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Asa Andersson

Publications and source records attributed to Asa Andersson.

11 recordsLinked to original sources
PubMed2006

Identification of genetic regions of importance for reproductive performance in female mice.

Both environmental and genetic factors can dramatically affect reproductive performance in mice. In this study we have focused on the identification of genetic regions, quantitative trait loci (QTL), which affect the breeding capacity of female mice. We have identified polymorphic microsatellite markers for the mouse strains used and performed a genomewide scan on 237 females from a gene-segregating backcross between a high breeder and a relatively poor breeder. The high-breeder mouse strain we used is the inbred NFR/N mouse (MHC haplotype H-2q), which has extraordinary good breeding properties. The moderate breeder chosen for F(1) and N2 progeny was B10.Q, which is a genetically well-characterized MHC-congenic mouse of the H-2q haplotype. Each of the 237 females of the N2 generation was allowed to mate twice with MHC-congenic B10.RIII (H-2r) males and twice with B10.Q males. A predetermined number of phenotypes related to reproductive performance were recorded, and these included litter size, neonatal growth, and pregnancy rate. Loci controlling litter size were detected on chromosomes 1 (Fecq3) and 9 (Fecq4). The neonatal growth phenotype was affected by Fecq3 and a locus on chromosome 9 (Neogq1). On chromosome 11 two loci affecting the pregnancy rate (Pregq1 and Pregq2) were identified. Furthermore, on chromosomes 13 and 17 we found loci (Pregq3 and Pregq4) influencing the outcome of allogeneic pregnancy (allogeneic by means of MHC disparity between mother and fetuses). A locus on chromosome 1 affecting maternal body weight was also identified and has been denoted Bwq7. It is well known that reproductive performance is polygenically controlled, and the identification of the major loci in this complex process opens the possibility of investigating the natural genetic control of reproduction.

Animals↗
PubMed2006

Identification of collagen-induced arthritis loci in aged multiparous female mice.

Collagen-induced arthritis in mice is one of the most commonly used autoimmune experimental models, with many similarities to rheumatoid arthritis. Since collagen-induced arthritis is a complex polygenic disease there is a need for identification of several major disease-controlling genes. Because rheumatoid arthritis particularly affects aged women, we have in the present study identified new genetic regions critical for collagen-induced arthritis by studying aged female mice of a cross between NFR/N and B10.Q (H-2q haplotype). The mice in the present study had different reproductive histories, which did not significantly affect the onset, incidence or severity of the disease. A total of 200 female mice were used in a total genome-wide screening with 125 microsatellite markers. We found one new significant quantitative trait locus affecting the arthritis incidence, severity and day of onset on chromosome 11 (denoted Cia40), which colocalizes with a locus controlling pregnancy failure. Furthermore, a quantitative trait locus of suggestive significance associated with the incidence, severity and day of onset was identified on chromosome 1. Finally, a suggestively significant quantitative trait locus associated with collagen type II antibody titers was identified on chromosome 13. This study indicates that several gene loci control arthritis in aged multiparous females, and that at least one of these loci coincides with pregnancy failure.

Age of Onset↗
PubMed2005

Genetic interactions in Eae2 control collagen-induced arthritis and the CD4+/CD8+ T cell ratio.

The Eae2 locus on mouse chromosome 15 controls the development of experimental autoimmune encephalomyelitis (EAE); however, in this study we show that it also controls collagen-induced arthritis (CIA). To find the smallest disease-controlling locus/loci within Eae2, we have studied development of CIA in 676 mice from a partially advanced intercross. Eae2 congenic mice were bred with mice congenic for the Eae3/Cia5 locus on chromosome 3, previously shown to interact with Eae2. To create a large number of genetic recombinations within the congenic fragments, the offspring were intercrossed, and the eight subsequent generations were analyzed for CIA. We found that Eae2 consists of four Cia subloci (Cia26, Cia30, Cia31, and Cia32), of which two interacted with each other, conferring severe CIA. Genes within the other two loci independently interacted with genes in Eae3/Cia5. Investigation of the CD4/CD8 T cell ratio in mice from the partially advanced intercross shows that this trait is linked to one of the Eae2 subloci through interactions with Eae3/Cia5. Furthermore, the expression of CD86 on stimulated macrophages is linked to Eae2.

Animals↗
PubMed2005

A genetic basis for shared autoimmunity in mouse models.

