Recent genetic evidence points towards endogenous retroviruses as playing a pivotal role in the causation of multiple sclerosis and possibly other autoimmune diseases. We discuss various ways in which this association could be brought about. Specifically, we suggest that two endogenous retroviruses, HERV-Fc1 and HERV-K13, on chromosomes X and 19, respectively, contribute to the development of autoimmune T cells by transforming them in multiple sclerosis.
View Article and Find Full Text PDFAnti-tumour necrosis factor-α (TNF-α) is used for treatment of severe cases of inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). However, one-third of the patients do not respond to the treatment. A recent study indicated that genetically determined high activity of pro-inflammatory cytokines, including interleukin-1β (IL-1β), IL-6 and interferon gamma (IFN-γ), are associated with non-response to anti-TNF therapy.
View Article and Find Full Text PDFRetroviruses can be transmitted in two fundamentally different ways: 1) They can be horizontally transmitted as infectious virus, or 2) they can integrate in the germ line and be transmitted to offspring and the offsprings' offspring as DNA. The latter is called endogenous viruses. The mode of transmission is called vertical.
View Article and Find Full Text PDFBackground: Two endogenous retroviral loci seem to be involved in the human disease Multiple sclerosis (MS).
Results: The two retroviral loci synergize in and contribute to MS (shown by ANOVA). Synergy probably means recombination or complementation of the activated viruses.
Multiple myeloma (MM) is a severe, incurable neoplasm of the plasma cells. In this study we have used genetic epidemiology to associate the risk of MM with endogenous retroviral loci in humans. We used SNP analysis on a Sequenom platform and statistical analysis in SPSS.
View Article and Find Full Text PDFAutoimmune diseases encompass a plethora of conditions in which the immune system attacks its own tissue, identifying them as foreign. Multiple factors are thought to contribute to the development of immune response to self, including differences in genotypes, hormonal milieu, and environmental factors. Viruses including human endogenous retroviruses have long been linked to the occurrence of autoimmunity, but never proven to be causative factors.
View Article and Find Full Text PDFIn an ongoing screen for DNA sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conduct a genome-wide association study (GWAS) of 24,988,228 SNPs and small indels detected through whole-genome sequencing of 2,636 Icelanders and imputed into 4,572 BCC patients and 266,358 controls. Here we show the discovery of four new BCC susceptibility loci: 2p24 MYCN (rs57244888[C], OR=0.76, P=4.
View Article and Find Full Text PDFIntroduction: The objective of this study was to evaluate the outcome of anti-tumour necrosis factor-α (anti-TNF) treatment in a large cohort of patients with inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) in clinical practice and to establish a cohort for future studies of genetic markers associated with treatment response.
Methods: A national, clinically based cohort of previously naïve anti-TNF treated patients from 18 medical departments was established. The patients were screened for tuberculosis prior to treatment initiation.
Background: Little is known about how the genetic variation in vitamin D modulating genes influences ultraviolet (UV)B-induced 25-hydroxyvitamin D [25(OH)D] concentrations. In the Food with vitamin D (VitmaD) study, we showed that common genetic variants rs10741657 and rs10766197 in 25-hydroxylase (CYP2R1) and rs842999 and rs4588 in vitamin D binding protein (GC) predict 25(OH)D concentrations at late summer and after 6-mo consumption of cholecalciferol (vitamin D₃)-fortified bread and milk.
Objectives: In the current study, called the Vitamin D in genes (VitDgen) study, we analyzed associations between the increase in 25(OH)D concentrations after a given dose of artificial UVB irradiation and 25 single nucleotide polymorphisms located in or near genes involved in vitamin D synthesis, transport, activation, or degradation as previously described for the VitmaD study.
Background: It has been suggested that polymorphisms in Toll-like Receptors (TLRs) are associated with Rheumatoid Arthritis (RA), but the implicated alleles have differed between studies. The aim of this investigation was to explore whether polymorphisms of TLR genes are associated with RA in a predominantly Caucasian population from Denmark using a case-control approach.
Findings: DNA samples (3 university hospital outpatient clinics) were obtained from patients with RA (n = 704) and healthy controls (n = 639) in a Danish population.
Common genetic variants rs10741657 and rs10766197 in CYP2R1 and rs4588 and rs842999 in GC and a combined genetic risk score (GRS) of these four variants influence late summer 25-hydroxyvitamin D (25(OH)D) concentrations. The objectives were to identify those who are most at risk of developing low vitamin D status during winter and to assess whether vitamin D3-fortified bread and milk will increase 25(OH)D concentrations in those with genetically determined low 25(OH)D concentrations at late summer. We used data from the VitmaD study.
View Article and Find Full Text PDFAntitumor necrosis factor-α (TNF-α) is used for treatment of severe cases of inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). However, one-third of the patients do not respond to the treatment. Genetic markers may predict individual response to anti-TNF therapy.
