Decreased expression of the glucocorticoid receptor-GILZ pathway in Kupffer cells promotes liver inflammation in obese mice.

BACKGROUND & AIMS: Kupffer cells (KC) play a key role in the onset of inflammation in non-alcoholic steatohepatitis (NASH). The glucocorticoid receptor (GR) induces glucocorticoid-induced leucine zipper (GILZ) expression in monocytes/macrophages and is involved in several inflammatory processes. We hypothesized that the GR-GILZ axis in KC may contribute to the pathophysiology of obesity-induced liver inflammation. METHODS: By using a combination of primary cell culture, pharmacological experiments, mice deficient for the Gr specifically in macrophages and transgenic mice overexpressing Gilz in macrophages, we explored the involvement of the Gr-Gilz axis in KC in the pathophysiology of obesity-induced liver inflammation. RESULTS: Obesity was associated with a downregulation of the Gr and Gilz, and an impairment of Gilz induction by lipopolysaccharide (LPS) and dexamethasone (DEX) in KC. Inhibition of Gilz expression in isolated KC transfected with Gilz siRNA demonstrated that Gilz downregulation was sufficient to sensitize KC to LPS. Conversely, liver inflammation was decreased in obese transgenic mice specifically overexpressing Gilz in macrophages. Pharmacological inhibition of the Gr showed that impairment of Gilz induction in KC by LPS and DEX in obesity was driven by a downregulation of the Gr. In mice specifically deficient for Gr in macrophages, Gilz expression was low, leading to an exacerbation of obesity-induced liver inflammation. CONCLUSIONS: Obesity is associated with a downregulation of the Gr-Gilz axis in KC, which promotes liver inflammation. The Gr-Gilz axis in KC is an important target for the regulation of liver inflammation in obesity.

CXCR4 dysfunction in non-alcoholic steatohepatitis in mice and patients.

Homing of inflammatory cells to the liver is key in the progression of non-alcoholic steatohepatitis (NASH). An abnormal response of CD4+ T-cells from obese mice to the chemotactic effect of CXCL12 has been reported but the mechanism involved in this process and relevance in patients are unknown. We aimed to explore the mechanism involved in the abnormal chemotaxis of CXC chemokine ligand 12 (CXCL12) in several mouse models of NASH and the relevance in the context of human non-alcoholic fatty liver disease (NAFLD). We assessed chemotactic responsiveness of CD4+ T-cells to CXCL12, the effect of AMD3100, a CXC chemokine receptor 4 (CXCR4) antagonist, in mice and lymphocytes from patients with NAFLD, and the affinity of CXCL12 for CXCR4. CXCL12-promoted migration of CD4+ T-cells from three different mouse models of NASH was increased and dependent of CXCR4. CD4+ T-cells from patients with NASH, but not from patients with pure steatosis, responded more strongly to the chemotactic effect of CXCL12, and this response was inhibited by AMD3100. Treatment with AMD3100 decreased the number of CD4+ T-cells to the liver in ob/ob mice. CXCL12 expression in the liver, CXCR4 and CXCR7 expression in CD4+ T-cells were not increased in three different mouse models of NASH. However, the affinity of CXCL12 for CXCR4 was increased in CD4+ T-cells of ob/ob mice. In conclusion, the CXCL12/CXCR4 pathway contributes in both mice and patients to the enhanced recruitment of CD4+ T-cells in NASH. An increased affinity of CXCL12 to CXCR4 rather than a higher expression of the chemokine or its receptors is involved in this process.

Glucocorticoid-induced leucine zipper enhanced expression in dendritic cells is sufficient to drive regulatory T cells expansion in vivo.

