| 1. |
- Ayoglu, Burcu, et al.
(author)
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Anoctamin 2 identified as an autoimmune target in multiple sclerosis
- 2016
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In: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences of the USA. - 0027-8424 .- 1091-6490. ; 113:8, s. 2188-2193
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Journal article (peer-reviewed)abstract
- Multiple sclerosis (MS) is the most common chronic inflammatory disease of the central nervous system and also is regarded as an autoimmune condition. However, the antigenic targets of the autoimmune response in MS have not yet been deciphered. In an effort to mine the autoantibody repertoire within MS, we profiled 2,169 plasma samples from MS cases and population-based controls using bead arrays built with 384 human protein fragments selected from an initial screening with 11,520 antigens. Our data revealed prominently increased autoantibody reactivity against the chloride-channel protein anoctamin 2 (ANO2) in MS cases compared with controls. This finding was corroborated in independent assays with alternative protein constructs and by epitope mapping with peptides covering the identified region of ANO2. Additionally, we found a strong interaction between the presence of ANO2 autoantibodies and the HLA complex MS-associated DRB1*15 allele, reinforcing a potential role for ANO2 autoreactivity in MS etiopathogenesis. Furthermore, immunofluorescence analysis in human MS brain tissue showed ANO2 expression as small cellular aggregates near and inside MS lesions. Thus this study represents one of the largest efforts to characterize the autoantibody repertoire within MS. The findings presented here demonstrate that an ANO2 autoimmune subphenotype may exist in MS and lay the groundwork for further studies focusing on the pathogenic role of ANO2 autoantibodies in MS.
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| 2. |
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| 3. |
- Engdahl, Elin, et al.
(author)
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Increased Serological Response Against Human Herpesvirus 6A Is Associated With Risk for Multiple Sclerosis
- 2019
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In: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 10
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Journal article (peer-reviewed)abstract
- Human herpesvirus (HHV)-6A or HHV-6B involvement in multiple sclerosis (MS) etiology has remained controversial mainly due to the lack of serological methods that can distinguish the two viruses. A novel multiplex serological assay measuring IgG reactivity against the immediate-early protein 1 from HHV-6A (IE1A) and HHV-6B (IE1B) was used in a MS cohort (8,742 persons with MS and 7,215 matched controls), and a pre-MS cohort (478 individuals and 476 matched controls) to investigate this further. The IgG response against IE1A was positively associated with MS (OR = 1.55, p = 9 × 10-22), and increased risk of future MS (OR = 2.22, p = 2 × 10-5). An interaction was observed between IE1A and Epstein-Barr virus (EBV) antibody responses for MS risk (attributable proportion = 0.24, p = 6 × 10-6). In contrast, the IgG response against IE1B was negatively associated with MS (OR = 0.74, p = 6 × 10-11). The association did not differ between MS subtypes or vary with severity of disease. The genetic control of HHV-6A/B antibody responses were located to the Human Leukocyte Antigen (HLA) region and the strongest association for IE1A was the DRB1*13:01-DQA1*01:03-DQB1*06:03 haplotype while the main association for IE1B was DRB1*13:02-DQA1*01:02-DQB1*06:04. In conclusion a role for HHV-6A in MS etiology is supported by an increased serological response against HHV-6A IE1 protein, an interaction with EBV, and an association to HLA genes.
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| 4. |
- Häggmark-Månberg, Anna, et al.
