Skip Navigation


Human Molecular Genetics Advance Access originally published online on July 8, 2003
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
12/17/2087    most recent
ddg224v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (9)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Ribbhammar, U.
Right arrow Articles by Lorentzen, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ribbhammar, U.
Right arrow Articles by Lorentzen, J. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Human Molecular Genetics, 2003, Vol. 12, No. 17 2087-2096
DOI: 10.1093/hmg/ddg224
© 2003 Oxford University Press

High resolution mapping of an arthritis susceptibility locus on rat chromosome 4, and characterization of regulated phenotypes

Ulrica Ribbhammar1, Line Flornes2,{dagger}, Liselotte Bäckdahl1,{dagger}, Holger Luthman3, Sigbjörn Fossum2 and Johnny C. Lorentzen1,*

1Department of Medicine, Rheumatology Unit, Karolinska Institutet, S-171 76 Stockholm, Sweden, 2Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, N-0317 Oslo, Norway and 3Department of Diabetes and Endocrinology, Lund University, S-205 02 Malmö, Sweden

Received March 3, 2003; Accepted July 2, 2003


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 RESULTS
 DISCUSSION
 MATERIALS AND METHODS
 REFERENCES
 
The rat Natural Killer cell gene Complex (NKC) encodes molecules that can regulate immunity. It is located within an interval on DA rat chromosome 4 (RNO4) that is linked to immune-mediated inflammatory joint diseases, including oil-induced arthritis (OIA). We aimed to test the hypothesis that NKC regulates arthritis, by performing advanced mapping of arthritis and additional phenotypes induced by an intradermal injection of incomplete Freund's adjuvant-oil. Reciprocal transfer of RNO4 intervals established that alleles from DA confer arthritis susceptibility to inbred LEW.1AV1 and PVG.1AV1 rats, whereas LEW.1AV1 and PVG.1AV1 alleles confer resistance to inbred DA. Subcongenic strains with PVG.1AV1 alleles introduced on DA allowed mapping of disease predisposition to 0.8 cM on the cytogenetic band 4q42, within the quantitative trait locus oil-induced arthritis-2 (Oia2), but outside the NKC. Alleles in Oia2 regulated arthritis in an additive fashion, and determined arthritis incidence, severity and day of onset, in both males and females. Besides macroscopic joint-inflammation, Oia2 also regulated other oil-induced phenotypes, including lymphoplasia and plasma levels of the inflammation marker {alpha}1-acid glycoprotein. The high-impact Oia2 region harbors gene sequences similar to human C3AR1, Ribosomal protein L7, DNAJA2, C-type lectins, C1s and CD163. These candidate disease genes may be of general interest, given that rat 4q42, and the syntenic mouse 6F2 and human 12p13 regions are linked to several inflammatory diseases, including rheumatoid arthritis.


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
RESULTS
 DISCUSSION
 MATERIALS AND METHODS
 REFERENCES
 
Rheumatoid arthritis (RA) is a chronic and destructive inflammatory joint disease, which affects approximately 1% of populations worldwide. Complex interactions between genetic and environmental factors are thought to contribute to arthritis development, as indicated by the concordance rates in monozygotic and dizygotic twins, which are 15 and 4%, respectively (1,2). Definition of the underlying genetic factors may enable development of strategies to prevent and cure RA, but so far, only major histocompatibility complex (MHC) genes have been conclusively linked to the disease, and have been estimated to account for ~30% of the genetic influence (3,4). The remaining genetic influences are believed to be exerted by several genes, which, in combination with the clinical heterogeneity of RA, is a major obstacle for genetic dissection of RA. Experimental arthritis provides opportunities to both control and manipulate genetic and environmental effects, in order to facilitate their identification and characterization. For example, poly-arthritis can be triggered in disease-prone rat strains by a wide range of non-immunogenic, but immunostimulating adjuvants (5,6), including oils (5,7). This incited a Swedish epidemiological survey, which now provides evidence that oil exposure increases the relative risk for RA (8). In order to genetically dissect models that display the pathological effects of oil exposure, we initiated a search for genes that regulate arthritis triggered by incomplete Freund's adjuvant (IFA), an oil that induces T-cell mediated arthritis in DA rats, but not in other inbred rat strains (7,9–11).

Initial genetic analyses of oil-induced arthritis (OIA) in DA rats and MHC congenic rat strains revealed that susceptibility to OIA is determined by DA genes located both within and outside the MHC (Oia1) (10,12). Subsequent genome-wide linkage analysis of a cross between DA and MHC-identical but arthritis-resistant LEW.1AV1 identified a chromosome 4 region, designated Oia2, that was linked to arthritis susceptibility (13). Subsequent genome scans in pristane-induced arthritis (PIA) and collagen-induced arthritis (CIA) identified arthritis-regulating DA alleles in overlapping intervals, which were designated Pia7 and Cia13, respectively (14,15). The Oia2/Pia7/Cia13 region contains many genes that exert important functions in the immune system. Among these candidate disease genes, the natural killer cell gene complex (NKC) was particularly noted (13,15–17), because it regulates an aberrant NK cell activity of DA rats in natural toxicity, i.e. inability to lyse intravenously injected allogenic lymphocytes (18–20). It was therefore conceivable that the general and high disease susceptibility of DA rats could relate to aberrant function of leukocytes expressing DA alleles in the NKC. As a first test of this hypothesis, we demonstrated that PVG alleles, which are linked to normal NKC mediated natural cytotoxicity (20), were also linked to arthritis-resistance in a DA(DAxPVG.1AV1) back-cross (16). Here we aimed to further test the hypothesis by fine-mapping of Oia2 in relation to NKC, and also to functionally characterize the influence of Oia2 on arthritis development and other adjuvant oil-induced phenotypes.

First, congenic strains were produced to determine if Oia2 from DA can confer arthritis susceptibility when transferred to LEW.1AV1 and PVG.1AV1, and if Oia2 from LEW.1AV1 and PVG.1AV1 can confer arthritis resistance to DA. Second, Oia2 was fine-mapped in relation to NKC using two sets of independently derived congenic and recombinant strains with PVG chromosome 4 alleles introduced on the DA genome in both homozygous and heterozygous form. Third, Oia2 regulation of oil-induced phenotypes beside arthritis were determined, such as changes in plasma levels of {alpha}1-acid glycoprotein (AGP), body weight and weight of lymph nodes, thymus, liver and spleen. Finally, candidate disease genes in Oia2 were identified. Homologous chromosomal regions and genes were determined in mouse and human, and reported disease linkage(s) were compiled in the three species.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 RESULTS
DISCUSSION
 MATERIALS AND METHODS
 REFERENCES
 
Evaluation of arthritis susceptibility in Oia2 congenics compared with parental strains
As reported previously, LEW.1AV1 (11–13,21) and PVG.1AV1 (11,16) were completely resistant to induction of OIA, whereas DA were susceptible (Table 1). The first signs of inflammation typically occurred 11–14 days post injection (d.p.i.) in ankles or metatarsal joints. The inflammation progressed, often symmetrically, to include larger paw areas and additional types of joints, including finger joints. However, inflammation never engaged an entire paw (score <4), and severity was moderate or low (score <13). Arthritis in more detrimental models (often score 16) can become chronic, but in OIA, disease subsides before 30 d.p.i., leaving no or limited signs of disease at 40 d.p.i., approximately.


