A novel human autoantigen, endothelial cell growth factor, is a target of T and B cell responses in patients with Lyme disease

Hospital and Harvard Medical School, Boston, Massachusetts
Arthritis & Rheumatology (Impact Factor: 7.87). 01/2013; 65(1). DOI: 10.1002/art.37732
Source: PubMed

ABSTRACT OBJECTIVE.: Autoantigen presentation by HLA-DR molecules is thought to be a central component of many autoimmune diseases, but uncovering disease-relevant autoantigens has been a difficult challenge. Our goal was to identify autoantigens in patients with antibiotic-refractory Lyme arthritis, which is thought to result from infection-induced autoimmunity. METHODS.: Using tandem mass spectrometry, naturally presented HLA-DR self-peptides from a patient's synovium were identified, synthesized and reacted with his peripheral blood mononuclear cells (PBMC). Immunoreactive peptides and their source proteins were then tested for T and B cell responses using large numbers of patients' cells or sera. RESULTS.: Of 120 HLA-DR-presented self-peptides identified from one patient, one peptide derived from endothelial cell growth factor (ECGF) caused his PBMC to proliferate. We then found that T and B cell responses to ECGF occurred systemically in about 10-30% of patients with early or late manifestations of Lyme disease, primarily in those with refractory arthritis-associated HLA-DR alleles, such as DRB1*0101 and 0401. Compared with patients with antibiotic-responsive arthritis, those with antibiotic-refractory arthritis had significantly higher concentrations of ECGF in synovial fluid (P<0.0001) and more often had ECGF antibody reactivity. In non-antibiotic-treated historic patients who developed arthritis, 26% had ECGF reactivity, which often developed before the onset of arthritis and was associated with significantly longer courses of arthritis. CONCLUSION.: T and B cell responses to ECGF occur in a subset of patients with Lyme disease, particularly in those with antibiotic-refractory arthritis, providing the first direct evidence for autoimmune T and B cell responses in this illness. © 2012 American College of Rheumatology.