(author)
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Autoantibody targets in vaccine-associated narcolepsy
- 2016
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In: Autoimmunity. - : Taylor & Francis. - 0891-6934 .- 1607-842X. ; 49:6, s. 421-433
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Journal article (peer-reviewed)abstract
- Narcolepsy is a chronic sleep disorder with a yet unknown cause, but the specific loss of hypocretin-producing neurons together with a strong human leukocyte antigen (HLA) association has led to the hypothesis that autoimmune mechanisms might be involved. Here, we describe an extensive effort to profile autoimmunity repertoires in serum with the aim to find disease-related autoantigens. Initially, 57 serum samples from vaccine-associated and sporadic narcolepsy patients and controls were screened for IgG reactivity towards 10 846 fragments of human proteins using planar microarrays. The discovered differential reactivities were verified on suspension bead arrays in the same sample collection followed by further investigation of 14 antigens in 176 independent samples, including 57 narcolepsy patients. Among these 14 antigens, methyltransferase-like 22 (METTL22) and 5'-nucleotidase cytosolic IA (NT5C1A) were recognized at a higher frequency in narcolepsy patients of both sample sets. Upon sequence analysis of the 14 proteins, polymerase family, member 3 (PARP3), acyl-CoA-binding domain containing 7 (ARID4B), glutaminase 2 (GLS2) and cyclin-dependent kinase-like 1 (CDKL1) were found to contain amino acid sequences with homology to proteins found in the H1N1 vaccine. These findings could become useful elements of further clinical assays that aim towards a better phenotypic understanding of narcolepsy and its triggers.
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| 5. |
- Lima Bomfim, Izaura
(author)
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Investigation of genetic factors in multiple sclerosis
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Multiple sclerosis (MS) is a chronic disease where the transmission of signals in the central nervous system is affected leading to a broad range of symptoms. The aetiology of the disease is unknown but multiple genetic and environmental factors are believed to play a part. While no environmental factor has been unequivocally established a lot has happened with regard to our knowledge of the genetic component of MS. Besides the consistent replication of associations with the HLA Class II region, association analyses have disclosed several genes of interest in MS including IL7R, IL2RA, CLEC16A, CD58 and RPL5. The HLA association shows the strongest effect on risk for MS, odds ratio for the other genes are in the range 1.1 1.4. It is not known how many genes that are implicated in MS pathogenesis, an estimation is that there will be 20-100 genes, thus there remain genetic variants yet uncovered. The main aim of this thesis was to identify genetic variants that affect susceptibility to MS. Such knowledge could aid in the development of better therapies whilst current therapy highlights potential candidate genes to be studied for association with disease. We investigated eight genes for association with susceptibility to MS - in total 113 genetic markers were evaluated using a case-control candidate gene association approach. Over 4,700 patients and approximately 5,000 controls contributed to this research where single nucleotide polymorphisms (SNPs) in the following genes were studied: ITGA4, the gene coding for the target of the MS-drug Tysabri®; IL23R, a gene associated with the autoimmune disease inflammatory bowel disease (IBD); TRAF1/C5, a region reported to be associated with the autoimmune disease rheumatoid arthritis (RA); NGFR, RTN4R, LINGO1, TNFRSF19, four genes which codes for the Nogo receptor complex, a potential therapeutical target, and IRF5, a gene associated with other autoimmune diseases including systemic lupus erythematosus (SLE) and RA. We found two SNPs (rs4728142 and rs3807306) and one insertion/deletion polymorphism (CGGGG) located in the promoter and first intron of IRF5 to be associated with MS susceptibility (OR=1.1 for all three markers, P=10-5 for the two SNPs and P=10-4 for CGGGG) based on a combined analysis of association results from a Spanish, a Finnish and a Scandinavian cohort. 9,125 individuals contributed to the finding including 3,847 patients, 3,745 controls and 511 trio families (one patient and both parents). Furthermore, one SNP (rs741072) located in exon 6 of NGFR was found to be associated with risk of MS (OR=1.16, P=0.001) based on a dataset consisting of 2,108 patients and 1,871 controls of Scandinavian ancestry. Further studies are needed to verify the role of IRF5 and NGFR in the pathogenesis of MS.
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| 6. |
- Lind, Alexander, et al.
(author)
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A/H1N1 antibodies and TRIB2 autoantibodies in narcolepsy patients diagnosed in conjunction with the Pandemrix vaccination campaign in Sweden 2009-2010.