Tolerance induction by dendritic cells (DCs) is, in part, mediated by the activation of regulatory T cells (Tregs). We have previously shown in vitro that human DCs treated with glucocorticoids (GCs), IL-10, or TGF-ß upregulate the GC-Induced Leucine Zipper protein (GILZ). GILZ overexpression promotes DC differentiation into regulatory cells that generate IL-10-producing Ag-specific Tregs. To investigate whether these observations extend in vivo, we have generated CD11c-GILZ(hi) transgenic mice. DCs from these mice constitutively overexpress GILZ to levels observed in GC-treated wild-type DCs. In this article, we establish that GILZ(hi) DCs display an accumulation of Foxp3(+) Tregs in the spleens of young CD11c-GILZ(hi) mice. In addition, we show that GILZ(hi) DCs strongly increase the Treg pool in central and peripheral lymphoid organs of aged animals. Upon adoptive transfer to wild-type recipient mice, OVA-loaded GILZ(hi) bone marrow-derived DCs induce a reduced activation and proliferation of OVA-specific T cells as compared with control bone marrow-derived DCs, associated with an expansion of thymus-derived CD25(+)Foxp3(+) CD4 T cells. Transferred OVA-loaded GILZ(hi) DCs produce significantly higher levels of IL-10 and express reduced levels of MHC class II molecules as compared with OVA-loaded control DCs, emphasizing the regulatory phenotype of GILZ(hi) DCs in vivo. Thus, our work demonstrates in vivo that the GILZ overexpression alone is sufficient to promote a tolerogenic mode of function in DCs.

Expression of CXCL12 receptors in B cells from Mexican Mestizos patients with systemic Lupus erythematosus.

BACKGROUND: Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by B-cell hyper-reactivity and the production of pathogenic anti-nuclear-directed auto-antibodies (Abs). B-cell ontogeny is partly dependent on the CXCL12/CXCR4 axis for which the contribution to SLE pathogenesis remains unclear. CXCR7, the novel receptor for CXCL12, is differentially expressed among memory B-cell subsets. However, its biological role in SLE remains to be explored. METHODS: Relative CXCR4 and CXCR7 expression levels were compared by quantitative PCR in leukocytes from blood samples of 41 Mexican Mestizos patients with SLE and 45 ethnicity-matched healthy subjects. Intracellular and membrane expression of both receptors was analyzed by flow cytometry in naive and Ab-secreting B cells. B-cell responsiveness to CXCL12 was investigated using Transwell-based chemotaxis assays. Data were analyzed using the Kruskal-Wallis test for comparisons of values amongst healthy controls and patients with inactive or active SLE, and non-parametrically using the Mann-Whitney U-test for multiple comparisons and unpaired samples. Correlations were determined by Spearman's ranking. RESULT: SLE leukocytes displayed reduced levels of CXCR4 and CXCR7 transcripts. In SLE patients, a significant defect in CXCR4 expression was detected at the surface of naive and Ab-secreting B cells, associated with an abnormal intracellular localization of the receptor. CXCR7 predominantly localized in cytosolic compartments of B cells from healthy and SLE individuals. Disease activity did not impact on these expression patterns. Altered receptor compartmentalization correlated with an impaired CXCL12-promoted migration of SLE B cells. CONCLUSIONS: Our data highlight a down-regulation of CXCL12 receptors on circulating B cells from SLE patients that likely influences their migratory behavior and distribution.

Continuous versus intermittent treatment strategies during primary HIV-1 infection: the randomized ANRS INTERPRIM Trial.

OBJECTIVES: The ANRS-112 INTERPRIM trial assessed whether fixed-cycles of antiretroviral treatment interruption (ART-STI) combined or not with pegylated interferon alpha-2b (peg-IFN) could lower viral load and achieve a healthier immune system in patients diagnosed during primary HIV-1-infection (PHI). DESIGN AND METHODS: Patients were randomized to receive either continuous ART (cART) during 72 weeks, or cART during 36 weeks followed by three ART-STIs, or the same ART-STIs associated with peg-IFN during the first 14 weeks and each interruption (ART-STI-IFN). Treatment was stopped at week 72. Final evaluation was based on plasma HIV-RNA level 6 months after the last treatment interruption. RESULTS: Eighty-seven percent of patients achieved undetectable HIV-RNA at week 32, with no deleterious impact of sequential treatment interruptions (STIs). Viral rebounds during interruptions were lower in the ART-STI-IFN than in the ART-STI group and during the second and third interruptions compared with the first one. However, HIV-RNA levels, CD4 T-cell counts and CD4 T/CD8 T ratios were similar between groups after the 6-month interruption, with a persistent effect on CD4 T cells and total cell-associated HIV-DNA levels. Predictive factors of virological outcome were HIV-RNA and HIV-DNA levels at PHI and HIV-DNA levels at treatment interruption. HIV-specific responses did not differ between strategies and were not associated with outcome. Forty-eight percent of patients experienced treatment resumption during long-term follow-up without difference between groups. CONCLUSION: When initiated during PHI, STIs associated or not with IFN did not result in a different outcome as compared to cART. All regimens showed a high response rate and a sustained immunological benefit after cessation.

