus is different from that of Type 1 diabetes.

Diabetes Mellitus

HLA polymorphisms and evolution.

Polymorphisms within the human MHC are of interest to immunologists, for their functional significance, and to geneticists, as markers of populations. Here, Eleanor Riley and Olle Olerup describe how molecular analysis of the HLA complex is beginning to reveal the true extent of class II diversity, and demonstrate the use of this information to clarify the historical relationships between different human populations.

Africa

Identification of the HLA-DRB1*04, -DRB1*07, and -DRB1*09 alleles by PCR amplification with sequence-specific primers (PCR-SSP) in 2 hours.

The clinical applicability of genomic HLA class II typing techniques has increased after the introduction of PCR-based typing strategies. In typing by PCR amplification using sequence-specific primers (PCR-SSP), amplification of specific alleles or groups of alleles is achieved, provided that the mismatch(es) of the SSP is located in the 3' end of the primer. Thus, the specificity of the typing system becomes part of the amplification step, which reduces the total typing time to a minimum by simplifying the postamplification processing of samples. The set of primers presented here identifies all of the alleles of the DR4 group, DRB1*0401-DRB1*0411, as well as the DRB1*07 and DRB1*0901 alleles. In the present study of DR4 alleles, PCR-SSP was compared with hybridization with sequence-specific oligonucleotide probes following group-specific PCR amplification (PCR-SSO). The two typing strategies gave completely concordant results in the 90 DR4-positive and the 32 DR4-negative individuals and cell lines studied. DR7,DQ9/DR9,DQ9 discrimination using PCR-SSP, was compared with MspI DQA RFLP typing, also with concordant results in the 33 DR7- and/or DR9-positive and 36 DR7- and DR9-negative individuals and cell lines tested. No false-negative or false-positive typing results were obtained. Genomic typing by PCR-SSP was performed in the overall time of 2 hours, including rapid DNA preparation, PCR amplification, postamplification processing, documentation, and interpretation of results. This makes the PCR-SSP strategy for HLA class II typing attractive not only in population- and disease-association studies, but also in routine clinical practice, including donor-recipient matching prior to cadaveric transplantation.

Alleles

No association or linkage with HLA-DR or -DQ genes in south Indians with pulmonary tuberculosis.

Studies of the HLA class II genes were performed in patients and multiple families with pulmonary tuberculosis from South India to seek any association of disease susceptibility with an individual allele or haplotype. TaqI RFLP analysis of HLA-DRB, -DQA and -DQB genes was done in 38 patients and 36 healthy control subjects. No significant association with any particular allele or haplotype was obtained. Linkage analysis performed in 12 families and haplotype sharing analysis in 9 families showed that the genetic susceptibility to pulmonary tuberculosis was not linked to the HLA region. The results suggest that the RFLP patterns of HLA class II genes DRB, DQA and DQB are not associated with susceptibility to pulmonary tuberculosis and that the genes controlling susceptibility or resistance may be located outside the HLA region.

Blotting, Southern

MHC and malaria: the relationship between HLA class II alleles and immune responses to Plasmodium falciparum.

In mice, immune responses to subunits of defined malaria antigens are regulated by genes mapping within the MHC and it has been suggested that such genetic restriction will be a major obstacle in the development of a human malaria vaccine. The relationship between class II human leukocyte antigen (HLA) genes and immune recognition of three candidate antigens for a vaccine against Plasmodium falciparum malaria has been investigated in a human population living in a malaria endemic area of West Africa. The study population was shown to be extremely heterogeneous for HLA class II alleles and marked differences in allelic frequency were detected between members of different ethnic groups. One class II DQA-DQB combination (serological specificity DQw2) was particularly common among members of the Fula ethnic group. This haplotype was significantly associated with higher than average levels of antibody to a peptide epitope, (EENV)6, of the malaria antigen Pf155/RESA. There was little evidence of association between HLA class II genotype and cellular proliferative or interferon gamma responses to the antigens tested. Overall, the number of significant associations between immune responses and specific HLA class II haplotypes was greater than would be expected by chance but less than would be expected if class II-dependent genetic restriction were a major factor governing human immune responses to malaria antigens. Thus, although some qualitative variation in the immune response to vaccine antigens may occur in ethnically different target populations, widespread HLA-associated nonresponsiveness to a multivalent subunit malaria vaccine is unlikely.

Adolescent

HLA-DR typing by PCR amplification with sequence-specific primers (PCR-SSP) in 2 hours: an alternative to serological DR typing in clinical practice including donor-recipient matching in cadaveric transplantation.

In most PCR-based tissue typing techniques the PCR amplification is followed by a post-amplification specificity step. In typing by PCR amplification with sequence-specific primers (PCR-SSP), typing specificity is part of the amplification step, which makes the technique almost as fast as serological tissue typing. In the present study primers were designed for DR "low-resolution" typing by PCR-SSP, i.e. identifying polymorphism corresponding to the serologically defined series DR1-DRw18. This resolution was achieved by performing 19 PCR reactions per individual, 17 for assigning DR1-DRw18 and 2 for the DRw52 and DRw53 superspecificities. Thirty cell lines and 121 individuals were typed by the DR "low-resolution" PCR-SSP technique, TaqI DRB-DQA-DQB RFLP analysis and serology. The concordance between PCR-SSP typing and RFLP analysis was 100%. The reproducibility was 100% in 40 samples typed on two separate occasions. No false-positive or false-negative typing results were obtained. All homozygous and heterozygous combinations of DR1-DRw18 could be distinguished. Amplification patterns segregated according to dominant Mendelian inheritance. DNA preparation, PCR amplification and post-amplification processing, including gel detection, documentation and interpretation, were performed in 2 hours. In conclusion, PCR-SSP is an accurate typing technique with high sensitivity, specificity and reproducibility. The method is rapid and inexpensive. DR "low-resolution" typing by the PCR-SSP technique is ideally suited for analyzing small numbers of samples simultaneously and is an alternative to serological DR typing in routine clinical practice including donor-recipient matching in cadaveric transplantations.

