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Printed peptide arrays identify prognostic TNC serumantibodies in glioblastoma patients.
Mock, A, Warta, R, Geisenberger, C, Bischoff, R, Schulte, A, Lamszus, K, Stadler, V, Felgenhauer, T, Schichor, C, Schwartz, C, et al
Oncotarget. 2015;(15):13579-90
Abstract
Liquid biopsies come of age offering unexploited potential to monitor and react to tumor evolution. We developed a cost-effective assay to non-invasively determine the immune status of glioblastoma (GBM) patients. Employing newly developed printed peptide microarrays we assessed the B-cell response against tumor-associated antigens (TAAs) in 214 patients. Firstly, sera of long-term (36+ months, LTS, n=10) and short-term (6-10 months, STS, n=14) surviving patients were screened for prognostic antibodies against 1745 13-mer peptides covering known TAAs (TNC, EGFR, GLEA2, PHF3, FABP5, MAGEA3). Next, survival associations were investigated in two retrospective independent multicenter validation sets (n=61, n=129, all IDH1-wildtype). Reliability of measurements was tested using a second array technology (spotted arrays). LTS/STS screening analyses identified 106 differential antibody responses. Evaluating the Top30 peptides in validation set 1 revealed three prognostic peptides. Prediction of TNC peptide VCEDGFTGPDCAE was confirmed in a second set (p=0.043, HR=0.66 [0.44-0.99]) and was unrelated to TNC protein expression. Median signals of printed arrays correlated with pre-synthesized spotted microarrays (p<0.0002, R=0.33). Multiple survival analysis revealed independence of age, gender, KPI and MGMT status. We present a novel peptide microarray immune assay that identified increased anti-TNC VCEDGFTGPDCAE serum antibody titer as a promising non-invasive biomarker for prolonged survival.
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The human immune system recognizes neopeptides derived from mitochondrial DNA deletions.
Duvvuri, B, Duvvuri, VR, Wang, C, Chen, L, Wagar, LE, Jamnik, V, Wu, J, Yeung, RS, Grigull, J, Watts, TH, et al
Journal of immunology (Baltimore, Md. : 1950). 2014;(10):4581-91
Abstract
Mutations in mitochondrial (mt) DNA accumulate with age and can result in the generation of neopeptides. Immune surveillance of such neopeptides may allow suboptimal mitochondria to be eliminated, thereby avoiding mt-related diseases, but may also contribute to autoimmunity in susceptible individuals. To date, the direct recognition of neo-mtpeptides by the adaptive immune system has not been demonstrated. In this study we used bioinformatics approaches to predict MHC binding of neopeptides identified from known deletions in mtDNA. Six such peptides were confirmed experimentally to bind to HLA-A*02. Pre-existing human CD4(+) and CD8(+) T cells from healthy donors were shown to recognize and respond to these neopeptides. One remarkably promiscuous immunodominant peptide (P9) could be presented by diverse MHC molecules to CD4(+) and/or CD8(+) T cells from 75% of the healthy donors tested. The common soil microbe, Bacillus pumilus, encodes a 9-mer that differs by one amino acid from P9. Similarly, the ATP synthase F0 subunit 6 from normal human mitochondria encodes a 9-mer with a single amino acid difference from P9 with 89% homology to P9. T cells expanded from human PBMCs using the B. pumilus or self-mt peptide bound to P9/HLA-A2 tetramers, arguing for cross-reactivity between T cells with specificity for self and foreign homologs of the altered mt peptide. These findings provide proof of principal that the immune system can recognize peptides arising from spontaneous somatic mutations and that such responses might be primed by foreign peptides and/or be cross-reactive with self.
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A randomized, double-blind study of larazotide acetate to prevent the activation of celiac disease during gluten challenge.