View this table:
[in this window]
[in a new window]
  		Table 1. Evaluation of oil-induced arhritis in rats made congenic for chromosome 4 intervals (C4), harboring Oia2, in comparison with inbred DA, LEW.1AV1 and PVG.1AV1
 
In rats made congenic for chromosome 4 (C4) intervals, as depicted in Figure 1, arthritis incidences of 0–10% in DA.C4(LEW) and DA.C4(PVG) demonstrated that OIA resistance was transferred together with LEW or PVG C4 intervals into the DA strain. Conversely, incidences of 15% in LEW.1AV1.C4(DA) and 69% in PVG.AV1.C4(DA) demonstrated transfer of OIA susceptibility together with DA C4 intervals into the LEW.1AV1 and PVG.1AV1 strains (Tables 1 and 2). After injection of the more arthritogenic oil squalene, the arthritis incidence was increased to 43% in LEW.1AV1.C4(DA) (3/7 males, 3/7 females) as compared with 14% in LEW.1AV1 (4/22 in females and 1/14 in males, combined data from two previous studies) (22,23).



View larger version (17K):
[in this window]
[in a new window]
  		Figure 1. Genetic map of rat chromosome 4 (RNO4), aligned with transferred chromosomal intervals in congenic strains, and arthritis-linked QTLs. The figure shows rat chromosome 4 (RNO4) as a long vertical bar, not in scale. Microsatellite markers are placed along the chromosome with cM positions for selected markers derived from a SHRSPxBN genetic map available at http://rgd.mcw.edu/. To the right of RNO4, vertical bars indicate homozygous chromosomal intervals transferred to obtain the chromosome 4 (C4) congenic strains (in black), with flanking regions within which recombinations have occurred (in gray). To the left of RNO4, arthritis-regulating QTLs are depicted with gray bars that indicate the peak LOD–2 LOD interval, with horizontal black bars representing peak marker positions, and QTL designations underlined. The arthritis-linked QTLs were identified in the following models and crosses: Oia2, OIA, F2(DAxLEW.1AV1) (13), and DA(DAxPVG.1AV1) (16); Pia2, Pia5 and Pia7, PIA, F2(DAxE3) (14,57); Aia3 and Aia2, AIA, F2(DAxF344) (58); Cia3, CIA, F2(DAxF344) (59), and Cia13, CIA, F2(DAxBN) (15).

 

View this table:
[in this window]
[in a new window]
  		Table 2. Susceptibility to oil-induced arthritis of DA.C4(PVG) recombinant animals
 
Evaluation of macroscopic arthritis in DA made congenic for Oia2/NKC from PVG, and mapping of arthritis susceptibility in recombinant strains
DA rats carrying PVG and/or DA alleles in C4 intervals, harboring Oia2/NKC (Fig. 1), were independently produced in Sweden (S) and Norway (N), and were tested in a standardized and collaborative manner. Both DA.C4(PVG)/S and DA.C4(PVG)/N displayed almost complete arthritis resistance, and heterozygotes (PVG/DA) were also markedly less susceptible than DA. In the Norwegian experiments, incidences were 0/7 in DA.C4(PVG), 8/13 in DA.C4(PVG/DA) and 13/13 in DA.C4(DA). Two recombinant (R) strains were tested, DA.C4R1/N and DA.C4R2/N, both covering the NKC (Fig. 2). The incidences were 7/7 in DA.C4R2(PVG)/N, 3/3 in DA.C4R2(PVG/DA)/N and 3/3 in DA.C4R2(DA)/N demonstrating lack of arthritis-regulation. In contrast, DA.C4R1(PVG)/N, which covers a larger interval centromeric of NKC, displayed low incidence, 3/12, demonstrating arthritis regulation. Taken together, this provides evidence that the structural gene associated with OIA susceptibility is situated outside the NKC. These results were corroborated and extended in the Swedish study, where analysis of arthritis data for recombinants DA.C4R3-R16 (Table 2), in relation to alignment of congenic intervals along rat chromosome 4 (Fig. 2), narrowed the arthritis-regulating region to an ~1 cM interval, hereafter defined as Oia2, between the microsatellite markers D4Got126 and D4Got136 (Fig. 2).



View larger version (27K):
[in this window]
[in a new window]
  		Figure 2. Fine-mapping of Oia2 in recombinant strains. The figure shows rat chromosome 4 (RNO4) as a long vertical bar, not to scale. Microsatellite markers, and corresponding genes in bold, are placed along the chromosome in relative positions obtained from extensive genotyping in DA.C4(PVG) recombinants, and with cM positions for selected markers (in brackets) derived from a SHRSPxBN genetic map available at http://rgd.mcw.edu/. The markers define intervals that were transferred from PVG.1AV1 to DA; they are depicted as vertical bars consisting of black or gray, representing PVG alleles or non-determined alleles, respectively. Recombinants harboring the transferred intervals were injected with IFA and the impact on OIA development was determined (Table 2). Intervals are placed to the right or left of RNO4 depending on observed regulation or non-regulation of OIA, respectively. The dotted horizontal lines to the right and left represent intervals where PVG alleles are always present or absent (or non-determined), respectively. An arthritis-regulating gene is located within the intervals defined by the dotted lines on each side of RNO4.

 
Positioning of Oia2 on a linkage map
The chromosomal positions of microsatellite markers, used to define Oia2 in recombinant strains, were determined by PCR analyses on genomic DNA obtained from a panel of (DAxPVG)F1xDA rats, previously used for mapping of the NKC on rat chromosome 4 (20) (Fig. 3). The rat NKC spans 1 to 2 Mbp, with the NKR-P1 gene cluster situated at the centromeric end of the complex. Linkage mapping showed that the Oia2 interval, as defined in recombinants, lies ~9.2 cM centromeric to Nkrp1b, with D4Got136 defining the telomeric end of the interval, and with a distance of 0.8 cM between D4Got136 and D4Got126 (Fig. 3). No crossovers were detected between D4Rat90, D4Got 136 and Eno2, whereas results from the Stockholm recombinant strains show that D4Rat90 lies proximal to D4Got136, i.e. within the Oia2 interval.



