Day 2 :
Keynote Forum
L. Courtney Smith
George Washington University , USA
Keynote: Innate immunity in the purple sea urchin; diversity of the Sp185/333 system
Time : 09:00-09:30
Biography:
L Courtney Smith has been investigating invertebrate immune systems since 1980, during which she worked on allograft rejection in marine sponges and initiated a research program on the innate immune system of sea urchins. She is author of 60 publications on invertebrate immunity. She serves on the editorial board for Developmental and Comparative Immunology and is currently a special editor of that journal. She is a member of the International Society of Developmental and Comparative Immunology and was a member of the Executive Board from 2003-2012. She has participated in numerous review panels for the US National Science Foundation since 2000.
Abstract:
The innate immune system of the purple sea urchin, Strongylocentrotus purpuratus is complex and sophisticated, functioning with several large gene families that encode pathogen detection and immune response proteins. One example is the Sp185/333 gene family, composed of ~50 small genes that are tightly linked in clusters. The genes share blocks of sequence called elements that are present in mosaic patterns, include a variety of repeats, and each gene is surrounded by microsatellites. The genomic regions harboring Sp185/333 genes are predicted to be unstable based on the repeats and shared sequence, and diversity may be driven by gene recombination, conversion, duplications, deletions, and meiotic mispairing. A single Sp185/333 gene is expressed in single phagocytes, which suggests that each cell expresses and secretes a single version of the Sp185/333 proteins that may function synergistically in response to pathogen challenge. The Sp185/333 proteins are highly diverse in sequence, which is expanded by RNA editing, yet are structurally similar with a leader, a glycine rich region, an RGD motif, and a histidine rich region. Sp185/333 proteins opsonize bacteria, induce phagocytosis, and retard the growth of most bacteria. One Sp185/333 recombinant protein (rSp0032) binds specifically to Vibrio and yeast, but not to Bacillus. It also binds LPS ï¢,1-3,glucan, and flagellin with specificity and high affinity, but does not bind peptidoglycan. rSp0032 binds phosphatidic acid (PA) and can deform liposomes composed of 10% PA. rSp0032 is intrinsically disordered until bound to LPS or PA, which induces a switch to ï¡ï€ helical structure, suggesting “shapeshifter” capabilities for binding lipids, sugars and proteins. Each of the Sp185/333 isoforms may have a range of overlapping binding activities resulting in highly effective host protection against a wide range of pathogens.
- Track 3: Cell based effector mechanisms Track 7:Case Studies Track 15: Host defense in invertebrates
Chair
L. Courtney Smith
George Washington University, USA
Session Introduction
Jessy Deshane
Division of Pulmonary Allergy and Critical Care Medicine, University of Alabama at Birmingham, USA
Title: Myeloid-Derived Regulatory Cells and Immune regulation in Asthma
Time : 9:30-9:55
Biography:
Dr. Deshane is a pulmonary immunologist with expertise in immune regulation in asthma. She investigates Myeloid-Derived Regulatory Cell biology and free radical mechanisms that regulate their differentiation and function. She pioneered these investigations both in mouse models and human asthma. Dr. Deshane has authored 46 peer-reviewed publications, including high impact journals like Journal of Experimental Medicine, Journal of Clinical Investigations, Journal of Allergy and Clinical Immunology, Immunity and Cancer Research. She serves on the editorial boards for the journals Allergy and American Journal of Respiratory Cell and Molecular Biology and serves on grant review committees. Dr. Deshane is a Parker B Francis Fellow and funded by FAMRI and NIH.
Abstract:
This lecture will address the expanding role for macrophages and their plasticity highlighting their potent inflammatory and immunoregulatory activities in chronic lung diseases, specifically asthma. The intriguing role played by environmental exposures that regulate their plasticity, both in differentiation and function of these immature myeloid cells will be discussed. Important insights will be shared regarding how proportions and functions of subsets of regulatory myeloid cells can discriminate asthma from chronic obstructive pulmonary disease. In addition, this lecture will discuss new paradigms on pathogenesis of asthma based on a major role for myeloid-derived regulatory cells as regulators of balance between immune tolerance and inflammation by eliciting a pathologic immune/inflammatory response that represents a novel form of autoimmunity.
