977 resultados para linked immunosorbent assay
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The cancer-testis antigen NY-ESO-1 has been targeted as a tumor-associated antigen by immunotherapeutical strategies, such as cancer vaccines. The prerequisite for a T-cell-based therapy is the induction of T cells capable of recognizing the NY-ESO-1-expressing tumor cells. In this study, we generated human T lymphocytes directed against the immunodominant NY-ESO-1(157-165) epitope known to be naturally presented with HLA-A*0201. We succeeded to isolate autorestricted and allorestricted T lymphocytes with low, intermediate or high avidity TCRs against the NY-ESO-1 peptide. The avidity of the established CTL populations correlated with their capacity of lysing HLA-A2-positive, NY-ESO-1-expressing tumor cell lines derived from different origins, e.g. melanoma and myeloma. The allorestricted NY-ESO-1-specific T lymphocytes displayed TCRs with the highest avidity and best anti-tumor recognition activity. TCRs derived from allorestricted, NY-ESO-1-specific T cells may be useful reagents for redirecting primary T cells by TCR gene transfer and, therefore, may facilitate the development of adoptive transfer regimens based on TCR-transduced T cells for the treatment of NY-ESO-1-expressing hematological malignancies and solid tumors.
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BACKGROUND: The central function of dendritic cells (DC) in inducing and preventing immune responses makes them ideal therapeutic targets for the induction of immunologic tolerance. In a rat in vivo model, we showed that dexamethasone-treated DC (Dex-DC) induced indirect pathway-mediated regulation and that CD4+CD25+ T cells were involved in the observed effects. The aim of the present study was to investigate the mechanisms underlying the acquired immunoregulatory properties of Dex-DC in the rat and human experimental systems. METHODS: After treatment with dexamethasone (Dex), the immunogenicity of Dex-DC was analyzed in T-cell proliferation and two-step hyporesponsiveness induction assays. After carboxyfluorescein diacetate succinimidyl ester labeling, CD4+CD25+ regulatory T-cell expansion was analyzed by flow cytometry, and cytokine secretion was measured by ELISA. RESULTS: In this study, we demonstrate in vitro that rat Dex-DC induced selective expansion of CD4+CD25+ regulatory T cells, which were responsible for alloantigen-specific hyporesponsiveness. The induction of regulatory T-cell division by rat Dex-DC was due to secretion of interleukin (IL)-2 by DC. Similarly, in human studies, monocyte-derived Dex-DC were also poorly immunogenic, were able to induce T-cell anergy in vitro, and expand a population of T cells with regulatory functions. This was accompanied by a change in the cytokine profile in DC and T cells in favor of IL-10. CONCLUSION: These data suggest that Dex-DC induced tolerance by different mechanisms in the two systems studied. Both rat and human Dex-DC were able to induce and expand regulatory T cells, which occurred in an IL-2 dependent manner in the rat system.
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The death-inducing receptor Fas is activated when cross-linked by the type II membrane protein Fas ligand (FasL). When human soluble FasL (sFasL, containing the extracellular portion) was expressed in human embryo kidney 293 cells, the three N-linked glycans of each FasL monomer were found to be essential for efficient secretion. Based on the structure of the closely related lymphotoxin alpha-tumor necrosis factor receptor I complex, a molecular model of the FasL homotrimer bound to three Fas molecules was generated using knowledge-based protein modeling methods. Point mutations of amino acid residues predicted to affect the receptor-ligand interaction were introduced at three sites. The F275L mutant, mimicking the loss of function murine gld mutation, exhibited a high propensity for aggregation and was unable to bind to Fas. Mutants P206R, P206D, and P206F displayed reduced cytotoxicity toward Fas-positive cells with a concomitant decrease in the binding affinity for the recombinant Fas-immunoglobulin Fc fusion proteins. Although the cytotoxic activity of mutant Y218D was unaltered, mutant Y218R was inactive, correlating with the prediction that Tyr-218 of FasL interacts with a cluster of three basic amino acid side chains of Fas. Interestingly, mutant Y218F could induce apoptosis in murine, but not human cells.