Alleles

HLA class II genes in primary sclerosing cholangitis and chronic inflammatory bowel disease: no HLA-DRw52a association in Swedish patients with sclerosing cholangitis.

The familial predisposition to chronic inflammatory bowel disease and the increased concordance rate in monozygotic twins with Crohn's disease, suggest that genetic factors influence disease susceptibility. A 100% association with the supertypic HLA class II specificity DRw52a was recently described in white North American patients with primary sclerosing cholangitis, with or without concurrent ulcerative colitis. HLA class II alleles of the DR, DQ, and DP subregions were determined by genomic typing techniques in a large group of Swedish patients with ulcerative colitis or Crohn's disease as well as in a series of patients with primary sclerosing cholangitis. No statistically significant HLA class II association was observed in any of the investigated diseases or when the patients were subgrouped according to disease site or occurrence of extraintestinal manifestations, except an insignificant increase of the DRw17, DQw2 haplotype in patients with primary sclerosing cholangitis. The failure to confirm the well established DRw17 association in Swedish patients with sclerosing cholangitis probably represents a statistical type II error. Furthermore, this study did not verify the recently described strong DRw52a association in sclerosing cholangitis--52% of the patients were DRw52a positive compared with 28% of the controls (p less than 0.05, pc NS). This discrepancy was probably caused by different typing techniques. The DRw52a specificity was determined directly by hybridising HLA-DRB3 genes, group specifically amplified by the polymerase chain reaction, with an allele specific oligonucleotide probe, whereas in the previously mentioned study DRw52a was assigned by indirect serological criteria, which overestimate the frequency of this allele.

Blotting, Southern

An immunogenetic heterogeneity in multiple sclerosis.

Two clinical forms of multiple sclerosis (MS), primarily chronic progressive MS (PCP MS) and relapsing/remitting MS (R/R MS) have been shown to differ in several respects. The results of genomic HLA class II typing with restriction fragment length polymorphism analysis of 62 MS patients from Western Norway, 42 with R/R MS and 20 PCP MS, are reported on here. As in previous studies of Swedish patients, the haplotype DRw17(3), DQw2 was found to be five times more common in R/R MS than in PCP MS. This finding supports the hypothesis that R/R and PCP MS are immunogenetically separate entities. In contrast with a previous investigation of Norwegian MS patients, no association of MS with glutamine at position 34 of the HLA-DQ alpha chain or with defined sequences of the HLA-DQB1 gene was found.

Adult

T-cell receptor alpha chain germline gene polymorphisms in multiple sclerosis.

It has been proposed that genetic predisposition to multiple sclerosis (MS) and other diseases with autoimmune features is conferred by T-cell receptor (TcR) genes in addition to HLA class II genes. Although a family study has suggested linkage of susceptibility to MS to TcR genes, reports of disease associations with restriction fragment length polymorphism (RFLP)-defined alleles of TcR genes have been difficult to confirm, including a report of association of MS with TcR beta-chain gene RFLPs. We report here the distribution of three sets of RFLPs of the TcR alpha chain genes. Similar frequencies in patients and controls were observed for TaqI and BglII RFLPs of the TcR alpha constant segment (C alpha), the latter earlier reported to be associated with MS. A previously reported MS-associated PssI RFLP of the V alpha 12 and C alpha gene segments could not be confirmed. Our results indicate that these seemingly polymorphic restriction fragments are possibly the results of incomplete enzymatic cleavage of DNA in the RFLP analysis. We conclude that no convincing evidence exists for the association of MS with RFLPs of the TcR alpha or beta chain genes.

Alleles

Conjugal multiple sclerosis: immunogenetic characterization and analysis of T- and B-cell reactivity to myelin proteins.

We describe two families with conjugal multiple sclerosis. Onset of symptoms in the husbands occurred 11 and 17 years after onset of relapsing/remitting symptoms in their wives. There were no similarities regarding clinical manifestations of MS within each family. Evaluation of T-cell repertoire by enumeration of cells secreting interferon-gamma in response to proteolipid protein (PLP), myelin basic protein (MBP), and to various synthetic MBP peptides revealed similar patterns of T-cell reactivity within the families both in MS-affected parents and unaffected children. Genomic HLA-DR-DQ typing showed that T-cell reactivity was independent of HLA class II phenotype. Analysis of B-cell responses in blood showed low numbers of cells secreting IgG, IgA, or IgM antibodies against MBP, PLP, myelin-associated glycoprotein, and myelin-oligodendrocyte glycoprotein both in MS-affected and unaffected family members. In conclusion, our study of two families with conjugal MS has shown a dominant T-cell response against the same MBP peptide within the family both in MS-affected parents and unaffected children, and this T-cell response seems to be independent of the HLA class II phenotypes of the family members.

Adult

[Identification of HLA class II polymorphism with molecular biology techniques].

All the biologically relevant HLA class II allelic variants can not be identified with conventional serological tissue typing techniques. During the past few years considerable advances have been made in HLA class II typing with molecular techniques now widely used in routine clinical tissue typing. The next few years are likely to see the development of tissue typing techniques based on the polymerase chain reaction (PCR), for use in acute transplantation. A new method for the rapid identification of genetic polymorphisms is described--allele-specific PCR amplification.

HLA-D Antigens