Proper desensitization of CXCR4 is required for lymphocyte development and peripheral compartmentalization in mice.

Desensitization controls G protein-dependent signaling of chemokine receptors. We investigate the physiologic implication of this process for CXCR4 in a mouse model harboring a heterozygous mutation of the Cxcr4 gene, which engenders a desensitization-resistant receptor. Such anomaly is linked to the warts, hypogammaglobulinemia, infections, myelokathexis (WHIM) syndrome, a human rare combined immunodeficiency. Cxcr4(+/mutant(1013)) mice display leukocytes with enhanced responses to Cxcl12 and exhibit leukopenia as reported in patients. Treatment with CXCL12/CXCR4 antagonists transiently reverses blood anomalies, further demonstrating the causal role of the mutant receptor in the leukopenia. Strikingly, neutropenia occurs in a context of normal bone marrow architecture and granulocyte lineage maturation, indicating a minor role for Cxcr4-dependent signaling in those processes. In contrast, Cxcr4(+/1013) mice show defective thymopoiesis and B-cell development, accounting for circulating lymphopenia. Concomitantly, mature T and B cells are abnormally compartmentalized in the periphery, with a reduction of primary follicles in the spleen and their absence in lymph nodes mirrored by an unfurling of the T-cell zone. These mice provide a model to decipher the role of CXCR4 desensitization in the homeostasis of B and T cells and to investigate which manifestations of patients with WHIM syndrome may be overcome by dampening the gain of CXCR4 function.

Influence of replacing tuberculin skin test with ex vivo interferon γ release assays on decision to administer prophylactic antituberculosis antibiotics before anti-TNF therapy.

BACKGROUND: The recommendations for detecting latent tuberculosis infection (LTBI) before antitumour necrosis factor (anti-TNF) therapy are based on the tuberculin skin test (TST), which lacks both specificity and sensitivity and can lead to unnecessary treatment with antibiotics. A study was undertaken to investigate the effect of replacing TST with interferon γ (IFNγ) release assays (IGRA) in screening for LTBI and deciding to begin prophylactic antituberculosis (TB) antibiotics before anti-TNF therapy in immune-mediated inflammatory diseases. METHODS: In 15 tertiary care hospitals, consecutive patients with rheumatoid arthritis, spondylarthropathies or Crohn's disease were screened for LTBI before anti-TNF therapy with TST, QuantiFERON TB Gold in tube (QTF-Gold IT) and T-SPOT.TB at the same time. The potential diagnosis of LTBI and the effect on the decision to begin antibiotic prophylaxis were assessed. RESULTS: Among 429 patients, 392 had results for the three tests. The results for TST, T-SPOT.TB and QTF Gold IT were positive for 35.2%, 15.1% and 9.9% of patients, respectively (p<0.0001). Antibiotics were required for 177 patients (45.2%) if positive TST results were included in the LTBI definition, 107 patients (27.3%) if TST results were replaced with results from one of the IGRA tests and 84 patients (21.4%) if TST results were replaced with QTF-Gold IT results (p<0.0001). The decision on the use of antibiotic prophylaxis was changed for 113 patients (28.8%, 95% CI 24.4% to 33.6%) if TST results were replaced with QTF-Gold IT results. CONCLUSIONS: Replacing TST with IGRA for determining LTBI allowed the proportion of patients with immune-mediated inflammatory diseases needing prophylactic anti-TB antibiotics before beginning anti-TNF agents to be reduced by half.

Housekeeping gene variability in the liver of alcoholic patients.

BACKGROUND: Quantification of gene expression using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) requires normalization to an endogenous reference gene termed housekeeping gene (HKG). Many of the commonly used HKGs are regulated and vary under experimental conditions and disease stages. Alcoholic liver disease (ALD) is associated with several different liver histological lesions that may modulate HKG expression. We investigated the variability of commonly used HGKs (18S, ß-actin, glyceraldehyde-3-phosphate [GAPDH], and arginine/serine-rich splicing factor [SFRS4]) in the liver of patients with ALD. METHODS: Fifty consecutive patients at different stages of ALD underwent liver biopsy. The stability of HKG was assessed according to liver histological lesions. RESULTS: ß-actin had the highest coefficient of dispersion (COD) (23.9). ß-actin tended to decrease with steatosis and to increase with alcoholic hepatitis; ß-actin also increased in patients with both alcoholic hepatitis and cirrhosis. GAPDH and SFRS4 COD were 2.8 and 2.1, respectively. GAPDH was decreased with steatosis and increased with alcoholic hepatitis and fibrosis. 18S had the lowest COD (1.4). Both 18S and SFRS4 levels were not significantly modified with respect to all alcohol-induced liver histological lesions. CONCLUSIONS: In patients with ALD, the most constantly expressed HKGs are 18S and SFRS4. These genes are appropriate reference genes for normalization of RT-qPCR in the liver of patients with ALD. The use of other HKGs such as ß-actin or GAPDH would lead to misinterpretation of the results.