View larger version (12K):
[in this window]
[in a new window]
  		Figure 3. Linkage mapping of the Oia2 interval. Linkage map of rat chromosome 4 based on segregation of alleles in 223 [(DAxPVG)F1xDA rats] back-crossed rats, previously used to map NKC, including the marker Nkrp1b (20,60). Linkage analysis was performed using the MAPMAKER/EXP computer package (61), and map distances are shown in cM. Oia2 is located at least 9.2 cM centromeric of Nkrp1b, within the 0.8 cM interval, defined by D4Got126 and D4Got136.

 
Excluding the presence of arthritis-regulating PVG alleles outside the Oia2 interval in the congenic strains
In the Swedish mapping material, we compared all inbred DA (n=48) with each group of ‘essentially DA’ that were used as controls, i.e. the progeny from crosses between recombinants and DA that lacked PVG alleles within the Oia2 region. None of these groups of ‘essentially DA’ deviated from inbred DA. Comparing all ‘essentially DA’ as a group (n=127) with inbred DA yielded almost identical phenotype data: incidence 97 and 96%; day of onset 13.9 and 14.6; severity 6.8 for both groups. The results demonstrate that ‘essentially DA’ do not contain arthritis-regulating PVG alleles in their genomes.

Extended analysis of macroscopic arthritis in relation to gender and Oia2 haplotype
Analysis of sex influence in ‘essential DA’ revealed phenotype differences between 59 males and 68 females (M versus F): severity 7.4 versus 6.2 (P=0.010); day of onset 13.4 versus 14.3 (P=0.048); incidence 97% for both groups. Gender influence has not been reported before, most likely because the effect is small and requires large numbers of animals to be detected. The gender difference was similar, but not significant, in 24 male and 24 female inbred DA (Table 3). We then determined the impact of Oia2, defined according to genotype in the D4Got126–D4Got136 interval, on arthritis phenotypes. All DA.C4/S and DA.C4R3-16/S animals were categorized as being Oia2(PVG/PVG), Oia2(PVG/DA) or Oia2(DA/DA), yielding groups consisting of 55, 71 and 56 animals, respectively. Phenotype data for the respective groups were compiled and compared, yielding the following results (Table 3): incidence 9.1, 54.9 and 97.8%; severity, 2.0, 2.6 and 6.7; and day of onset, 20.8, 16.3 and 13.7. Repeated analysis in relation to gender demonstrated that Oia2 influences arthritis in both males and females, with regulation more pronounced in males.


View this table:
[in this window]
[in a new window]
  		Table 3. Impact on arthritis phenotypes and Oia2 alleles introduced on DA, compared with inbred DA
 
Evaluation of additional adjuvant-oil induced phenotypes, beside macroscopic arthritis
DA.C4R3(PVG) were compared with DA and PVG.1AV1 concerning macroscopic arthritis (Fig. 4A), changes in body weight (Fig. 4B) and plasma levels of the inflammation marker AGP (Fig. 4C), an acute phase protein that increases during inflammation and acute phase reactions. The analysis revealed an arrested body weight gain in DA that lasted from arthritis onset to recovery, i.e. 10–30 d.p.i. DA.C4R3(PVG) followed the DA body weight curve closely, although they did not develop arthritis. In contrast, there was no pronounced arrest in body weight gain in arthritis-resistant PVG.1AV1. In this strain, levels of AGP were increased at 5 and 10 d.p.i., demonstrating an early systemic response to the injected adjuvant oil. However, the levels were considerably higher in DA at 5 d.p.i., and remained elevated until 30 d.p.i., approximately. In DA.C4R3(PVG), AGP levels were intermediate at 5 d.p.i., and remained elevated until 30 d.p.i., which is markedly longer than in PVG.1AV1. This indicates that a gene within Oia2 regulates AGP levels. However, the arrested body weight gain and prolonged elevated AGP levels in arthritis-resistant DA.C4R3(PVG) indicate that these phenotypes do not relate directly to macroscopic disease.



View larger version (16K):
[in this window]
[in a new window]
  		Figure 4. Impact of Oia2 on disease> course, body weight and plasma AGP. Inbred DA, PVG.1AV1 and DA.C4R3(PVG) were injected with IFA and monitored until 40 d.p.i. for arthritis susceptibility (A), relative body weight (B), and plasma levels of AGP (C). The figures show that PVG alleles in Oia2 inhibit OIA, reduce plasma AGP, but do not affect body weight. DA (n=15) and DA.C4R3(PVG) (n=37) are also in Table 2 and experiment 4, PVG.1AV1 (n=15) is also included in Table 1.

 
AGP plasma levels and relative weights of liver, thymus, spleen and lymph nodes (adjusted for body weight, and expressed as g tissue/kg body weight) were then compared between male DA.C4R9(PVG) and DA before and after injection of adjuvant oil (10 d.p.i.). Before oil exposure there were no clearcut differences between the strains, except lower AGP levels and slightly larger thymuses in DA (Table 4). After injection of adjuvant oil, both strains displayed elevated AGP, increased relative weight of lymph nodes and decreased relative liver and thymus weights. DA.C4R9(PVG) displayed the same physiological changes, except that the relative splenic weights were increased in DA and reduced in DA.C4R9(PVG) rats. Furthermore, the changes in AGP levels (DA versus R9: 4.4 versus 2.0), lymph node weights (4.5 versus 2.9) and thymic weights (0.49 versus 0.65) were far more pronounced in DA than in DA.C4R9(PVG) rats. The results demonstrate systemic effects of intradermal injections of small doses of mineral oil, and that the effects of DA versus PVG allele on an otherwise uniform background are quantitative rather than all or none, except for changes in relative weights of spleens.


View this table:
[in this window]
[in a new window]
  		Table 4. Levels of plasma AGP and weights of lymph nodes, spleen, thymus, and liver in DA and Oia2 congenic rats before and after injection of adjuvant oil
 
Definition of Oia2 and syntenic chromosome regions in mouse and humans
As mapped here, Oia2 is a 0.8 cM region rat chromosome 4 (RNO4), defined by the microsatellite markers D4Got126 and D4Got136. Database searches reveal that D4Got126 correspond to FoxJ2, and that D4Got 136 is located close to, and centromeric of, Pex5. The region between FoxJ2 and Pex5 spans 1.2 Mb at the cytogenetic position 4q42, and contains a limited number of candidate genes and gene-like sequences, as depicted in Figure 5. The syntenic mouse region on 6F2 is highly homologous, whereas the corresponding human genes, with one exception, seem to be dispersed into a larger region at the cytogenetic position 12p13.31–12p13.32. The rat gene sequence similar to DnaJ (DNAJA2) is located at human 16p11.



