Francesco Ciccia

Overexpression of interleukin-23, but not interleukin-17, as an immunologic signature of subclinical intestinal inflammation in ankylosing spondylitis

OBJECTIVE Subclinical gut inflammation is common in spondylarthritis, but the immunologic abnormalities underlying this process are undefined. Perturbation of the interleukin-23 (IL-23)/Th17 axis has emerged as a fundamental trigger of chronic inflammation. This study was undertaken to investigate the expression and tissue distribution of IL-23/Th17-related molecules in Crohns disease (CD) and in subclinical gut inflammation in ankylosing spondylitis (AS). METHODS Quantitative gene expression analysis of Th1/Th2 and IL-23/Th17 responses was performed in intestinal biopsy samples obtained from 12 patients with CD, 15 patients with AS, and 13 controls. IL-23 tissue distribution and identification of IL-23-producing cells were evaluated by immunohistochemistry. RESULTS We demonstrated a strong and significant up-regulation of IL-23p19 transcripts in the terminal ileum in patients with AS and patients with CD. IL-23 was abundantly produced by infiltrating monocyte-like cells in inflamed mucosa from AS and CD patients. Notably, we also identified Paneth cells as a major source of IL-23 in patients with AS, patients with CD, and normal controls. Unlike CD, in AS patients, IL-23 was not associated with up-regulation of IL-17 and the IL-17-inducing cytokines IL-6 and IL-1beta. Finally, while the Th1-related cytokines interferon-gamma, IL-12p35, and IL-27p28 were overexpressed only in CD patients, IL-4, IL-5, and STAT-6 were also significantly increased in AS patients. CONCLUSION Our findings indicate that overexpression of IL-23, but not IL-17, is a pivotal feature of subclinical gut inflammation in AS. Identification of resident Paneth cells as a pivotal source of IL-23 in physiologic and pathologic conditions strongly suggests that IL-23 is a master regulator of gut mucosal immunity, providing a pathophysiologic significance to the reported association between IL-23 receptor polymorphisms and intestinal inflammation.

Exosomes as Intercellular Signaling Organelles Involved in Health and Disease: Basic Science and Clinical Applications

Cell to cell communication is essential for the coordination and proper organization of different cell types in multicellular systems. Cells exchange information through a multitude of mechanisms such as secreted growth factors and chemokines, small molecules (peptides, ions, bioactive lipids and nucleotides), cell-cell contact and the secretion of extracellular matrix components. Over the last few years, however, a considerable amount of experimental evidence has demonstrated the occurrence of a sophisticated method of cell communication based on the release of specialized membranous nano-sized vesicles termed exosomes. Exosome biogenesis involves the endosomal compartment, the multivesicular bodies (MVB), which contain internal vesicles packed with an extraordinary set of molecules including enzymes, cytokines, nucleic acids and different bioactive compounds. In response to stimuli, MVB fuse with the plasma membrane and vesicles are released in the extracellular space where they can interact with neighboring cells and directly induce a signaling pathway or affect the cellular phenotype through the transfer of new receptors or even genetic material. This review will focus on exosomes as intercellular signaling organelles involved in a number of physiological as well as pathological processes and their potential use in clinical diagnostics and therapeutics.

Intestinal dysbiosis in ankylosing spondylitis.

Ankylosing spondylitis (AS) is a common, highly heritable immune‐mediated arthropathy that occurs in genetically susceptible individuals exposed to an unknown but likely ubiquitous environmental trigger. There is a close relationship between the gut and spondyloarthritis, as exemplified in patients with reactive arthritis, in whom a typically self‐limiting arthropathy follows either a gastrointestinal or urogenital infection. Microbial involvement in AS has been suggested; however, no definitive link has been established. The aim of this study was to determine whether the gut in patients with AS carries a distinct microbial signature compared with that in the gut of healthy control subjects.

Brief Report: Intestinal Dysbiosis in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a common, highly heritable immune‐mediated arthropathy that occurs in genetically susceptible individuals exposed to an unknown but likely ubiquitous environmental trigger. There is a close relationship between the gut and spondyloarthritis, as exemplified in patients with reactive arthritis, in whom a typically self‐limiting arthropathy follows either a gastrointestinal or urogenital infection. Microbial involvement in AS has been suggested; however, no definitive link has been established. The aim of this study was to determine whether the gut in patients with AS carries a distinct microbial signature compared with that in the gut of healthy control subjects.

