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Editorial Cigarette smoking and the risk of systemic lupus erythematosus and rheumatoid arthritis. free! 2006
Majka DS, Holers VM. · No affiliation provided · Ann Rheum Dis. · Pubmed #16611864 links to free full text
This publication has no abstract.
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Editorial Can we accurately predict the development of rheumatoid arthritis in the preclinical phase? free! 2003
Majka DS, Holers VM. · No affiliation provided · Arthritis Rheum. · Pubmed #14558071 links to free full text
This publication has no abstract.
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Review Antibodies to citrullinated proteins: pathogenic and diagnostic significance. 2007
Holers VM. · Division of Rheumatology, Department of Medicine, University of Colorado at Denver and Health Sciences Center, Mail Stop B115, P.O. Box 6511, Aurora, CO 80045, USA. · Curr Rheumatol Rep. · Pubmed #17915095 No free full text.
Abstract: The recent demonstration of efficacy in the treatment of rheumatoid arthritis with B-cell-depleting therapy, along with the increasing understanding of the role of anticitrullinated protein antibodies (ACPA) have begun to provide new insights into the pathogenesis of this complex disease. This manuscript reviews the current understanding of ACPA with regard to clinical associations and pathogenic mechanisms in preclinical animal models. These data are synthesized into a model of the development of rheumatoid arthritis that refocuses attention on the role of B cells and immune complexes, returning in part to the origins of scientific investigation in this disease, and points to directions of research that are necessary to achieve the full therapeutic, diagnostic, and prognostic potential of the ACPA antigen-antibody system.
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Article REL, encoding a member of the NF-kappaB family of transcription factors, is a newly defined risk locus for rheumatoid arthritis. 2009
Gregersen PK, Amos CI, Lee AT, Lu Y, Remmers EF, Kastner DL, Seldin MF, Criswell LA, Plenge RM, Holers VM, Mikuls TR, Sokka T, Moreland LW, Bridges SL, Xie G, Begovich AB, Siminovitch KA. · The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY, USA. · Nat Genet. · Pubmed #19503088 No free full text.
Abstract: We conducted a genome-wide association study of rheumatoid arthritis in 2,418 cases and 4,504 controls from North America and identified an association at the REL locus, encoding c-Rel, on chromosome 2p13 (rs13031237, P = 6.01 x 10(-10)). Replication in independent case-control datasets comprising 2,604 cases and 2,882 controls confirmed this association, yielding an allelic OR = 1.25 (P = 3.08 x 10(-14)) for marker rs13031237 and an allelic OR = 1.21 (P = 2.60 x 10(-11)) for marker rs13017599 in the combined dataset. The combined dataset also provides definitive support for associations at both CTLA4 (rs231735; OR = 0.85; P = 6.25 x 10(-9)) and BLK (rs2736340; OR = 1.19; P = 5.69 x 10(-9)). c-Rel is an NF-kappaB family member with distinct functional properties in hematopoietic cells, and its association with rheumatoid arthritis suggests disease pathways that involve other recently identified rheumatoid arthritis susceptibility genes including CD40, TRAF1, TNFAIP3 and PRKCQ.
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Article Plasma 25,OH vitamin D concentrations are not associated with rheumatoid arthritis (RA)-related autoantibodies in individuals at elevated risk for RA. 2009
Feser M, Derber LA, Deane KD, Lezotte DC, Weisman MH, Buckner JH, Mikuls T, O'Dell J, Gregersen PK, Holers VM, Norris JM. · Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Denver, Colorado, USA. · J Rheumatol. · Pubmed #19286844 No free full text.
Abstract: OBJECTIVE: To evaluate the association between rheumatoid arthritis (RA)-related autoantibodies and plasma 25,OH vitamin D in subjects at risk for RA. METHODS: In 1210 subjects without RA, 76 were positive for anti-cyclic citrullinated peptide antibodies or for at least 2 rheumatoid factors (RF; by nephelometry: RF-IgM, RF-IgG, RF-IgA). 25,OH vitamin D was measured in these cases and 154 autoantibody-negative controls from this cohort. RESULTS: 25,OH vitamin D levels did not differ between cases and controls (adjusted OR 1.23, 95% CI 0.93-1.63). CONCLUSION: Vitamin D concentrations are not associated with RA-related autoimmunity in unaffected subjects at increased risk for RA.