View larger version (17K):
[in this window]
[in a new window]
  		Figure 5. The Oia2 interval, and candidate disease genes. The figure shows Oia2 on rat chromosome 4 (RNO4), located between the microsatellite markers D4Got126 and D4Got136, approximately representing the genes Foxj2 and Pex5. The interval harbors a set of vomeronasalneuron putative pheromonereceptor genes not depicted. Candidate disease genes, or sequences with similarities to genes, include C3ar1 (complement component 3a receptor), DnaJ, Clecsf6 (C-type lectin superfamily member 6), Clecsf10, Clecsf8, Clecsf9, C1s-like, Cd163, Pex5 (Peroxin 5, peroxisome receptor 1). Data for microsatellite markers on RNO4 were retrieved from Rat Genome Database (http://rgd.mcw.edu/). Rat genes proximal to the two flanking markers of the Oia2 region, D4Got126 and D4Got136, were identified by selecting marker positive BAC clones from the HTGS library at NCBI (www.ncbi.nlm.nih.gov/genome/seq/RnBlast.html). The genes were retrieved by running the HTGS clone sequence in a gene-prediction program at http://compbio.ornl.gov/grailexp/. All identified genes were mouse homologs, except C3ar1, which was identified in the rat. (a)Six different Clecsf6 sequences were retrieved. One homolog to mouse Clecsf6, and five homologs to mouse sequences similar to Clecsf6. (b)C1s short sequence, two exons.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 RESULTS
 DISCUSSION
MATERIALS AND METHODS
 REFERENCES
 
It was recently demonstrated, for the first time, that introduction of an arthritis-promoting QTL on an arthritis-resistant genome can confer arthritis susceptibility (23). Here we provide additional examples, demonstrating that OIA can be induced in both PVG.1AV1 and LEW.1AV1 when they are made congenic for Oia2 from DA. In the reciprocal congenic strains, we established that DA rats made congenic for Oia2 from LEW or PVG, were almost completely arthritis-resistant.

In the PVG.1AV1 to DA strain combination, DA.C4(PVG), two independently derived congenic strains displayed OIA resistance, and both were used to produce independent recombinants for mapping of Oia2 in relation to the major candidate disease locus NKC. In both sets of recombinants, the arthritis-regulating locus mapped centromeric of NKC, which rejects the hypothesis that Oia2 equals a gene in the natural killer cell complex (13). High-resolution mapping delimited Oia2 to a 0.8 cM interval located at the cytogenetic position 4q42, ~1–2 cM centromeric of Eno2, at the same position as peak markers in the genome-scan where Oia2 was first identified (13).

Interestingly, our mapping results in DA.C4(PVG)/S recombinants suggest that Oia2 is the only locus with a detectable impact on OIA. This is notable because the DA.C4(PVG)/S strain harbors a large PVG interval, centromeric of Oia2, which overlaps with five DA quantitative trait loci (QTL) identified in other arthritis models. This raises the question why these QTLs were not detected. It is possible that the QTLs are disease-specific and regulate other arthritis models than OIA. Alternative explanations are that PVG alleles influence disease-phenotypes that are not monitored here (such as chronicity), or they exert weak effects that escaped detection, or PVG alleles are identical to DA, in which case they would not influence any phenotype in our experimental system.

For Oia2, alleles at this locus exerted additive or co-dominant effects in both males and females. Thus, one PVG allele at Oia2 in DA reduced arthritis incidence, delayed the day of onset, and decreased severity, while two PVG alleles conferred almost complete arthritis resistance. We next determined additional oil-induced phenotypes (22,24,25) that could discriminate susceptible DA from resistant homozygous congenics. This revealed that both strains displayed a period of weight loss and arrested weight gain, and had a prolonged acute phase response, which was possibly less pronounced in congenic rats. Relative weights of liver and thymus were decreased, whereas draining lymph nodes were hyperplastic. These results establish that dramatic physiological changes take place also in resistant congenic rats. However, the acute phase response and the lymph node hyperplasia were more pronounced in DA. The latter may indicate a higher level of regional immune activation (24,25), considering that T cells from lymph nodes can transfer OIA (26,27). Another notable result was that the relative weights of spleens were increased in DA but decreased in congenics.

Altogether, our results demonstrate that Oia2 regulates some, but not all, adjuvant oil-induced phenotypes. In addition, we have recently reported that PVG alleles in the region defined by DA.C4R3(PVG) also regulate arthritis induced with the cartilage autoantigen collagen type II emulsified in IFA (CIA), as well as arthritis induced by other adjuvant oils such as pristane and squalene (SIA) (28). This suggests that Oia2 regulates arthritis induced both by specific and non-specific activation of the immune system. We propose, therefore, that Oia2 is identical to the overlapping QTLs Pia7 and Cia13. If this is correct, arthritis-resistance alleles should be present in the strains used to define these loci: E3 for Pia7; F344 for Cia13; LEW, PVG and BN (unpublished data) for Oia2. This functional information will be important when candidate genes are being sequenced.

Beside the impact on arthritis, Oia2 has previously been linked to phenotypes in an experimental model for multiple sclerosis, i.e. myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (MOG-EAE) (29). In accordance, we have recently demonstrated that DA.C4R3(PVG) differs from DA in MOG-EAE (30). This regulation of an additional organ-specific inflammatory disease may relate to adjuvant-specific use of IFA together with MOG for induction of EAE (IFA is routinely used together with autoantigens to break tolerance and induce pathogenic autoimmunity). However, it is also possible that Oia2 regulation of different diseases reflects broader actions of genes involved in inflammatory responses, or containment of inflammatory responses. A general role in inflammation and autoimmunity may be supported by the fact that the region on rat 4q42, and the syntenic regions on 12p13 in human and 6F2 in mouse have been linked to several inflammatory diseases and associated phenotypes (31), including arthritis (13–15,22,32–34), systemic lupus erythematosus (35), spontaneous diabetes (36,37), atherosclerosis (38,39), encephalomyelitis (29,40), asthma or airway responsiveness (41,42) and allergy (43–45).

As defined here, Oia2 harbors a limited number of candidate disease genes encoding molecules with functions in the immune system. This includes C3a anaphylatoxin receptor, Ribosomal protein L7, which is a target of autoreactive responses in rheumatic diseases (46), and CD163, which scavenges hemoglobin/haptoglobin complexes and may lead to activation in terms of secretion of pro-inflammatory cytokines after receptor cross-linking on the surface of macrophages (47,48). Another gene sequence shows similarity to DnaJ, a 40 kDa heat shock protein (HSP 40) that may regulate inflammatory responses. This molecule may also be a target of crossreactive autoimmune responses (49,50), since some microbial DnaJ contain an amino acid sequence that constitutes a suggested ‘shared epitope’ (51,52) of HLA DRB1 alleles associated with RA. Interestingly, the Oia2 region also encodes several C-type lectin superfamily members (CLECSF) (53) that are likely to regulate functions of macrophages and dendritic cells in immune responses and inflammation.

