DOCSLIB.ORG

Granzyme a in the Pathogenesis of Type 1 Diabetes: the Yes and the No

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Granzyme a in the Pathogenesis of Type 1 Diabetes: the Yes and the No Diabetes Volume 66, December 2017 2937 Granzyme A in the Pathogenesis of Type 1 Diabetes: The Yes and the No Thomas Mandrup-Poulsen Diabetes 2017;66:2937–2939 | https://doi.org/10.2337/dbi17-0037 Two major unanswered questions related to the pathogen- GrzmA, discovered by Tschopp and colleagues (9) in esis of type 1 diabetes (T1D) prevent progress in our ability 1986, belongs to the granzyme family of serine proteases to intervene in disease development: What breaks immune encompassing 10 members in the mouse and 5 members in tolerance to the pancreatic b-cells? And what kills the the human (10,11). They have trypsin-, chymotrypsin-, and b-cells? elastase-like proteolytic activities, but in contrast to these By the surprising demonstration that knockout of the broad serine proteases, granzymes have higher substrate tryptase granzyme A (GrzmA), conventionally considered to specificity conferred by a substrate binding pocket. Gran- be a key proapoptotic mediator of immune killer cell cyto- zymes are expressed mainly in cytotoxic T cells and natural toxicity, does not protect but markedly accelerates and in- killer (NK) cells in response to interleukin (IL)-2 in synergy creases incidence of T1D in the nonobese diabetic (NOD) with IL-12 (12,13), with GrzmA being the most abundantly mouse, Mollah et al. (1) add to answering both of these expressed but also having lower cytotoxic activity than questions. On one hand, they show that GrzmA does not GrzmB. GrzmA and GrzmB are also expressed in gdT cells, COMMENTARY contribute to b-cell killing. On the other hand, their striking a subset of the intraepithelial lymphocytes abundant in the finding that diabetes resistance in the proinsulin II trans- intestinal mucosa, and in thymocytes, suggesting roles in genic mouse is broken by GrzmA knockout provides evi- both central tolerance and gut immunity. GrzmB, but as yet dence of an important role of GrzmA for maintenance of not GrzmA, is also found to be expressed in plasmacytoid peripheral tolerance. dendritic cells (pDCs) (14), the innate master producer of By answering “No” to the question as to whether GrzmA the antiviral type I interferon (IFN) IFNa.Apartfromme- is important in b-cell killing, this study adds to reports diating T-cell and NK-cell granule-dependent cytotoxicity, showing that granzyme B (GrzmB) (2), Fas (3,4), and per- granzymes regulate B lymphocyte proliferation, inhibit viral forin (5,6) are dispensable in b-cell killing in the NOD replication, and kill bacteria. mouse. These observations challenge the view that b-cell In granule-dependent cytotoxicity granzymes are delivered destruction in T1D is caused by classic effector T-cell to early endosomes by clathrin- and dynamin-dependent en- mechanisms and support the notion that these cells do ensure docytosis after entering the target cell via perforin, a mem- antigen-specific homing and reactivity but then interact with brane pore-forming molecule cosecreted with granzymes innate immune cells to orchestrate an intraislet inflamma- (Fig. 1). Granzymes enter the cytosol from the endosomal tory reaction leading to b-cell killing, the selectivity of which compartment and are then activated by the near-neutral pH is in part determined by differentiation-dependent sensitiv- of the cytosol, where they in turn trigger the caspase- ity of b-cells to cytotoxic inflammatory mediators (7). dependent intrinsic death pathway (11). Until recently it The “Yes” to the question as to whether GrzmA contrib- was believed that GrzmA was a mere “backup” for GrzmB utes to maintain peripheral tolerance is perhaps even more in perforin-mediated apoptosis and activated identical important because it identifies new potential