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espanolComo parte de la polemica Bienal del Whitney Museum de 1993, el artista puertorriqueno Pepon Osorio recreo el interior de una casa neoyorquina en su obra Scene of the Crime (Whose Chrime?). El presente articulo se propone analizar la dimension critica de la instalacion para argumentar que esta va mas alla de la mera critica institucional. Para ello, me centrare en primer lugar en la particular disrupcion en el espacio del museo llevada a cabo por el artista. Por otro lado, analizare su intencionado uso del kitsch como gesto de resistencia cultural: a traves de la exacerbada acumulacion de objetos e imagenes, la obra de Osorio pone en tela de juicio los sistemas convencionales de visibilidad que operan en el ambito institucional. EnglishAs part of the controversial 1993 Whitney Biennial, Puerto Rican artist Pepon Osorio recreated the interior of a Nuyorican home in his work Scene of the Crime (Whose Crime?). This paper aims to unpack the installation’s critical dimension, to argue that it goes beyond the mere institutional critique. To that end, I will first examine the particular disruption of the aseptic museum’s space prompted by Osorio’s installation. Secondly, I will analyze the artist’s intentional use of Kitsch as a gesture of cultural resistance: through the exaggerated accumulation of objects and imageries, Osorio deftly called into question the conventional systems of visibility that operate within the institutional realm.

The cytokine interleukin-6 (IL-6) signals through three mechanisms called classic signaling, trans-signaling, and trans-presentation. IL-6 trans-signaling is distinctly mediated through a soluble form of its transmembrane receptor IL-6R (sIL-6R) and the coreceptor gp130 and is implicated in multiple autoimmune diseases. Although a soluble form of gp130 (sgp130) inhibits only IL-6 trans-signaling, it also blocks an analogous trans-signaling mechanism of IL-11 and its soluble receptor sIL-11R. Here, we report miniaturized chimeric soluble gp130 variants that efficiently trap IL-6:sIL-6R but not IL-11:sIL-11R complexes. We designed a novel IL-6 trans-signaling trap by fusing a miniaturized sgp130 variant to an IL-6:sIL-6R complex–binding nanobody and the Fc portion of immunoglobulin G (IgG). This trap, called cs-130Fc, exhibited improved inhibition of as well as increased selectivity for IL-6 trans-signaling compared to the conventional fusion protein sgp130Fc. We introduced affinity-enhancing mutations in cs-130Fc and sgp130Fc that further improved selectivity toward IL-6 trans-signaling. Moreover, cs-130Fc efficiently inhibited the expansion of T helper 17 (TH17) cells in cultures of mouse CD4+ T cells treated with IL-6:sIL-6R. Thus, these variants may provide or lead to the development of more precisely targeted therapeutics for inflammatory disorders associated with IL-6 trans-signaling.

