We investigated effects of the paracrine factors secreted by human mesenchymal stem cells (hMSCs) on endothelial cell migration, extracellular matrix invasion, proliferation, and survival in vitro. Human mesenchymal stem cells were cultured as a monolayer or as three-dimensional aggregates in hanging drops (hMSC spheroids). We performed analysis of paracrine factors in medium conditioned by a monolayer of hMSCs and hMSC spheroids. Concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor, angiogenin, procathepsin B, interleukin (<em>IL</em>)-11, and bone morphogenic protein 2 were increased 5-<em>20</em> times in medium conditioned by hMSC spheroids, whereas concentrations of <em>IL</em>-6, <em>IL</em>-8, and monocyte hemoattractant protein-1 were not increased. Concentrations of VEGF and angiogenin in medium conditioned by hMSC spheroids showed a weak dependence on the presence of serum, which allows serum-free conditioned medium with elevated concentrations of angiogenic cytokines to be obtained. Medium conditioned by hMSC spheroids was more effective in stimulation of umbilical vein endothelial cell proliferation, migration, and basement membrane invasion than medium conditioned by a monolayer of hMSCs. This medium also promotes endothelial cell survival in vitro. We suggest that culturing of hMSCs as three-dimensional cellular aggregates provides a method to concentrate proangiogenic factors secreted by hMSCs and allows for reduction of serum concentration in conditioned medium. Our data support the hypothesis that hMSCs serve as trophic mediators for endothelial cells. Disclosure of potential conflicts of interest is found at the end of this article.

Although the histological changes seen in psoriasis have long been well characterized, the underlying cellular and molecular mechanisms have only begun to be elucidated over the past <em>20</em> years. Proinflammatory factors such as tumor necrosis factor (TNF)-α have a central role in psoriasis pathogenesis, and many T-helper 1 (Th1) cytokines and messenger RNAs are elevated in psoriatic lesions. <em>IL</em>-17A, <em>IL</em>-17F, and other Th17 cell-derived cytokines have been shown in murine models to induce features that mimic human psoriasis. This review focuses on the emerging biology of the <em>IL</em>-17 cytokine family in psoriasis, and on the molecular and genetic information gained from animal models and human clinical studies that confirm <em>IL</em>-17 as a crucial proinflammatory cytokine in psoriasis. Expression of <em>IL</em>-17A, <em>IL</em>-17C, and <em>IL</em>-17F is strikingly increased in psoriatic lesions, and successful therapy is associated with restoration of the expression of a wide range of genes (including effector molecules downstream of <em>IL</em>-17 such as cytokines, chemokines, and antimicrobial peptides) to near-normal levels. Therapeutic agents in development that target <em>IL</em>-17 are discussed, and an emerging model of the key role of <em>IL</em>-17 in the pathogenesis of psoriasis is presented.

The production of cytokines in monocytes/macrophages is regulated by several different cytokines that have activating or inhibitory effects. Interleukin (<em>IL</em>)-10, <em>IL</em>-4, <em>IL</em>-13, and transforming growth factor (TGF)-beta are usually considered to be the most important macrophage-deactivating factors, with inhibitory effects on cytokine production. Unlike <em>IL</em>-10 and TGF-beta, which appear to act as downmodulators of many phagocytic cell functions, the mode of action of <em>IL</em>-4 and <em>IL</em>-13 is more complex. Addition of <em>IL</em>-4 and <em>IL</em>-13 to peripheral blood mononuclear cell (PBMC) cultures inhibited production of <em>IL</em>-12, tumor necrosis factor (TNF)-alpha, <em>IL</em>-10, and <em>IL</em>-1 beta induced by lipopolysaccharide (LPS) or Staphylococcus aureus added simultaneously with the cytokines. However, pretreatment of PBMC with <em>IL</em>-4 or <em>IL</em>-13 for>> or = <em>20</em> h enhanced the production of <em>IL</em>-12 and TNF-alpha in response to LPS or S. aureus several fold in these cells; this <em>IL</em>-4-induced priming for the two cytokines was inhibited by anti-<em>IL</em>-4 neutralizing antibodies. <em>IL</em>-4 priming also enhanced the accumulation of <em>IL</em>-12 and TNF-alpha mRNA induced by LPS and S. aureus. The enhanced accumulation of transcripts for the <em>IL</em>-12 p35 and p40 chains by <em>IL</em>-4 priming was reflected in enhanced secretion of both the <em>IL</em>-12 free p40 chain and the p70 heterodimer. These results suggest an unexpected complexity in the regulatory role of <em>IL</em>-4 and <em>IL</em>-13 in immune responses.

