Detection of IL-2 at mRNA and protein levels in synovial infiltrates from inflammatory arthropathies using biotinylated oligonucleotide probes in situ.

A non-radioactive in situ hybridization method for IL-2 mRNA detection based on the use of four biotinylated oligonucleotide probes, plus appropriate positive and negative control probes was developed and applied to synovial surgical and needle biopsies from rheumatoid arthritis (RA), spondyloarthropathy (SpA), psoriatic arthritis (PsA) and juvenile chronic arthritis (JCA) patients. In eight surgical biopsies (six RA, one SpA, one PsA) this non-radioactive system showed similar sensitivity to that of a previously described 32P-labelled probe system, and in addition detected IL-2 mRNA in five out of seven biopsies from SpA and PsA patients and in two out of two JCA needle biopsies. IL-2 mRNA was found in the absence of IL-2 protein in RA biopsies (six surgical, 12 needle), but variable amounts of IL-2 protein were detected in six out of seven needle biopsies from SpA, PsA and JCA patients, where CD3+ lymphoid infiltrates were present. These data suggest differences in IL-2 regulation and expression in RA and non-RA inflammatory arthropathies.     

IL-1, IL-18, and IL-33 families of cytokines

Summary: The interleukin-1 (IL-1), IL-18, and IL-33 families of cytokines are related by mechanism of origin, receptor structure, and signal transduction pathways utilized. All three cytokines are synthesized as precursor molecules and cleaved by the enzyme caspase-1 before or during release from the cell. The NALP-3 inflammasome is of crucial importance in generating active caspase-1. The IL-1 family contains two agonists, IL-1α and IL-1β, a specific inhibitor, IL-1 receptor antagonist (IL-1Ra), and two receptors, the biologically active type IL-1R and inactive type II IL-1R. Both IL-1RI and IL-33R utilize the same interacting accessory protein (IL-1RAcP). The balance between IL-1 and IL-1Ra is important in preventing disease in various organs, and excess production of IL-1 has been implicated in many human diseases. The IL-18 family also contains a specific inhibitor, the IL-18-binding protein (IL-18BP), which binds IL-18 in the fluid phase. The IL-18 receptor is similar to the IL-1 receptor complex, including a single ligand-binding chain and a different interacting accessory protein. IL-18 provides an important link between the innate and adaptive immune responses. Newly described IL-33 binds to the orphan IL-1 family receptor T1/ST2 and stimulates T-helper 2 responses as well as mast cells.     

Immunoregulatory properties of IL-13 in patients with inflammatory bowel disease; comparison with IL-4 and IL-10

Activated monocytes with increased expression of proinflammatory cytokines play a major role in inflammatory bowel disease (IBD). Immunoregulatory cytokines such as IL-4 and IL-10 can effectively suppress the proinflammatory response of activated monocytes. IL-13 is a recently described antiinflammatory agent in vitro. The aim of our study was to determine the in vitro immunosuppressive capacity of IL-13, IL-4 and IL-10 in patients with IBD. Peripheral blood monocytes were isolated from 27 patients with ulcerative colitis (UC), 27 patients with Crohn's disease (CD) and 16 healthy controls. Cells were stimulated with pokeweed mitogen (PWM) after treatment with IL-13, IL-4 and IL-10, and secretion of IL-1β, tumour necrosis factor-alpha (TNF-α) and IL-6 was assessed using sandwich ELISA systems. Peripheral blood monocytes secreted significantly increased amounts of TNF-α and IL-6 under stimulation with PWM in patients with CD, while UC patients showed significantly elevated levels of IL-1β. The antiinflammatory cytokines IL-13, IL-4 and IL-10 were all capable of inhibiting monocyte secretion of IL-1β in a dose-dependent manner. With regard to IL-13 and IL-4, there was no significant suppression of TNF-α and IL-6 in patients with active IBD. By contrast, IL-10 was able to down-regulate all proinflammatory cytokines in active IBD as well as in controls. Proinflammatory cytokines from patients with inactive IBD could be significantly down-regulated by all three immunoregulatory cytokines. The inhibitory effect of IL-13 on TNF-α and IL-6 production in differentiated macrophages was diminished in IBD patients, as well as in controls. In disease controls we also observed a reduced inhibition of TNF-α and IL-6 after treatment with IL-13. In conclusion, the antiinflammatory activity of IL-13 is partially reduced in patients with active IBD. The hyporesponsiveness of activated and differentiated monocytes to IL-13 and IL-4 does not seem to be a disease-specific phenomenon.     