- 2014
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In: Journal of Autoimmunity. - : Elsevier BV. - 0896-8411 .- 1095-9157. ; 50:Jan 28, s. 99-106
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Journal article (peer-reviewed)abstract
- Narcolepsy is a lifelong sleep disorder related to hypocretin deficiency resulting from a specific loss of hypocretin-producing neurons in the lateral hypothalamic area. The disease is thought to be autoimmune due to a strong association with HLA-DQB1*06:02. In 2009 the World Health Organization (WHO) declared the H1N1 2009 flu pandemic (A/H1N1PDM09). In response to this, the Swedish vaccination campaign began in October of the same year, using the influenza vaccine Pandemrix(®). A few months later an excess of narcolepsy cases was observed. It is still unclear to what extent the vaccination campaign affected humoral autoimmunity associated with narcolepsy. We studied 47 patients with narcolepsy (6-69 years of age) and 80 healthy controls (3-61 years of age) selected after the Pandemrix vaccination campaign. The first aim was to determine antibodies against A/H1N1 and autoantibodies to Tribbles homolog 2 (TRIB2), a narcolepsy autoantigen candidate as well as to GAD65 and IA-2 as disease specificity controls. The second aim was to test if levels and frequencies of these antibodies and autoantibodies were associated with HLA-DQB1*06:02. In vitro transcribed and translated [(35)S]-methionine and -cysteine-labeled influenza A virus (A/California/04/2009/(H1N1)) segment 4 hemagglutinin was used to detect antibodies in a radiobinding assay. Autoantibodies to TRIB2, GAD65 and IA-2 were similarly detected in standard radiobinding assays. The narcolepsy patients had higher median levels of A/H1N1 antibodies than the controls (p = 0.006). A/H1N1 antibody levels were higher among the <13 years old (n = 12) compared to patients who were older than 30 years (n = 12, p = 0.014). Being HLA-DQB1*06:02 positive was associated with higher A/H1N1 antibody levels in both patients and controls (p = 0.026). Serum autoantibody levels to TRIB2 were low overall and high binders did not differ between patients and controls. We observed an association between levels of A/H1N1 antibodies and TRIB2 autoantibody levels particularly among the youngest narcolepsy patients (r = 0.819, p < 0.001). In conclusion, following the 2009 influenza pandemic vaccination, A/H1N1 antibody levels were associated with young age-at-onset narcolepsy patients positive for HLA-DQB1*06:02. The possibility that TRIB2 is an autoantigen in narcolepsy remains to be clarified. We could verify autoantibody responses against TRIB2 which needs to be determined in larger patient cohorts and control populations.
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| 7. |
- Lind, Alexander, et al.
(author)
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Antibody Affinity Against 2009 A/H1N1 Influenza and Pandemrix Vaccine Nucleoproteins Differs Between Childhood Narcolepsy Patients and Controls
- 2017
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In: Viral immunology. - : Mary Ann Liebert Inc. - 0882-8245 .- 1557-8976. ; 30:8, s. 590-600
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Journal article (peer-reviewed)abstract
- Increased narcolepsy incidence was observed in Sweden following the 2009 influenza vaccination with Pandemrix((R)). A substitution of the 2009 nucleoprotein for the 1934 variant has been implicated in narcolepsy development. The aims were to determine (a) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (NP-CA2009) and Pandemrix-[A/Puerto Rico/8/1934(H1N1)] (NP-PR1934) nucleoproteins in 43 patients and 64 age-matched controls; (b) antibody affinity in reciprocal competitive assays in 11 childhood narcolepsy patients compared with 21 age-matched controls; and (c) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (H1N1 NS1), not a component of the Pandemrix vaccine. In vitro transcribed and translated S-35-methionine-labeled H1N1 influenza A virus proteins were used in radiobinding reciprocal competition assays to estimate