Preclinical models suggest that focal high-dose radiation can make tumors more immunogenic. We performed a pilot study of stereotactic body radiation therapy (SBRT) followed by high-dose interleukin-2 (<em>IL</em>-2) to assess safety and tumor response rate and perform exploratory immune monitoring studies. Patients with metastatic melanoma or renal cell carcinoma (RCC) who had received no previous medical therapy for metastatic disease were eligible. Patients received one, two, or three doses of SBRT (<em>20</em> Gy per fraction) with the last dose administered 3 days before starting <em>IL</em>-2. <em>IL</em>-2 (600,000 IU per kilogram by means of intravenous bolus infusion) was given every 8 hours for a maximum of 14 doses with a second cycle after a 2-week rest. Patients with regressing disease received up to six <em>IL</em>-2 cycles. Twelve patients were included in the intent-to-treat analysis, and 11 completed treatment per the study design. Response Evaluation Criteria in Solid Tumors criteria were used to assess overall response in nonirradiated target lesions. Eight of 12 patients (66.6%) achieved a complete (CR) or partial response (PR) (1 CR and 7 PR). Six of the patients with PR on computed tomography had a CR by positron emission tomography imaging. Five of seven (71.4%) patients with melanoma had a PR or CR, and three of five (60%) with RCC had a PR. Immune monitoring showed a statistically significantly greater frequency of proliferating CD4(+) T cells with an early activated effector memory phenotype (CD3(+)CD4(+)Ki67(+)CD25(+)FoxP3(-)CCR7(-)CD45RA(-)CD27(+)CD28(+/-)) in the peripheral blood of responding patients. SBRT and <em>IL</em>-2 can be administered safely. Because the response rate in patients with melanoma was significantly higher than expected on the basis of historical data, we believe that the combination and investigation of CD4(+) effector memory T cells as a predictor of response warrant further study.

BACKGROUND

Atopic dermatitis (AD) and psoriasis are the two most common chronic inflammatory skin diseases. Both of these diseases have distinct clinical findings and specific inflammatory cell infiltrates. Previous reports have focused individually on one or two genes or gene products in the lesions of both skin diseases. However, they have not captured the complex gene expression that must occur to induce specific cellular infiltrates in the skin lesions of these two diseases. DNA microarray studies allow the simultaneous comparison of thousands of messenger RNAs that may identify the disease-specific pattern of tissue inflammatory responses.

OBJECTIVE

To compare the complex gene expression pattern of AD versus psoriasis skin lesions.

METHODS

RNA was extracted from skin biopsy specimens of 6 patients with AD and 7 patients with psoriasis and analyzed with the use of Hu-U95Av.GeneChip microarrays. To confirm GeneChip results, real-time PCR of selected genes were performed.

RESULTS

In AD skin, a total of 18 genes including the CC chemokines, CCL-13/MCP-4, CCL-18/PARC, and CCL-27/CTACK showed a statistically significant, >2-fold increase of gene expression compared with psoriasis. In psoriasis skin, a total of 62 genes including CCL-4/MIP-1beta, CCL-<em>20</em>/MIP-3alpha, CXCL-2/GRO-beta CXCL-8/<em>IL</em>-8, and CXCR2/<em>IL</em>-8R showed a >2-fold increase of gene expression compared with AD skin. Real-time PCR confirmed several of these GeneChip results.

CONCLUSIONS

These results show a very distinctive gene expression pattern in AD as compared with psoriasis that may explain several features of AD and psoriasis including the specific inflammatory cell infiltrates observed in these disorders, that is, T(H)2 cells, eosinophils, and mast cells in AD and T(H)1 cells and neutrophils in psoriasis. Such observations may contribute to a characteristic "signature" for these two skin diseases.

OBJECTIVE

To evaluate the efficacy and safety of secukinumab, a fully human, anti-interleukin (IL)-17A monoclonal antibody, in patients with psoriatic arthritis (PsA).

METHODS

42 patients with active PsA fulfilling ClASsification for Psoriatic ARthritis (CASPAR) criteria were randomly assigned (2:1) to receive two intravenous secukinumab doses (10 mg/kg; n=28) or placebo (n=14) 3 weeks apart. The primary endpoint was the proportion of American College of Rheumatology (ACR) 20 responses at week 6 for secukinumab versus placebo (one-sided p<0.1).

RESULTS

Primary endpoint: ACR20 responses at week 6 were 39% (9/23) for secukinumab versus 23% (3/13) for placebo (p=0.27). ACR20 responses were greater with secukinumab versus placebo at week 12 (39% (9/23) vs 15% (2/13), p=0.13) and week 24 (43% (10/23) vs 18% (2/11), p= 0.14). At week 6, 'good' European League Against Rheumatism response was seen in 21.7% (5/23) secukinumab versus 9.1% (1/11) placebo patients. Compared with placebo at week 6, significant reductions were observed among secukinumab recipients for C reactive protein (p=0.039), erythrocyte sedimentation rate (p=0.038), Health Assessment Questionnaire Disability Index (p=0.002) and Short Form Health Survey (SF-36; p=0.030) scores. The overall adverse event (AE) frequency was comparable between secukinumab (26 (93%)) and placebo (11 (79%)) recipients. Six serious AEs (SAEs) were reported in four secukinumab patients and one SAE in one placebo patient.

CONCLUSIONS

Although the primary endpoint was not met, clinical responses, acute-phase reactant and quality of life improvements were greater with secukinumab versus placebo, suggesting some clinical benefit. Secukinumab exhibited satisfactory safety. Larger clinical trials of secukinumab in PsA are warranted.