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Article Rheumatoid arthritis (RA)-specific autoantibodies in patients with interstitial lung disease and absence of clinically apparent articular RA. 2009
Gizinski AM, Mascolo M, Loucks JL, Kervitsky A, Meehan RT, Brown KK, Holers VM, Deane KD. · Division of Rheumatology, University of Michigan, Ann Arbor, MI, USA. · Clin Rheumatol. · Pubmed #19252818 No free full text.
Abstract: The purpose of this study was to identify rheumatoid arthritis (RA)-related autoantibodies in subjects with interstitial lung disease (ILD) and no articular findings of RA, supporting the hypothesis that RA-related autoimmunity may be generated in non-articular sites, such as the lung. This was a retrospective chart review utilizing clinic databases of patients with ILD to identify cases with lung disease, RA-related autoantibody positivity, and no clinical evidence of articular RA. Four patients with ILD, RF, and anti-CCP positivity and no articular findings of RA were identified. All four patients were male with a mean age at time of diagnosis of ILD of 70 years old. All had a history of smoking. Three patients died within 2 years of diagnosis of ILD and never developed articular symptoms consistent with RA; the final case met full criteria for articular RA several months after stopping immunosuppressive treatment for ILD. RF and anti-CCP can be present in smokers with ILD without clinical evidence of articular RA and in one case symptomatic ILD and autoantibody positivity preceded the development of articular RA. These findings suggest that RA-specific autoimmunity may be generated due to immunologic interactions in the lung and may be related to environmental factors such as smoking.
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Article Antibody responses to Porphyromonas gingivalis (P. gingivalis) in subjects with rheumatoid arthritis and periodontitis. 2009
Mikuls TR, Payne JB, Reinhardt RA, Thiele GM, Maziarz E, Cannella AC, Holers VM, Kuhn KA, O'Dell JR. · Department of Medicine, Nebraska Arthritis Outcomes Research Center (NAORC), University of Nebraska Medical Center and Omaha Veterans Affairs Medical Center, Omaha, NE, USA. · Int Immunopharmacol. · Pubmed #18848647 No free full text.
Abstract: SUMMARY: Antibody titers to P. gingivalis are increased in patients with rheumatoid arthritis and are associated with disease-specific autoimmunity. BACKGROUND: Periodontitis (PD) has been implicated as a risk factor for rheumatoid arthritis (RA). We sought to characterize antibody titers to P. gingivalis (a pathogen in PD) in subjects with RA, PD, and in healthy controls and to examine their relationship with disease autoantibodies. METHODS: P. gingivalis antibody was measured in subjects with RA (n=78), PD (n=39), and in controls (n=40). Group frequencies of bacterial titer elevations were compared using the Chi-square test and antibody titers were compared using non-parametric tests. Correlations of P. gingivalis titer with C-reactive protein (CRP), antibody to cyclic citrullinated peptide (anti-CCP), and rheumatoid factor (RF) were examined in those with RA while CRP and autoantibody concentrations were compared based on seropositivity to P. gingivalis. RESULTS: Antibody titers to P. gingivalis were highest in PD, lowest in controls, and intermediate in RA (p=0.0003). Elevations in P. gingivalis (titer> or =800) were more common in RA and PD (67% and 77%, respectively) than in controls (40%) (p=0.002). In RA, there were significant correlations with P. gingivalis titer with CRP, anti-CCP-IgM, and -IgG-2. CRP (p=0.006), anti-CCP-IgM (p=0.01) and -IgG2 (p=0.04) concentrations were higher in RA cases with P. gingivalis titers > or =800 compared to cases with titers <800. CONCLUSION: Antibodies to P. gingivalis are more common in RA subjects than controls, although lower than that in PD. Associations of P. gingivalis titers with RA-related autoantibody and CRP concentrations suggests that infection with this organism plays a role in disease risk and progression in RA.
