| 1. |
- Kess, Daniel, et al.
(författare)
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Identification of susceptibility loci for skin disease in a murine psoriasis model
- 2006
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Ingår i: Journal of Immunology. - 1550-6606. ; 177:7, s. 4612-4619
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Tidskriftsartikel (refereegranskat)abstract
- Psoriasis is a frequently occurring inflammatory skin disease characterized by thickened erythematous skin that is covered with silvery scales. It is a complex genetic disease with both heritable and environmental factors contributing to onset and severity. The CD18 hypomorphic PL/J mouse reveals reduced expression of the common chain of beta(2) integrins (CD11/CD18) and spontaneously develops a skin disease that closely resembles human psoriasis. In contrast, CD18 hypomorphic C57BL/6J mice do not demonstrate this phenotype. In this study, we have performed a genome-wide scan to identify loci involved in psoriasiform dermatitis under the condition of low CD18 expression. Backcross analysis of a segregating cross between susceptible CD18 hypomorphic PL/J mice and the resistant CD18 hypomorphic C57BL/6J strain was performed. A genome-wide linkage analysis of 94 phenotypically extreme mice of the backcross was undertaken. Thereafter, a complementary analysis of the regions of interest from the genome-wide screen was done using higher marker density and further mice. We found two loci on chromosome 10 that were significantly linked to the disease and interacted in an additive fashion in its development. In addition, a locus on chromosome 6 that promoted earlier onset of the disease was identified in the most severely affected mice. For the first time, we have identified genetic regions associated with psoriasis in a mouse model resembling human psoriasis. The identification of gene regions associated with psoriasis in this mouse model might contribute to the understanding of genetic causes of psoriasis in patients and pathological mechanisms involved in development of disease.
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| 2. |
- Lindqvist, Anna-Karin, et al.
(författare)
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Backcross and partial advanced intercross analysis of nonobese diabetic gene-mediated effects on collagen-induced arthritis reveals an interactive effect by two major loci.
- 2006
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Ingår i: Journal of Immunology. - Rockville, MD : American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 177:6, s. 3952-3959
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Tidskriftsartikel (refereegranskat)abstract
- Genetic segregation analysis between NOD and C57BL strains have been used to identify loci associated with autoimmune disease. Only two loci (Cia2 and Cia9) had earlier been found to control development of arthritis, whereas none of the previously identified diabetes loci was of significance for arthritis. We have now made a high-powered analysis of a backcross of NOD genes on to the B10.Q strain for association with collagen-induced arthritis. We could confirm relevance of both Cia2 and Cia9 as well as the interaction between them, but we did not identify any other significant arthritis loci. Immune cellular subtyping revealed that Cia2 was also associated with the number of blood macrophages. Congenic strains of the Cia2 and Cia9 loci on the B10.Q background were made and used to establish a partial advanced intercross (PAI). Testing the PAI mice for development of collagen-induced arthritis confirmed the loci and the interactions and also indicated that at least two genes contribute to the Cia9 locus. Furthermore, it clearly showed that Cia2 is dominant protective but that the protection is not complete. Because these results may indicate that the Cia2 effect on arthritis is not only due to the deficiency of the complement C5, we analyzed complement functions in the Cia2 congenics as well as the PAI mice. These data show that not only arthritis but also C5-dependent complement activity is dominantly suppressed, confirming that C5 is one of the major genes explaining the Cia2 effect.
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| 3. |
- Wang, Honglin, et al.
(författare)
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A 9-centimorgan interval of chromosome 10 controls the T cell-dependent psoriasiform skin disease and arthritis in a murine psoriasis model
- 2008
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Ingår i: Journal of Immunology. - 1550-6606. ; 180:8, s. 5520-5529
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Tidskriftsartikel (refereegranskat)abstract
- Psoriasis is a complex genetic disease of unresolved pathogenesis with both heritable and environmental factors contributing to onset and severity. In addition to a disfiguring skin inflammation, approximately 10-40% of psoriasis patients suffer from destructive joint involvement. Previously, we reported that the CD18 hypomorphic PL/J mouse carrying a mutation resulting in reduced expression of the common chain of beta(2) integrins (CD11/CD18) spontaneously develops a skin disease that closely resembles human psoriasis. In contrast, the same mutation on C57BL/6J background did not demonstrate this phenotype. By a genome-wide linkage analysis, two major loci were identified as contributing to the development of psoriasiform dermatitis under the condition of low CD18 expression. Using a congenic approach, we now demonstrate that the introduction of a 9-centimorgan fragment of chromosome 10 derived from the PL/J strain into the disease-resistant CD18 hypomorphic C57BL/6J was promoting the development of psoriasiform skin disease and notably also arthritis. We therefore designated this locus psoriasiform skin disease-associated locus 1 (PSD1). High numbers of CD4(+) T cells and TNF-alpha producing macrophages were detected both in inflamed skin and joints in these congenic mice, with a complete resolution upon TNF-alpha inhibitor therapy or depletion of CD4(+) T cells. For the first time, we have identified a distinct genetic element that contributes to the T cell-dependent development of both psoriasiform skin disease and associated arthritis. This congenic model will be suitable to further investigations of genetic and molecular pathways that cause psoriasiform dermatitis and arthritis, and it may also be relevant for other autoimmune diseases.