Trough levels and antibodies to infliximab may not predict response to intensification of infliximab therapy in patients with inflammatory bowel disease.

BACKGROUND: Infliximab is effective for the treatment of refractory inflammatory bowel disease (IBD). Nevertheless, up to 40% of patients lose response to infliximab over time. The aim was to assess the clinical value of measuring infliximab trough levels and antibodies to infliximab (ATI) concentrations in IBD patients who lost response to infliximab therapy. METHODS: We retrospectively studied records of IBD patients who lost response to infliximab therapy. We first assessed clinical responses of different therapeutic strategies that were applied when patients lost response to infliximab and then we looked at the correlation between clinical response and infliximab trough levels and ATI concentrations. RESULTS: Seventy-six IBD patients were included. 31/76 patients (41%) continued infliximab therapy without any modification, 39 patients (51%) had an intensification of infliximab therapy, five patients (7%) had switched to adalimumab therapy, and one patient (1%) underwent surgery. Clinical response was observed in 27 patients (69%) with an intensification of infliximab therapy. There was no significant difference in mean infliximab trough level at inclusion in patients who responded to intensification of infliximab therapy (3.3 ± 4.1 µg/mL) as compared with patients who did not respond (2.3 ± 2.2 µg/mL, P = 0.85). In all, 16/76 patients (22.4%) presented detectable ATI in the serum. Ten ATI-positive patients had an intensification of infliximab therapy and six (60%) demonstrated a clinical response. After intensification of infliximab therapy the ATI concentration decreased in five patients. CONCLUSIONS: In patients with IBD who lose response to infliximab, clinical improvement may occur upon intensification of infliximab therapy, irrespective of infliximab serum concentration or presence of ATI.

Identification of the chemokine CX3CL1 as a new regulator of malignant cell proliferation in epithelial ovarian cancer.

BACKGROUND: Little is known about the molecules that contribute to the growth of epithelial ovarian carcinomas (EOC), which remain the most lethal gynecological cancer in women. The chemokine Fractalkine/CX(3)CL1 has been widely reported to play a biologically relevant role in tumor growth and spread. We report here the first investigation of the expression and role of CX(3)CL1 in EOC. RESULTS: Epithelial cells from the surface of the ovary and the Fallopian tubes and from benign, borderline and malignant tumors all stained positive for CX(3)CL1. In tumor specimens from 54 women who underwent surgical treatment for EOC diagnosis, CX(3)CL1 immunoreactivity was unevenly distributed in epithelial tumor cells, and ranged from strong (33%) to absent (17%). This uneven distribution of CX(3)CL1 did not reflect the morphological heterogeneity of EOC. It was positively correlated with the proliferation index Ki-67 and with GILZ (glucocorticoid-induced leucine zipper), previously identified as an activator of the proliferation of malignant EOC cells. Hierarchical clustering analysis, including age at diagnosis, tumor grade, FIGO stage, Ki-67 index, CX(3)CL1, SDF-1/CXCL12 and GILZ immunostaining scores, distinguished two major clusters corresponding to low and high levels of proliferation and differing in terms of GILZ and CX(3)CL1 expression. GILZ overexpression in the carcinoma-derived BG1 cell line resulted in parallel changes in CX(3)CL1 products. Conversely, CX(3)CL1 promoted through its binding to CX(3)CR1 AKT activation and proliferation in BG1 cells. In a mouse subcutaneous xenograft model, the overexpression of GILZ was associated with higher expression of CX(3)CL1 and faster tumor growth. CONCLUSION: Our findings highlight the previously unappreciated constitutive expression of CX(3)CL1 preceding tumorigenesis in ovarian epithelial cells. Together with GILZ, this chemokine emerges as a regulator of cell proliferation, which may be of potential clinical relevance for the selection of the most appropriate treatment for EOC patients.