Evidence that autophagy, but not the unfolded protein response, regulates the expression of IL-23 in the gut of patients with ankylosing spondylitis and subclinical gut inflammation

Objectives Interleukin (IL)-23 has been implicated in the pathogenesis of ankylosing spondylitis (AS). The aim of the study was to clarify the mechanisms underlying the increased IL-23 expression in the gut of AS patients. Methods Consecutive gut biopsies from 30 HLA-B27+ AS patients, 15 Crohns disease (CD) patients and 10 normal subjects were obtained. Evidence for HLA-B27 misfolding was studied. Unfolded protein response (UPR) and autophagy were assessed by RT-PCR and immunohistochemistry. The contribution of UPR and autophagy in the regulation of IL-23 expression was evaluated in in vitro experiments on isolated lamina propria mononuclear cells (LPMCs). Results Intracellular colocalisation of SYVN1 and FHCs but not a significant overexpression of UPR genes was observed in the gut of AS patients. Conversely, upregulation of the genes involved in the autophagy pathway was observed in the gut of AS and CD patients. Immunohistochemistry showed an increased expression of LC3II, ATG5 and ATG12 but not of SQSTM1 in the ileum of AS and CD patients. LC3II was expressed among infiltrating mononuclear cells and epithelial cells resembling Paneth cells (PC) and colocalised with ATG5 in AS and CD. Autophagy but not UPR was required to modulate the expression of IL-23 in isolated LPMCs of AS patients with chronic gut inflammation, CD patients and controls. Conclusions Our data suggest that HLA-B27 misfolding occurs in the gut of AS patients and is accompanied by activation of autophagy rather than a UPR. Autophagy appears to be associated with intestinal modulation of IL-23 in AS.

Potential involvement of IL-22 and IL-22-producing cells in the inflamed salivary glands of patients with Sjögren's syndrome

Objectives In chronic inflammatory disorders, interleukin (IL)-22 may act either as a protective or as a pro-inflammatory cytokine. At mucosal sites, IL-22 is mainly produced by CD4+ T cells and by a subset of mucosal natural killer (NK) cells expressing the receptor NKp44 (NKp44+ NK cells). The aim of this study was to investigate the IL-22 expression in the salivary glands of patients with primary Sjögrens syndrome (pSS). Methods Minor salivary gland biopsies were obtained from 19 patients with pSS and 16 with non-specific chronic sialoadenitis. Quantitative gene expression analysis by TaqMan real-time PCR and immunohistochemistry for IL-17, IL-22, IL-23 and STAT3 (signal transducer and activator of transcription) was performed on salivary glands from patients and controls. The cellular sources of IL-22 among infiltrating inflammatory cells were also determined by fluorescence-activated cell sorting analysis and immunohistochemistry. Results IL-22, IL-23 and IL-17 were significantly increased at both protein and mRNA levels in the inflamed salivary glands of patients with pSS. STAT3 mRNA and the tyrosine phosphorylated corresponding protein were also significantly increased in pSS. Th17 and NKp44+ NK cells were the major cellular sources of IL-22 in patients with pSS. Conclusions Our results suggest that, together with IL-17 and IL-23, IL-22 may play a pro-inflammatory role in the pathogenesis of pSS.

Type 3 innate lymphoid cells producing IL-17 and IL-22 are expanded in the gut, in the peripheral blood, synovial fluid and bone marrow of patients with ankylosing spondylitis

Background The aim of the study was to better characterise the immunological origin and the behaviour of interleukin (IL)-23-responsive innate lymphoid cells (ILCs) in the gut, synovial fluid (SF) and bone marrow (BM) of patients with ankylosing spondylitis (AS). Methods ILC1, ILC2 and ILC3 cells were determined and characterised by confocal microscopy and flow cytometry in ileal and BM biopsies, in peripheral blood (PB) and SF mononuclear cells obtained from patients with AS and controls. Mucosal vascular addressin cell adhesion molecule 1 (MADCAM-1), IL-7, IL-15 and aggregates of lymphoid tissue inducer cells (LTi) were evaluated by immunohistochemistry. The in vitro ability of epithelial cells in driving the differentiation of ILC3 and the effect of tumour necrosis factor inhibitors (TNFi) on the frequency of ILC3 and the expression of MADCAM1 were also assessed. Results ILC3 characterised as Lyn−RORc−Tbet+ NKp44+ cells were significantly expanded in the gut, SF and BM of patients with AS compared with controls, produced high levels of IL-17 and IL-22 and expressed α4β7. MADcAM1 was overexpressed in BM and ileal high endothelial venules. IL-7 was significantly increased in AS gut, especially in the context of Paneth cells, and accompanied by the presence of aggregates of c-kit/IL-7R+ cells (LTi). In in vitro experiments, epithelial cells from patients with AS actively induced differentiation of ILC3 from LTi. TNFi efficacy was accompanied by a significant decrease in the percentage of intestinal and circulating ILC3 and in the expression of MADCAM1. Conclusions Gut-derived IL-17+ and IL-22+ILC3 are expanded in the peripheral blood, SF and inflamed BM of patients with AS, suggesting the presence of an active homing axis between the gut and the inflamed sacroiliac joints.