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| 4. |
- Hjelmervik, Trond Ove R., et al.
(författare)
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The influence of the NOD Nss1/Idd5 loci on sialadenitis and gene expression in salivary glands of congenic mice
- 2007
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Ingår i: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- The nonobese diabetic ( NOD) Nss1 and Idd5 loci have been associated with sialadenitis development in mice. In this study the NOD Nss1 and Idd5 loci were backcrossed onto the healthy control strain B10. Q by using the speed congenic breeding strategy, resulting in three congenic strains: B10. Q. Nss1, B10. Q. Nss1/Idd5 heterozygous and B10. Q. Nss1/Idd5 homozygous. We investigated the effects of the Nss1 and Idd5 loci on sialadenitis and gene expression in NOD congenic mice. One submandibular salivary gland from each mouse was used for histological analysis of sialadenitis, whereas the contralateral salivary gland was used for gene expression profiling with the Applied Biosystems Mouse Genome Survey chip v. 1.0. The results were validated using quantitative reverse transcriptase PCR. The NOD Nss1 and Idd5 loci had clear influence on the onset and progression of sialadenitis in congenic mice. Double congenic mice exhibited the most severe phenotype. We successfully identified several genes that are located in the NOD congenic regions to be differentially expressed between the congenic strains and the control strain. Several of these were found to be co-regulated, such as Stat1, complement component C1q genes and Tlr12. Also, a vast contingency of interferon-regulated genes ( such as Ltb, Irf7 and Irf8) and cytokine and chemokine genes ( such as Ccr7 and Ccl19) were differentially expressed between the congenic strains and the control strain. Over-representation of inflammatory signalling pathways was observed among the differentially expressed genes. We have found that the introgression of the NOD loci Nss1 and Idd5 on a healthy background caused sialadenitis in NOD congenic mouse strains, and we propose that genes within these loci are important factors in the pathogenesis. Furthermore, gene expression profiling has revealed several differentially expressed genes within and outside the NOD loci that are similar to genes found to be differentially expressed in patients with Sjogren's syndrome, and as such are interesting candidates for investigation to enhance our understanding of disease mechanisms and to develop future therapies.
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| 5. |
- Johannesson, Martina, et al.
(författare)
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Gene expression profiling of arthritis using a QTL chip reveals a complex gene regulation of the Cia5 region in mice.
- 2005
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1476-5470 .- 1466-4879. ; 6:7, s. 575-583
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Tidskriftsartikel (refereegranskat)abstract
- One of the major quantitative trait loci (QTLs) associated with arthritis in crosses between B10.RIII and RIIIS/J mice is the Cia5 on chromosome 3. Early in the congenic mapping process it was clear that the locus was complex, consisting of several subloci with small effects. Therefore, we developed two novel strategies to dissect a QTL: the partial advanced intercross (PAI) strategy, with which we recently found the Cia5 region to consist of three loci, Cia5, Cia21 and Cia22, and now we introduce the QTL-chip strategy, where we have combined congenic mapping with a QTL-restricted expression profiling using a novel microarray design. The expression of QTL genes was compared between parental and congenic mice in lymph node, spleen and paw samples in five biological replicates and in dye-swapped experiments at three time points during the induction phase of arthritis. The QTL chip approach revealed 4 genes located in Cia21, differently expressed in lymph nodes, and 14 genes in Cia22, located within two clusters. One cluster contains six genes, differently expressed in spleen, and the second cluster contains eight genes, differently expressed in paws. We conclude the QTL-chip strategy to be valuable in the selection of candidate genes to be prioritized for further investigation.
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| 6. |
- Johannesson, Martina, et al.
(författare)
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Identification of epistasis through a partial advanced intercross reveals three arthritis loci within the Cia5 QTL in mice
- 2005
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Ingår i: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 6:3, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Identification of genes controlling complex diseases has proven to be difficult; however, animal models may pave the way to determine how low penetrant genes interact to promote disease development. We have dissected the Cia5/Eae3 susceptibility locus on mouse chromosome 3 previously identified to control disease in experimental models of multiple sclerosis and rheumatoid arthritis. Congenic strains showed significant but small effects on severity of both diseases. To improve the penetrance, we have now used a new strategy that defines the genetic interactions. The QTL interacted with another locus on chromosome 15 and a partial advanced intercross breeding of the two congenic strains for eight generations accumulated enough statistical power to identify interactions with several loci on chromosome 15. Thereby, three separate loci within the original QTL could be identified; Cia5 affected the onset of arthritis by an additive interaction with Cia31 on chromosome 15, whereas the Cia21 and Cia22 affected severity during the chronic phase of the disease through an epistatic interaction with Cia32 on chromosome 15. The definition of genetic interactions was a prerequisite to dissect the Cia5 QTL and we suggest the partial advanced intercross strategy to be helpful also for dissecting other QTL controlling complex phenotypes.