It is possible that only one of the described genes regulates phenotypes mapped to Oia2 and syntenic regions, but it is also possible that more than one gene may be of general importance in inflammatory diseases. We suggest, therefore, that the described high-resolution mapping of candidate disease genes offers a valuable shortcut to detection of disease pathways and genetic disease associations in human diseases, including RA.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 RESULTS
 DISCUSSION
 MATERIALS AND METHODS
REFERENCES
 
Animals
Inbred PVG.1AV1 originated from Harlan UK Ltd (Oxon, UK), while inbred DA and LEW.1AV1 originated from Zentralinstitut für Versuchstierzucht, Hannover, Germany. Congenic and recombinant strains were derived from these strains by standard congenization procedures, essentially as described by Greenhouse (54). Animals were bred, kept and used under specific pathogen-free conditions, as determined by a health monitoring program (FELASA) at the National Veterinary Institute in Uppsala. They were reared in climate-controlled environment with 12 h light/dark cycles, housed in polystyrene cages containing wood shavings, and had free access to standard rodent food and water. Inbred strains and congenic strains were established in parallel, in Sweden and Norway: in Sweden, at the Biomedical Center in Uppsala or the Center for Molecular Medicine, Karolinska Institutet, Stockholm; in Norway, at The Institute of Basic Medical Sciences, University of Oslo. All procedures involving animals were performed according to guidelines provided by the central Board for Animal Experiments at the Swedish and Norwegian Departments of Agriculture, and were approved by the ethics committees of Stockholm North and Oslo.

Congenic and recombinant strains
The congenic and recombinant strains were made by transfer of chromosome 4 (C4) intervals (Figs 1 and 2) between strains, as follows: LEW.1AV1 containing a C4 interval from DA [back-crossed (bc) for 10 generations, including the first intercross generation], i.e. LEW.1AV1.C4(DA) (bc10); PVG.1AV1.C4(DA) (bc10); and DA.C4(LEW) (bc10). DA.C4(PVG) were produced in both Norway (N) and Sweden (S), i.e. DA.C4(PVG)/N (bc11) and DA.C4(PVG)/S (bc10), respectively. Recombinants (R) were made from DA.C4(PVG)/S by at least three additional backcrosses (Bc13, or more), and from DA.C4(PVG)/N as follows: DA.C4R1(PVG)/N (bc15); and DA.C4R2(PVG)/N (bc13).

Genetic analysis
Tailtips were collected, and genomic DNA was purified according to a standard protocol (55). Genotypes were determined by PCR amplification of tandemly repeated sequences (microsatellites) that are polymorphic between the parental strains, essentially as previously described (56), except 33P-{gamma} ATP was used to label one of the primers in each pair allowing genotypes to be determined by autoradiography. Markers used for genotyping are depicted in Figures 1 and 2, and where purchased from Research Genetics (Huntsville, AL). Genotypes are denoted DA for DA homozygotes, and PVG or LEW for PVG and LEW homozygotes, respectively. Heterozygotes are designated with both alleles, e.g. PVG/DA.

Arthritis induction and evaluation
Arthritis was induced by an intradermal injection of 200 µl of IFA (Difco, Detroit, USA) at the base of the tail of anesthesized animals that were sex- and age-matched for each experiment. Arthritis development was monitored every second to fourth day, using a macroscopic scoring system that ranges from 0 to 4 for each of the four limbs (1, enlargement of one type of joint; 2, enlargement of two types of joints; 3, more than two types of joints involved; and 4, severe arthritis in the whole paw), yielding a score of 0–16 per animal. The following macroscopic phenotypes were analyzed: susceptibility—the maximal score recorded in each individual rat (score 0–16); incidence—the cumulated number of affected rats over time, divided by all tested rats; severity—the maximal score attained by each individual affected rat (score 1–16); day of onset—the first day post injection with joint inflammation. Although the disease course of OIA performed on DA rats in Norway was mild and monophasic, concern from the supervising veterinary enforced early euthanazation of diseased animals, or treatment with prednisolone. This weakens data for severity and susceptibility, but not for incidence and day of onset.

Determination of phenotypes other than macroscopic arthritis
To monitor oil-induced fluctuations of AGP, individual plasma samples were prepared from blood obtained from tailtips. Then, AGP levels were determined in samples from different strains and time-points using a radial immunodiffusion kit (Cardiotech, Louisville, KY). One test per sample was used, since the coefficient of variation is less than 4% in repeated measurements of identical aliquots of the same test specimen, according to the manufacturer. To monitor oil-induced changes in size of organs, animals were sacrificed, and inguinal lymph nodes, spleen, thymus and liver were dissected out and weighed.

Statistical methods
Susceptibility was analyzed using non-parametric Mann–Whitney U-test. Severity, day of onset, AGP levels, weights of organs were analyzed using Student's t-test. The chi-square test was used for analysis of incidence. P-values below 0.05 were considered significant.


   ACKNOWLEDGEMENTS
 
This project was supported by Astra Zeneca, by a grant from the ‘Network for Inflammation Research’ funded by the Swedish Foundation for Strategic Research, and by grants from the Swedish Medical Research Council, the Swedish Rheumatism Association, King Gustav V 80th Birthday Jubilee Foundation, Åke Wibergs Foundation, Alex and Eva Wallström Foundation and Nanna Svartz Foundation. J.C.L. is a recipient of a research fellowship from the Swedish Medical Research Council.


   FOOTNOTES
 
* To whom correspondence should be addressed at: Rheumatology Unit, Center for Molecular Medicine, L8:04, Karolinska Hospital, S-171 76 Stockholm, Sweden. Tel: +46 851775609; Fax: +46 851775562; Email: johnny.lorentzen{at}cmm.ki.se Back

{dagger} The authors wish it to be known that, in their opinion, these authors contributed equally to this work. Back


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 RESULTS
 DISCUSSION
 MATERIALS AND METHODS
 REFERENCES
 

  1. Aho, K., Koskenvuo, M., Tuominen, J. and Kaprio, J. (1986) Occurrence of rheumatoid arthritis in a nationwide series of twins. J. Rheumatol., 13, 899–902.[Web of Science][Medline]

  2. Silman, A.J., MacGregor, A.J., Thomson, W., Holligan, S., Carthy, D., Farhan, A. and Ollier, W.E. (1993) Twin concordance rates for rheumatoid arthritis: results from a nationwide study. Br. J. Rheumatol., 32, 903–907.[Abstract/Free Full Text]

  3. Deighton, C.M., Walker, D.J., Griffiths, I.D. and Roberts, D.F. (1989) The contribution of HLA to rheumatoid arthritis. Clin. Genet., 36, 178–182.[Web of Science][Medline]

  4. Wordsworth, P. and Bell, J. (1991) Polygenic susceptibility in rheumatoid arthritis. Ann. Rheum. Dis., 50, 343–346.[Free Full Text]

  5. Lorentzen, J.C. (1999) Identification of arthritogenic adjuvants of self and foreign origin. Scand. J. Immunol., 49, 45–50.[CrossRef][Web of Science][Medline]

  6. Holmdahl, R., Lorentzen, J.C., Lu, S., Olofsson, P., Wester, L., Holmberg, J. and Pettersson, U. (2001) Arthritis induced in rats with nonimmunogenic adjuvants as models for rheumatoid arthritis. Immunol. Rev., 184, 184–202.[CrossRef][Web of Science][Medline]

  7. Kleinau, S., Erlandsson, H., Holmdahl, R. and Klareskog, L. (1991) Adjuvant oils induce arthritis in the DA rat. I. Characterization of the disease and evidence for an immunological involvement. J. Autoimmun., 4, 871–880.[CrossRef][Web of Science][Medline]

  8. Klareskog, L., Lorentzen, J., Padyukov, L. and Alfredsson, L. (2002) Genes and environment in arthritis: can RA be prevented? Arthritis Res., 4, S31–S36.