BACKGROUND

In this study, we analysed the number of IL-17(+) cells in facet joints, in the peripheral blood (PB) and synovial fluid (SF) of spondyloarthritis (SpA) patients and compared these results with those of patients with other rheumatic diseases and controls.

METHODS

Immunohistochemical analysis of IL-17(+) cells was performed in facet joints of 33 ankylosing spondylitis (AS) patients and compared with data from 20 osteoarthritis (OA) patients. The frequency of IL-17(+)CD4(+) T cells in PB and SF of SpA patients (PB n = 30, SF n = 11), rheumatoid arthritis (RA) patients (PB n = 14, SF n = 7), OA patients (PB n = 10) and healthy controls (PB n = 12) was analysed after stimulation with Staphylococcus aureus Enterotoxin B and phorbol 12-myristate 13-acetate/ionomycin and quantified by flow cytometry.

RESULTS

In AS facet joints, the frequency of IL-17-secreting cells was significantly higher than in samples obtained from OA patients (P < 0.001), with a slight predominance of IL-17(+) cells among the mononuclear cells (61.5% ± 14.9%) compared to cells with polysegmental nuclei. Immunofluorescence microscopy revealed that the majority of IL-17(+) cells were myeloperoxidase-positive (35.84 ± 13.06/high-power field (HPF) and CD15(+) neutrophils (24.25 ± 10.36/HPF), while CD3(+) T cells (0.51 ± 0.49/HPF) and AA-1(+) mast cells (2.28 ± 1.96/HPF) were less often IL-17-positive. The frequency of IL-17(+)CD4(+) T cells in the PB and SF of SpA patients did not differ significantly compared to RA patients, OA patients or healthy controls.

CONCLUSIONS

Our data suggest an important role for IL-17 in the inflammatory processes in AS. However, the innate immune pathway might be of greater relevance than the Th17-mediated adaptive immune response.

To evaluate the safety and potential therapeutic activity of humanized anti-<em>IL</em>-2 receptor mAb (Daclizumab) therapy in the treatment of patients with severe, sight-threatening, intermediate and posterior noninfectious uveitis, a nonrandomized, open-label, pilot study was performed. Patients with uveitis were treated with a minimum of <em>20</em> mg of prednisone, cyclosporine, antimetabolites, or any combination of these agents were eligible. Patients were weaned off their systemic immunosuppressive agents according to a standardized schedule, while ultimately receiving Daclizumab infusions every 4 weeks. Anti-<em>IL</em>-2 receptor antibody therapy, given intravenously with intervals of up to 4 weeks in lieu of standard immunosuppressive therapy, appeared to prevent the expression of severe sight-threatening intraocular inflammatory disease in 8 of 10 patients treated over a 12-month period, with noted improvements in visual acuity. One patient met a primary endpoint with a loss of vision of 10 letters or more from baseline in one eye and another patient discontinued therapy because of evidence of increased ocular inflammation. All patients were able to tolerate the study medications without the need for dose reduction. We report effective long-term use of anti-<em>IL</em>-2 therapy for an autoimmune indication. These initial findings would suggest that anti-<em>IL</em>-2 receptor therapy may be an effective therapeutic approach for uveitis and, by implication, other disorders with a predominant Th1 profile.

One half of a group of <em>20</em> patients with human papillomavirus type 16 (HPV16)-induced vulvar intraepithelial neoplasia grade 3 displayed a complete regression (CR) after therapeutic vaccination with HPV16 E6/E7 synthetic long peptides. Patients with relatively larger lesions generally did not display a CR. To investigate immune correlates of treatment failure, patients were grouped according to median lesion size at study entry, and HPV16-specific immunity was analyzed at different time points by complementary immunological assays. The group of patients with smaller lesions displayed stronger and broader vaccine-prompted HPV16-specific proliferative responses with higher IFNgamma (P = 0.0003) and <em>IL</em>-5 (P < 0.0001) levels than patients with large lesions. Characteristically, this response was accompanied by a distinct peak in cytokine levels after the first vaccination. In contrast, the patient group with larger lesions mounted higher frequencies of HPV16-specific CD4(+)CD25(+)Foxp3(+) T cells (P = 0.005) and displayed a lower HPV16-specific IFNgamma/<em>IL</em>-10 ratio after vaccination (P < 0.01). No disparity in T memory immunity to control antigens was found, indicating that the differences in HPV-specific immunity did not reflect general immune failure. We observed a strong correlation between a defined set of vaccine-prompted specific immune responses and the clinical efficacy of therapeutic vaccination. Notably, a high ratio of HPV16-specific vaccine-prompted effector T cells to HPV16-specific CD4(+)CD25(+)Foxp3(+) T cells was predictive of clinical success. Foxp3(+) T cells have been associated previously with impaired immunity in malignancies. Here we demonstrate that the vaccine-prompted level of this population is associated with early treatment failure.