Background A third of Sjögren’s syndrome (SS) patients develop ectopic lymphoid structures (ELS) in their salivary glands (SG). ELS play an active role in autoimmunity and contribute to the development of MALT lymphoma. Interleukin 27 (IL-27) exerts key immunomodulatory actions on numerous immune cells but its role in the formation and regulation of ELS in the SG of SS is unknown. Here we used a murine model of SG ELS to elucidate the role of IL-27 and its interaction with IL-17 in the development, regulation and function of ELS. We extended our observations on a cohort of SS patients to identify IL-27 cellular source, target cells and functional properties in modulating CD4 T cells function. Methods A single dose of reporter-encoding adenovirus was delivered directly to the SG of wild-type (WT) and IL-27RA-deficient (KO) mice to trigger ELS formation. For IL-17 blockade, anti-mouse IL-17A antibody was used. ELS development and peripheral immune responses were tracked by immuno-histopathology, FACS, and qPCR. Minor SG biopsies were collected from SS and non-specific sialadenitis (sicca) patients. Peripheral blood mononuclear cells (PBMC) isolated from SS and rheumatoid arthritis (RA) patients and age/sex-matched healthy donors (HD). For in vitro experiments PBMCs were incubated with IL-27 and analysed by FACS and cytokines levels were measured in culture supernatants. Tissue IL-27 was assessed by multicolour immunofluorescence. Results In WT mice, SG ELS formation was preceded by upregulation of IL-27p28 and infiltration of IL-27 producing cells. KO mice displayed larger, more abundant ELS in the SG. Higher expression levels of ELS-related genes (Cxcl13, Ccl19, Ltb, Aid) compared to WT mice were measured. KO mice showed an uncontrolled SG Th17 response and systemic IL-17A blockade caused a reduction in ELS size and in the expression of ELS-related genes. In SS patients SG and serum, we observed higher expression levels of IL-27 transcripts and protein, compared to sicca. SG IL-27 was selectively increased in ELS+ patients. IL-27 staining was detected in the T cell-rich areas of SG ELS often co-localizing with DC-LAMP+ dendritic cells. While IL-27 was able to significantly downregulate IL-17 production in HD and RA, CD4 T cells from patients with SS failed to downregulate IL-17 but showed an aberrant IFNγ release upon IL-27 incubation. Conclusion The IL-27-mediated restriction of Th17 expansion plays a critical role in the regulation of germinal centre response. Both in murine inducible ELS and in patients with SS, dendritic cells appear as the main cellular source of IL-27. IL-27 consistently failed to downregulate IL-17 release in CD4 T cells from SS patients, albeit its expression was increased in the ELS+ subset of SS, suggesting that a profound dysregulation of the IL-27/IL-17 axis play an important role in ELS formation in this condition. Disclosures D. Lucchesi None. R. Coleby None. E. Pontarini None. E. Prediletto None. F. Rivellese None. D. Hill None. A. Derrac Soria None. S. Jones None. I. Humphreys None. N. Sutcliffe None. A. Tappuni None. C. Pitzalis None. G. Jones None. M. Bombardieri None.

Background Approximately 30% of Sjogren’s Syndrome (SS) patients develop Ectopic Lymphoid Structures (ELS) in their salivary glands (SG). ELS play an active role in autoimmunity and contribute to the development of MALT lymphoma. Interleukin 27 (IL-27) exerts key immunomodulatory actions on CD4 T cells with both pro and anti-inflammatory roles but its role in the formation and regulation of ELS in the salivary glands of SS is unknown. Objectives We first used a murine model of inducible SG ELS to elucidate the role of IL-27 and its interaction with IL-17 in the regulation of ELS formation and function. We then extended our observations on a cohort of SS patients to identify IL-27 cellular source, target cells and functional properties in modulating peripheral and lesional CD4 T cells function. Methods To trigger ELS formation a single dose of reporter-encoding adenovirus was delivered directly to the SG of wild-type (WT) and IL-27RA-deficient (KO) mice. For IL-17 blockade anti-mouse IL-17A antibody was administered systemically. ELS development and peripheral immune responses were tracked by immuno-histopathology, FACS, and qPCR. Minor SG biopsies were collected from SS and non-specific sialadenitis (sicca) patients. Peripheral blood mononuclear cells (PBMC) isolated from patients and age/sex matched healthy donors (HD). For in vitro experiments PBMCs, isolated CD4 T cells and parotid gland MCs were incubated with IL-27 and analysed by FACS for CD4 T cell subsets while cytokines levels were measured intracellularly by FACS and in culture supernatants. Tissue IL-27 was assessed in SS SG sections by multicolour immunofluorescence to identify IL-27 producing cells. Results In WT mice, SG ELS formation was preceded by an upregulation of IL-27p28 and infiltration of IL-27 producing cells (CD11b+ first followed by CD4 and CD8 T cells). KO mice displayed larger, more abundant ELS in the SG with more germinal centres and higher levels of ELS-related genes (Cxcl13, Ccl19, Ltb, Aid) compared to WT mice. During ELS formation, KO mice had an uncontrolled SG Th17 response and systemic IL-17A blockade caused reduction in ELS size and in the expression of ELS-related genes. In SS patients SG and serum, we observed higher expression levels of IL-27 transcripts and protein, respectively, compared to sicca, while SG IL-27 was selectively increased in the ELS+ subset of SS. Immunofluorescence staining for IL-27 revealed its presence primarily in the T cell rich areas of SG ELS with frequent co-localization with DC-LAMP+ dendritic cells. Finally, while IL-27 was able to significantly downregulate IL-17 production in HD, CD4 T cells from patients with SS failed to downregulate IL-17 but showed an aberrant IFNγ release upon IL-27 incubation. We did not observe any difference in IL-27R expression or downstream STAT1/3 phosphorylation between SS and HD. Conclusion IL-27 is a critical regulator of the magnitude of the germinal centre response in the SG by restricting Th17 expansion. Both in murine inducible ELS and in patients with SS, dendritic cells appear as the main cellular source of IL-27. Although SG IL-27 was increased in the ELS+ subset of SS, it consistently failed to downregulate IL-17 release in CD4 T cells from SS patients suggesting that a profound dysregulation of the IL-27/IL-17 axis play an important role in ELS formation in this condition. Disclosure of Interests Davide Lucchesi: None declared, Rachel Coleby: None declared, Elena Pontarini: None declared, Edoardo Prediletto: None declared, David Hill: None declared, Alicia Derrac Soria: None declared, Felice Rivellese: None declared, Costantino Pitzalis Grant/research support from: Celgene, Simon Jones: None declared, Gareth Jones: None declared, Michele Bombardieri Grant/research support from: Celgene, Consultant for: Medimmune