  9. Holmdahl, R., Goldschmidt, T.J., Kleinau, S., Kvick, C. and Jonsson, R. (1992) Arthritis induced in rats with adjuvant oil is a genetically restricted, alpha beta T-cell dependent autoimmune disease. Immunology, 76, 197–202.[Web of Science][Medline]

  10. Cannon, G.W., Woods, M.L., Clayton, F. and Griffiths, M.M. (1993) Induction of arthritis in DA rats by incomplete Freund's adjuvant. J. Rheumatol., 20, 7–11.[Web of Science][Medline]

  11. Lorentzen, J.C. and Klareskog, L. (1996) Susceptibility of DA rats to arthritis induced with adjuvant oil or rat collagen is determined by genes both within and outside the major histocompatibility complex. Scand. J. Immunol., 44, 592–598.[CrossRef][Web of Science][Medline]

  12. Lorentzen, J.C., Olsson, T. and Klareskog, L. (1995) Susceptibility to oil-induced arthritis in the DA rat is determined by MHC and non-MHC genes. Transplant. Proc., 27, 1532–1534.[Web of Science][Medline]

  13. Lorentzen, J.C., Glaser, A., Jacobsson, L., Galli, J., Fakhrai-Rad, H., Klareskog, L. and Luthman, H. (1998) Identification of rat susceptibility loci for adjuvant-oil-induced arthritis. Proc. Natl Acad. Sci. USA, 95, 6383–6387.[Abstract/Free Full Text]

  14. Nordquist, N., Olofsson, P., Vingsbo-Lundberg, C., Petterson, U. and Holmdahl, R. (2000) Complex genetic control in a rat model for rheumatoid arthritis. J. Autoimmun., 15, 425–432.[CrossRef][Web of Science][Medline]

  15. Griffiths, M.M., Wang, J., Joe, B., Dracheva, S., Kawahito, Y., Shepard, J.S., Reese, V.R., McCall-Vining, S., Hashiramoto, A., Cannon, G.W. et al. (2000) Identification of four new quantitative trait loci regulating arthritis severity and one new quantitative trait locus regulating autoantibody production in rats with collagen-induced arthritis. Arthritis Rheum., 43, 1278–1289.[CrossRef][Web of Science][Medline]

  16. Jansson, A.M., Jacobsson, L., Luthman, H. and Lorentzen, J.C. (1999) Susceptibility to oil-induced arthritis is linked to Oia2 on chromosome 4 in a DA(DAxPVG.1AV1) backcross. Transplant. Proc., 31, 1597–1599.[CrossRef][Web of Science][Medline]

  17. Rolstad, B., Naper, C., Lovik, G., Vaage, J.T., Ryan, J.C., Backman-Petersson, E., Kirsch, R.D. and Butcher, G.W. (2001) Rat natural killer cell receptor systems and recognition of MHC class I molecules. Immunol. Rev., 181, 149–157.[CrossRef][Web of Science][Medline]

  18. Rolstad, B. and Fossum, S. (1987) Allogeneic lymphocyte cytotoxicity (ALC) in rats: establishment of an in vitro assay, and direct evidence that cells with natural killer (NK) activity are involved in ALC. Immunology, 60, 151–157.[Web of Science][Medline]

  19. Fossum, S., Ager, A. and Rolstad, B. (1987) Specific inhibition of natural killer (NK) activity against different alloantigens. Immunogenetics, 26, 329–338.[CrossRef][Web of Science][Medline]

  20. Dissen, E., Ryan, J.C., Seaman, W.E. and Fossum, S. (1996) An autosomal dominant locus, Nka, mapping to the Ly-49 region of a rat natural killer (NK) gene complex, controls NK cell lysis of allogeneic lymphocytes. J. Exp. Med., 183, 2197–2207.[Abstract/Free Full Text]

  21. Lorentzen, J.C. and Klareskog, L. (1997) Comparative susceptibility of DA, LEW, and LEW.1AV1 rats to arthritis induced with different arthritogens: mineral oil, mycobacteria, muramyl dipeptide, avridine and rat collagen type II. Transplant. Proc., 29, 1692–1693.[CrossRef][Web of Science][Medline]

  22. Carlson, B.C., Jansson, A.M., Larsson, A., Bucht, A. and Lorentzen, J.C. (2000) The endogenous adjuvant squalene can induce a chronic T-cell-mediated arthritis in rats. Am. J. Pathol., 156, 2057–2065.[Abstract/Free Full Text]

  23. Holm, B.C., Xu, H., Jacobsson, L., Larsson, A., Luthman, H. and Lorentzen, J. (2001) Rats made congenic for Oia3 on chromosome 10 become susceptible to squalene-induced arthritis. Hum. Mol. Genet., 10, 565–572.[Abstract/Free Full Text]

  24. Svelander, L., Holm, B.C., Bucht, A. and Lorentzen, J.C. (2001) Responses of the rat immune system to arthritogenic adjuvant oil. Scand. J. Immunol., 54, 599–605.[CrossRef][Web of Science][Medline]

  25. Holm, B.C., Svelander, L., Bucht, A. and Lorentzen, J.C. (2002) The arthritogenic adjuvant squalene does not accumulate in joints, but gives rise to pathogenic cells in both draining and non-draining lymph nodes. Clin. Exp. Immunol., 127, 430–435.[CrossRef][Web of Science][Medline]

  26. Kleinau, S. and Klareskog, L. (1993) Oil-induced arthritis in DA rats passive transfer by T cells but not with serum. J. Autoimmun., 6, 449–458.[CrossRef][Web of Science][Medline]

  27. Svelander, L., Mussener, A., Erlandsson-Harris, H. and Kleinau, S. (1997) Polyclonal Th1 cells transfer oil-induced arthritis. Immunology, 91, 260–265.[CrossRef][Web of Science][Medline]

  28. Backdahl, L., Ribbhammar, U. and Lorentzen, J.C. (2003) Mapping and functional characterization of rat chromosome 4 regions that regulate arthritis models and phenotypes in congenic strains. Arthritis Rheum., 48, 551–559.[CrossRef][Web of Science][Medline]