therapeutic death pathways. It is now clear that not only do GrzmA- targets. T-cell GrzmA expression and production is reduced and GrzmB-deficient mice have differential susceptibility in human T1D by yet unknown mechanisms (8). Under- to different infections, but GrzmA also triggers noncaspase- standing of these mechanisms and restoration of GrzmA dependent cell death by activating the DNA-degrading SET levels may have therapeutic perspectives. Key in this respect complex (Fig. 1) (10,11). This activity relates to a unique abil- would be clarification of the regulation and mechanism of ity of GrzmA to homodimerize, thereby exposing an ex- action of GrzmA. tended exosite that determines its substrate specificity. Department of Biomedical Sciences, Faculty of Health and Medical Sciences, © 2017 by the American Diabetes Association. Readers may use this article as University of Copenhagen, Copenhagen, Denmark long as the work is properly cited, the use is educational and not for profit, and the Corresponding author: Thomas Mandrup-Poulsen, [email protected]. work is not altered. More information is available at http://www.diabetesjournals .org/content/license. See accompanying article, p. 3041. 2938 Commentary Diabetes Volume 66, December 2017 Figure 1—GrzmA activates a caspase-independent death pathway but prevents accumulation of ssDNA. GrzmA (closed scissors) is delivered through perforin (*) to the early endosome, is liberated from the endosome, and is activated (open scissors) by the neutral pH in the cytosol. It then first enters the mitochondrial matrix and next cleaves a component of the electron transport complex I NDUFS3, thereby perturbing mitochondrial redox function, ATP generation, and maintenance of the mitochondrial membrane potential, as well as causing reactive oxygen species (ROS) formation. ROS drive nuclear translocation of the endoplasmic reticulum (ER)-associated oxidative stress response complex SET that contains six components: three nucleases, the base excision repair endonuclease Ape1, the endonuclease NM23-H1, and the 59–39 exonuclease TREX1; the chromatin modifying proteins SET and pp32; and HMGB2, a DNA binding protein that recognizes distorted DNA. SET normally serves to repair abasic sites caused by oxidative damage in DNA. GrzmA translocating to the nucleus cleaves histone 1 and cuts histone tails. Hereby the chromatin structure is opened up allowing access to nucleases. GrzmA then cleaves Ape1, HMGB2, and SET, which otherwise binds and inhibits NM23-H1. Activated NM23-H1 in turn nicks DNA (pliers), which is further degraded by TREX1 (pliers), thereby preventing liberation of ssDNA fragments into the cytosol. Mollah et al. (1) suggest that in the absence of GrzmA, ssDNA fragments accumulate, are liberated, and activate Toll-like receptors on pDCs, triggering type I IFN production, which breaks immune tolerance. Having shown that enhanced diabetes development in numbers, but NK cells are IFNg—not type I IFN—producers. 2 2 GrzmA / NOD mice depended on type I IFN signaling and Although ssDNA did not accumulate in GrzmA-expressing that innate immune cell accumulation of ssDNA was asso- Tcells,b-cell antigen–specificCD8+ T cells were increased ciated with a type I IFN–related islet gene expression sig- in islets, lymph nodes, and spleen. Regulatory T-cell nature, Mollah et al. (1) make the case that GrzmA deficiency number and function were unaffected. Taken together, permits liberation of ssDNA fragments into the cytosol in these observations suggest that GrzmA may directly regu- pDCs due to lack of GrzmA-mediated activation of the SET late the autoreactive T-cell pool. Thus GrzmB has been complex nuclease activity and that the ssDNA fragments shown to mediate activation-induced cell death in T cells subsequently promote type I IFN production (likely via (15), and pDC-derived GrzmB suppresses effector T-cell Toll-like