In <em>20</em>01, six immune mediators (<em>IL</em>-10, <em>IL</em>-19, <em>IL</em>-<em>20</em>, <em>IL</em>-22, <em>IL</em>-24, and <em>IL</em>-26) were grouped into the so-called <em>IL</em>-10 family of cytokines based on their similarities with respect to the structure and location of their encoding genes, their primary and secondary protein structures, and the receptor complexes used. Surprisingly, despite all these similarities, <em>IL</em>-10 family members possess different biological functions. The currently known facts regarding the biological effects of these six immune mediators give the impression that at least <em>IL</em>-10, <em>IL</em>-<em>20</em>, and <em>IL</em>-22 play an important role in the pathogenesis of some chronic inflammatory diseases. This review provides an overview of the most important and common aspects of the <em>IL</em>-10 family members.

OBJECTIVE

To conduct in vitro studies as well as a phase 2 clinical trial in patients with smoldering or indolent multiple myeloma to determine if interleukin 1 (IL-1) inhibitors can delay or prevent active myeloma.

METHODS

Stromal cells were cocultured with IL-1beta-expressing myeloma cells in the presence of dexamethasone, IL-1 receptor antagonist (IL-1Ra), or both. Levels of interleukin 6 (IL-6) and of apoptosis were also quantified. Between November 19, 2002, and May 24, 2007, 47 patients were enrolled in the study and subsequently treated with IL-1Ra. In 25 (53%) of the 47 study patients, low-dose dexamethasone (20 mg/wk) was added. The primary end point was progression-free survival (PFS).

RESULTS

In vitro, IL-1Ra was superior to dexamethasone at inhibiting IL-6 production; maximal IL-6 inhibition and apoptosis induction were achieved by addition of both IL-1Ra and dexamethasone. In the clinical trial, 3 patients achieved a minor response to IL-1Ra alone; 5 patients achieved a partial response and 4 patients a minor response after addition of dexamethasone. Seven patients showed a decrease in the plasma cell labeling index that paralleled a decrease in high-sensitivity C-reactive protein (hs-CRP) levels. The median overall PFS was 37.5 months. The median PFS for patients without (n=12) or with (n=35) a greater than 15% decrease in 6-month vs baseline hs-CRP levels was 6 months and more than 3 years, respectively (P=.002). Disease stability was maintained in 8 patients who received therapy for more than 4 years.

CONCLUSIONS

In patients with smoldering or indolent multiple myeloma who were at risk of progression to active myeloma, treatment with IL-1 inhibitors decreased the myeloma proliferative rate and hs-CRP levels in those who responded, leading to a chronic disease state and an improved PFS.

BACKGROUND

clinicaltrials.gov identifier: NCT00635154.

OBJECTIVE

Interleukin-15 (<em>IL</em>-15) is a proinflammatory, innate response cytokine that mediates pleiotropic effector function in rheumatoid arthritis (RA) inflammatory synovitis. Our objective was to study the ability of HuMax-<em>IL</em>15, a human IgG1 anti-<em>IL</em>-15 monoclonal antibody, to neutralize exogenous and endogenous <em>IL</em>-15 activity in vitro and to perform a phase I-II dose-escalation trial with HuMax-<em>IL</em>15 in patients with active RA.

METHODS

Mononuclear cells from blood and synovial fluid (SF) of RA patients were isolated and cultured in vitro under experimental conditions involving the addition of HuMax-<em>IL</em>15. HuMax-<em>IL</em>15 was administered to 30 RA patients who received no other disease-modifying antirheumatic drugs in a 12-week, dose-ascending, placebo-controlled, double-blind, phase I-II proof-of-concept study.

RESULTS

In vitro studies showed that HuMax-<em>IL</em>15 suppressed proliferation and induced apoptosis in an <em>IL</em>-15-dependent cell line, BDB2, and was capable of suppressing the release of interferon-gamma by synovial fluid mononuclear cell (SFMC) cultures induced by exogenous <em>IL</em>-15. Furthermore, HuMax-<em>IL</em>15 F(ab')2 fragments suppressed exogenous <em>IL</em>-15-induced CD69 expression in RA peripheral blood mononuclear cells and SFMCs, which indicates that HuMax-<em>IL</em>15 can specifically neutralize several biologic effects of <em>IL</em>-15 in synovial tissue in vitro. In a phase I-II clinical trial, HuMax-<em>IL</em>15 was well tolerated clinically, with no significant effects on T lymphocyte subset and natural killer cell numbers. Substantial improvements in disease activity were observed according to the American College of Rheumatology criteria for 20% improvement (63% of patients), 50% improvement (38%), and 70% improvement (25%).

CONCLUSIONS

These clinical data suggest for the first time that IL-15 could represent a novel therapeutic target in RA.

The synovial fluids (SF) of patients with rheumatoid arthritis (RA) were investigated for their effects on thymocytes of C3H/HeJ mice. Of the <em>20</em> SF tested, 17 (85%) showed an augmentation of the phytohaemagglutinin (PHA) induced thymocyte stimulation. Out of 16 SF of patients with osteoarthrosis, such an activity was detected in only one (6.25%). Further characterisation of the amplification factor revealed that (1) the SF of RA patients augmented both the PHA and the Concanavalin A response of the thymocytes (2) in the absence of mitogens, SF-treated thymocytes showed an increased uptake of 3H-thymidine, (3) the SF did not propagate the growth of an interleukin 2 dependent ovalbumin specific T cell clone, but (4) the SF were found to be required for optimal interleukin 2 release by spleen cells stimulated with suboptimal doses of lectin. Based on these biological effects the factor in the SF of RA patients is suggested to represent an interleukin 1 (<em>IL</em>-1). <em>IL</em>-1 produced in cultures by activated macrophages has been shown to stimulate T and B cell functions and to induce the production of collagenase and prostaglandins by cultured synovial cells. Both properties of <em>IL</em>-1 could be relevant in the pathogenesis of RA.

