AB0054 CXCL4 potentiates TLR-driven polarization of human dendritic cells towards cytokine production, antigen cross-presentation and increases stimulation of CD8+T-cells

SC Silva-Cardoso, AJ Affandi, L Spel, M Cossu, M Boes, TR Radstake
2017 Abstracts Accepted for Publication   unpublished
Scientific Abstracts 1065 gelatinase expressed in three major forms: dimer, monomer and a complex with neutrophil gelatin-associated lipocalin (NGAL). Interleukin-(IL)-6 is a pleiotropic cytokine expressed by a variety of immune and non-immune cells. However, the mechanisms by which IL-6 contributes to the pathogenesis of chronic arthropathies are not fully understood. Objectives: The purpose of the present work was to perform a comparative study of the IL-6 production and MMP-9 activity in FLS
more » ... P-9 activity in FLS stimulated with SF from patients with osteoarthritis (OA), rheumatoid arthritis (RA) or spondyloarthritis (SpA). In addition, the effect of IL-6 blockade on MMP-9 activity was evaluated. Methods: Primary FLS were obtained from SF of the RA patients. Furthermore, the SW982 human synovial cell line was used. The SF of patients with OA (n=11), RA (n=11) or SpA (n=9) patients were pooled. The FLS were stimulated with OA, RA or SpA SF pools and supernatants (SN) were collected after 24, 48 and 72 h. The IL-6 levels were assessed in the SN by ELISA. The gelatinase activity of the SN was determined by zymography. The IL-6 function was blocked with the anti-IL-6 receptor antagonist tocilizumab (TCZ) (200μg/ml). Results: Earlier induction of IL-6 in SW982 cell line was observed by RA and SpA SF stimulation since significant levels were detected at 24 h (p<0.001 and p<0.01 compared with non-stimulated cells, respectively), whilst OA SF induced significant IL-6 secretion at 72 h (p<0.01). Similar results were observed in primary FLS. In contrast to SF of OA patients, SF of patients with RA or SpA induced increased and sustained secretion of active MMP-9. Moreover, the molecular weight band corresponding with NGAL-MMP-9 complex, considered a protected form of MMP-9, was detected with higher intensity in the SN of FLS stimulated with RA or SpA SF compared with OA SF (p<0.001). In the presence of TCZ, significant inhibition in the gelatinase activity of all MMP-9 forms was observed at 48h of stimulation with RA or SpA SF (p<0.001 for MMP-9 dimer and NGAL-MMP-9 complex; p<0.01 for MMP-9 monomer, compared with FLS stimulated in absence of TCZ). Conclusions: We conclude that SF of patients with inflammatory arthritis recreate a differential microenvironment for FLS that impacts on early phenotypic changes of these cells. The IL-6 provokes augmented and persistent MMP-9 activity in FLS stimulated with RA or SpA SF. This work identifies TCZ as an inhibitor of all forms of MMP-9. Background: CD8+ T cell responses to viral pathogens is crucial for the prompt resolution of acute infections. SLE patients are more likely to have infections due to suppression of immune system by long-term glucocorticoid and immunosuppressive agent intake. Our previous study showed that low-dose IL-2 is effective in SLE. Objectives: The present study is to evaluate the potential anti-infection effect of low-dose IL-2 in refractory SLE patients. Methods: Nine refractory SLE patients and 9 health controls (HCs) were recruited three cycles of 1 million IU recombinant human IL-2 (rhIL-2), administered subcutaneously every other day for 2 weeks, followed by a 2-week break. The disease activitise were evaluated by rheumatologist. The frequencies of T cell subsets were assayed by flow cytometry. Virus-specific CD8 T cells responses were determined based on TNF-a, IFN-g and Grazmy B producing CD8 T cells upon CMV-EBV-Flu (CEF) viral peptide pool stimulation and subsequent intracellular staining. Results: Most patients showed good clinical responses after three cycles of low-dose IL-2 treatment. Clinical improvement was observed in SIR-4 response, improved complement 3 and 4 serum level and decreased anti-ds-DNA serum level. Functional profiling of CD8 T cells in low-dose IL-2 treated patients revealed an increased in the frequencies of CEF viral peptide specific TNF-a + and Grazmy-B + CD8 T cells. Moreover, low-dose IL-2 treated patients showed stronger antigen-specific response demonstrated by an increased stimulated/nonstimulate TNF-a-producing CD 8 T cells proliferation fold. Compared with HCs, SLE patients showed significantly lower frequencies of CEF specific Grazmy-B producing CD8 T cell, and treatment with low-dose IL-2 significantly increased the frequency of these Grazmy-B + CD8 T cells in SLE patients. Conclusions: Low-dose IL-2 treatment was effective and safe in refractory SLE patients. Virus-specific antigen-specific CD8 T cell response could be enhanced upon this treatment which might be potentially valuable in anti-infection in SLE. References : [1] Bilate AM, Lafaille JJ. Induced CD4+Foxp3+ regulatory T cells in immune tolerance. Annu Rev Immunol. 2012;30:733-58. [2] Blattman JN, Grayson JM, Wherry EJ, Kaech SM, Smith KA, Ahmed R. Therapeutic use of IL-2 to enhance antiviral T-cell responses in vivo. Nat Med. 2003;9(5):540-7. [3] Palucka K, Banchereau J. Diversity and collaboration for effective immunotherapy. Nat Med. 2016;22(12):1390-1. † ILD vs non-ILD p=0.864. ‡ ILD vs non-ILD p=0.146. Conclusions: Our findings indicate that TGF-β and GDF-15 are increased in CTD patients but, they are not a specific markers for CTD-ILD
doi:10.1136/annrheumdis-2017-eular.4890 fatcat:oondbhsyxfg4hihncyjm5edoxu