Interleukin-22 and interleukin-22-producing NKp44+ natural killer cells in subclinical gut inflammation in ankylosing spondylitis.

OBJECTIVE The intestinal inflammation observed in patients with ankylosing spondylitis (AS) is characterized by an overexpression of interleukin-23 (IL-23). IL-23 is known to regulate IL-22 production through lamina propria NKp44+ natural killer (NK) cells, which are thought to be involved in protective mucosal mechanisms. This study was undertaken to evaluate the frequency of NKp44+ NK cells and the expression of IL-22 in the ileum of AS patients. METHODS Tissue NKp44+ NK cells, NKp46+ NK cells, and IL-22-producing cells were analyzed by flow cytometry. Quantitative gene expression analysis of IL-22, IL-23, IL-17, STAT-3, and mucin 1 (MUC-1) was performed by reverse transcriptase-polymerase chain reaction on ileal samples from 15 patients with AS, 15 patients with Crohns disease (CD), and 15 healthy controls. NKp44, pSTAT-3, and IL-22 expression was analyzed by immunohistochemistry. RESULTS The frequency of NKp44+ but not NKp46+ NK cells was increased in the inflamed ileum of AS patients compared to CD patients and controls. The frequency of NKp46+ NK cells was significantly increased only in CD patients. Among CD4+ lymphocytes and NKp44+ NK cell subsets, the latter were the major source of IL-22 on lamina propria mononuclear cells from AS patients. Significant up-regulation of IL-22, IL-23p19, MUC-1, and STAT-3 transcripts in the terminal ileum of patients with AS was observed. Immunohistochemical analysis confirmed the increased IL-22 and pSTAT-3 expression in inflamed mucosa from AS and CD patients. CONCLUSION Our findings indicate that overexpression of IL-22, together with an increased number of IL-22-producing NKp44+ NK cells, occurs in the gut of AS patients, where it appears to play a tissue-protective role.

Anti-tumour necrosis factor monoclonal antibody treatment for ocular Behçet's disease

Ocular involvement is a common and serious component of Behcets disease (BD). This manifestation worsens without treatment, and loss of vision occurs an average of 3.3 years after the onset of eye symptoms.1 High levels of tumour necrosis factor (TNF) α have been found in the serum of patients with BD together with other proinflammatory cytokines.2,3 Many studies indicate a strong polarised Th1 immune response as in rheumatoid arthritis and Crohns disease.4 High affinity monoclonal anti-TNFα antibody treatment has been recently introduced for patients with Crohns disease or rheumatoid arthritis who were resistant to standard treatment. We describe the use of the anti-TNFα chimeric monoclonal antibody, infliximab (Remicade; Centocor Inc, Malvern, PA; Schering Plough SpA, Italy) in a patient with BD who exhibited a severe ocular involvement refractory to standard treatment. An 18 year old man with BD was admitted in January 2001. He …

Anti-tumour necrosis factor α monoclonal antibody therapy for recalcitrant cerebral vasculitis in a patient with Behçet’s syndrome

Behcet’s disease (BD) is a relapsing systemic vasculitis of unknown definite cause, mainly characterised by recurrent oral and genital ulceration, uveitis, skin lesions, and arthritis. It is also one of the best recognised condition known to cause vasculitis in the central nervous system (CNS), presenting as one of the most devastating manifestations of the disease. Corticosteroids and immunosuppressive agents are the preferred drugs in the treatment of both primary and secondary CNS vasculitis. Immunosuppressive agents (for example, azathioprine, cyclosporin, cyclophosphamide, and chlorambucil), however, given alone or in different combinations, have not been shown to prevent the development of neurological complications of the disease, to reduce its exacerbations, or stop its progression. The aetiopathogenesis of BD has not yet been fully elucidated; however, increased concentrations of tumour necrosis factor α (TNFα) and soluble TNF receptors have been found in the serum of patients with active disease.1 Therapeutic TNF blockade …