We have recently reported that experimental autoimmune encephalomyelitis (EAE) can be suppressed by the oral administration of myelin basic protein (MBP). The oral introduction of <em>20</em> mg MBP together with a trypsin inhibitor results in inhibition of EAE clinical signs, decreased CNS histopathologic changes and dramatically reduced MBP-specific proliferative responses in fed and challenged Lewis rats. In the present study, we have investigated the mechanism underlying MBP-induced oral tolerance in EAE. Neither lymphoid cells (lymph node cells, spleen cells, Peyer's patch lymphocytes, thymocytes) nor humoral elements derived from tolerant donors were capable of transferring the tolerance to naive recipients. Moreover, lymphoid cells obtained from orally tolerant donors exhibited a marked decrease in their capacity to transfer EAE to naive recipient rats, even after in vitro activation with MBP or Con A. We observed that EAE could be readily transferred into orally tolerant rats using MBP-specific encephalitogenic T cell lines. In vitro cell mixing studies showed that the proliferation of lymphocytes from MBP-sensitized donors was not inhibited by the addition of lymphoid cells from tolerant donors, arguing against the role of a suppressor cell. Investigation of MBP-stimulated lymphokine production showed that both <em>IL</em>-2 and IFN-gamma levels were substantially decreased in spleen and lymph node cell cultures from MBP-fed rats compared to vehicle-fed control animals. Furthermore, limiting dilution analyses revealed that MBP-fed rats exhibited a profound decrease in MBP-reactive, <em>IL</em>-2-secreting lymphocytes relative to control animals. Thus, because lymphocytes from MBP-fed rats neither proliferate nor secrete <em>IL</em>-2 or IFN-gamma in response to MBP and we can find no compelling evidence for the role of suppressor cells, we propose that the oral administration of MBP results in a state of clonal anergy.

YKL-40 is a chitin-binding protein that is elevated in patients with various inflammatory conditions associated with ongoing remodeling. We investigated whether the levels of YKL-40 were up-regulated in the circulation and the airways of patients with chronic obstructive pulmonary disease (COPD), and whether it promoted the production of inflammatory mediators from macrophages. Serum, bronchoalveolar lavage (BAL), bronchial biopsies, lung tissue specimens, and alveolar macrophages from never-smokers (n = 15), smokers without COPD (n = <em>20</em>), and smokers with COPD (n = 30) were assessed for YKL-40 levels and immunolocalization. In addition, YKL-40-induced mediator release from alveolar macrophages was examined. We found that smokers with COPD had elevated levels of YKL-40 in serum (p </= 0.027) and BAL (p </= 0.007), more YKL-40-positive cells in bronchial biopsies (p </= 0.03), and a greater proportion of alveolar macrophages expressing YKL-40 than smokers without COPD or never-smokers. YKL-40 levels in serum and BAL were associated with airflow obstruction (pre-beta(2) agonist forced expiratory volume in 1 s, r(s) = -0.3892, p = 0.0072 and r(s) = -0.5491, p < 0.0001, respectively) and impaired diffusion lung capacity (transfer factor of the lung for carbon monoxide, r(s) = -0.4667, p = 0.002 and r(s) = -0.3854, p = 0.0045, respectively). TNF-alpha stimulated YKL-40 synthesis in alveolar macrophages from smokers with COPD, and exposure of these cells to YKL-40 promoted the release of <em>IL</em>-8, MCP-1, MIP-1alpha, and metalloproteinase-9. We conclude that YKL-40 is up-regulated in COPD, in which it may contribute to tissue inflammation and remodeling by sustaining the synthesis of proinflammatory and fibrogenic chemokines and of metalloproteinases by alveolar macrophages.

Deregulation of the inflammatory response plays a major role in the age-related decline of physical performance. The causal pathway leading from inflammation to disability has not been fully clarified, but several researches suggest that interleukin-6 (<em>IL</em>-6) causes a reduction of physical performance in elderly through its effect on muscle function. In vitro studies demonstrated that <em>IL</em>-6 inhibits the secretion of insulin-like growth factor I (IGF-I) and its biological activity, suggesting that the negative effect of <em>IL</em>-6 on muscle function might be mediated through IGF-I. We evaluated the joint effect of IGF-I and <em>IL</em>-6 on muscle function in a population-based sample of 526 persons with a wide age range (<em>20</em>-102 yr). After adjusting for potential confounders, such as age, sex, body mass index, <em>IL</em>-6 receptor, and <em>IL</em>-6 promoter polymorphism, <em>IL</em>-6, IGF-I, and their interaction were significant predictors of handgrip and muscle power. In analyses stratified by <em>IL</em>-6 tertiles, IGF-I was an independent predictor of muscle function only in subjects in the lowest <em>IL</em>-6 tertile, suggesting that the effect of IGF-I on muscle function depends on <em>IL</em>-6 levels. This mechanism may explain why <em>IL</em>-6 is a strong risk factor for disability.