Efficacy and onset of action of fluticasone propionate aqueous nasal spray on nasal symptoms, eosinophil count, and mediator release after nasal allergen challenge in patients with seasonal allergic rhinitis

We studied the effect and onset of action of fluticasone propionate aqueous nasal spray (FPANS) on mediator release and eosinophil accumulation in nasal secretions and on nasal symptoms of patients with seasonal allergic rhinitis after nasal allergen challenge (NAC). At the end of the pollen season, 28 patients were randomized in a double-blind and crossover design to receive 7 days' treatment with FPANS (200 μg, once daily) and matching placebo. NACs were performed before and at 6 h and 1. 2. 3. and 7 days during treatment with FPANS or placebo. Nasal secretions were collected for a quantitative determination of mediators and eosinophil count before and 5 min after each challenge. Nasal symptoms were assessed by scales grading the severity of symptoms at the same time. Results showed that for mediator concentrations there was a significant decrease of leukotriene C4 (P<0.001) at 7 days after the first administration of FPANS as compared to placebo. Two days after FPANS. both eosinophil counts and eosinophil cationic protein (ECP) concentrations were lower than those of placebo (eosinophils; f=0.032; ECP; F=0.038). The onset became even more important at day 7 (eosinophils; P=0.001; ECP; P=0.009) during the FPANS treatment period. For the subjective nasal symptoms, a significant reduction of symptom scores for nasal obstruction occurred also at day 3 (F=0.017) and for sneezing at day 7 (f=0.003). There was not yet any significant improvement of the objective nasal airway resistance after the different NACs during the study period. In conclusion, this study demonstrated that topical fluticasone propionate is effective in the treatment of mucosal inflammation induced by NAC. For optimal control of nasal symptoms induced by repeated maximal allergen challenges, a treatment period of more than 1 week is required.     

CD137 (ILA/4-1BB), expressed by primary human monocytes, induces monocyte activation and apoptosis of B lymphocytes

Human CD137 is a member of the tumor necrosis factor (TNF) receptor family and the homologue of murine 4-1BB. Recent studies have demonstrated that CD137 promotes accessory T cell activation, and regulates proliferation and survival of T lymphocytes. This study reports on the expression and function of CD137 in peripheral blood monocytes. While monocytes showed constitutive expression in 10 out of 18 healthy donors, CD137 was not expressed on resting T or B lymphocytes. Immobilized antibodies to CD137 markedly induced the production of IL-8 and TNF-alpha protein and mRNA, and led to inhibition of IL-10 expression by primary monocytes. Furthermore, cross-linking of CD137 on monocytes resulted in an increase of B lymphocyte apoptosis mediated by direct cell-cell contact of both cell populations. In conclusion, this study identified CD137 as a new receptor involved in monocyte activation by inducing a characteristic cytokine release profile. In addition, CD137 may play a role in monocyte-dependent control of B lymphocyte survival.     

Giant inflammatory polyposis of the descending colon associated with a Crohn's disease-like colitis

A case of giant inflammatory polyposis associated with a localized inflammatory bowel disease of the descending colon in a 49-year-old man is presented. Lower abdominal distension rapidly appeared without any previous history of gastrointestinal disease. Two months later, he underwent a left hemicolectomy. Postoperative recovery was complete and he remains in good health more than 2 years later. The resected colon showed a giant and bizarre polyposis measuring up to 12 cm in length and 2 cm in height and covering the entire circumference of the colon. The polyposis consisted of narrow worm- or noodle-like polyps that bridged over the irregularly shaped ulcers, which sometimes extended into muscularis propria. Although longitudinal ulcers or scars, stricture, and a cobble-stone appearance were not observed, transmural inflammation and deep fissures were found in the interpolypoid area. From these findings, this case seems to be more similar to Crohn's disease than other inflammatory bowel diseases.     