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Article The HLA-DRB1 shared epitope is associated with susceptibility to rheumatoid arthritis in African Americans through European genetic admixture. free! 2008
Hughes LB, Morrison D, Kelley JM, Padilla MA, Vaughan LK, Westfall AO, Dwivedi H, Mikuls TR, Holers VM, Parrish LA, Alarcón GS, Conn DL, Jonas BL, Callahan LF, Smith EA, Gilkeson GS, Howard G, Moreland LW, Patterson N, Reich D, Bridges SL. · University of Alabama at Birmingham 35294-2182, USA. · Arthritis Rheum. · Pubmed #18240241 links to free full text
Abstract: OBJECTIVE: To determine whether shared epitope (SE)-containing HLA-DRB1 alleles are associated with rheumatoid arthritis (RA) in African Americans and whether their presence is associated with higher degrees of global (genome-wide) genetic admixture from the European population. METHODS: In this multicenter cohort study, African Americans with early RA and matched control subjects were analyzed. In addition to measurement of serum anti-cyclic citrullinated peptide (anti-CCP) antibodies and HLA-DRB1 genotyping, a panel of >1,200 ancestry-informative markers was analyzed in patients with RA and control subjects, to estimate the proportion of European ancestry. RESULTS: The frequency of SE-containing HLA-DRB1 alleles was 25.2% in African American patients with RA versus 13.6% in control subjects (P = 0.00005). Of 321 patients with RA, 42.1% had at least 1 SE-containing allele, compared with 25.3% of 166 control subjects (P = 0.0004). The mean estimated percent European ancestry was associated with SE-containing HLA-DRB1 alleles in African Americans, regardless of disease status (RA or control). As reported in RA patients of European ancestry, there was a significant association of the SE with the presence of the anti-CCP antibody: 86 (48.9%) of 176 patients with anti-CCP antibody-positive RA had at least 1 SE allele, compared with 36 (32.7%) of 110 patients with anti-CCP antibody-negative RA (P = 0.01, by chi-square test). CONCLUSION: HLA-DRB1 alleles containing the SE are strongly associated with susceptibility to RA in African Americans. The absolute contribution is less than that reported in RA among populations of European ancestry, in which approximately 50-70% of patients have at least 1 SE allele. As in Europeans with RA, the SE association was strongest in the subset of African American patients with anti-CCP antibodies. The finding of a higher degree of European ancestry among African Americans with SE alleles suggests that a genetic risk factor for RA was introduced into the African American population through admixture, thus making these individuals more susceptible to subsequent environmental or unknown factors that trigger the disease.
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Article Cigarette smoking, disease severity and autoantibody expression in African Americans with recent-onset rheumatoid arthritis. 2008
Mikuls TR, Hughes LB, Westfall AO, Holers VM, Parrish L, van der Heijde D, van Everdingen M, Alarcón GS, Conn DL, Jonas B, Callahan LF, Smith EA, Gilkeson G, Howard G, Moreland LW, Bridges SL. · Department of Medicine, University of Nebraska Medical Center and Omaha VA Medical Center, Omaha, NE 68198-6270, USA. · Ann Rheum Dis. · Pubmed #18198196 No free full text.
Abstract: OBJECTIVE: To examine the association of smoking with clinical and serological features in African Americans with recent-onset rheumatoid arthritis (RA) and to explore whether this association is dependent on the presence of the HLA-DRB1 shared epitope (SE). METHODS: In African Americans with recent-onset RA (n = 300), we examined the association of cigarette smoking (current versus past versus never and pack-years of exposure) with anti-cyclic citrullinated peptide antibody, rheumatoid factor (RF) (IgM and IgA), rheumatoid nodules and baseline radiographic erosions using logistic and cumulative logistic regression (adjusting for SE status). We also examined for evidence of interaction between smoking status and SE for all outcomes. RESULTS: Although there was no association with RF-IgA seropositivity, current smokers were approximately twice as likely as never smokers to have higher IgA-RF concentrations (based on tertiles; OR = 1.74; 95% CI 1.05 to 2.88) and nodules (OR = 2.43; 95% CI 1.13 to 5.22). These associations were most pronounced in those with more than 20 pack-years of exposure. There was no association of smoking status or cumulative tobacco exposure with anti-cyclic citrullinated peptide antibody, IgM-RF or radiographic erosions. There was also no evidence of a biological or statistical SE-smoking interaction for any of the outcomes examined. CONCLUSIONS: This is the first study to systematically examine the association of cigarette smoking with RA-related features in African Americans. Cigarette smoking is associated with both subcutaneous nodules and higher serum concentrations of IgA-RF in African Americans with RA, associations that may have important implications for long-term outcomes in this population.