Cytokines that signal through Class II receptors form a distinct family that includes the interferons and interleukin 10 (<em>IL</em>-10). Recent identification of several <em>IL</em>-10 homologs has defined a cytokine subfamily that includes AK155, <em>IL</em>-19, <em>IL</em>-<em>20</em>, <em>IL</em>-22, and <em>IL</em>-24. Within this subfamily, <em>IL</em>-19, <em>IL</em>-<em>20</em>, and <em>IL</em>-24 exhibit substantial sharing of receptor complexes; all three are capable of signaling through <em>IL</em>-<em>20</em>RA/<em>IL</em>-<em>20</em>RB, and <em>IL</em>-<em>20</em> and <em>IL</em>-24 both can also use <em>IL</em>-22R/<em>IL</em>-<em>20</em>RB. However, the biological effects of these three cytokines appear quite distinct: immune activity with <em>IL</em>-19, skin biology with <em>IL</em>-<em>20</em>, and tumor apoptosis with <em>IL</em>-24. To more fully elucidate their interactions with the receptor complexes, we have performed a series of in vitro assays. Reporter, proliferation, and direct STAT activation assays using cell lines expressing transfected receptors revealed differences between the receptor complexes. <em>IL</em>-19 and <em>IL</em>-24 also exhibited growth inhibition on a cell line endogenously expressing all three receptor subunits, an effect that was seen at cytokine levels two orders of magnitude above those required for STAT activation or proliferation. These results demonstrate that, although this subclass exhibits receptor complex redundancy, there are differences in ligand/receptor interactions and in signal transduction that may lead to specificity and a distinct biology for each cytokine.

Type 2 diabetes patients exhibit subclinical inflammation but the regulatory mechanisms are poorly understood. We sought to evaluate the role of miR-146a expression along with its downstream proinflammatory signals in relation to glycemic control and insulin resistance. Study subjects (n = <em>20</em> each) comprised of clinically well characterized Type 2 diabetes patients and control non-diabetic subjects. miRNA and mRNA expression levels were probed in peripheral blood mononuclear cells (PBMC) by Real-time RT-PCR and plasma levels of TNFα and <em>IL</em>-6 were measured by ELISA. The miR-146a expression levels were significantly decreased in PBMCs from patients with Type 2 diabetes compared to control subjects. Among the target genes of miR-146a, TRAF-6 mRNA expression was significantly increased in patients with Type 2 diabetes while there was no significant difference in the mRNA levels of IRAK1 in the study groups. In contrast, there were significantly increased levels of NFκB expression in patients with Type 2 diabetes. There was an increased trend in the levels of TNFα and <em>IL</em>-6 mRNA in patients with type 2 diabetes. While SOCS-3 mRNA levels increased, plasma TNFα and <em>IL</em>-6 levels were also significantly higher in patients with type 2 diabetes. miR-146a expression was negatively correlated to glycated hemoglobin, insulin resistance, TRAF6, and NFκB mRNA levels and circulatory levels of TNFα and <em>IL</em>-6. Reduced miR-146a levels are associated with insulin resistance, poor glycemic control, and several proinflammatory cytokine genes and circulatory levels of TNFα and <em>IL</em>-6 in Asian Indian Type 2 diabetic patients.

A recently developed pneumonia caused by SARS-CoV-2 bursting in Wuhan, China, has quickly spread across the world. We report the clinical characteristics of 82 cases of death from COVID-19 in a single center. Clinical data on 82 death cases laboratory-confirmed as SARS-CoV-2 infection were obtained from a Wuhan local hospital's electronic medical records according to previously designed standardized data collection forms. All patients were local residents of Wuhan, and a large proportion of them were diagnosed with severe illness when admitted. Due to the overwhelming of our system, a total of 14 patients (17.1%) were treated in the ICU, 83% of deaths never received Critical Care Support, only 40% had mechanical ventilation support despite 100% needing oxygen and the leading cause of death being pulmonary. Most of the patients who died were male (65.9%). More than half of the patients who died were older than 60 years (80.5%), and the median age was 72.5 years. The bulk of the patients who died had comorbidities (76.8%), including hypertension (56.1%), heart disease (<em>20</em>.7%), diabetes (18.3%), cerebrovascular disease (12.2%), and cancer (7.3%). Respiratory failure remained the leading cause of death (69.5%), followed by sepsis/MOF (28.0%), cardiac failure (14.6%), hemorrhage (6.1%), and renal failure (3.7%). Furthermore, respiratory, cardiac, hemorrhagic, hepatic, and renal damage were found in 100%, 89%, 80.5%, 78.0%, and 31.7% of patients, respectively. On admission, lymphopenia (89.2%), neutrophilia (74.3%), and thrombocytopenia (24.3%) were usually observed. Most patients had a high neutrophil-to-lymphocyte ratio of >5 (94.5%), high systemic immune-inflammation index of >500 (89.2%), and increased C-reactive protein (100%), lactate dehydrogenase (93.2%), and D-dimer (97.1%) levels. A high level of <em>IL</em>-6 (>10 pg/ml) was observed in all detected patients. The median time from initial symptoms to death was 15 days (IQR 11-<em>20</em>), and a significant association between aspartate aminotransferase (p = 0.002), alanine aminotransferase (p = 0.037) and time from initial symptoms to death was remarkably observed. Older males with comorbidities are more likely to develop severe disease and even die from SARS-CoV-2 infection. Respiratory failure is the main cause of COVID-19, but the virus itself and cytokine release syndrome-mediated damage to other organs, including cardiac, renal, hepatic, and hemorrhagic damage, should be taken seriously as well.