receptors) that in turn breaks tolerance (Fig. 1). How- proliferation by degrading the T-cell receptor z-chain (16). ever, it remains to be shown that pDCs express GrzmA, It would be relevant to determine whether GrzmA has and GrzmA deficiency did not increase IFNa in pDC culture similar actions. medium or in circulation. ssDNA was increased in What is the human relevance of this study? T1D risk is GrzmA-expressing NK cells correlating with increased NK increased in clinical trials of type I IFN (17), underpinning diabetes.diabetesjournals.org Mandrup-Poulsen 2939 that aberrant production of type I IFN may break tolerance. 7. Hansen JB, Tonnesen MF, Madsen AN, et al. Divalent metal transporter 1 Yet targeting type I IFN alone does not prevent diabetes regulates iron-mediated ROS and pancreatic b cell fate in response to cytokines. Cell Metab 2012;16:449–461 development in the NOD mouse (18). There are no human + studies of anti-IFNa in T1D. The authors raise the caveat 8. Hamel Y, Mauvais FX, Pham HP, et al. A unique CD8 T lymphocyte signature in pediatric type 1 diabetes. J Autoimmun 2016;73:54–63 that NOD mice carry endogenous nonpathogenic retro- 9. Masson D, Zamai M, Tschopp J. Identification of granzyme A isolated from viruses that may be the source of accumulating cytosolic cytotoxic T-lymphocyte-granules as one of the proteases encoded by CTL-specific ssDNA. However, common human diseases are caused by genes. FEBS Lett 1986;208:84–88 DNA viruses (adenovirus, herpes simplex virus, poxviruses, 10. Trapani JA. Granzymes: a family of lymphocyte granule serine proteases. and hepatitis B virus), prompting human studies. Also since Genome Biol 2001;2:reviews3014.1–reviews3014.7 IL-2 deficiency is a central defect in T1D pathogenesis (19) 11. Lieberman J. Granzyme A activates another way to die. Immunol Rev 2010; and since GrzmA expression is driven by IL-2, the observa- 235:93–104 tion that T-cell GrzmA is reduced in children with T1D (8) 12. Janas ML, Groves P, Kienzle N, Kelso A. IL-2 regulates perforin and granzyme + further emphasizes the translational implications of the gene expression in CD8 T cells independently of its effects on survival and pro- study by Mollah et al. (1). Larger clinical trials of IL-2 in liferation. J Immunol 2005;175:8003–8010 T1D, now shown in small studies to be safe and yielding 13.
Load more

Recommended publications
  • Transplant Immunology
    Basic Immunology in Medical Practice น.พ. สกานต์ บุนนาค งานโรคไต กลุ่มงานอายุรศาสตร์ รพ.ราชวิถี Basic immunology • Innate immunity • Ready to be used • Less specificity • Comprise of • External barriers: skin, mucus, washing fluid etc. • Molecule: complement, acute-phase protein and cytokine • inflammatory mediator secreting cells: basophil, mast cell, eosinophil and natural killer cell • Phagocytic cells: neutrophil, monocyte, and macrophage Basis immunology • Adaptive immunity • Active after expose to specific Ag. • High specificity • Comprise of • Humoral immune response (HIR) : B lymphocyte, Memory B lymphocyte, plasma cell and antibody • Cell mediated immune response (CMIR) : T lymphocyte • Effector T lymphocyte • CD4+ T cell Helper T cell (Th1, Th2, Th17 etc.) • CD8+ T cell Cytotoxic T cell • Regulatory T lymphocyte • Memory T lymphocyte Innate immunity Cellular component of innate immunity • Activated by pathogen-associated molecular patterns (PAMPs) via pattern reconition receptors (PRRs). • PAMPs • Shared by a larged group of infectious agens • Unlikely to mutate • Clearly distinguishable from self pattern (commonly not present on mammalian cell surface • Gram-negative LPS, gram-positive lipoteichoic acid, yeast cell wall mannan etc. Phagocytic cells • Neutrophils, monocyte and macrophage • Killing machanisms • Reactive oxygen radicals • Oxygen-independent machanism: α – defencin, cathepsin G, lysozyme, lactoferin etc. Mast cells Mast cells Natural killer (NK) cells Activating NK-R FAS-L perforin FAS Granzyme-B Caspase cascade