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| 7. |
- Kidd-Ljunggren, Karin, et al.
(författare)
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High levels of hepatitis B virus DNA in body fluids from chronic carriers.
- 2006
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Ingår i: Journal of Hospital Infection. - : Elsevier BV. - 0195-6701. ; 64:4, s. 352-357
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Tidskriftsartikel (refereegranskat)abstract
- infection with hepatitis B virus (HBV) is a major global health problem. Transmission is mainly blood-borne, although the route of infection during horizontal transmission in childhood is unclear. Nosocomial outbreaks of HBV have been widely reported, but have mainly focused on blood-borne transmission. There is Limited knowledge of the viral Load Levels in other body fluids. In the present study, chronic HBV carriers were tested for the presence of HBV DNA in serum, saliva, nasopharyngeal fluid, urine and tears by means of qualitative and quantitative polymerase chain reaction (PCR) methods. Twenty-five patients who were positive for HBV DNA with both PCRs were included. Low titres in real-time PCR corresponded with weak bands in the qualitative assay. HBV DNA was found in two urine samples, 10 saliva samples, five nasopharyngeal, swabs and in tear fluid from four patients. One highly viraemic HBeAg-positive carrier with serum HBV DNA Levels of 7 x 10(9) genome copies had high copy numbers detected in both saliva and nasopharyngeal fluid. These results demonstrate that highly viraemic HBV carriers may have high titres of HBV DNA in other body fluids. This has particular importance for infection control programmes and regulations, underlining the importance of aiming towards regular HBV DNA testing and thus infectivity assessment of chronic carriers in order to prevent transmission. (c) 2006 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.
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| 8. |
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| 9. |
- Lindqvist, Anna-Karin, et al.
(författare)
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Influence on spontaneous tissue inflammation by the major histocompatibility complex region in the nonobese diabetic mouse.
- 2005
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Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 61:2, s. 119-127
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the role of the major histocompatibility complex (MHC) region in the specificity of autoimmunity by analysing specifically the development of sialadenitis, but also insulitis, nephritis and autoantibody production in autoimmune-prone nonobese diabetic (NOD) mice where the MHC H2g7 haplotype had been exchanged for the H2q (NOD.Q) or H2p (NOD.P) haplotype. The exchange of H2 haplotype did not affect the frequency of sialadenitis because the H2q and H2p congenic NOD strains developed sialadenitis with the same incidence as NOD. However, the severity of sialadenitis varied among the strains, as NOD.Q > NOD > NOD.P. At 11–13 weeks of age, the NOD.Q (H2q) female mice developed more severe sialadenitis compared to NOD.P (H2p) (P = 0.038). At 20 weeks, the NOD (H2g7) female mice showed more severe sialadenitis than NOD.P (P = 0.049). This is in contrast to the development of insulitis in the present strains, because the incidence of insulitis was almost completely inhibited by the replacement of the H2g7 haplotype of NOD. The incidence of insulitis in NOD.Q was 11–22%, compared to 75% in NOD, which correlated well with lower titres of anti-glutamic acid decarboxylase (anti-GAD) antibodies in NOD.Q compared to NOD (P = 0.009). However, the introduction of the H2q haplotype into the NOD strain instead directed the autoimmune response towards the production of lupus types of autoantibodies, because the incidence of antinuclear antibodies (ANA) in NOD.Q was 89% compared with 11% in NOD.P and 12% in NOD mice, which in turn correlated with a high incidence of nephritis in NOD.Q compared to NOD. Consequently, we show that different haplotypes of MHC are instrumental in directing the specificity of the spontaneous autoimmune inflammation. This article is cited by:
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| 10. |
- Lindqvist Appell, Malin, 1976-, et al.
(författare)
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Explaining TPMT genotype/phenotype discrepancy by haplotyping of TPMT*3A and identification of a novel sequence variant, TPMT*23
- 2007
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Ingår i: Pharmacogenetics and Genomics. - 1744-6872. ; 17:10, s. 891-895
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Tidskriftsartikel (refereegranskat)abstract
- Thiopurine methyltransferase (TPMT) is a polymorphic enzyme involved in the metabolism of thiopurine drugs. Owing to polymorphisms in the TPMT gene (TPMT*2-*22), the enzyme activity varies interindividually. Patients with reduced TPMT activity may develop adverse reactions when treated with standard doses of thiopurines. This work focuses on a TPMT genotype/phenotype discrepancy found in a patient during routine testing. The patient displayed very low TPMT enzyme activity and she was genotyped by pyrosequencing as being heterozygous for the 460G>A and 719A>G polymorphisms (TPMT*3A). Complete sequencing in combination with haplotyping of the TPMT gene revealed a novel sequence variant, 500C>G, on one allele and TPMT*3A on the other allele, giving rise to the novel genotype TPMT*3A/*23. When investigating the patient's relatives, they too had the TPMT*3A/*23 genotype in combination with low enzyme activity. We conclude that this novel variant allele affects enzyme activity, as the individuals carrying it had almost undetectable TPMT activity. © 2007 Lippincott Williams & Wilkins, Inc.
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