Dr. Lauri Diehl
Genentech, South San Francisco, CA 94080, USA
Title: Dendritic cells in gut mucosal homeostasis
Time : 9:55-10:20
Biography:
Biography: Dr. Diehl is a senior pathologist and group leader at Genentech. She has more than 10 years of drug development experience in the area of immunologically mediated disease, especially inflammatory bowel disease. Her research interest is the role of the innate immune system in maintenance of intestinal mucosal homeostasis.
Abstract:
Dysfunction of the mucosal immune system leading to inappropriate recognition of commensal bacteria plays a central role in development of inflammatory bowel disease. Dendritic cells (DCs) are emerging as critical mediators of immune homeostasis through selective induction of immune responses. DCs form an extensive network in the intestinal lamina propria, project transepithelial dendrities to sample the luminal environment, and deliver antigens to mesenteric lymph nodes to induce either tolerance or immune response. While DCs are recognized as critical in maintaining mucosal homeostasis, the mechanisms by which they fulfill this role have not been fully elucidated. The role of CD83 homotypic interactions in DC regulation and other emerging mechanisms will be reviewed.
Augusto Jean-François
Université d’Angers, France
Title: Anti-Pentraxin 3 autoantibodies: a new maker of ANCA-associated vasculitisa new maker of ANCA-associated vasculitis
Time : 10:20-10:45
Biography:
Jean-François Augusto is Associate Professor of Nephrology in Angers University Hospital, France. He has studied Innate Immunity and has completed his PhD from Angers University, France, in April 2015. He has expertise in Clinical Nephrology, including auto-immune and systemic diseases, and Critical Care Medicine. His main interest is the study of innate immunity and especially pattern recognition receptor biology and their implication in pathophysiology of systemic and auto-immune diseases.
Abstract:
Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) are a group of human life-threatening diseases characterized by multiorgan involvement. AAV diagnosis relies on the histological identification of small vessel vasculitis in an affected organ and on the identification of ANCA directed to myeloperoxidase (MPO) or proteinase 3 (PR3). ANCA detection allows a rapid diagnosis and the initiation of immunosuppressive treatments. However, up to 15% of affected patients are ANCA negatives, which frequently delays the treatment initiation. Pentraxin 3 (PTX3), such as MPO and PR3, is stored in human neutrophil granules and is expressed on apoptotic neutrophil surface. We therefore investigated the presence of anti-PTX3 autoantibodies (aAbs) in the sera of AAV patients, to evaluate the potential interest of this novel biological marker in the diagnosis of AAV. Presence of anti-PTX3 autoantibodies was analyzed by a specific ELISA in sera from 150 AAV patients and in sera of 227 healthy subjects (HS). Using indirect immunofluorescence on human fixed neutrophils, we also analyzed the staining pattern associated with the presence of anti-PTX3 aAbs. Anti-PTX3 aAbs were detected in 56 of 150 (37.3%) of the AAV patients (versus 12 of 227 (5.3%) of HS, p<0.001) and, interestingly, in 7 of 14 MPO and PR3 ANCA negative AAV patients. Moreover, by indirect immunofluorescence on fixed neutrophils, anti-PTX3 aAbs gave rise to a specific cytoplasmic fluorescence pattern distinct from the classical cytoplasmic (c-ANCA), perinuclear (p-ANCA), and atypical (a-ANCA) pattern. No association between anti-PTX3 aAb titers and disease activity was found. Anti-PTX3 aAbs appear thus as a promising novel biomarker in the diagnosis of AAV, especially in patients without detectable MPO and PR3 ANCA.
Ester Boix
Universitat Autònoma de Barcelona,Spain
Title: Human secretory RNases as multifaceted antimicrobial proteins.