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Article A complement C3 inhibitor specifically targeted to sites of complement activation effectively ameliorates collagen-induced arthritis in DBA/1J mice. free! 2007
Song H, Qiao F, Atkinson C, Holers VM, Tomlinson S. · Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC 29425, USA. · J Immunol. · Pubmed #18025232 links to free full text
Abstract: Collagen-induced arthritis (CIA) represents an animal model of autoimmune polyarthritis with similarities to human rheumatoid arthritis, and therapy with various systemic complement-inhibitory proteins has been investigated in this model with varying results. We investigated the use of complement receptor 2 (CR2)-Crry, a complement inhibitor with the ability to target C3 breakdown products deposited in a rheumatic joint. Following induction of CIA in DBA/1J mice, animals were treated with either PBS or CR2-Crry (every other day, every 4 days, or with a single injection). The severity of clinical disease was significantly reduced in all CR2-Crry-treated groups compared with controls. Joints from mice receiving multiple doses of CR2-Crry showed significantly decreased inflammatory cell infiltrate, cartilage damage, pannus formation, and bone damage. CR2-Crry treatment also significantly decreased production of anti-collagen IgG and the inflammatory cytokines TNF-alpha and IL-1beta. IL-10 and IL-1Ra levels were increased in CR2-Crry-treated mice. CR2-Crry localized preferentially in the joints of mice with CIA. Analysis of IgG and C3 deposition in the joints of treated animals indicated that both complement regulation and the modulation of anti-collagen Ab production contributed to the protective effects of CR2-Crry. Of interest, a previous study reported that Crry-Ig, an untargeted counterpart of CR2-Crry, had minimal effect on disease, even when administered at a sufficiently high dose to maintain chronic complement inhibition.
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Article Duration of preclinical rheumatoid arthritis-related autoantibody positivity increases in subjects with older age at time of disease diagnosis. 2008
Majka DS, Deane KD, Parrish LA, Lazar AA, Barón AE, Walker CW, Rubertone MV, Gilliland WR, Norris JM, Holers VM. · Division of Rheumatology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA. · Ann Rheum Dis. · Pubmed #17974596 No free full text.
Abstract: OBJECTIVES: To investigate factors that may influence the prevalence and timing of appearance of rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies during the preclinical phase of rheumatoid arthritis (RA) development. METHODS: 243 serial prediagnosis serum samples from 83 subjects with RA were examined for the presence of RF and anti-CCP antibodies. RESULTS: Of the 83 cases, 47 (57%) and 51 (61%) subjects had at least one prediagnosis sample positive for RF or anti-CCP, respectively. Gender and race were not significantly associated with the prevalence or timing of preclinical antibody appearance. Preclinical anti-CCP positivity was strongly associated with the development of erosive RA (odds ratio = 4.64; 95% confidence interval 1.71 to 12.63; p<0.01), but RF was not (p = 0.60). Additionally, as age at the time of diagnosis of RA increased the duration of prediagnosis antibody positivity for RF and anti-CCP increased, with the longest duration of preclinical antibody positivity seen in patients diagnosed with RA over the age of 40. In no subjects did symptom onset precede the appearance of RF or anti-CCP antibodies. CONCLUSIONS: The period of time that RF and anti-CCP are present before diagnosis lengthens as the age at the time of diagnosis of RA increases. This finding suggests that factors such as genetic risk or environmental exposure influencing the temporal relationship between the development of RA-related autoantibodies and clinically apparent disease onset may differ with age.
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Article Anti-cyclic citrullinated peptide antibody and rheumatoid factor isotypes in African Americans with early rheumatoid arthritis. free! 2006
Mikuls TR, Holers VM, Parrish L, Kuhn KA, Conn DL, Gilkeson G, Smith EA, Kamen DL, Jonas BL, Callahan LF, Alarcón GS, Howard G, Moreland LW, Bridges SL. · University of Nebraska Medical Center, Omaha Veterans Administration Medical Center, Omaha, NE, USA. · Arthritis Rheum. · Pubmed #16948136 links to free full text
This publication has no abstract.
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Article Are anti-cyclic citrullinated peptide antibodies pathogenic in rheumatoid arthritis? 2006
Holers VM. · Division of Rheumatology, University of Colorado Health Sciences Center, Denver, CO 80262, USA. · Nat Clin Pract Rheumatol. · Pubmed #16932728 No free full text.
This publication has no abstract.