    [Show full text]
  • Purification and Identification of a Binding Protein for Pancreatic
    Biochem. J. (2003) 372, 227–233 (Printed in Great Britain) 227 Purification and identification of a binding protein for pancreatic secretory trypsin inhibitor: a novel role of the inhibitor as an anti-granzyme A Satoshi TSUZUKI*1,2,Yoshimasa KOKADO*1, Shigeki SATOMI*, Yoshie YAMASAKI*, Hirofumi HIRAYASU*, Toshihiko IWANAGA† and Tohru FUSHIKI* *Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan, and †Laboratory of Anatomy, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18-Nishi 9, Kita-ku, Sapporo 060-0818, Japan Pancreatic secretory trypsin inhibitor (PSTI) is a potent trypsin of GzmA-expressing intraepithelial lymphocytes in the rat small inhibitor that is mainly found in pancreatic juice. PSTI has been intestine. We concluded that the PSTI-binding protein isolated shown to bind specifically to a protein, distinct from trypsin, on from the dispersed cells is GzmA that is produced in the the surface of dispersed cells obtained from tissues such as small lymphocytes of the tissue. The rGzmA hydrolysed the N-α- intestine. In the present study, we affinity-purified the binding benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT), and the BLT protein from the 2 % (w/v) Triton X-100-soluble fraction of hydrolysis was inhibited by PSTI. Sulphated glycosaminoglycans, dispersed rat small-intestinal cells using recombinant rat PSTI. such as fucoidan or heparin, showed almost no effect on the Partial N-terminal sequencing of the purified protein gave a inhibition of rGzmA by PSTI, whereas they decreased the inhi- sequence that was identical with the sequence of mouse granzyme bition by antithrombin III.
    [Show full text]
  • Granzyme a Released Upon Stimulation of Cytotoxic T Lymphocytes Activates the Thrombin Receptor on Neuronal Cells and Astrocytes HANA S
    Proc. Nail. Acad. Sci. USA Vol. 91, pp. 8112-8116, August 1994 Neurobiology Granzyme A released upon stimulation of cytotoxic T lymphocytes activates the thrombin receptor on neuronal cells and astrocytes HANA S. SUIDAN*, JACQUES BOUVIERt, ESTHER SCHAERERt, STUART R. STONES, DENIS MONARD*, AND JURG TSCHOPPt *Fnednch Miescher-Institut, P.O. Box 2543, CH-4002 Basel, Switzerland; tInstitute of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland; and tDepartment of Haematology, University of Cambridge, Medical Research Council Centre, Hills Road, Cambridge CB2 2QH, United Kingdom Communicated by Hans Neurath, May 4, 1994 ABSTRACT Granzymes are a family of serine proteases for example, myelin destruction is believed to be mediated by that are harbored in cytoplasmic granules of activated T these immune effector cells (19, 20). Experimental autoim- lymphocytes and are released upon target cell interaction. mune encephalomyelitis (EAE), a rodent multiple sclerosis- Immediate and complete neurite retraction was induced in a like disease, can be caused by T lymphocytes reactive against mouse neuronal cell line when total extracts ofgranule proteins myelin basic protein (MBP) (21). The encephalitogenic MBP- were added. This activity was isolated and identified as gran- specific T lymphocytes are in most cases CD4+ and major zyme A. This protease not only induced neurite retraction at histocompatibility complex class lI-restricted (17). The nanomolar concentrations but also reversed the stellation of pathogenicity in the central nervous system involves homing, astrocytes. Both effects were critically dependent on the ester- extravasation, and induction of tissue damage. olytic activity of granzyme A. As neurite retraction is known to Little is known about the molecular mechanism by which be induced by thrombin, possible cleavage and activation ofthe encephalitogenic T lymphocytes induce tissue destruction in thrombin receptor were investigated.