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The antibody display technology (ADT) such as phage display (PD) has substantially improved the production of monoclonal antibodies (mAbs) and Ab fragments through bypassing several limitations associated with the traditional approach of hybridoma technology. In the current study, we capitalized on the PD technology to produce high affinity single chain variable fragment (scFv) against tumor necrosis factor-alpha (TNF- α), which is a potent pro-inflammatory cytokine and plays important role in various inflammatory diseases and malignancies. To pursue production of scFv antibody fragments against human TNF- α, we performed five rounds of biopanning using stepwise decreased amount of TNF-α (1 to 0.1 μ g), a semi-synthetic phage antibody library (Tomlinson I + J) and TG1 cells. Antibody clones were isolated and selected through enzyme-linked immunosorbent assay (ELISA) screening. The selected scFv antibody fragments were further characterized by means of ELISA, PCR, restriction fragment length polymorphism (RFLP) and Western blot analyses as well as fluorescence microscopy and flow cytometry. Based upon binding affinity to TNF-α , 15 clones were selected out of 50 positive clones enriched from PD in vitro selection. The selected scFvs displayed high specificity and binding affinity with Kd values at nm range to human TNF-α . The immunofluorescence analysis revealed significant binding of the selected scFv antibody fragments to the Raji B lymphoblasts. The effectiveness of the selected scFv fragments was further validated by flow cytometry analysis in the lipopolysaccharide (LPS) treated mouse fibroblast L929 cells. Based upon these findings, we propose the selected fully human anti-TNF-α scFv antibody fragments as potential immunotherapy agents that may be translated into preclinical/clinical applications.
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New approaches to the clinical treatment of traumatic nerve injuries may one day utilize stem cells to enhance nerve regeneration. Adipose-derived stem cells (ASC) are found in abundant quantities and can be harvested by minimally invasive procedures that should facilitate their use in such regenerative applications. We have analyzed the properties of human ASC isolated from the deep and superficial layers of abdominal fat tissue obtained during abdominoplasty procedures. Cells from the superficial layer proliferate significantly faster than those from the deep layer. In both the deep and superficial layers, ASC express the pluripotent stem cell markers oct4 and nanog and also the stro-1 cell surface antigen. Superficial layer ASC induce the significantly enhanced outgrowth of neurite-like processes from neuronal cell lines when compared with that of deep layer cells. However, analysis by reverse transcription with the polymerase chain reaction and by enzyme-linked immunosorbent assay has revealed that ASC isolated from both layers express similar levels of the following neurotrophic factors: nerve growth factor, brain-derived neurotrophic factor and glial-derived neurotrophic factor. Thus, human ASC show promising potential for the treatment of traumatic nerve injuries. In particular, superficial layer ASC warrant further analysis of their neurotrophic molecules.
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Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.
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Background To determine the diagnostic and prognostic capability of urinary and tumoral syndecan-1 (SDC-1) levels in patients with cancer of the urinary bladder. Methods SDC-1 levels were quantitated by enzyme-linked immunosorbent assay (ELISA) in 308 subjects (102 cancer subjects and 206 non-cancer subjects) to assess its diagnostic capabilities in voided urine. The performance of SDC-1 was evaluated using the area under the curve of a receiver operating characteristic curve. In addition, immunohistochemical (IHC) staining assessed SDC-1 protein expression in 193 bladder specimens (185 cancer subjects and 8 non-cancer subjects). Outcomes were correlated to SDC-1 levels. Results Mean urinary levels of SDC-1 did not differ between the cancer subjects and the non-cancer subjects, however, the mean urinary levels of SDC-1 were reduced in high-grade compared to low-grade disease (p < 0.0001), and in muscle invasive bladder cancer (MIBC) compared to non-muscle invasive bladder cancer (NMIBC) (p = 0.005). Correspondingly, preliminary data note a shift from a membranous cellular localization of SDC-1 in normal tissue, low-grade tumors and NMIBC, to a distinctly cytoplasmic localization in high-grade tumors and MIBC was observed in tissue specimens. Conclusion Alone urinary SDC-1 may not be a diagnostic biomarker for bladder cancer, but its urinary levels and cellular localization were associated with the differentiation status of patients with bladder tumors. Further studies are warranted to define the potential role for SDC-1 in bladder cancer progression.