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Available from: Elise E Drouin, Oct 06, 2014
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    ABSTRACT: OBJECTIVE.: To explore the role of immune dysregulation in antibiotic-refractory Lyme arthritis, the phenotype, frequency and function of CD4+ Teff and Treg cells were compared in patients with antibiotic-responsive or antibiotic-refractory arthritis. In the latter condition, infection-induced autoimmunity is thought to have a pathogenic role. METHODS.: Matched peripheral blood (PB) and synovial fluid (SF) samples from 15 patients with antibiotic-responsive arthritis were compared with those from 16 patients with antibiotic-refractory arthritis using flow cytometry, suppression and cytokine assays. RESULTS.: Critical differences between the 2 patient groups were found in the SF CD4+CD25hi+ populations, a subset of cells usually composed of FOXP3-positive Treg cells. In patients with antibiotic-refractory arthritis, this cell population often had fewer FOXP3-positive cells, and greater frequencies of FOXP3-negative (Teff) compared to patients with antibiotic-responsive arthritis. Moreover, in the refractory group, CD4+CD25hi+ cells had significantly greater expression of GITR and OX-40, two co-receptors that augment T cell function. Suppression assays showed that CD4+CD25hi+ cells in patients with refractory arthritis did not effectively suppress proliferation of CD4+CD25- cells, or secretion of IFN-γ or TNF-α, whereas those from patients with responsive arthritis did. Finally, in the refractory group, higher ratios of CD25hi+FOXP3-/CD25hi+FOXP3+ cells correlated directly with longer post-treatment durations of arthritis. CONCLUSION.: Patients with antibiotic-refractory Lyme arthritis often had lower frequencies of Treg, higher expression of activation co-receptors, and less effective inhibition of pro-inflammatory cytokines. This suggests that immune responses in these patients were excessively amplified leading to immune dysregulation and refractory arthritis. © 2013 American College of Rheumatology.
    Arthritis & Rheumatology 06/2013; 65(6). DOI:10.1002/art.37910
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    ABSTRACT: Natural killer (NK) and natural killer T (NKT) cells provide a first line of defense against infection. However, these cells have not yet been examined in patients with Lyme arthritis, a late disease manifestation. Lyme arthritis usually resolves with antibiotic treatment. However, some patients have persistent arthritis after spirochetal killing, which may result from excessive inflammation, immune dysregulation and infection-induced autoimmunity. We determined the frequencies and phenotypes of NK cells and invariant NKT (iNKT) cells in paired peripheral blood (PB) and synovial fluid (SF) samples from eight patients with antibiotic-responsive arthritis and fifteen patients with antibiotic-refractory arthritis using flow cytometry and cytokine analyses. In antibiotic-responsive patients, who were seen during active infection, high frequencies of CD56bright NK cells were found in SF, the inflammatory site, compared with PB (P <0.001); at both sites, a high percentage of cells expressed the activation receptor NKG2D and the chaperone CD94, a low percentage expressed inhibitory killer immunoglobulin-like receptors (KIR), and a high percentage produced IFN-γ. In antibiotic-refractory patients, who were usually evaluated near the conclusion of antibiotics when few if any live spirochetes remained, the phenotype of CD56bright cells in SF was similar to that in patients with antibiotic-responsive arthritis, but the frequency of these cells was significantly less (P = 0.05), and the frequencies of CD56dim NK cells tended to be higher. However, unlike typical NKdim cells, these cells produced large amounts of IFN-γ, suggesting that they were not serving a cytotoxic function. Lastly, iNKT cell frequencies in the SF of antibiotic-responsive patients were significantly greater compared with that of antibiotic-refractory patients where these cells were often absent (P = 0.003). In patients with antibiotic-responsive arthritis, the high percentage of activated, IFN-γ-producing CD56bright NK cells in SF and the presence of iNKT cells suggest that these cells still have a role in spirochetal killing late in the illness. In patients with antibiotic-refractory arthritis, the frequencies of IFN-γ-producing CD56bright and CD56dim NK cells remained high in SF, even after spirochetal killing, suggesting that these cells contribute to excessive inflammation and immune dysregulation in joints, and iNKT cells, which may have immunomodulatory effects, were often absent.
    Arthritis research & therapy 11/2013; 15(6):R183. DOI:10.1186/ar4373
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    ABSTRACT: Background. The causes of post-Lyme disease symptoms are unclear. Herein, we investigated whether specific immune responses correlated with such symptoms. Methods. The levels of 23 cytokines and chemokines, representative of innate and adaptive immune responses, were assessed in sera from 86 antibiotic-treated European patients with erythema migrans, 45 with post-Lyme symptoms and 41 without symptoms, who were evaluated prior to treatment and 2, 6, and 12 months thereafter. Results. At study entry, significant differences between groups were observed for the TH1-associated chemokines, CXCL9 and CXCL10, which were associated with negative Borrelia cultures, and the TH17-associated cytokine, IL-23, which was associated with positive cultures and the development of post-Lyme symptoms (P<0.02). Moreover, of the 41 patients with detectable IL-23 levels, 25 (61%) developed post-Lyme symptoms, and all 7 with IL-23 levels >230 ng/ml had such symptoms. Furthermore, antibody responses to the ECGF autoantigen were more common in patients with post-Lyme symptoms (P=0.07) and they correlated directly with IL-23 levels (P=0.02). Despite the presence of post-Lyme symptoms, all post-treatment culture results were negative, anti-borrelial antibody responses declined, and there were no objective signs of disseminated disease, suggesting that spirochetal eradication had occurred with treatment in all patients. Conclusions. High TH1-associated responses correlated with more effective immune-mediated spirochetal killing, whereas high TH17-associated immune responses, often accompanied by autoantibodies, correlated with post-Lyme symptoms, providing a new paradigm for the study of post-infectious symptoms in a subset of patients with Lyme disease.
    Clinical Infectious Diseases 11/2013; 58(3). DOI:10.1093/cid/cit735
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