    [Show full text]
  • Defining the Characteristics of Serine Protease-Mediated Cell Death Cascades ⁎ A.R
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Biochimica et Biophysica Acta 1773 (2007) 1491–1499 www.elsevier.com/locate/bbamcr Minireview A more serine way to die: Defining the characteristics of serine protease-mediated cell death cascades ⁎ A.R. O’Connell, C. Stenson-Cox National Centre for Biomedical and Engineering Science, National University of Ireland, Galway, Ireland Received 23 February 2007; received in revised form 11 July 2007; accepted 1 August 2007 Available online 14 August 2007 Abstract The morphological features observed by Kerr, Wylie and Currie in 1972 define apoptosis, necrosis and autophagy. An appreciable number of alternative systems do not fall neatly under these categories, warranting a review of alternative proteolytic machinery and its contribution to cell death. This review aims to pinpoint key molecular features of serine protease-mediated pro-apoptotic signalling. The profile created will contribute to a standard set of biochemical criteria that can serve in differentiating within cell death subtypes. © 2007 Elsevier B.V. All rights reserved. Keywords: Apoptosis; Serine protease; Caspase; Mitochondria 1. Introduction ability (MOMP) triggering the release of apoptogenic factors. Although the underlying mechanism of MOMP induction has The knowledge that cell death is an essential event in the life not been fully ascertained it is known to be regulated by of multi-cellular organisms has been around for more than members of the Bcl-2 family (Fig. 11). Anti-apoptotic Bcl-2 and 150 years. In 1972 Kerr et al., coined the term ‘apoptosis’ to Bcl-xl proteins block MOMP, whilst pro-apoptotic BH-3 describe a distinct morphological pattern of physiologically domain only proteins; Bim and Bid promote MOMP through occurring cell death [1].
    [Show full text]
  • Original Article
    Original Article Dipeptidyl Peptidase IV Inhibition for the Treatment of Type 2 Diabetes Potential Importance of Selectivity Over Dipeptidyl Peptidases 8 and 9 George R. Lankas,1 Barbara Leiting,2 Ranabir Sinha Roy,2 George J. Eiermann,3 Maria G. Beconi,4 Tesfaye Biftu,5 Chi-Chung Chan,6 Scott Edmondson,5 William P. Feeney,7 Huaibing He,5 Dawn E. Ippolito,3 Dooseop Kim,5 Kathryn A. Lyons,5 Hyun O. Ok,5 Reshma A. Patel,2 Aleksandr N. Petrov,3 Kelly Ann Pryor,2 Xiaoxia Qian,5 Leah Reigle,5 Andrea Woods,8 Joseph K. Wu,2 Dennis Zaller,8 Xiaoping Zhang,2 Lan Zhu,2 Ann E. Weber,5 and Nancy A. Thornberry2 Dipeptidyl peptidase (DPP)-IV inhibitors are a new ap- important to an optimal safety profile for this new class of proach to the treatment of type 2 diabetes. DPP-IV is a antihyperglycemic agents. Diabetes 54:2988–2994, 2005 member of a family of serine peptidases that includes quiescent cell proline dipeptidase (QPP), DPP8, and DPP9; DPP-IV is a key regulator of incretin hormones, but the functions of other family members are unknown. To deter- herapies that increase the circulating concentra- mine the importance of selective DPP-IV inhibition for the tions of insulin have proven beneficial in the treatment of diabetes, we tested selective inhibitors of DPP-IV, DPP8/DPP9, or QPP in 2-week rat toxicity studies treatment of type 2 diabetes. Dipeptidyl pepti- and in acute dog tolerability studies. In rats, the DPP8/9 Tdase (DPP)-IV inhibitors are a promising new inhibitor produced alopecia, thrombocytopenia, reticulocy- approach to type 2 diabetes that function, at least in part, topenia, enlarged spleen, multiorgan histopathological as indirect stimulators of insulin secretion (1).