antibody levels and affinity (Kd). Childhood patients had higher NP-CA2009 (p=0.0339) and NP-PR1934 (p=0.0246) antibody levels compared with age-matched controls. These childhood controls had lower NP-CA2009 (p=0.0221) and NP-PR1934 (p=0.00619) antibodies compared with controls 13 years or older. In contrast, in patients 13 years or older, the levels of NP-PR1934 (p=0.279) and NP-CA2009 (p=0.0644) antibodies did not differ from the older controls. Childhood antibody affinity (Kd) against NP-CA2009 was comparable between controls (68ng/mL) and patients (74ng/mL; p=0.21) with NP-CA2009 and NP-PR1934 displacement (controls: 165ng/mL; patients: 199ng/mL; p=0.48). In contrast, antibody affinity against NP-PR1934 was higher in controls with either NP-PR1934 (controls: 9ng/mL; patients: 20ng/mL; p=0.0031) or NP-CA2009 (controls: 14ng/mL; patients: 23ng/mL; p=0.0048). A/H1N1-NS1 antibodies were detected in 0/43 of the narcolepsy patients compared with 3/64 (4.7%) controls (p=0.272). Similarly, none (0/11) of the childhood patients and 1/21 (4.8%) of the childhood controls had A/H1N1-NS1 antibodies. The higher antibody affinities against NP-PR1934 in controls suggest better protection against wild-type virus. In contrast, the reduced NP-PR1934 antibody affinities among childhood narcolepsy patients suggest poor protection from the wild-type A/H1N1 virus and possibly increased risk for viral damage.
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| 8. |
- Sawcer, Stephen, et al.
(author)
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Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis
- 2011
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 476:7359, s. 214-219
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Journal article (peer-reviewed)abstract
- Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.
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| 9. |
- Tengvall, Katarina, 1980-, et al.
(author)
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Molecular mimicry between Anoctamin 2 and Epstein-Barr virus nuclear antigen 1 associates with multiple sclerosis risk
- 2019
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In: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 116:34, s. 16955-16960
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Journal article (peer-reviewed)abstract
- Multiple sclerosis (MS) is a chronic inflammatory, likely autoimmune disease of the central nervous system with a combination of genetic and environmental risk factors, among which Epstein-Barr virus (EBV) infection is a strong suspect. We have previously identified increased autoantibody levels toward the chloride-channel protein Anoctamin 2 (ANO2) in MS. Here, IgG antibody reactivity toward ANO2 and EBV nuclear antigen 1 (EBNA1) was measured using bead-based multiplex serology in plasma samples from 8,746 MS cases and 7,228 controls. We detected increased anti-ANO2 antibody levels in MS (P = 3.5 x 10(-36)) with 14.6% of cases and 7.8% of controls being ANO2 seropositive (odds ratio [OR] = 1.6; 95% confidence intervals [95% CI]: 1.5 to 1.8). The MS risk increase in ANO2-seropositive individuals was dramatic when also exposed to 3 known risk factors for MS: HLA-DRB1*15: 01 carriage, absence of HLA-A*02: 01, and high anti-EBNA1 antibody levels (OR = 24.9; 95% CI: 17.9 to 34.8). Reciprocal blocking experiments with ANO2 and EBNA1 peptides demonstrated antibody cross-reactivity, mapping to ANO2 [aa 140 to 149] and EBNA1 [aa 431 to 440]. HLA gene region was associated with anti-ANO2 antibody levels and HLADRB1*04: 01 haplotype was negatively associated with ANO2 seropositivity (OR = 0.6; 95% CI: 0.5 to 0.7). Anti-ANO2 antibody levels were not increased in patients from 3 other inflammatory disease cohorts. The HLA influence and the fact that specific IgG production usually needs T cell help provides indirect evidence for a T cell ANO2 autoreactivity in MS. We propose a hypothesis where immune reactivity toward EBNA1 through molecular mimicry with ANO2 contributes to the etiopathogenesis of MS.
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