View Article and Find Full Text PDFTo search for new sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conducted a genome-wide association study of 38.5 million single nucleotide polymorphisms (SNPs) and small indels identified through whole-genome sequencing of 2230 Icelanders. We imputed genotypes for 4208 BCC patients and 109 408 controls using Illumina SNP chip typing data, carried out association tests and replicated the findings in independent population samples.
View Article and Find Full Text PDFWe recently described that the autoimmune, central nervous system disease, multiple sclerosis (MS), is genetically associated with the human endogenous retroviral locus, HERV-Fc1, in Scandinavians. A number of dominant human genes encoding factors that restrict retrovirus replication have been known for a long time. Today human restriction genes for retroviruses include amongst others TRIMs, APOBEC3s, BST2 and TREXs.
View Article and Find Full Text PDFObjectives: Toll-like receptors (TLRs) are pattern-associated receptors in innate immunity that may be involved in the recognition of self-antigens and the production of pathogenic autoantibodies. This study was undertaken to examine whether polymorphisms of TLR genes are associated with SLE and to determine the expression of various TLRs in peripheral blood mononuclear cells (PBMCs) of patients with SLE.
Methods: The TLR polymorphisms in a cohort of 143 Danish lupus patients and 432 healthy Danish blood donors were analysed.
The possibility that retroviruses play a role in multiple sclerosis (MS) has long been considered; accumulating findings suggest this to be most likely in the form of human endogenous retroviruses (HERVs). A genetic test series of fifty endogenous retroviral loci for association with MS in Danes showed SNP markers near a specific endogenous retroviral locus, HERV-Fc1 located on the X-chromosome, to be positive. Bout Onset MS was associated with the HERV-Fc1 locus, while a rarer form, Primary Progressive MS, was not.
View Article and Find Full Text PDFBackground: The recovery of biological samples for genetic epidemiological studies can be cumbersome. Blood clots are routinely collected for serological examinations. However, the extraction of DNA from blood clots can be difficult and often results in low yields.
View Article and Find Full Text PDFDNA methylation and histone acetylation are epigenetic modifications that act as regulators of gene expression. DNA methylation is considered an important mechanism for silencing of retroelements in the mammalian genome. However, the methylation of human endogenous retroviruses (HERVs) is not well investigated.
View Article and Find Full Text PDFBackground: Human endogenous retroviruses (HERVs) are suspected to play a role in the development of multiple sclerosis (MS). This suspicion has in part been based on increased expression of viral RNA or proteins or antibodies targeting retroviral products in MS patients. Recently, our group provided genetic evidence for association between the endogenous retrovirus HERV-Fc1 and MS, suggesting that HERV-Fc1 plays a role in this multifactorial disease.
View Article and Find Full Text PDFMultiple sclerosis (MS) is considered to be an autoimmune disease with an unknown cause and with immune system dysregulation. Among environmental factors, viruses are most often connected with the etiology of MS. Human endogenous retroviruses (HERVs) constitute 5 to 8% of human genomic DNA and have been detected as transcripts and proteins in the central nervous system (CNS) and peripheral blood, frequently in the context of neuroinflammation.
View Article and Find Full Text PDFWe have previously described the occurrence of multiple sclerosis (MS) to be associated with human endogenous retroviruses, specifically the X-linked viral locus HERV-Fc1. The aim of this study was to investigate a possible association of the HERV-Fc1 locus with subtypes of MS. MS patients are generally subdivided into three categories: Remitting/Relapsing and Secondary Progressive, which together constitute Bout Onset MS, and Primary Progressive.
View Article and Find Full Text PDFTo identify new risk variants for cutaneous basal cell carcinoma, we performed a genome-wide association study of 16 million SNPs identified through whole-genome sequencing of 457 Icelanders. We imputed genotypes for 41,675 Illumina SNP chip-typed Icelanders and their relatives. In the discovery phase, the strongest signal came from rs78378222[C] (odds ratio (OR) = 2.
View Article and Find Full Text PDFLittle is known on the impact of polymorphisms in the IL1B gene on outcome in multiple myeloma. In a population-based study of 348 Danish myeloma patients treated with high-dose treatment (HDT), 146 patients treated with INF-α maintenance treatment, and in 243 patients with relapse, we analysed the impact on outcome of HDT, INF-α maintenance treatment, and treatment with thalidomide and bortezomib at relapse, in relation to the major identified functional polymorphisms in the promoter region of IL1B. The wild-type C-allele of IL1B C-3737T and non-carriage of the IL1B promoter haplotype TGT (-3737(T), -1464(G) and -31(T)), giving high IL1B promoter activity, were associated with longer time-to-treatment failure (TTF) (HR, 1.
View Article and Find Full Text PDFWe have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease.
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