Leffler, DA, Kelly, CP, Abdallah, HZ, Colatrella, AM, Harris, LA, Leon, F, Arterburn, LA, Paterson, BM, Lan, ZH, Murray, JA
The American journal of gastroenterology. 2012;(10):1554-62
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Abstract
OBJECTIVES In patients with celiac disease, enteropathy is caused by the entry of gluten peptides into the lamina propria of the intestine, in which their immunogenicity is potentiated by tissue transglutaminase (tTG) and T-helper type 1-mediated immune responses are triggered. Tight junction disassembly and paracellular permeability are believed to have an important role in the transport of gluten peptides to the lamina propria. Larazotide acetate is a tight-junction regulator peptide that, in vitro, prevents the opening of intestinal epithelial tight junctions. The aim of this study was to evaluate the efficacy and tolerability of larazotide acetate in protecting against gluten-induced intestinal permeability and gastrointestinal symptom severity in patients with celiac disease. METHODS In this dose-ranging, placebo-controlled study, 86 patients with celiac disease controlled through diet were randomly assigned to larazotide acetate (0.25, 1, 4, or 8 mg) or placebo three times per day with or without gluten challenge (2.4 g/day) for 14 days. The primary efficacy outcome was the urinary lactulose/mannitol (LAMA) fractional excretion ratio. Secondary endpoints included gastrointestinal symptom severity, quality-of-life measures, and antibodies to tTG. RESULTS LAMA measurements were highly variable in the outpatient setting. The increase in LAMA ratio associated with the gluten challenge was not statistically significantly greater than the increase in the gluten-free control. Among patients receiving the gluten challenge, the difference in the LAMA ratios for the larazotide acetate and placebo groups was not statistically significant. However, larazotide acetate appeared to limit gluten-induced worsening of gastrointestinal symptom severity as measured by the Gastrointestinal Symptom Rating Scale at some lower doses but not at the higher dose. Symptoms worsened significantly in the gluten challenge-placebo arm compared with the placebo-placebo arm, suggesting that 2.4 g of gluten per day is sufficient to induce reproducible gluten toxicity. Larazotide acetate was generally well tolerated. No serious adverse events were observed. The most common adverse events were headache and urinary tract infection. CONCLUSIONS LAMA variability in the outpatient setting precluded accurate assessment of the effect of larazotide acetate on intestinal permeability. However, some lower doses of larazotide acetate appeared to prevent the increase in gastrointestinal symptom severity induced by gluten challenge.
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Endomorphin-1 inhibits the activation and the development of a hyporesponsive-like phenotype in lipopolysaccharide- stimulated THP-1 monocytes.
Izzi, V, Chiurchiù, V, D'Aquilio, F, Martino, A, Tresoldi, I, Modesti, A, Baldini, PM
International journal of immunopathology and pharmacology. 2008;(4):833-43
Abstract
Endomorphin-1 (EM-1) is an endogenous opioid peptide selectively binding to micro opioid receptors (MORs). Besides its analgesic effects on the central nervous system (CNS), it has been recently reported that EM-1 can cross the blood-brain barrier (BBB) and diffuse into the blood, behaving as an analgesic/anti-inflammatory molecule on peripheral tissues, thus leading to the hypothesis that it could represent a soluble modulator of immune cell functions. Interestingly, nothing is known about its possible effects on monocytes, the main circulating cell-type involved in those systemic responses, such as fever and septic states, involving the release of high amounts of pyrogenic inflammatory factors. The aim of this work is to evaluate possible EM-1effects on lipopolisaccharide (LPS)-stimulated THP-1 monocytes in terms of the production of inflammatory mediators and the instauration of a hyporesponsive-like phenotype which is a main feature of systemic inflammatory responses, and on the development of peripheral monocytes to DC. Our data demonstrate for the first time that EM-1 is able to inhibit both LPS-stimulated monocyte activation, in terms of arachidonic acid, PGE2, ROI and NO2 production and instauration of a hyporesponsive phenotype without any macroscopic effect on DC development. These data support the hypothesis that EM-1 could be involved in modulating monocyte functions during systemic inflammatory reactions, also providing new evidence for its eventual clinical application in endotoxic states.