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BACKGROUND: Single-nucleotide polymorphisms (SNPs) in immune genes have been associated with susceptibility to invasive mold infection (IMI) among hematopoietic stem cell but not solid-organ transplant (SOT) recipients. METHODS: Twenty-four SNPs from systematically selected genes were genotyped among 1101 SOT recipients (715 kidney transplant recipients, 190 liver transplant recipients, 102 lung transplant recipients, 79 heart transplant recipients, and 15 recipients of other transplants) from the Swiss Transplant Cohort Study. Association between SNPs and the end point were assessed by log-rank test and Cox regression models. Cytokine production upon Aspergillus stimulation was measured by enzyme-linked immunosorbent assay in peripheral blood mononuclear cells (PBMCs) from healthy volunteers and correlated with relevant genotypes. RESULTS: Mold colonization (n = 45) and proven/probable IMI (n = 26) were associated with polymorphisms in the genes encoding interleukin 1β (IL1B; rs16944; recessive mode, P = .001 for colonization and P = .00005 for IMI, by the log-rank test), interleukin 1 receptor antagonist (IL1RN; rs419598; P = .01 and P = .02, respectively), and β-defensin 1 (DEFB1; rs1800972; P = .001 and P = .0002, respectively). The associations with IL1B and DEFB1 remained significant in a multivariate regression model (P = .002 for IL1B rs16944; P = .01 for DEFB1 rs1800972). The presence of 2 copies of the rare allele of rs16944 or rs419598 was associated with reduced Aspergillus-induced interleukin 1β and tumor necrosis factor α secretion by PBMCs. CONCLUSIONS: Functional polymorphisms in IL1B and DEFB1 influence susceptibility to mold infection in SOT recipients. This observation may contribute to individual risk stratification.
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STUDY DESIGN: Case-control study. OBJECTIVES: To assess serum myostatin levels, bone mineral density (BMD), appendicular skeletal muscle mass (ASMM) and serum sclerostin levels in chronic spinal cord injured (SCI) patients and healthy controls. SETTING: SCI centre in Italy. METHODS: Blood samples, whole-body bioelectrical impedance analysis and BMD measurement with the ultrasound technique at the calcaneus level were taken from patients suffering from chronic SCI (both motor complete and incomplete) and healthy control subjects. RESULTS: A total of 28 SCI patients and 15 healthy controls were enrolled. Serum myostatin levels were statistically higher (P<0.01) in SCI patients compared with healthy controls. Similar results were found comparing both the motor complete and the motor incomplete SCI subgroups to healthy controls. Serum sclerostin was significantly higher in patients with SCI compared with healthy controls (P<0.01). BMD, stiffness and mean T-score values in SCI patients were significantly lower than those in healthy controls. Serum myostatin concentrations in the motor complete SCI subgroups correlated only with serum sclerostin levels (r(2)=0.42; P=0.001) and ASMM (r(2)=0.70; P=0.002) but not in healthy controls. DISCUSSION: Serum myostatin and serum sclerostin are significantly higher in chronic SCI patients compared with healthy controls. They are potential biomarkers of muscle and bone modifications after SCI. This is the first study reporting an increase in serum myostatin in patients suffering from chronic SCI and a correlation with ASMM.