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Article Antibodies against citrullinated proteins enhance tissue injury in experimental autoimmune arthritis. free! 2006
Kuhn KA, Kulik L, Tomooka B, Braschler KJ, Arend WP, Robinson WH, Holers VM. · Department of Immunology and Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA. · J Clin Invest. · Pubmed #16585962 links to free full text
Abstract: Antibodies against citrullinated proteins are specific and predictive markers for rheumatoid arthritis although the pathologic relevance of these antibodies remains unclear. To investigate the significance of these autoantibodies, collagen-induced arthritis (CIA) in mice was used to establish an animal model of antibody reactivity to citrullinated proteins. DBA/1J mice were immunized with bovine type II collagen (CII) at days 0 and 21, and serum was collected every 7 days for analysis. Antibodies against both CII and cyclic citrullinated peptide, one such citrullinated antigen, appeared early after immunization, before joint swelling was observed. Further, these antibodies demonstrated specific binding to citrullinated filaggrin in rat esophagus by indirect immunofluorescence and citrullinated fibrinogen by Western blot. To evaluate the role of immune responses to citrullinated proteins in CIA, mice were tolerized with a citrulline-containing peptide, followed by antigen challenge with CII. Tolerized mice demonstrated significantly reduced disease severity and incidence compared with controls. We also identified novel murine monoclonal antibodies specific to citrullinated fibrinogen that enhanced arthritis when coadministered with a submaximal dose of anti-CII antibodies and bound targets within the inflamed synovium of mice with CIA. These results demonstrate that antibodies against citrullinated proteins are centrally involved in the pathogenesis of autoimmune arthritis.
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Article Antibodies against cyclic citrullinated peptide are associated with HLA-DR4 in simplex and multiplex polyarticular-onset juvenile rheumatoid arthritis. free! 2005
Ferucci ED, Majka DS, Parrish LA, Moroldo MB, Ryan M, Passo M, Thompson SD, Deane KD, Rewers M, Arend WP, Glass DN, Norris JM, Holers VM. · Division of Rheumatology, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA. · Arthritis Rheum. · Pubmed #15641089 links to free full text
Abstract: OBJECTIVE: Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been detected in patients with juvenile rheumatoid arthritis (JRA), particularly in those with polyarticular, rheumatoid factor (RF)-positive JRA. Our objectives were to determine whether anti-CCP antibodies are associated with HLA-DR4 in children with polyarticular JRA, whether anti-CCP antibodies are associated with clinical features of disease, and whether affected sibling pairs (ASPs) with JRA are concordant for this antibody. METHODS: Stored serum samples obtained from 230 HLA-typed patients with JRA (77 with polyarticular-onset disease and 153 with pauciarticular- or systemic-onset disease), 100 JRA ASPs, and 688 healthy children were tested for anti-CCP antibodies and RF. RESULTS: Thirteen percent of the patients with polyarticular-onset JRA and 2% of the other JRA patients exhibited anti-CCP antibodies, compared with only 0.6% of the controls. Fifty-seven percent of RF-positive patients with polyarticular-onset JRA had anti-CCP antibodies. HLA-DR4-positive patients with polyarticular-onset JRA were more likely to have anti-CCP antibodies than were those without HLA-DR4 alleles (odds ratio [OR] 5.20, 95% confidence interval [95% CI] 1.30-20.9). Anti-CCP antibodies were associated with polyarticular onset (OR 7.46, 95% CI 1.99-28.0), a polyarticular disease course (OR 9.78, 95% CI 1.25-76.7), and erosive disease (OR 14.3, 95% CI 3.01-67.9). Concordance rates for anti-CCP antibodies among ASPs were statistically significant. CONCLUSION: These data demonstrate increased anti-CCP antibody formation in HLA-DR4-positive patients with polyarticular-onset JRA. The overall prevalence of anti-CCP antibodies in JRA is low, but a substantial proportion of RF-positive patients with polyarticular-onset JRA have these antibodies. Anti-CCP antibodies in JRA are associated with polyarticular onset, a polyarticular course, and erosive disease.
