13. Minisymposium „Infektion und Immunabwehr“ Burg

13. Minisymposium „Infektion und Immunabwehr“ Burg Rothenfels, 12. – 14. März 2009

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

SCIENTIFIC PROGRAM

13. Minisymposium „Infektion und Immunabwehr“ Burg Rothenfels, 12. – 14. März 2009 PROGRAMM

Organisation:

C. Hölscher, Borstel D. Schlüter, Magdeburg G. van Zandbergen, Ulm

Donnerstag, 12.3.08 14.45

Abfahrt Bus-Shuttle Würzburg Hauptbahnhof (Vorplatz)

15.30 – 16.30

Ankunft, Zimmerverteilung, Kaffee und Gebäck

16.30 – 17.40

Session 1: Signalling and effector molecules Chair: Alexander Dalpke

1

Murine 65 kDa GBPs : important effector molecules in Toxoplasma infection. Daniel Degrandi et al., Düsseldorf

2

Identification of a novel subcellular localization pattern of Suppressor of Cytokine Signalling – 1 (SOCS-1) Julia Strebovsky et al., Heidelberg

3

SOCS-1 enhances Pasteurella multocida Toxin induced STAT3 activity Katharina F. Kubatzky et al., Heidelberg 2

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

4

The role of Frizzled1 in M. tuberculosis infection : Modes of induction and first insights into function Jan Neumann et al., Kiel

5

Wnt ligands differentially regulate the inflammatory response of macrophages upon mycobacterial infection Kolja Schaale et al., Kiel

6

Influence of optineurin on adenovirus E3-14.7K mediated TNF-resistance Wulf Schneider-Brachert et al., Regensburg

7

Downregulation of AP-1 proteins in Chlamydia pneumoniae infected host cells Christiane Jugert et al., Luebeck

17.40-18.00

Pause

18.00 – 19.00

Session 2: T and B cells Chair: Andreas Limmer

1

Delayed type hypersensitivity versus humoral immune response – Influence of high and low antigen doses on the cytokine expression within spleenic compartments Claudia Stamm et al., Luebeck

2

Injury – induced Th cell suppression after injury is restored through targeting dendritic cells in the regenerating tissue Florian Wirsdörfer et al., Essen

3

Apoptotic Leishmania major mediate a Th2 response in BALB/c mice Julia Barthelmann et al., Luebeck

4

Bacterial DRiPs, Yes or No Silke Grauling – Halama et al., Heidelberg 3

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

5

In E.coli Nissle 1917 monocolonized Rag1 deficient mice CD4+ T cells are essential for the protection against dissemination and septic shock Ute Eberle et al., Tuebingen

6

The regulatory T cell response during acute viral infection is locally defined and controls the magnitude and duration of the virus-specific cytotoxic T cell response Kirsten Dietze et al., Essen

19.00 – 20.00

20.00

Abendessen

Key note lecture 1 Introduction: Dirk Schlüter Frank Kirchof, Ulm: Mechanisms of HIV-1 immune evasion

ab ca. 21 Uhr

Chill out

Freitag, 13.3.08 9.00 – 10.30

Session 3: TLRs and innate immune responses Chair: Christian Bogdan

1

TLR against R848 inhibits differentiation of mDCs and leads to differentiaton of tolerogenic APc from CD14+ monocytes Sabine Woelfle et al., Heidelberg

2

Improvement of host defense in the lung Thomas Tschernig et al., Hannover 4

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

3

The phosphatidylserine binding protein annexin A5 can interfere with chlamydial infection. Lisa Pfleiderer et al., Ulm

4

Characterization of dual production of IFN-beta and IL12/23 p40 on a single cell basis after TLR stimulation. Magdalena Kocur et al., Düsseldorf

5

Antiretroviral effects of Toll-like receptor ligands Kathrin Gibbert et al., Essen

6

Functional analysis of cells from IFIT-2 knockout mice Alexandra Siegfried et al., Tuebingen

7

The role of cytokines for NK cell activation in visceral leishmaniasis Simone Haeberlein et al., Erlangen

8

Acute treatment against cutaneous leishmaniasis with a two component gel developing nitric oxide Beate Lorenz et al., Mainz

9

The role of Natural killer (NK) T cells for protection against Leishmania major infection Klaus Griewank et al., Mainz

10:30 – 11:00

Kaffeepause

11.00 – 12.30

Session 4a: Cytokines Chair: Stefan Ehlers

1

Tumor-derived Prostaglandin E2 and TGF-beta synergize to inhibit PDCderived IFN-alpha Marijo Parcina et al., Heidelberg 5

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

2

Role of type I IFNs in innate defence to Legionella pneumophila Bastian Opitz Berlin

3

The visualization of IFN-beta producing cells versus their infection state in time course studies during of MCMV infection Stephanie Borkens et al., Duesseldorf

4

Induction of pro-inflammatory IL-!2 in Plasmodium berghei infected BALB/c mice breaks blood-brain-barrier and leads to cerebral malaria Kim Ellen Schmidt et al., Bonn