Through DNA microarray analysis and quantitative PCR verification, we have identified additional <em>IL</em>-17A-inducible genes-<em>IL</em>-19, CXCL-1, -2, -3, -5, and -6-in well-differentiated normal human bronchial epithelial cells. These genes, similar to previously described human beta-defensin-2 (HBD-2) and CCL-<em>20</em>, were induced by a basolateral treatment of <em>IL</em>-17A, and regulated by PI3K signaling and NF-kappaB activation. For PI3K signaling, increases of cellular PIP(3) and phosphorylation of downstream molecules, such as Akt and glycogen synthase kinase-3beta (GSK3beta) (S9), were detected. Induced gene expression and HBD-2 promoter activity were attenuated by LY294002, p110alpha small-interfering RNA (siRNA), as well as by an overexpression of constitutively active GSK3beta(S9A) or wild-type phosphatase and tensin homolog. Increased phosphorylation of JAK1/2 after <em>IL</em>-17A treatment was detected in primary normal human bronchial epithelium cells. Transfected siRNAs of JAK molecules and JAK inhibitor I decreased <em>IL</em>-17A-induced gene expression and GSK3beta(S9) phosphorylation. However, both JAK inhibitor I and PI3K inhibitor had no effect on the DNA-binding activities of p65 and p50 to NF-kappaB consensus sequences. This result suggested a JAK-associated PI3K signaling axis is independent from NF-kappaB activation. With siRNA to knockdown STIR (similar expression to fibroblast growth factor and <em>IL</em>-17R; Toll-<em>IL</em>-1R)-related signaling molecules, such as Act1, TNFR-associated factor 6 (TRAF6), and TGF-beta-activated kinase 1 (TAK1), and transfection of A52R, an inhibitor of the MyD88/TRAF6 complex, or dominant-negative TAK1, <em>IL</em>-17A-inducible gene expression and HBD-2 promoter activity were reduced. Additionally, <em>IL</em>-17A-induced p65 and p50 NF-kappaB activations were confirmed and their nuclear translocations were down-regulated by siRNAs of TRAF6 and TAK1. These results suggest that two independent and indispensable signaling pathways-1) JAK1-associated PI3K signaling and 2) Act1/TRAF6/TAK1-mediated NF-kappaB activation-are stimulated by <em>IL</em>-17A to regulate gene induction in human airway epithelial cells.

OBJECTIVE

To investigate the role of interleukin-17 (IL-17) in inflammatory arthritis by blockade with an IL-17 receptor/human IgG1 Fc fusion protein (muIL-17R:Fc) in adjuvant-induced arthritis (AIA) in the rat.

METHODS

AIA was induced in 39 DA rats with the use of Freund's complete adjuvant. Rats received either 7.3 or 20 mg/kg of muIL-17R:Fc or phosphate buffered saline intraperitoneally every other day from the time of arthritis induction for approximately 17 days. Paw volume, arthritis severity, and weight were assessed every 3-4 days. Rats were killed between days 21 and 23 post-induction. Ankles were removed for quantitative radiology and histology and for immunohistochemistry for T cells.

RESULTS

Treatment with muIL-17R:Fc attenuated paw volume in a dose-dependent manner. Both the 7.3 and 20 mg/kg doses of muIL-17R:Fc significantly reduced radiographic scores in the treated rats compared with the controls. The 20 mg/kg dose of muIL-17R:Fc significantly reduced histology scores compared with the controls. T cell numbers were unchanged in the muIL-17R:Fc-treated rats as a function of dose.

CONCLUSIONS

In vivo blockade of IL-17 by muIL-17R:Fc treatment attenuated AIA and reduced joint damage, suggesting that IL-17 plays an important role in the inflammation and joint destruction of AIA. IL-17 may be a potential therapeutic target for inflammatory diseases in humans, such as rheumatoid arthritis.

BACKGROUND

About 5-10% of patients with asthma suffer from poorly controlled disease despite corticosteroid (CS) treatment, which may indicate the presence of CS insensitivity. A study was undertaken to determine whether relative CS insensitivity is present in alveolar macrophages from patients with severe asthma and its association with p38 mitogen-activated protein kinase (MAPK) activation and MAPK phosphatase-1 (MKP-1).