B-1 cells are pivotal for in vivo inflammatory giant cell formation

The mechanisms that govern giant cell (GC) formation in inflammatory, neoplastic and physiologic conditions are far from being understood. Here, we demonstrate that B-1 cells are essential for foreign-body GC formation in the mouse. GCs were analysed on the surface of glass cover slips implanted into the subcutaneous tissue of the animals. It was demonstrated that GCs are almost absent on cover slips implanted into the subcutaneous tissue of BALB/c or CBA/N X-linked immunodeficient mice. As these animals do not have B-1 cells in the peritoneal cavity, they were reconstituted with B-1 cells obtained from cultures of adherent mouse peritoneal cells. Results showed that in B-1-reconstituted animals, the number of GCs on the implant surface surpassed the values obtained with preparations from wild animals. In animals selectively irradiated (pleural and peritoneal cavities) to deplete these cavities of B-1 cells, GCs were also not formed. Enriched suspensions of B-1 cells grown in culture were labelled with [(3)H]-tymidine and injected into the peritoneal cavity of naive mice before implantation of glass cover slips. After 4 days, about 17% of mononuclear cells had their nuclei labelled, and almost 70% of GCs had one or more of their nuclei labelled when analysed by histoautoradiographic technique. A few GCs expressed an immunoglobulin M when analysed by immunostaining and confocal microscopy. Overall, these data demonstrate that B-1 cells are pivotal in the mechanisms of foreign-body GC formation in the mouse.     

Immunoglobulin leakiness in scid mice with CD4(+) T-cell-induced chronic colitis

Inflammatory bowel disease in scid mice is initiated by transplantation of CD4(+) T-cells from immunocompetent syngenic donor mice. As the disease progresses, immunoglobulin (Ig)-containing cells appear in the gut lamina propria, suggesting that locally accumulating Ig may play a role in disease development. In the present work we have investigated the relationship between disease progression and patterns or levels of Ig isotypes in the feces of scid mice suffering from an ongoing colitis. The data clearly showed that the severity or progression of the disease did not influence the levels of IgA, IgG1, IgG2a, IgG2b, and IgG3, whereas the level of fecal IgM increased during the course of colitis. The presence of the serum protein alpha-1-antitrypsin in fecal extracts from diseased mice suggests that some of the fecal Ig has leaked through the inflamed epithelial membrane into the gut lumen. Finally, Ig-containing cells were observed in mesenteric lymph nodes and in the spleen, suggesting that the fecal Ig is produced both systemically and locally in the gut wall. In conclusion, the present results demonstrate that the level of IgM increases as colitis progresses. Also, the five remaining major Ig isotypes are increased in the gut lumen of scid mice with colitis, but the individual Ig types vary randomly during the course of the disease. Thus, it is unlikely that immunoglobulins are involved in the immunopathogenesis of this model of colitis.     

HLA class II haplotypes associated with pulmonary interstitial lesions of polymyositis/dermatomyositis in Japanese patients

To elucidate the immunogenetic background of idiopathic inflammatory myopathies (IIM) such as polymyositis (PM), dermatomyositis (DM) and any overlapping subsets, with other collagen vascular diseases, HLA class I antigens and class II alleles were determined and compared from individuals with various clinical and serological features of IIM, including pulmonary interstitial lesions (PI). Seventy-three Japanese patients with myositis (32 PM, 18 DM, 23 overlapped subsets) and 62 healthy unrelated controls were enrolled onto the study. Statistical differences between groups were determined by the Fisher's exact probability test. Serum fluorescent antinuclear antibody, rheumatoid factor (RF), anti-SS-A/Ro antibody, anti-Jo1 antibody and anti-U1 RNP antibody were examined using routine methods. PI was detected by chest X-ray and/or computed tomography. In patients with DM, the frequency of the HLA-DRB1*1302-DQA1*0102-DQB1*0604 haplotype was significantly higher than in the healthy controls (42.1% vs 17.7%), and in the patients with PM (42.1% vs 9.4%). Furthermore, the frequency of the HLA-DRB1*0405-DQA1*03-DQB1*0401 haplotype was higher in the PM patients with PI than in the controls (50.0% vs 17.7%), and PM without PI (50.0% vs 5.5%). These results suggest that in terms of HLA class II association, Japanese DM and PM, and PM with and without PI, belong to different clinical groups.