[CXCR4, a therapeutic target in rare immunodeficiencies?]. / CXCR4, une cible thérapeutique dans certains déficits immunitaires rares?

Currently, more than 200 primary immunodeficiency diseases have been discovered. In most cases, genetic defects affect the expression or the function of proteins involved in immune development and homeostasis. Some orphan immuno-hematological disorders are characterized by an abnormal leukocyte trafficking, a notion predictive of an anomaly of the chemokine/chemokine receptor system. In this review, we focus on recent advances in the characterization of dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in two rare human immunodeficiencies, one associated with a loss of CXCR4 function, the Idiopathic CD4(+) T-cell Lymphocytopenia, and the other with a gain of CXCR4 function, the WHIM syndrome.

CXCL12 expression by healthy and malignant ovarian epithelial cells.

BACKGROUND: CXCL12 has been widely reported to play a biologically relevant role in tumor growth and spread. In epithelial ovarian cancer (EOC), CXCL12 enhances tumor angiogenesis and contributes to the immunosuppressive network. However, its prognostic significance remains unclear. We thus compared CXCL12 status in healthy and malignant ovaries, to assess its prognostic value. METHODS: Immunohistochemistry was used to analyze CXCL12 expression in the reproductive tracts, including the ovaries and fallopian tubes, of healthy women, in benign and borderline epithelial tumors, and in a series of 183 tumor specimens from patients with advanced primary EOC enrolled in a multicenter prospective clinical trial of paclitaxel/carboplatin/gemcitabine-based chemotherapy (GINECO study). Univariate COX model analysis was performed to assess the prognostic value of clinical and biological variables. Kaplan-Meier methods were used to generate progression-free and overall survival curves. RESULTS: Epithelial cells from the surface of the ovary and the fallopian tubes stained positive for CXCL12, whereas the follicles within the ovary did not. Epithelial cells in benign, borderline and malignant tumors also expressed CXCL12. In EOC specimens, CXCL12 immunoreactivity was observed mostly in epithelial tumor cells. The intensity of the signal obtained ranged from strong in 86 cases (47%) to absent in 18 cases (<10%). This uneven distribution of CXCL12 did not reflect the morphological heterogeneity of EOC. CXCL12 expression levels were not correlated with any of the clinical parameters currently used to determine EOC prognosis or with HER2 status. They also had no impact on progression-free or overall survival. CONCLUSION: Our findings highlight the previously unappreciated constitutive expression of CXCL12 on healthy epithelia of the ovary surface and fallopian tubes, indicating that EOC may originate from either of these epithelia. We reveal that CXCL12 production by malignant epithelial cells precedes tumorigenesis and we confirm in a large cohort of patients with advanced EOC that CXCL12 expression level in EOC is not a valuable prognostic factor in itself. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00052468.

Alpha interferon administration during structured interruptions of combination antiretroviral therapy in patients with chronic HIV-1 infection: INTERVAC ANRS 105 trial.

Interferon-α administration during structured treatment interruptions (STIs) was studied in a phase III trial. We randomized 168 chronically infected HIV undetectable under combined antiretroviral therapy patients to have three STIs with or without α-interferon. The number of patients who had to resume treatment during post-STI follow-up was not significantly different between the two arms. Patients with a low CD4 nadir and a high baseline HIV-DNA had a higher risk of treatment resumption in the interferon arm.

Treatment failure with antagonists of TNF-α: mechanisms and implications for the care of patients.

The use of TNF-α antagonists has substantially improved the care of many patients with inflammatory and autoimmune diseases. However, approximately one third of such patients fail to respond well to treatment, regardless of the antagonist used or of the underlying disease. The mechanisms underlying these failures are analyzed in this review, and proposals made concerning how best to adapt therapeutic decisions in these instances.

Harmful effect of adipose tissue on liver lesions in patients with alcoholic liver disease.