  29. Dahlman, I., Lorentzen, J.C., de Graaf, K.L., Stefferl, A., Linington, C., Luthman, H. and Olsson, T. (1998) Quantitative trait loci disposing for both experimental arthritis and encephalomyelitis in the DA rat; impact on severity of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis and antibody isotype pattern. Eur. J. Immunol., 28, 2188–2196.[CrossRef][Web of Science][Medline]

  30. Becanovic, K., Backdahl, L., Wallstrom, E., Aboul-Enein, F., Lassmann, H., Olsson, T. and Lorentzen, J.C. (2003) Paradoxical effects of arthritis-regulating chromosome 4 regions on myelin oligodendrocyte glycoprotein-induced encephalomyelitis in congenic rats. Eur. J. Immunol., 33, 1907–1916.[CrossRef][Web of Science][Medline]

  31. Becker, K.G., Simon, R.M., Bailey-Wilson, J.E., Freidlin, B., Biddison, W.E., McFarland, H.F. and Trent, J.M. (1998) Clustering of non-major histocompatibility complex susceptibility candidate loci in human autoimmune diseases. Proc. Natl Acad. Sci. USA, 95, 9979–9984.[Abstract/Free Full Text]

  32. Cornelis, F., Faure, S., Martinez, M., Prud'homme, J.F., Fritz, P., Dib, C., Alves, H., Barrera, P., de Vries, N., Balsa, A. et al. (1998) New susceptibility locus for rheumatoid arthritis suggested by a genome-wide linkage study. Proc. Natl Acad. Sci. USA, 95, 10746–10750.[Abstract/Free Full Text]

  33. McIndoe, R.A., Bohlman, B., Chi, E., Schuster, E., Lindhardt, M. and Hood, L. (1999) Localization of non-Mhc collagen-induced arthritis susceptibility loci in DBA/1j mice. Proc. Natl Acad. Sci. USA, 96, 2210–2214.[Abstract/Free Full Text]

  34. Jawaheer, D., Seldin, M.F., Amos, C.I., Chen, W.V., Shigeta, R., Monteiro, J., Kern, M., Criswell, L.A., Albani, S., Nelson, J.L. et al. (2001) A genomewide screen in multiplex rheumatoid arthritis families suggests genetic overlap with other autoimmune diseases. Am. J. Hum. Genet., 68, 927–936.[CrossRef][Web of Science][Medline]

  35. Kono, D.H., Burlingame, R.W., Owens, D.G., Kuramochi, A., Balderas, R.S., Balomenos, D. and Theofilopoulos, A.N. (1994) Lupus susceptibility loci in New Zealand mice. Proc. Natl Acad. Sci. USA, 91, 10168–10172.[Abstract/Free Full Text]

  36. Melanitou, E., Joly, F., Lathrop, M., Boitard, C. and Avner, P. (1998) Evidence for the presence of insulin-dependent diabetes-associated alleles on the distal part of mouse chromosome 6. Genome Res., 8, 608–620.[Abstract/Free Full Text]

  37. Rogner, U.C., Boitard, C., Morin, J., Melanitou, E. and Avner, P. (2001) Three loci on mouse chromosome 6 influence onset and final incidence of type I diabetes in NOD.C3H congenic strains. Genomics, 74, 163–171.[CrossRef][Web of Science][Medline]

  38. Welch, C.L., Bretschger, S., Latib, N., Bezouevski, M., Guo, Y., Pleskac, N., Liang, C.P., Barlow, C., Dansky, H., Breslow, J.L. et al. (2001) Localization of atherosclerosis susceptibility loci to chromosomes 4 and 6 using the Ldlr knockout mouse model. Proc. Natl Acad. Sci. USA, 98, 7946–7951.[Abstract/Free Full Text]

  39. Ko, C., Lee, T.L., Lau, P.W., Li, J., Davis, B.T., Voyiaziakis, E., Allison, D.B., Chua, S.C. Jr and Huang, L.S. (2001) Two novel quantitative trait loci on mouse chromosomes 6 and 4 independently and synergistically regulate plasma apoB levels. J. Lipid Res., 42, 844–855.[Abstract/Free Full Text]

  40. Xu, C., Day, Y., Lorentzen, JC., Dahlman, I., Olsson, T., Hillert, J. (2001) Linkage analysis in multiple sclerosis of chromosomal regions syntenic to experimental autoimmune disease loci. Eur. J. Hum. Genet., 9, 458–463.[CrossRef][Web of Science][Medline]

  41. De Sanctis, G.T., Singer, J.B., Jiao, A., Yandava, C.N., Lee, Y.H., Haynes, T.C., Lander, E.S., Beier, D.R. and Drazen, J.M. (1999) Quantitative trait locus mapping of airway responsiveness to chromosomes 6 and 7 in inbred mice. Am. J. Physiol., 277, L1118–L1123.

  42. Haston, C.K., Zhou, X., Gumbiner-Russo, L., Irani, R., Dejournett, R., Gu, X., Weil, M., Amos, C.I. and Travis, E.L. (2002) Universal and radiation-specific loci influence murine susceptibility to radiation-induced pulmonary fibrosis. Cancer Res., 62, 3782–3788.[Abstract/Free Full Text]

  43. Sudweeks, J.D., Todd, J.A., Blankenhorn, E.P., Wardell, B.B., Woodward, S.R., Meeker, N.D., Estes, S.S. and Teuscher, C. (1993) Locus controlling Bordetella pertussis-induced histamine sensitization (Bphs), an autoimmune disease-susceptibility gene, maps distal to T-cell receptor beta-chain gene on mouse chromosome 6. Proc. Natl Acad. Sci. USA, 90, 3700–3704.[Abstract/Free Full Text]

  44. Yokouchi, Y., Shibasaki, M., Noguchi, E., Nakayama, J., Ohtsuki, T., Kamioka, M., Yamakawa-Kobayashi, K., Ito, S., Takeda, K., Ichikawa, K. et al. (2002) A genome-wide linkage analysis of orchard grass-sensitive childhood seasonal allergic rhinitis in Japanese families. Genes Immun., 3, 9–13.[CrossRef][Web of Science][Medline]

  45. Haagerup, A., Bjerke, T., Schoitz, P.O., Binderup, H.G., Dahl, R. and Kruse, T.A. (2001) Allergic rhinitis—a total genome-scan for susceptibility genes suggests a locus on chromosome 4q24–q27. Eur. J. Hum. Genet., 9, 945–952.[CrossRef][Web of Science][Medline]

  46. Neu, E., Hemmerich, P.H., Peter, H.H., Krawinkel, U. and von Mikecz, A.H. (1997) Characteristic epitope recognition pattern of autoantibodies against eukaryotic ribosomal protein L7 in systemic autoimmune diseases. Arthritis Rheum., 40, 661–671.[Web of Science][Medline]