    [Show full text]
  • Serine Proteases with Altered Sensitivity to Activity-Modulating
    (19) & (11) EP 2 045 321 A2 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 08.04.2009 Bulletin 2009/15 C12N 9/00 (2006.01) C12N 15/00 (2006.01) C12Q 1/37 (2006.01) (21) Application number: 09150549.5 (22) Date of filing: 26.05.2006 (84) Designated Contracting States: • Haupts, Ulrich AT BE BG CH CY CZ DE DK EE ES FI FR GB GR 51519 Odenthal (DE) HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI • Coco, Wayne SK TR 50737 Köln (DE) •Tebbe, Jan (30) Priority: 27.05.2005 EP 05104543 50733 Köln (DE) • Votsmeier, Christian (62) Document number(s) of the earlier application(s) in 50259 Pulheim (DE) accordance with Art. 76 EPC: • Scheidig, Andreas 06763303.2 / 1 883 696 50823 Köln (DE) (71) Applicant: Direvo Biotech AG (74) Representative: von Kreisler Selting Werner 50829 Köln (DE) Patentanwälte P.O. Box 10 22 41 (72) Inventors: 50462 Köln (DE) • Koltermann, André 82057 Icking (DE) Remarks: • Kettling, Ulrich This application was filed on 14-01-2009 as a 81477 München (DE) divisional application to the application mentioned under INID code 62. (54) Serine proteases with altered sensitivity to activity-modulating substances (57) The present invention provides variants of ser- screening of the library in the presence of one or several ine proteases of the S1 class with altered sensitivity to activity-modulating substances, selection of variants with one or more activity-modulating substances. A method altered sensitivity to one or several activity-modulating for the generation of such proteases is disclosed, com- substances and isolation of those polynucleotide se- prising the provision of a protease library encoding poly- quences that encode for the selected variants.
    [Show full text]
  • Cells and at Immune-Privileged Sites Dendritic Inhibitor 9, Is Mainly
    The Granzyme B Inhibitor, Protease Inhibitor 9, Is Mainly Expressed by Dendritic Cells and at Immune-Privileged Sites1 Bellinda A. Bladergroen,* Merel C. M. Strik,† Niels Bovenschen,* Oskar van Berkum,* George L. Scheffer,* Chris J. L. M. Meijer,* C. Erik Hack,†‡ and J. Alain Kummer2* Granzyme B is released from CTLs and NK cells and an important mediator of CTL/NK-induced apoptosis in target cells. The human intracellular serpin proteinase inhibitor (PI)9 is the only human protein able to inhibit the activity of granzyme B. As a first step to elucidate the physiological role of PI9, PI9 protein expression in various human tissues was studied. A mAb directed against human PI9 was developed, which specifically stained PI9-transfected COS-7 cells, and was used for immunohistochem- istry. Both in primary lymphoid organs and in inflammatory infiltrates, PI9 was present in different subsets of dendritic cells. Also T-lymphocytes in primary and organ-associated lymphoid tissues were PI9 positive. Endothelial cells of small vessels in most organs tested as well as the endothelial layer of large veins and arteries showed strong PI9 staining. Surprisingly, high PI9 protein expression was also found at immune-privileged sites like the placenta, the testis, the ovary, and the eye. These data fit with the hypothesis that PI9 is expressed at sites where degranulation of CTL or NK cells is potentially deleterious. The Journal of Immunology, 2001, 166: 0000–0000. ytotoxic cells such as NK cells and CTL form an impor- phocytes, and Fas-associated death domain-like IL-1-converting tant line of defense against virally infected cells and tu- enzyme-inhibitory protein (3), which directly inhibits the Fas-me- C mor cells.
    [Show full text]
  • Granzyme a in Human Platelets Regulates the Synthesis of Proinflammatory Cytokines by Monocytes in Aging
    Granzyme A in Human Platelets Regulates the Synthesis of Proinflammatory Cytokines by Monocytes in Aging This information is current as Robert A. Campbell, Zechariah Franks, Anish Bhatnagar, of November 27, 2017. Jesse W. Rowley, Bhanu K. Manne, Mark A. Supiano, Hansjorg Schwertz, Andrew S. Weyrich and Matthew T. Rondina J Immunol published online 22 November 2017 http://www.jimmunol.org/content/early/2017/11/22/jimmun Downloaded from ol.1700885 Supplementary http://www.jimmunol.org/content/suppl/2017/11/22/jimmunol.170088 Material 5.DCSupplemental http://www.jimmunol.org/ Why The JI? • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists by guest on November 27, 2017 • Speedy Publication! 4 weeks from acceptance to publication *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2017 by The American Association of Immunologists, Inc. All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. Published November 22, 2017, doi:10.4049/jimmunol.1700885 The Journal of Immunology Granzyme A in Human Platelets Regulates the Synthesis of Proinflammatory Cytokines by Monocytes in Aging Robert A. Campbell,*,† Zechariah Franks,* Anish Bhatnagar,* Jesse W. Rowley,*,‡ Bhanu K. Manne,* Mark A.