BACKGROUND & AIMS: Adipose tissue is an important source of cytokines. Excess weight is an independent risk factor for steatosis, acute alcoholic hepatitis (AAH), and cirrhosis in patients with alcoholic liver disease (ALD). In this study, we investigated the role of adipose tissue in human ALD. PATIENTS AND METHODS: Fifty patients with ALD underwent liver and abdominal subcutaneous adipose tissue biopsies and supplied blood samples for the investigation of cytokine gene expression and secretion, as well as liver histology. RESULTS: The levels of TNF-alpha and IL-10 in adipose tissue were higher in patients with AAH. IL-10 level in adipose tissue was also correlated with fibrosis score. TNF-alpha gene expression in adipose tissue was correlated with Maddrey score, blood C-reactive protein (CRP) concentration and liver IL-6 concentration. IL-6 production levels in the liver were higher in patients with AAH and correlated with AAH score, liver histological lesions, liver TNF-alpha concentration, Maddrey score, and blood CRP concentration. Plasma concentrations of soluble forms of TNF-receptor were correlated with inflammatory lesions in the liver, Maddrey score and fibrosis score. CONCLUSION: In patients with ALD, inflammation occurs not only in the liver, but also in the adipose tissue. Adipose tissue inflammation is correlated with the severity of pathological features in the liver. Our findings may account for the harmful interactions between body mass index, AAH, fibrosis, and cirrhosis in alcoholic patients.

[Dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in the WHIM syndrome and the idiopathic CD4(+) T-cell lymphocytopenia]. / Anomalies de l'axe de signalisation CXCL12 (SDF-1)/CXCR4 dans le syndrome WHIM et la lymphopénie T CD4(+) idiopathique.

Chemokines are small cytokine-like secreted proteins that govern migration of leukocytes to their specific niches in lymphoid organs and to inflammatory sites. They mediate their functions by binding to and activating chemokine receptors, which belong to the heptahelical G protein-coupled receptor family. The CXC chemokine Stromal cell Derived Factor-1 (SDF-1/CXCL12) is the sole natural ligand for the broadly expressed CXCR4 receptor and acts as a chemoattractant for many leukocyte subsets. The CXCL12/CXCR4 axis exerts critical activities in homeostatic processes such as organogenesis, hematopoiesis and leukocyte trafficking. Dysregulations of CXCR4 signaling and/or expression are associated with several infectious, inflammatory, autoimmune and malignant conditions. In light of recent data, we review here CXCR4 dysfunctions unveiled in two rare human immunodeficiency disorders, one characterized by a gain of CXCR4 function, the WHIM syndrome, and the other by a loss of CXCR4 function, the idiopathic CD4(+) T-cell lymphocytopenia.

Identification of glucocorticoid-induced leucine zipper as a key regulator of tumor cell proliferation in epithelial ovarian cancer.

BACKGROUND: Little is known about the molecules that contribute to tumor progression of epithelial ovarian cancer (EOC), currently a leading cause of mortality from gynecological malignancies. Glucocorticoid-Induced Leucine Zipper (GILZ), an intracellular protein widely expressed in immune tissues, has been reported in epithelial tissues and controls some of key signaling pathways involved in tumorigenesis. However, there has been no report on GILZ in EOC up to now. The objectives of the current study were to examine the expression of GILZ in EOC and its effect on tumor cell proliferation. RESULTS: GILZ expression was measured by immunohistochemical staining in tissue sections from 3 normal ovaries, 7 benign EOC and 50 invasive EOC. GILZ was not detected on the surface epithelium of normal ovaries and benign tumors. In contrast, it was expressed in the cytoplasm of tumor cells in 80% EOC specimens. GILZ immunostaining scores correlated positively to the proliferation marker Ki-67 (Spearman test in univariate analysis, P < 0.00001, r = 0.56). They were also higher in tumor cells containing large amounts of phosphorylated protein kinase B (p-AKT) (unpaired t test, P < 0.0001). To assess the effect of GILZ on proliferation and AKT activation, we used the BG-1 cell line derived from ovarian tumor cells as a cellular model. GILZ expression was either enhanced by stable transfection or decreased by the use of small interfering (si) RNA targeting GILZ. We found that GILZ increased cell proliferation, phospho-AKT cellular content and AKT kinase activity. Further, GILZ upregulated cyclin D1 and phosphorylated retinoblastoma (p-Rb), downregulated cyclin-dependent kinase inhibitor p21, and promoted the entry into S phase of cell cycle. CONCLUSION: The present study is the first to identify GILZ as a molecule produced by ovarian cancer cells that promotes cell cycle progression and proliferation. Our findings clearly indicate that GILZ activates AKT, a crucial signaling molecule in tumorigenesis. GILZ thus appears as a potential key molecule in EOC.

Circulating concentration of infliximab and response to treatment in ankylosing spondylitis: results from a randomized control study.