METHODS

Fibreoptic bronchoscopy and bronchoalveolar lavage (BAL) were performed in <em>20</em> patients with severe asthma and 19 with non-severe asthma and, for comparison, in 14 normal volunteers. Alveolar macrophages were exposed to lipopolysaccharide (LPS, 10 mug/ml) and dexamethasone (10(-8) and 10(-6) M). Supernatants were assayed for cytokines using an ELISA-based method. p38 MAPK activity and MKP-1 messenger RNA expression were assayed in cell extracts.

RESULTS

The inhibition of LPS-induced interleukin (IL)1beta, IL6, IL8, monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha release by dexamethasone (10(-6) M) was significantly less in macrophages from patients with severe asthma than in macrophages from patients with non-severe asthma. There was increased p38 MAPK activation in macrophages from patients with severe asthma. MKP-1 expression induced by dexamethasone and LPS, expressed as a ratio of LPS-induced expression, was reduced in severe asthma.

CONCLUSIONS

Alveolar macrophages from patients with severe asthma demonstrate CS insensitivity associated with increased p38 MAPK activation that may result from impaired inducibility of MKP-1.

<b>Objective:</b> To analyze the clinical characteristics of <em>20</em>19 novel coronavirus (<em>20</em>19-nCoV) pneumonia and to investigate the correlation between serum inflammatory cytokines and severity of the disease. <b>Methods:</b> 29 patients with <em>20</em>19-ncov admitted to the isolation ward of Tongji hospital affiliated to Tongji medical college of Huazhong University of Science and Technology in January <em>20</em><em>20</em> were selected as the study subjects. Clinical data were collected and the general information, clinical symptoms, blood test and CT imaging characteristics were analyzed. According to the relevant diagnostic criteria, the patients were divided into three groups: mild (15 cases), severe (9 cases) and critical (5 cases). The expression levels of inflammatory cytokines and other markers in the serum of each group were detected, and the changes of these indicators of the three groups were compared and analyzed, as well as their relationship with the clinical classification of the disease. <b>Results:</b> (1) The main symptoms of <em>20</em>19-nCoV pneumonia was fever (28/29) with or without respiratory and other systemic symptoms. Two patients died with underlying disease and co-bacterial infection, respectively. (2) The blood test of the patients showed normal or decreased white blood cell count (23/29), decreased lymphocyte count (<em>20</em>/29), increased hypersensitive C reactive protein (hs-CRP) (27/29), and normal procalcitonin. In most patients,serum lactate dehydrogenase (LDH) was significantly increased (<em>20</em>/29), while albumin was decreased(15/29). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (Tbil), serum creatinine (Scr) and other items showed no significant changes. (3) CT findings of typical cases were single or multiple patchy ground glass shadows accompanied by septal thickening. When the disease progresses, the lesion increases and the scope expands, and the ground glass shadow coexists with the solid shadow or the stripe shadow. (4) There were statistically significant differences in the expression levels of interleukin-2 receptor (<em>IL</em>-2R) and <em>IL</em>-6 in the serum of the three groups (P<0.05), among which the critical group was higher than the severe group and the severe group was higher than the mildgroup. However, there were no statistically significant differences in serum levels of tumor necrosis factor-alpha (TNF-α), <em>IL</em>-1, <em>IL</em>-8, <em>IL</em>-10, hs-CRP, lymphocyte count and LDH among the three groups (P>0.05). <b>Conclusion:</b> The clinical characteristics of <em>20</em>19-nCoV pneumonia are similar to those of common viral pneumonia. High resolution CT is of great value in the differential diagnosis of this disease. The increased expression of <em>IL</em>-2R and <em>IL</em>-6 in serum is expected to predict the severity of the <em>20</em>19-nCoV pneumonia and the prognosis of patients.

Abnormal distribution of plasma fatty acids and increased inflammation are prominent features of metabolic syndrome. We tested whether these components of metabolic syndrome, like dyslipidemia and glycemia, are responsive to carbohydrate restriction. Overweight men and women with atherogenic dyslipidemia consumed ad libitum diets very low in carbohydrate (VLCKD) (1504 kcal:%CHO:fat:protein = 12:59:28) or low in fat (LFD) (1478 kcal:%CHO:fat:protein = 56:24:<em>20</em>) for 12 weeks. In comparison to the LFD, the VLCKD resulted in an increased proportion of serum total n-6 PUFA, mainly attributed to a marked increase in arachidonate (<em>20</em>:4n-6), while its biosynthetic metabolic intermediates were decreased. The n-6/n-3 and arachidonic/eicosapentaenoic acid ratio also increased sharply. Total saturated fatty acids and 16:1n-7 were consistently decreased following the VLCKD. Both diets significantly decreased the concentration of several serum inflammatory markers, but there was an overall greater anti-inflammatory effect associated with the VLCKD, as evidenced by greater decreases in TNF-alpha, <em>IL</em>-6, <em>IL</em>-8, MCP-1, E-selectin, I-CAM, and PAI-1. Increased <em>20</em>:4n-6 and the ratios of <em>20</em>:4n-6/<em>20</em>:5n-3 and n-6/n-3 are commonly viewed as pro-inflammatory, but unexpectedly were consistently inversely associated with responses in inflammatory proteins. In summary, a very low carbohydrate diet resulted in profound alterations in fatty acid composition and reduced inflammation compared to a low fat diet.