Development of autoimmune disease is the result of activation of the immune system that subsequently leads to tissue destruction. Although the clinical outcome significantly differs between autoimmune diseases, some pathogenic pathways could be shared. During the recent years, intense efforts to find the genetic factors behind development of the complex and polygenic autoimmune diseases have been undertaken. The difficulties in addressing what genetic factors predispose for autoimmunity in humans underline the importance of animal models in the understanding of the general mechanisms behind the initiation of disease. Interestingly, it has been observed in studies of experimental models of autoimmune diseases, that many of the genetic linkages to disease development are located in the same genetic regions and potentially could be controlled by the same gene. Furthermore, comparison of the mouse/rat genetic regions with regions of association to human inflammatory diseases, also demonstrates some homologous loci between species. Some mouse strains can develop disease in more than one model for autoimmunity. This not only argues for some general mechanisms, but it also supports mechanisms related to the specific tissues attacked in the various autoimmune diseases. Here, we will discuss some aspects of shared autoimmunity in mouse models from a genetic point of view.

Animals↗
PubMed2005

Natural killer T-cell populations in C57BL/6 and NK1.1 congenic BALB.NK mice-a novel thymic subset defined in BALB.NK mice.

Natural killer (NK) T lymphocytes are a subpopulation of T lymphocytes regarded as early regulators of immune responses. The majority of NKT cells are restricted by the CD1d molecule. NKT cells have mostly been studied in one single mouse strain, C57BL/6 (B6), because of the absence of NK1.1 in other common mouse strains, and the lack of other reliable surface markers for CD1d-restricted cells. To investigate NKT cell subsets in a mouse strain of a genetic background different from B6, we have back-crossed the NKT cell marker NK1.1 from the B6 mouse to the BALB/c mouse strain. We show that NKT cells in the congenic BALB.B6-NK1.1(b) mouse share many characteristics with their B6 counterparts, but seem to be deficient in the functional NKT cell subtype characterized by low interleukin-4 and high interferon-gamma production, and surface expression of CD49b but not CD69. Moreover, in the thymus but not the spleen of BALB.B6-NK1.1(b) mice we find a novel Valpha14-Jalpha18 invariant NKT cell subset which is devoid of a set of NK markers, suggesting that these cells represent a less differentiated NKT cell stage, and carries high levels of the T-cell receptor and uses a skewed T-cell receptor Vbeta-repertoire.

Animals↗
PubMed2005

Risk factors for coronary heart disease among immigrant women from Iran and Turkey, compared to women of Swedish ethnicity.

OBJECTIVES: The aim of the study was to compare a group of immigrant women from the Middle East living in Sweden to Swedish-born controls regarding the prevalence of certain cardiovascular risk factors. DESIGN: Health survey of randomly selected foreign-born women and women native in Sweden. SETTING: Uppsala, Sweden. SUBJECTS: A total of 107 immigrant women aged 35-64 years from the Middle East (Iran [N=71] and Turkey [N=36]) living in Uppsala and residents in Sweden for at least three years and a control group of ethnic Swedish women (N=50). MAIN OUTCOME MEASURES: A questionnaire and a clinical examination specially directed towards measuring cardiovascular risk factors and prevalence of obesity, diabetes mellitus, and hypertension. RESULTS: A less beneficial cardiovascular risk profile was found among immigrant women than among ethnic Swedish women. Turkish women had substantially higher body mass index (BMI), larger waist, higher waist/hip ratio and sagittal abdominal diameter, higher levels of serum triglycerides, and lower HDL cholesterol concentration compared with Swedish-born women. A similar tendency was seen also for Iranian women. CONCLUSION: The present study shows important ethnic differences in cardiovascular disease risk factor pattern. Immigrant women from Iran and Turkey are heavier than women born in Sweden and have a higher prevalence of abdominal obesity, an unfavorable lipid profile, and a high degree of physical inactivity during leisure time, which may predispose for a higher incidence of diabetes and atherosclerotic cardiovascular disease.

Adult↗
PubMed2004

Differential macrophage expression of IL-12 and IL-23 upon innate immune activation defines rat autoimmune susceptibility.