  47. Van den Heuvel, M.M., Tensen, C.P., van As, J.H., Van den Berg, T.K., Fluitsma, D.M., Dijkstra, C.D., Dopp, E.A., Droste, A., Van Gaalen, F.A., Sorg, C. et al. (1999) Regulation of CD 163 on human macrophages: cross-linking of CD163 induces signaling and activation. J. Leukoc. Biol., 66, 858–866.[Abstract]

  48. Schaer, D.J. (2002) The macrophage hemoglobin scavenger receptor (CD163) as a genetically determined disease modifying pathway in atherosclerosis. Comment to: Fernandez AZ et al.: intravascular hemolysis increases atherogenicity of diet-induced hypercholesterolemia in rabbits in spite of heme oxygenase-I gene and protein induction. Atherosclerosis, 163, 199–201.[CrossRef][Web of Science][Medline]

  49. Albani, S., Keystone, E.C., Nelson, J.L., Ollier, W.E., La Cava, A., Montemayor, A.C., Weber, D.A., Montecucco, C., Martini, A. and Carson, D.A. (1995) Positive selection in autoimmunity: abnormal immune responses to a bacterial dnaJ antigenic determinant in patients with early rheumatoid arthritis. Nat. Med., 1, 448–452.[CrossRef][Web of Science][Medline]

  50. La Cava, A., Nelson, J.L., Ollier, W.E., MacGregor, A., Keystone, E.C., Thorne, J.C., Scavulli, J.F., Berry, C.C., Carson, D.A. and Albani, S. (1997) Genetic bias in immune responses to a cassette shared by different microorganisms in patients with rheumatoid arthritis. J. Clin. Invest., 100, 658–663.[Web of Science][Medline]

  51. Gregersen, P.K., Silver, J. and Winchester, R.J. (1987) The shared epitope hypothesis. An approach to understanding the molecular genetics of susceptibility to rheumatoid arthritis. Arthritis Rheum., 30, 1205–1213.[Web of Science][Medline]

  52. Zanelli, E., Breedveld, F.C. and de Vries, R.R. (2000) HLA class II association with rheumatoid arthritis: facts and interpretations. Hum. Immunol., 61, 1254–1261.[CrossRef][Web of Science][Medline]

  53. Balch, S.G. Greaves, D.R., Gordon, S. and McKnight, A.J. (2002) Organization of the mouse macrophage C-type lectin (Mcl) gene and identification of a subgroup of related lectin molecules. Eur. J. Immunogenet., 29, 61–64.[CrossRef][Web of Science][Medline]

  54. Greenhouse, D.D., Festing, M.F.W., Hasan, S. and Cohen, A.L. (1990) Inbred strains of rats and mutants. In Hedrich, H.J. (ed.), Genetic Monitoring of Inbred Strains of Rats. Gustaf Fischer, Stuttgart, pp. 506–513.

  55. Laird, P.W., Zijderveld, A., Linders, K., Rudnicki, M.A., Jaenisch, R. and Berns, A. (1991) Simplified mammalian DNA isolation procedure. Nucl. Acids Res, 19, 4293.[Free Full Text]

  56. Jacob, H.J., Lindpaintner, K., Lincoln, S.E., Kusumi, K., Bunker, R.K., Mao, Y.P., Ganten, D., Dzau, V.J. and Lander, E.S. (1991) Genetic mapping of a gene causing hypertension in the stroke-prone spontaneously hypertensive rat. Cell, 67, 213–224.[CrossRef][Web of Science][Medline]

  57. Vingsbo-Lundberg, C., Nordquist, N., Olofsson, P., Sundvall, M., Saxne, T., Pettersson, U. and Holmdahl, R. (1998) Genetic control of arthritis onset, severity and chronicity in a model for rheumatoid arthritis in rats. Nat. Genet., 20, 401–404.[CrossRef][Web of Science][Medline]

  58. Kawahito, Y., Cannon, G.W., Gulko, P.S., Remmers, E.F., Longman, R.E., Reese, V.R., Wang, J., Griffiths, M.M. and Wilder, R.L. (1998) Localization of quantitative trait loci regulating adjuvant-induced arthritis in rats: evidence for genetic factors common to multiple autoimmune diseases. J. Immunol., 161, 4411–4419.[Abstract/Free Full Text]

  59. Remmers, E.F., Longman, R.E., Du, Y., O'Hare, A., Cannon, G.W., Griffiths, M.M. and Wilder, R.L. (1996) A genome scan localizes five non-MHC loci controlling collagen-induced arthritis in rats. Nat. Genet., 14, 82–85.[CrossRef][Web of Science][Medline]

  60. Dissen, E. and Fossum, S. (1996) Chromosomal localization of the genes encoding rat CD4, CD8alpha, and CD8beta. Immunogenetics, 44, 312–314.[CrossRef][Web of Science][Medline]

  61. Lander, E.S., Green, P., Abrahamson, J., Barlow, A., Daly, M.J., Lincoln, S.E. and Newburg, L. (1987) MAPMAKER: an interactive computer package for constructing primary genetic linkage maps of experimental and natural populations. Genomics, 1, 174–181.[CrossRef][Medline]


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
M. Packard, Y. Saad, W. T. Gunning, S. Gupta, J. Shapiro, and M. R. Garrett
Investigating the effect of genetic background on proteinuria and renal injury using two hypertensive strains
Am J Physiol Renal Physiol, April 1, 2009; 296(4): F839 - F846.
[Abstract] [Full Text] [PDF]

Home page
 Ann Rheum DisHome page
C Eklow, D Makrygiannakis, L Backdahl, L Padyukov, A-K Ulfgren, J C Lorentzen, and V Malmstrom
Cellular distribution of the C-type II lectin dendritic cell immunoreceptor (DCIR) and its expression in the rheumatic joint: identification of a subpopulation of DCIR+ T cells
Ann Rheum Dis, December 1, 2008; 67(12): 1742 - 1749.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. GenomicsHome page
B. Joe
Quest for arthritis-causative genetic factors in the rat
Physiol Genomics, January 12, 2007; 27(1): 1 - 11.
[Abstract] [Full Text] [PDF]

Home page
 Int ImmunolHome page
L. D. Spargo, L. G Cleland, M. P Cockshell, and G. Mayrhofer
Recruitment and proliferation of CD4+ T cells in synovium following adoptive transfer of adjuvant-induced arthritis
Int. Immunol., June 1, 2006; 18(6): 897 - 910.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
M. Jagodic, M. Marta, K. Becanovic, J. R. Sheng, R. Nohra, T. Olsson, and J. C. Lorentzen
Resolution of a 16.8-Mb Autoimmunity-Regulating Rat Chromosome 4 Region into Multiple Encephalomyelitis Quantitative Trait Loci and Evidence for Epistasis
J. Immunol., January 15, 2005; 174(2): 918 - 924.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
12/17/2087    most recent
ddg224v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (9)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Ribbhammar, U.
Right arrow Articles by Lorentzen, J. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ribbhammar, U.
Right arrow Articles by Lorentzen, J. C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?