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BACKGROUND: Inducible nitric oxide synthase (iNOS) and interleukin 8 (IL-8) are positive in approximately 50% of Helicobacter pylori-related diseases but it is not clear whether oxidative stress is also present in H. pylori asymptomatic humans. Our aim was to study the expression of iNOS, superoxide dismutase, catalase and IL-8 production in H. pylori-infected asymptomatic humans, and to investigate the effect of eradication of H. pylori. MATERIALS AND METHODS: Biopsies of corpus and antrum of asymptomatic H. pylori positive and negative humans served for determination of the gastritis score and H. pylori status; iNOS was measured by reverse transcriptase polymerase chain reaction and immunohistochemistry and superoxide dismutase and catalase by immunohistochemistry. IL-8 in biopsies was assessed by enzyme-linked immunosorbent assay. RESULTS: Immunostaining of iNOS, catalase and superoxide dismutase was significantly associated with H. pylori infection and was localized to inflammatory cells. IL-8 concentrations were greater in the H. pylori positive than H. pylori negative group and decreased after bacterial eradication. A decrease in staining for iNOS and catalase was observed after H. pylori eradication. CONCLUSIONS: INOS and antioxidant enzymes are present in gastric biopsies of asymptomatic H. pylori positive humans. Eradication caused a significant decrease in staining for iNOS and catalase. These results indicate that oxidative stress occurs in asymptomatic patients and can be modulated by H. pylori eradication.
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Introduction: Evidence suggests that citrullinated fibrin(ogen) may be a potential in vivo target of anticitrullinated protein/peptide antibodies (ACPA) in rheumatoid arthritis (RA). We compared the diagnostic yield of three enzyme-linked immunosorbent assay (ELISA) tests by using chimeric fibrin/filaggrin citrullinated synthetic peptides (CFFCP1, CFFCP2, CFFCP3) with a commercial CCP2-based test in RA and analyzed their prognostic values in early RA. Methods: Samples from 307 blood donors and patients with RA (322), psoriatic arthritis (133), systemic lupus erythematosus (119), and hepatitis C infection (84) were assayed by using CFFCP- and CCP2-based tests. Autoantibodies also were analyzed at baseline and during a 2-year follow-up in 98 early RA patients to determine their prognostic value. Results: With cutoffs giving 98% specificity for RA versus blood donors, the sensitivity was 72.1% for CFFCP1, 78.0% for CFFCP2, 71.4% for CFFCP3, and 73.9% for CCP2, with positive predictive values greater than 97% in all cases. CFFCP sensitivity in RA increased to 80.4% without losing specificity when positivity was considered as any positive anti-CFFCP status. Specificity of the three CFFCP tests versus other rheumatic populations was high (> 90%) and similar to those for the CCP2. In early RA, CFFCP1 best identified patients with a poor radiographic outcome. Radiographic progression was faster in the small subgroup of CCP2-negative and CFFCP1-positive patients than in those negative for both autoantibodies. CFFCP antibodies decreased after 1 year, but without any correlation with changes in disease activity. Conclusions: CFFCP-based assays are highly sensitive and specific for RA. Early RA patients with anti-CFFCP1 antibodies, including CCP2-negative patients, show greater radiographic progression.
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BACKGROUND: Pancreatic stone protein (PSP) has been identified as a promising sepsis marker in adults, children and neonates. However, data on population-based reference values are lacking. This study aimed to establish age-specific reference values for PSP. METHODS: PSP was determined using a specific ELISA. PSP serum concentrations were determined in 372 healthy subjects including 217 neonates, 94 infants and children up to 16 years, and 61 adults. The adjacent categories method was used to determine which age categories had significantly different PSP concentrations. RESULTS: PSP circulating levels were not gender-dependent and ranged from 1.0 to 99.4 ng/ml with a median of 9.2 ng/ml. PSP increased significantly between the age categories, from a median of 2.6 ng/ml in very preterm newborns, to 6.3 ng/ml in term newborns, to 16.1 ng/ml in older children (p < 0.001). PSP levels were higher on postnatal day three compared to levels measured immediately post delivery (p < 0.001). Paired umbilical artery and umbilical vein samples were strongly correlated (p < 0.001). Simultaneously obtained capillary heel-prick versus venous samples showed a good level of agreement for PSP (Rho 0.89, bias 19 %). CONCLUSIONS: This study provides age-specific normal values that may be used to define cut-offs for future trials on PSP. We demonstrate an age-dependent increase of PSP from birth to childhood.