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The peptide-binding specificity of HLA-A*3001 demonstrates membership of the HLA-A3 supertype.
Lamberth, K, Røder, G, Harndahl, M, Nielsen, M, Lundegaard, C, Schafer-Nielsen, C, Lund, O, Buus, S
Immunogenetics. 2008;(11):633-43
Abstract
Human leukocyte antigen class I (HLA-I) molecules are highly polymorphic peptide receptors, which select and present endogenously derived peptide epitopes to CD8+ cytotoxic T cells (CTL). The specificity of the HLA-I system is an important component of the overall specificity of the CTL immune system. Unfortunately, the large and rapidly increasing number of known HLA-I molecules seriously complicates a comprehensive analysis of the specificities of the entire HLA-I system (as of June 2008, the international HLA registry holds >1,650 unique HLA-I protein entries). In an attempt to reduce this complexity, it has been suggested to cluster the different HLA-I molecules into "supertypes" of largely overlapping peptide-binding specificities. Obviously, the HLA supertype concept is only valuable if membership can be assigned with reasonable accuracy. The supertype assignment of HLA-A*3001, a common HLA haplotype in populations of African descent, has variously been assigned to the A1, A3, or A24 supertypes. Using a biochemical HLA-A*3001 binding assay, and a large panel of nonamer peptides and peptide libraries, we here demonstrate that the specificity of HLA-A*3001 most closely resembles that of the HLA-A3 supertype. We discuss approaches to supertype assignment and underscore the importance of experimental verification.
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Screening of HLA-A24-restricted epitope peptides from prostate-specific membrane antigen that induce specific antitumor cytotoxic T lymphocytes.
Horiguchi, Y, Nukaya, I, Okazawa, K, Kawashima, I, Fikes, J, Sette, A, Tachibana, M, Takesako, K, Murai, M
Clinical cancer research : an official journal of the American Association for Cancer Research. 2002;(12):3885-92
Abstract
PURPOSE Prostate-specific membrane antigen (PSMA), which is a transmembrane glycoprotein predominantly expressed in prostate cancer, is an attractive target for tumor-specific immunotherapy. To identify human leukocyte antigen (HLA)-A24-restricted epitope peptides from PSMA for further application of the dendritic cell (DC)-based immunotherapy targeting prostate cancer, we have screened several PSMA-encoded HLA-A24-binding peptides for their capabilities to elicit specific antitumor CTL response in vitro. EXPERIMENTAL DESIGN The amino acid sequence of PSMA was screened for peptides consisting of 9 or 10 amino acids, which possess the known HLA-A24-binding motif. Nine candidate peptides were screened for binding to HLA-A24 molecules. Then, each of these nine peptides was studied to determine whether CTL responses could be induced by primary in vitro immunization of CD8(+) T cells using peptide-pulsed autologous DCs derived from peripheral blood mononuclear cells of HLA-A24(+) healthy donor as antigen-presenting cells. The antigen specificity of the CTL lines was confirmed using several tumor cell lines as target cells, which were genetically modified to express both HLA-A24 and PSMA. RESULTS Two peptides, LYSDPADYF and NYARTEDFF, were demonstrated to elicit CTL lines that lyse peptide-pulsed, HLA-A24(+) B-lymphoblastoid cells. Each of the CTL lines recognized their specific PSMA-expressing target cells in a HLA-A24-restricted manner. The capability to release IFN-gamma by the CTL lines was specifically inhibited by anti-MHC class I and anti-CD8 monoclonal antibodies but not by anti-MHC class II and anti-CD4 monoclonal antibodies. CONCLUSION Two novel HLA-A24-restricted PSMA-derived epitopes were identified in this study. These epitopes can be used to further evaluate the clinical utility of DC-based immunotherapeutic strategies for treatment of hormone-refractory prostate cancers.