| 1. |
- Snir, O., et al.
(författare)
-
Multiple antibody reactivities to citrullinated antigens in sera from patients with rheumatoid arthritis : association with HLA-DRB1 alleles
- 2009
-
Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 68:5, s. 736-743
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Autoantibodies to cyclic citrullinated peptides (anti-CCP) are present in most patients with rheumatoid arthritis ( RA), and associate with HLA-DRB1 shared epitope (SE) alleles. Objective: To investigate reactivities of anti-CCP to various citrullinated proteins/peptides, which represent potential autoantigens in RA, and to examine the relationship between such antibodies, and their association with genetic variants within HLA-DRB1 SE alleles. Methods: Serum samples from 291 patients with established RA and 100 sex- and age-matched healthy subjects were included in this study. Sera were first analysed for presence of anti-CCP antibodies and further for IgG and IgA antibodies towards candidate autoantigens in both their native and citrullinated form including: fibrinogen, alpha-enolase peptide-1 and the C1-epitope of type II collagen (C1(III)). Antibody specificity was confirmed by cross-reactivity tests. HLA-DR genotyping was performed. Results: 72% of patients with RA were anti-CCP positive. Among the candidate autoantigens examined, IgG antibodies to citrullinated fibrinogen were found in 66% of patients' sera and in 41% for both citrullinated alpha-enolase peptide-1 and citrullinated C1(III). These antibodies were mainly seen in the anti-CCP-positive patient group; they were specific for their respective antigen and displayed limited cross reactivity. IgA responses were also detected, but less frequently than IgG. Anti-CCP and anti-citrullinated protein antibodies were associated with HLA-DRB1*04 rather than with HLA-DRB1*01 alleles. Conclusions: Antibodies directed against several citrullinated antigens are present in CCP-positive RA, with many patients displaying multireactivity. All specific reactivities were primarily associated with the HLA-DRB1*04 alleles, suggesting common pathways of anti-citrulline immunity.
|
|
| 2. |
- Thunberg, Sarah, 1976-, et al.
(författare)
-
Immune regulation by CD4(+)CD25(+) T cells and interleukin-10 in birch pollen-allergic patients and non-allergic controls
- 2007
-
Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 37:8, s. 1127-1136
-
Tidskriftsartikel (refereegranskat)abstract
- CD4(+)CD25(+) regulatory T (Treg) cells and the cytokines IL-10 or TGF-beta play key roles in the maintenance of T cell homeostasis and tolerance to infectious and non-infectious antigens such as allergens. To investigate the regulation of immune responses to birch pollen allergen compared with influenza antigen by Treg cells obtained from birch pollen-allergic patients and non-allergic controls. Peripheral blood was collected from 10 birch pollen-allergic patients and 10 non-allergic healthy controls. CD4(+)CD25(+) and CD4(+)CD25(-) cells isolated by magnetic-activated cell sorting were co-cultured and stimulated with birch pollen extract or influenza vaccine in the absence or presence of anti-IL-10 or soluble TGF-beta RII. CD4(+)CD25(+) cells from non-allergic controls were able to suppress influenza antigen and birch pollen stimulated effector cell proliferation, whereas CD4(+)CD25(+) cells from allergic patients suppressed influenza antigen-, but not birch pollen-stimulated proliferation. The production of Th1 cytokines, but not Th2 cytokines, was suppressed by CD4(+)CD25(+) cells from both allergic patients and controls, upon stimulation with birch pollen extract. Neutralization of IL-10 led to significantly increased production of IFN-gamma in cultures with CD4(+)CD25(-) T effector cells. In addition, six-fold higher concentrations of TNF-alpha were detected after neutralization of IL-10 in both CD4(+)CD25(-) and CD4(+)CD25(+) cell cultures from allergic patients and controls. We demonstrate that the allergen-specific suppressive function of CD4(+)CD25(+) cells from allergic patients is impaired compared with non-allergic controls. Moreover, neutralization of IL-10 enhances the production of TNF-alpha, suggesting counter-acting properties of IL-10 and TNF-alpha, where IL-10 promotes tolerance and suppression by Treg cells and TNF-alpha promotes inflammatory responses.
|
|