OBJECTIVE: A minority of patients with ankylosing spondylitis (AS) fail to respond to infliximab treatment. This study compared the circulating infliximab concentration and the presence of clinical symptoms in patients continuously treated with infliximab or after treatment interruption. METHODS: Patients with active AS were randomly assigned at week 0 to receive infliximab either at weeks 4, 6, 10, and then every 6 weeks (continuous treatment), or at weeks 4, 6, and 10 and then upon symptom recurrence (on-demand treatment). The circulating concentration of infliximab was determined early during treatment and at weeks 46 and 52 for the continuous treatment group or upon relapse for the on-demand group. Response in the continuous treatment group was defined at week 58 using the ASsessment in AS International Working Group Criteria for 20% improvement. RESULTS: Among the 93 patients in the continuous treatment group, treatment failure was not associated with a low circulating concentration of infliximab, either during early treatment or at 1 year. Eleven (39.2%) of the 28 nonresponders had an infliximab concentration of >10 microg/ml at week 52, whereas 9 (13.8%) of the 65 responders had an infliximab concentration of <1 microg/ml. In the on-demand group, the infliximab concentration at relapse closely correlated with the time to relapse. However, 24 (36.9%) of 65 patients had a resurgence of clinical symptoms at an infliximab concentration of >10 microg/ml, whereas 25 patients (38.4%) had a relapse at an infliximab concentration of <0.5 microg/ml. CONCLUSION: Responsiveness to infliximab treatment is highly heterogeneous among individuals with AS, and this parameter overcomes the circulating infliximab concentration to explain treatment success or failure.

IFNalpha kinoid vaccine-induced neutralizing antibodies prevent clinical manifestations in a lupus flare murine model.

A major involvement of IFNalpha in the etiopathogenesis of systemic lupus erythematosus has been suggested by clinical observations, including the increase of serum levels of this cytokine in patients with active disease. Supporting this hypothesis, we have shown that expression of IFNalpha from a recombinant adenovirus (IFNalpha Adv) precipitates lupus manifestations in genetically susceptible New Zealand Black (NZB) x New Zealand White (NZW)F(1) mice (NZB/W) but not in BALB/c mice. In the present investigation, we have prepared an IFNalpha immunogen, termed IFNalpha kinoid, which, appropriately adjuvanted, induces transient neutralizing antibodies (Abs) but no cellular immune response to the cytokine and without apparent side effects. Using this preparation, we also showed that, in kinoid-vaccinated NZB/W mice, lupus manifestations, including proteinuria, histological renal lesions, and death triggered by IFNalpha Adv challenge were delayed/prevented as long as an effective threshold of anti-IFNalpha inhibitory capacity was present in the serum.

Obesity-induced lymphocyte hyperresponsiveness to chemokines: a new mechanism of Fatty liver inflammation in obese mice.

BACKGROUND & AIMS: Hepatic lipid retention (steatosis) predisposes hepatitis. We investigated the mechanisms of lymphocyte homing to fatty liver and the role of lipopolysaccharide (LPS) in the onset of inflammation in ob/ob mice. METHODS: We decreased intestinal bacterial compounds by oral antibiotic treatment to test the role of endogenous LPS in liver inflammation. Adoptive transfer of lymphocytes was used to study the respective contributions of steatosis and lymphocytes to liver inflammation. We tested lymphocyte response to chemokines by in vitro chemotaxis assays in ob/ob, their lean controls, and "non-obese ob/ob" mice, generated by controlling caloric intake to distinguish between the effects of obesity and leptin deficiency. RESULTS: Antibiotic treatment decreased liver infiltration with CD4(+) T, CD8(+) T, natural killer (NK)T, B, and NK cells. Adoptive transfer of lymphocytes from ob/ob or control mice showed that (1) steatosis increased lymphocyte recruitment to the liver; (2) CD4(+) T, CD8(+) T, and B cells from ob/ob mice had a greater propensity to migrate specifically to the liver. This migration was enhanced by LPS. These results were also observed in a model of high-fat diet-induced obesity. CD4(+) T and B cells were hyperresponsive to CXCL12 and CXCL13, respectively. Weight normalization in "non-obese ob/ob" mice decreased liver inflammation, lymphocyte response to chemokines, and homing to the liver. CONCLUSIONS: Our study provides the first evidence that liver inflammation in mice with genetic or diet-induced obesity results from both steatosis and lymphocyte hyperresponsiveness to chemokines expressed in the liver. These abnormalities are reversible with weight normalization.