Rodents typically demonstrate strain-specific susceptibilities to induced autoimmune models such as experimental arthritis and encephalomyelitis. A common feature of the local pathology of these diseases is an extensive infiltration of activated macrophages (MPhi). Different functional activation states can be induced in MPhi during innate immune activation, and it is this differential activation that might be important in susceptibility/resistance to induction or perpetuation of autoimmunity. In this study, we present an extensive, comparative analysis of the activation phenotypes of MPhi derived from autoimmune-susceptible and autoimmune-resistant rat strains to describe a cellular phenotype that defines the disease phenotype. We included investigation of receptor function, intracellular signaling pathways, cytokines, and other soluble mediators released after activation of cells using a panel of stimuli embracing many activation routes. We report that activation of MPhi from the autoimmune-susceptible strain was associated with alternative activation indicated by induction of arginase activity, a lower production of classical proinflammatory mediators, and a high production of interleukin (IL)-23, and MPhi from the autoimmune-resistant strains were associated with a higher production of proinflammatory mediators, a classical activation phenotype, and preferential induction of IL-12. These MPhi phenotypes thus reflect disparate, genetic cellular programs that define autoimmune susceptibility.

Animals↗
PubMed2003

Novel quantitative trait loci controlling development of experimental autoimmune encephalomyelitis and proportion of lymphocyte subpopulations.

The B10.RIII mouse strain (H-2(r)) develops chronic experimental autoimmune encephalomyelitis (EAE) upon immunization with the myelin basic protein 89-101 peptide. EAE was induced and studied in a backcross between B10.RIII and the EAE-resistant RIIIS/J strain (H-2(r)), and a complete genome scan with microsatellite markers was performed. Five loci were significantly linked to different traits and clinical subtypes of EAE on chromosomes 1, 5, 11, 15, and 16, three of the loci having sex specificity. The quantitative trait locus on chromosome 15 partly overlapped with the Eae2 locus, previously identified in crosses between the B10.RIII and RIIIS/J mouse strains. The loci on chromosomes 11 and 16 overlapped with Eae loci identified in other mouse crosses. By analyzing the backcross animals for lymphocyte phenotypes, the proportion of B and T cells in addition to the levels of CD4(+)CD8(-) and CD4(-)CD8(+) T cells and the CD4(+)/CD8(+) ratio in spleen were linked to different loci on chromosomes 1, 2, 3, 5, 6, 11, and 15. On chromosome 16, we found significant linkage to spleen cell proliferation. Several linkages overlapped with the quantitative trait loci for disease phenotypes. The identification of subphenotypes that are linked to the same loci as disease traits could be most useful in the search for candidate genes and biological pathways involved in the pathological process.

Animals↗
PubMed2002

Identification of susceptibility genes for experimental autoimmune encephalomyelitis that overcome the effect of protective alleles at the eae2 locus.

We have previously identified a locus on mouse chromosome 15 (eae2) that regulates susceptibility to experimental autoimmune encephalomyelitis in a cross between the susceptible strain B10.RIII and the resistant strain RIIIS/J. In an effort to verify the protective effect from having two RIIIS/J alleles at eae2, the resistant locus was bred into the susceptible strain in homozygous form. However, the expected effect was not as clear as in the original study. This might be due to an epistatic effect conferred by several unidentified genes in the genome of the resistant strain or due to the environment by genotype interactions, possibly overcoming the effect of protective alleles at eae2. To further the genetic understanding in this disease, a genome-wide linkage screening approach was employed on an F(2) intercross that carried the protective allele at eae2in homozygous form while the rest of the genome segregated between the B10.RIII and RIIIS/J strains as in the original investigation. In the present study we find one region on chromosome 7, not previously identified in this strain combination, that affects the disease at significant logarithm of the odds score and six regions showing suggestive evidence for linkage to disease phenotypes.

Animals↗
PubMedDate not supplied

Genetics of experimental autoimmune encephalomyelitis in the mouse.

Multiple sclerosis (MS) is an inflammatory, demyelinating disease in the central nervous system (CNS) affecting approximately 0.1% of the population in the northern part of the world. The factors behind the initiation of the inflammatory response are not known at present, but MS is considered as a complex disease depending on genetic as well as environmental factors. Experimental autoimmune encephalomyelitis (EAE) is the prevailing experimental rodent model for multiple sclerosis (MS). Disease is induced in genetically susceptible mice or rats by immunization with myelin proteins or peptides, which leads to an infiltration of leukocytes into the CNS. EAE has been subjected to investigations of genetic susceptibility to disease development. By the identification of genes predisposing to EAE, the hope is to get clues as to what genetic elements are also important in MS. To date, more than 25 Eae loci have been described in the mouse. The quantitative trait loci are linked to different disease traits and several show sex specificity. Here we discuss the current state of the genetics controlling susceptibility to EAE.

Animals↗