    [Show full text]
  • For Serine Proteas
    Ribeiro et al. BMC Structural Biology 2010, 10:36 http://www.biomedcentral.com/1472-6807/10/36 METHODOLOGY ARTICLE Open Access Analysis of binding properties and specificity through identification of the interface forming residues (IFR) for serine proteases in silico docked to different inhibitors Cristina Ribeiro1†, Roberto C Togawa2†, Izabella AP Neshich3, Ivan Mazoni3, Adauto L Mancini3, Raquel C de Melo Minardi5, Carlos H da Silveira4, José G Jardine3, Marcelo M Santoro1, Goran Neshich3* Abstract Background: Enzymes belonging to the same super family of proteins in general operate on variety of substrates and are inhibited by wide selection of inhibitors. In this work our main objective was to expand the scope of studies that consider only the catalytic and binding pocket amino acids while analyzing enzyme specificity and instead, include a wider category which we have named the Interface Forming Residues (IFR). We were motivated to identify those amino acids with decreased accessibility to solvent after docking of different types of inhibitors to sub classes of serine proteases and then create a table (matrix) of all amino acid positions at the interface as well as their respective occupancies. Our goal is to establish a platform for analysis of the relationship between IFR characteristics and binding properties/specificity for bi-molecular complexes. Results: We propose a novel method for describing binding properties and delineating serine proteases specificity by compiling an exhaustive table of interface forming residues (IFR) for serine proteases and their inhibitors. Currently, the Protein Data Bank (PDB) does not contain all the data that our analysis would require. Therefore, an in silico approach was designed for building corresponding complexes The IFRs are obtained by “rigid body docking” among 70 structurally aligned, sequence wise non-redundant, serine protease structures with 3 inhibitors: bovine pancreatic trypsin inhibitor (BPTI), ecotine and ovomucoid third domain inhibitor.
    [Show full text]
  • Death by Granzyme B
    RESEARCH HIGHLIGHTS APOPTOSIS Death by granzyme B DOI: 10.1038/nri1951 The death of effector T cells following pro-apoptotic ligands and effector lysosomal-associated membrane pro- Link activation is an important process molecules in AICD of T 1 cells and tein 1 (LAMP1; a marker of granules) Granzyme B H http://www.ncbi.nlm.nih.gov/ in the termination of an immune TH2 cells. Blocking the pro-apoptotic was observed in both resting TH1 entrez/viewer.fcgi?db=protein response. However, the mechanisms molecule CD95 ligand (also known cells and resting TH2 cells. However, &val=1247451 that are involved in this activation- as FAS ligand) with specific agents following TCR engagement, colocali- induced cell death (AICD) through inhibited AICD of TH1 cells, as previ- zation was observed only in TH1 cells, engagement of the T-cell receptor ously reported. However, these agents indicating that granzyme B is released (TCR) are not well understood. Now, had no effect on the death of TH2 from the granules on activation of TH2 new research published in Immunity cells. Similarly, blocking the activity of cells but not TH1 cells. Interestingly, shows that granzyme B has an impor- several caspases affected only TH1-cell the amount of SPI6, which is a tant role in AICD of T helper 2 (TH2) death, whereas inhibition of TRAIL protease inhibitor that specifically cells. (tumour-necrosis-factor-related inhibits the activity of granzyme B, Examination of the kinetics of apoptosis-inducing ligand) did not was found to be increased in activated AICD, by staining for annexin V affect either cell type.