The cytokine IL-6 controls the survival, proliferation and effector characteristics of lymphocytes through activation of the transcription factors STAT1 and STAT3. While STAT3 activity is an ever-present feature of IL-6 signaling in CD4+ T cells, prior T-cell receptor activation limits the IL-6 control of STAT1 in effector and memory populations. Here we show that STAT1 phosphorylation in response to IL-6 was regulated by protein tyrosine phosphatases (PTPN2, PTPN22) expressed in response to the activation of naïve CD4+ T cells. Transcriptomic and chromatin immunoprecipitation-sequencing of IL-6 responses in naïve and effector memory CD4+ T cells showed how the suppression of STAT1 activation shaped the functional identity and effector characteristics of memory CD4+ T cells. Thus, protein tyrosine phosphatases induced by activation of naïve T cells determined the way activated or memory CD4+ T cells sensed and interpreted cytokine signals.

Background ¾ Rheumatoid arthritis (RA) is one of the most common forms of autoimmune disease, affecting about 1% of the population and causing chronic inflammation that primarily affects the joints. Cytokines that signal via the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling pathway are major drivers of synovitis in patients with RA and contribute to the rapid progression of the disease. Biological agents targeting the cytokine interleukin (IL)-6, its receptor system or\ud downstream pathway have revolutionised the treatment of immune-mediated diseases and can induce drug-free remission. However, RA is a highly heterogeneous and complex disease and consequently, around 40% of patients do not respond to current frontline biologics. This has raised the need for alternative therapeutic strategies or precision medicine approaches that improve treatment decisions for RA patients. My thesis aimed to investigate the action of novel therapeutic modalities that target the IL-6 receptor system or downstream signalling cassette to improve understanding of the underlying inflammatory processes that drive synovitis.\ud Results ¾ Exploiting three novel classes of IL-6/STAT3 inhibitors, I have interrogated their mode of action in in vitro model systems and animal models of synovitis. (1) Using histopathology and RNA-sequencing of the inflamed synovium, I demonstrated that an anti-cancer therapy (CpG-Stat3siRNA) improved arthritis outcome, altered the balance of STAT1/STAT3 signalling and reduced the incidence of ectopic lymphoid-like structures in synovitis. (2) I also used a virus-derived SOCS3 modulator peptide that suppresses STAT3 activity through the induction of SOCS3. This agent was shown to block pathogenic Thelper (Th)17 cell differentiation in vitro and reduced disease pathology in mice with antigen-induced arthritis. (3) Blocking of IL-6 trans-signalling pathway with engineered inhibitors (cs-130Fc) based on regulatory domains of the sgp130 receptor proved efficacy over other related therapy variants (e.g., olamkicept) in inhibiting STAT3-driven Th17 cell expansion in vitro. In a final approach, I also examined the biology of genes that are suppressed by IL-6 and IL-27 in CD4+ T-cells. These factors might have immune-protective function in synovitis, and initial studies are presented on the identification of CRTAM as one such factor and its inflammatory regulation in mouse synovitis.\ud Conclusions ¾ These studies showcase how JAK/STAT signalling through the IL-6 receptor cassette may be controlled at multiple levels and further demonstrate how investigations\ud into their mode of action help to unearth new understanding of IL-6 biology in RA.