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BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by numerous fluid-filled cysts that frequently result in end-stage renal disease. While promising treatment options are in advanced clinical development, early diagnosis and follow-up remain a major challenge. We therefore evaluated the diagnostic value of Fetuin-A as a new biomarker of ADPKD in human urine. RESULTS: We found that renal Fetuin-A levels are upregulated in both Pkd1 and Bicc1 mouse models of ADPKD. Measurement by ELISA revealed that urinary Fetuin-A levels were significantly higher in 66 ADPKD patients (17.5 ± 12.5 μg/mmol creatinine) compared to 17 healthy volunteers (8.5 ± 3.8 μg/mmol creatinine) or 50 control patients with renal diseases of other causes (6.2 ± 2.9 μg/mmol creatinine). Receiver operating characteristics (ROC) analysis of urinary Fetuin-A levels for ADPKD rendered an optimum cut-off value of 12.2 μg/mmol creatinine, corresponding to 94% of sensitivity and 60% of specificity (area under the curve 0.74 ; p = 0.0019). Furthermore, urinary Fetuin-A levels in ADPKD patients correlated with the degree of renal insufficiency and showed a significant increase in patients with preserved renal function followed for two years. CONCLUSIONS: Our findings establish urinary Fetuin-A as a sensitive biomarker of the progression of ADPKD. Further studies are required to examine the pathogenic mechanisms of elevated renal and urinary Fetuin-A in ADPKD.
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To evaluate the avian influenza virus (AIV) circulation in Antarctic and sub-Antarctic penguins we carried out a serosurvey on six species from Livingston, Marion and Gough islands. Seropositivity against AIV was performed on serum samples using a competitive enzyme-linked immunosorbent assay and haemagglutination and neuraminidase inhibition assays. Some oropharyngeal and cloacal swabs were also assayed to detect influenza virus genomes by real time reverse transcription-polymerase chain reaction. Overall, 12.1% (n = 140) penguins were seropositive to AIV. By species, we detected 5% (n = 19) and 11% (n = 18) seroprevalence in sub-Antarctic rockhopper penguins (Eudyptes spp.) from Gough and Marion islands, respectively, 42% (n = 33) seroprevalence in macaroni penguins (Eudyptes chysolophus Brandt), but no positives in the three other species, gentoo (Pygoscelis papua Forster; n = 25) and chinstrap penguins (P. antarctica Forster; n = 16), from Livingston Island and king penguins (Aptenodytes patagonicus Miller; n = 27) from Marion Island. While seropositivity reflected previous exposure to the AIV, the influenza genome was not detected. Our results indicate that AIV strains have circulated in penguin species in the sub-Antarctic region, but further studies are necessary to determine the precise role that such penguin species play in AIV epidemiology and if this circulation is species (or genus) specific.
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BACKGROUND: In this study, we further investigated the association of two biomarkers, CCL18 and A1AT, with bladder cancer (BCa) and evaluated the influence of potentially confounding factors in an experimental model. METHODS: In a cohort of 308 subjects (102 with BCa), urinary concentrations of CCL18 and A1AT were assessed by enzyme-linked immunosorbent assay (ELISA). In an experimental model, benign or cancerous cells, in addition to blood, were added to urines from healthy controls and analyzed by ELISA. Lastly, immunohistochemical staining for CCL18 and A1AT in human bladder tumors was performed. RESULTS: Median urinary protein concentrations of CCL18 (52.84 pg/ml vs. 11.13 pg/ml, p < 0.0001) and A1AT (606.4 ng/ml vs. 120.0 ng/ml, p < 0.0001) were significantly elevated in BCa subjects compared to controls. Furthermore, the addition of whole blood to pooled normal urine resulted in a significant increase in both CCL18 and A1AT. IHC staining of bladder tumors revealed CCL18 immunoreactivity in inflammatory cells only, and there was no significant increase in these immunoreactive cells within benign and cancerous tissue and no association with BCa grade nor stage was noted. A1AT immunoreactivity was observed in the cytoplasm of epithelia cells and intensity of immunostaining increased with tumor grade, but not tumor stage. CONCLUSIONS: Further development of A1AT as a diagnostic biomarker for BCa is warranted.