    [Show full text]
  • Proteolytic Enzymes in Grass Pollen and Their Relationship to Allergenic Proteins
    Proteolytic Enzymes in Grass Pollen and their Relationship to Allergenic Proteins By Rohit G. Saldanha A thesis submitted in fulfilment of the requirements for the degree of Masters by Research Faculty of Medicine The University of New South Wales March 2005 TABLE OF CONTENTS TABLE OF CONTENTS 1 LIST OF FIGURES 6 LIST OF TABLES 8 LIST OF TABLES 8 ABBREVIATIONS 8 ACKNOWLEDGEMENTS 11 PUBLISHED WORK FROM THIS THESIS 12 ABSTRACT 13 1. ASTHMA AND SENSITISATION IN ALLERGIC DISEASES 14 1.1 Defining Asthma and its Clinical Presentation 14 1.2 Inflammatory Responses in Asthma 15 1.2.1 The Early Phase Response 15 1.2.2 The Late Phase Reaction 16 1.3 Effects of Airway Inflammation 16 1.3.1 Respiratory Epithelium 16 1.3.2 Airway Remodelling 17 1.4 Classification of Asthma 18 1.4.1 Extrinsic Asthma 19 1.4.2 Intrinsic Asthma 19 1.5 Prevalence of Asthma 20 1.6 Immunological Sensitisation 22 1.7 Antigen Presentation and development of T cell Responses. 22 1.8 Factors Influencing T cell Activation Responses 25 1.8.1 Co-Stimulatory Interactions 25 1.8.2 Cognate Cellular Interactions 26 1.8.3 Soluble Pro-inflammatory Factors 26 1.9 Intracellular Signalling Mechanisms Regulating T cell Differentiation 30 2 POLLEN ALLERGENS AND THEIR RELATIONSHIP TO PROTEOLYTIC ENZYMES 33 1 2.1 The Role of Pollen Allergens in Asthma 33 2.2 Environmental Factors influencing Pollen Exposure 33 2.3 Classification of Pollen Sources 35 2.3.1 Taxonomy of Pollen Sources 35 2.3.2 Cross-Reactivity between different Pollen Allergens 40 2.4 Classification of Pollen Allergens 41 2.4.1
    [Show full text]
  • Extended Cleavage Specificities of Two Mast Cell Chymase-Related
    International Journal of Molecular Sciences Article Extended Cleavage Specificities of Two Mast Cell Chymase-Related Proteases and One Granzyme B-Like Protease from the Platypus, a Monotreme Zhirong Fu, Srinivas Akula , Michael Thorpe and Lars Hellman * Department of Cell and Molecular Biology, Uppsala University, Uppsala, The Biomedical Center, Box 596, SE-751 24 Uppsala, Sweden; [email protected] (Z.F.); [email protected] (S.A.); [email protected] (M.T.) * Correspondence: [email protected]; Tel.: +46-(0)18-471-4532; Fax: +46-(0)18-471-4862 Received: 20 November 2019; Accepted: 31 December 2019; Published: 2 January 2020 Abstract: Mast cells (MCs) are inflammatory cells primarily found in tissues in close contact with the external environment, such as the skin and the intestinal mucosa. They store large amounts of active components in cytoplasmic granules, ready for rapid release. The major protein content of these granules is proteases, which can account for up to 35 % of the total cellular protein. Depending on their primary cleavage specificity, they can generally be subdivided into chymases and tryptases. Here we present the extended cleavage specificities of two such proteases from the platypus. Both of them show an extended chymotrypsin-like specificity almost identical to other mammalian MC chymases. This suggests that MC chymotryptic enzymes have been conserved, both in structure and extended cleavage specificity, for more than 200 million years, indicating major functions in MC-dependent physiological processes. We have also studied a third closely related protease, originating from the same chymase locus whose cleavage specificity is closely related to the apoptosis-inducing protease from cytotoxic T cells, granzyme B.
    [Show full text]