Time : 10:45-11:10
Biography:
Ester Boix defended her PhD at the Universitat Autònoma de Barcelona (Spain) and spent 5 years postdoctoral studies at the National Institutes of Health, Bethesda (USA) and Structural Biology Unit, University of Bath (UK). She has been awarded a Ramon y Cajal senior researcher contract in 2002. She is currently an Associate Professor at the Dpt. of Biochemistry and Molecular Biology at the Universitat Autònoma de Barcelona and principal investigator of the research group on Host defense ribonucleases. She has published more than 60 papers in peer-reviewed journals; her main interest focusing on the mechanism of action of antimicrobial RNases.
Abstract:
Human secretory RNases are wide-spectrum host defense proteins. They are secreted by innate cell types upon infection and constitute a first line immune barrier. Our research group is exploring their mechanism of action at distinct cellular levels. In this work we compare the three main human antimicrobial RNases: RNase 3 specifically secreted by eosinophils, RNase 6, expressed by neutrophils and monocytes, and RNase 7 predominant in keratinocytes. By applying site directed mutagenesis and peptide synthesis we have identified the main structural determinants for the proteins’ cytotoxicity on several Gram negative and Gram positive bacteria species together with Candida albicans yeast. Domains responsible for lipopolysaccharide binding, cell agglutination and membrane destabilization have been located at the protein N-terminus. The identified antimicrobial motives served as a template to design antimicrobial peptides. Protein derived peptides were engineered reproducing efficiently the parental protein antimicrobial properties. Moreover, together with an unspecific membrane lysis killing mechanism, the studied RNases were able to internalize at sublethal concentrations, blocking the cell viability and potentially targeting the cellular nucleic acids. We can conclude that human antimicrobial RNases work as host multitask proteins contributing to the clearing of the infection focus. Complementary, human RNases can also serve as templates towards a structure- based drug design of novel antimicrobial agents. In particular, potential contribution of the enzymatic activity in the RNases cytotoxicity envisages cellular RNA targeting as an effective strategy for alternative antibiotic development.
Amal Mahmoud Kamal Eldin
MiniaUiversity ,egypt
Title: Prediction of Preeclampsia with Novel Biomarkers at Second Trimester of Pregnancy
Time : 11:25-11:50
Biography:
Abstract:
Objective : To evaluate the ability of the soluble vascular endothelial growth factor receptor (sFlt-1), neutrophil-flt-1, monocyte-flt-1, pentraxin3 (PTX3), nitric oxide (NO) and alpha fetoprotein (AFP) measurements at gestational weeks 14-18 to predict preeclampsia (PE).
Subjects & Methods: Fifty pregnant females at second trimester of pregnancy divided into 25 normotensive pregnant females who remained normotensive till delivery (group I) and 25 high risk pregnant females who subsequently developed PE (group II). Twenty five healthy non-pregnant females served as control (group III). Maternal blood samples were collected at 14-18 gestational weeks. EDTA samples were investigated for both neutrophil- and monocyte-flt-1 by flowcytometer. Stored serum samples were analyzed for sFlt-1, PTX3, NO and AFP by ELISA.
Results: Alpha fetoprotein, sflt-1 and pentraxin 3 were found to be statistically significantly increased in group II when compared with group I (P-value = 0.024, < 0.001 & 0.006) and group III (P-value = < 0.001). However, there was statistically significant decrease in neutrophil-flt-1 and nitric oxide in group II when compared with group I (P-value = < 0.001 & 0.016). Group II had significant negative correlation between soluble flt-1 and both neutrophil- & monocyte-flt-1 (P-value = Ë‚ 0.001 & 0.009) and between neutrophil-flt-1 and PTX3 (P-value = 0.007). Soluble flt-1 was found to have the highest predictive value for predicting preeclampsia (AUC = 0.941& P-value = < 0.001)
Conclusion: Soluble flt-1 was the best single biomarker to predict preeclampsia at second trimester of pregnancy with the best diagnostic sensitivity and specificity.
Sung Su Yea
InjeUniversity College of Medicine, South Korea
Title: Differential regulation of NK cell functions by PI3K isoforms and mTOR complexes
Time : 11:50-12:15
Biography:
Sung Su Yea has completed his PhD from Korea Advanced Institute of Science and Technology on 2000.Since 2001, he has been working as a professor of Dept. of Biochemistry,Inje University College of Medicine, South Korea. He had been working as a visiting scholar at Michigan State University (1997-1998) and University of California, Irvine (2011-2013), USA.He has published more than 64 papers in reputed journals, 29 patents (including patents pending) and has been serving as an editorial board member of repute.