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Article Association of rheumatoid arthritis treatment response and disease duration with declines in serum levels of IgM rheumatoid factor and anti-cyclic citrullinated peptide antibody. free! 2004
Mikuls TR, O'Dell JR, Stoner JA, Parrish LA, Arend WP, Norris JM, Holers VM. · Department of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA. · Arthritis Rheum. · Pubmed #15593224 links to free full text
Abstract: OBJECTIVE: To examine the association of treatment response and disease duration with changes in rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody levels among patients with rheumatoid arthritis (RA). METHODS: The study sample included 66 RA patients who completed double-blind, randomized clinical protocols and for whom baseline and followup serum samples were available. Anti-CCP and RF levels were measured using commercially available assay kits. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to describe the association of response and disease duration with declines in antibody levels. RESULTS: Patients had a mean +/- SD age of 49.9 +/- 12.0 years and were predominantly female (n = 51; 77%). The mean +/- SD duration between the times at which the baseline and followup serum samples were obtained was 13.7 +/- 8.6 months. Among the 64 subjects with positive antibody at baseline, 33 (52%) experienced a > or =25% reduction in the anti-CCP antibody level during the course of treatment, and 35 patients (55%) had a > or =25% reduction in RF. After adjustment for the baseline anti-CCP antibody level, only a shorter disease duration (< or =12 months) was significantly associated with a decline in the level of anti-CCP antibody (OR 3.0, 95% CI 1.0-8.8), and no association with treatment response was observed. Conversely, treatment response was the only significant determinant of a decrease in RF levels (OR 3.6, 95% CI 1.2-10.4). CONCLUSION: Shorter disease duration predicts greater declines in anti-CCP antibody levels with treatment in RA. Although treatment response is a robust determinant of a decrease in RF, it does not appear to be associated with declines in the anti-CCP antibody level.
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Article Arthritis critically dependent on innate immune system players. 2002
Ji H, Ohmura K, Mahmood U, Lee DM, Hofhuis FM, Boackle SA, Takahashi K, Holers VM, Walport M, Gerard C, Ezekowitz A, Carroll MC, Brenner M, Weissleder R, Verbeek JS, Duchatelle V, Degott C, Benoist C, Mathis D. · Section on Immunology and Immunogenetics, Joslin Diabetes Center, Boston, MA 02215, USA. · Immunity. · Pubmed #11869678 No free full text.
Abstract: K/BxN T cell receptor transgenic mice are a model of inflammatory arthritis, similar to rheumatoid arthritis. Disease in these animals is focused specifically on the joints but stems from autoreactivity to a ubiquitously expressed antigen, glucose-6-phosphate isomerase (GPI). T and B cells are both required for disease initiation, but anti-GPI immunoglobulins (Igs), alone, can induce arthritis in lymphocyte-deficient recipients. Here, we show that the arthritogenic Igs act through both Fc receptors (in particular, FcgammaRIII) and the complement network (C5a). Surprisingly, the alternative pathway of complement activation is critical, while classical pathway components are entirely dispensable. We suggest that autoimmune disease, even one that is organ specific, can occur when mobilization of an adaptive immune response results in runaway activation of the innate response.
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Article Gamma-glutamyl transpeptidase is up-regulated on memory T lymphocytes. free! 1999
Karp DR, Carlisle ML, Mobley AB, Nichols TC, Oppenheimer-Marks N, Brezinschek RI, Holers VM. · The Simmons Arthritis Research Center and Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75235, USA. · Int Immunol. · Pubmed #10545483 links to free full text
Abstract: The ectoenzyme gamma-glutamyl transpeptidase (GGT) hydrolyzes glutathione (GSH), is required for the maintenance of normal intracellular GSH levels and modifies the activity of GSH-containing adducts. Previous data suggested that this enzyme was present on mitogen-activated T lymphocytes. However, the level of GGT protein expression on human mononuclear cell subsets has not been determined. A novel mAb to human GGT, 3A8, was developed. 3A8 was used to show that the expression of GGT is, in fact, highest on resting T cells that express markers of the memory phenotype, specifically CD45RO and decreased expression of CD45RB. The peripheral blood of patients with rheumatoid arthritis was found to have expanded numbers of T cells expressing levels of GGT up to 10-fold higher than controls. In addition, the CD4(+) T cell subset with the capacity to migrate across a human endothelial cell monolayer expresses high GGT levels. GGT expression was up-regulated on peripheral blood T cells following activation in vitro by either superantigen, phorbol ester, or IL-15, a stimulatory cytokine synthesized in rheumatoid synovium. Resting peripheral blood T cells that express GGT have higher levels of intracellular thiols than those that do not. These observations suggest that GGT may play an important role in the regulation of lymphocytes that are at a particular developmental stage.
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