Abstract:
Phosphoinositide 3-kinase (PI3K) and mechanistic target of rapamycin (mTOR) play fundamental roles in signal transduction for cell proliferation and survival. Recently, specific inhibitors of PI3K isoforms are being evaluated for their therapeutic potential in cancer. However, little is known about their roles in natural killer (NK) cell, an effector lymphocyte of innate immunity. Here we assessed how different classes of PI3K inhibitors and mTOR complex (mTORC) inhibitors affect the function of NK cells. Inhibitors of all class I isoforms (pan-PI3K) significantly impaired cell-mediated cytotoxicity and antibody-dependent cellular cytotoxicity of NK cells against tumor cells, whereas isoform-selective inhibitors had little effect; in particular, no significant effect was observed in NK cells treated with p110a-selective inhibitors. Production of cytokines and chemokines including IFN-g in NK cells stimulated through NKG2D and NK1.1 was blocked by a pan-PI3K inhibitor and partially reduced by a p110d inhibitor, with lesser effects of p110a inhibitors. NK cell-mediated cytotoxicity against tumor cells as well as IFN-g production through NKG2D were down-regulated by PP242, an inhibitor for both complex of mTOR, but not by rapamycin inhibiting mTORC1 only. In anti-NKG2D antibody-stimulated NK cells, pan-PI3K inhibitor decreased the phosphorylation of AKT and ERK1/2 phosphorylation, while p110a inhibition modestly reduced PI3K signaling output as measured by AKT and ERK1/2 phosphorylation. These results reveal the role of PI3K isoforms and mTOR complexes in NK cell functions and indicate that selective p110a inhibitors would provide a better therapeutic window for specific disease states than achieved by targeting all isoforms.
Carl E. I. Janssen
Department of Imaging & Pathology, Belgium
Title: The presence of granuloma-in-follicles in Crohn’s disease appendectomy is an independent prognostic factor to predict lymph node involvement
Time : 12:15-12:40
Biography:
Carl E I Janssen has completed his PhD at the age of 27 years from KU Leuven and published 6 papers in reputed journals. He was also involved in business plan writing for a university spin-off.
Abstract:
Granulomas are one of the diagnostic features of Crohn’s disease(CD). Genetic variants in nucleotide oligomerisation domain 2(NOD2) are linked with CD. We reported granulomas-in-follicles (GIF) are linked to increased IFNγ/IL1β/IL17/IL23R/RIP2 expression, polycyclic granulomas and extended disease to anus, appendix, lymph nodes or mouth in paediatric CD(pCD). We selected 10pCD cases with granulomatous appendicitis (pCD-A) and screened all available tissue for granulomas in intestinal lymph nodes. We studied granulomas by a standardized set of morphological features and immunohistochemistry; CD68 to detect microgranulomas, CD20 to visualize GIF, cytokines TNFα and IL17, and determined NOD2 variants p.R702W(rs2066844), p.G908R(rs2066845) and p.Leu1007fsX1008(rs2066847). At least one variant was present in 60% of pCD-A. Lymphocyte emperipolesis was observed in 60% of pCD-A and found in polycyclic granulomas irrespective of NOD2 variants, GIF or lymph node involvement. rs2066847 (30%), was not associated with GIF or lymph node involvement. rs2066845 was found in a single case with GIF, but without lymph node granulomas. rs2066844 (20%) was associated with GIF and lymph node involvement. All except one case exhibited tissue sclerosis. Polycyclic granulomas and eosinophils were common in NOD2+, but virtually absent in NOD2- cases. Coronary CD68+ granulomas, CD20+ GIF and lymph node involvement were prominent in NOD2-, but rare in NOD2+ cases. No significant difference in TNFα or IL17 staining was related to NOD2 variants, GIF or lymph node granulomas. This is the first pathological study of pCD-A granulomas. Although NOD2 variants were present in the majority of cases, they were independent of GIF, a novel feature linked to intestinal lymph node involvement.