5

The role of interleukin 22 in Toxoplasma gondii induced ileitis Melba Munoz et al., Berlin

6

The interleukin-13/ interleukin-4 receptor –alpha axis is involved in tuberculosis associated pathology Lisa Heitmann et al., Borstel

7

Blockade of IL-6 trans-signalling does not reactivate experimental tuberculosis Jan Christian Sodenkamp et al., Borstel

8

IL-17 maintains protective immunity during Mycobacterium tuberculosis infection Jochen Behrends et al., Borstel

9

The IL-23 / IL-17 axis is required for protective immune responses against Trypanosoma cruzi infection Hanna Erdmann et al., Borstel

12.30 – 13.30

Mittagessen anschließend Spaziergang und Kaffee

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

15.30 – 17.00

Session 4b: Dendritic cells and macrophages Chair: Christoph Hölscher

1

Molecular mechanisms involved in aberrant type 1 interferon-induction by S.aureus protein A. Sibel Durlanik et al., Heidelberg

2

Detrimental role of dendritic cells during Y.enterocolitica infection in vivo Philipp Warnke et al., Tübingen

3

Leishmania amastigote propagation in human host cells Elena Bank et al., Ulm

4

Role of Langerin+ skin-derived DC in Leishmania major infection Kordula Kautz-Neu et al., Mainz

5

Opsonization of L.major with cross-reactive anti-phospholipid antibodies promotes phagocytosis by dendritic cells (DC) and induction of protective immunity Susanna Lopez Kostka et al., Mainz

6

Role of hypoxia and HIF-1 alpa in dendritic cell immunobiology. Jonathan Jantsch et al., Erlangen

7

Conventional and plasmacytoid bone marrow-derived dendritic cells contribute to Toll like receptor-independent IFN-alpha/ beta production in response to inactivated parapoxvirus ovis Gottfried Alber et al., Leipzig

8

Activation of macrophages by the mycobacterial cord factor (TDM) and its synthetic analogue (TDB) Hanne Schoenen et al., Erlangen

7

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

9

Interaction of Mycobacterium tuberculosis and human macrophages under hypoxic conditions. Daniel Nickel et al., Ulm

17.00–17.30 Fachgruppenaktivitäten Ger van Zandbergen, Dirk Vorsitzende der Fachgruppe/des Arbeitskreises

17.30

Schlüter

Keynote lecture 2 Introduction: Ger van Zandbergen Freddy Frischknecht, Heidelberg: Imaging motile pathogens

ca. 18.30 Uhr

Buffet

Samstag, 14.3.08 9.00 – 10.10

Session 5a: Immunomodulation Chair: Norbert Reiling

1

Split tolerance after oral vaccination of mice with recombinant Escherichia coli Nissle 1917 expressing fimbrial adhesion K88 Katharina A. Remer et al., Würzburg

2

Acute graft-versus –host-disease after reduced intensity conditioning is mediated by MyD88 mediated TLR9 sensing of bacterial DNA and can be modulated by administration of TLR antagonist. Rita Plickert et al., Berlin

8

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

3

Long –term effect of sepsis –The influence of bacteremia and bacterial translocation on systemic adaptive immune responses Timo Schwandt et al., Bonn

4

Systemic bacterial infection alters differentiation of dendritic cells in the bone marrow and mediates chronic dendritic cell dysfunction. Eva Pastille et al., Essen

5

Increased susceptibility to infection with Aspergillus fumigatus in graft-versushost disease is not due to impaired pathogen clearance Bernd Echtenacher et al., Regensburg

6

Modulation of host macrophage apoptosis by Leishmania infection Stefanie Enzenmüller et al., Ulm

7

Protective effect of filarial infection inhibiting malaria outcome in mice Susanne Deininger et al., Bonn

10.10 – 10.30

Kaffepause

10.30 – 12.00

Session 5b: Organ-specific regulation of immune responses Chair: Gottfried Alber

1

Immune regulatory functions of alveolar type II epithelial cells Dunja Bruder et al Braunschweig

2

Airway epithelial cells modify immune responses Lotte M. Schmidt et al., Heidelberg

3

Corneal inflammation in response to filarial antigens Katrin Gentil et al., Bonn

9

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

4

The contribution of the innate, placental immune system to defend the fetus from infections Diana Friedrich et al., Erlangen

5

A crucial role of the spleen in the induction of pathogenic host responses towards P. berghei ANKA infection Beatrix Schumak et al., Bonn

6

The role of the intestinal microflora in infection with Citrobacter rodentium Ulrich Steinhoff et al., Berlin

7

IL-4/ IL-13-dependent alternative activation of macrophages but not microglial cells is associated with uncontrolled cerebral cryptococcosis Werner Stenzel et al., Berlin

8

Neuron and astrocyte –specific function of IKK-2 and NEMO in Toxoplasma encephalitis Ulrike Händel et al., Magdeburg

9

Toxoplasma gondii induces behavioural changes in infected mice M. Fahad Haroon et al., Magdeburg

12:00

Preisverleihung

12:05

Ende der Tagung Lunchpaket / Mittagessen

13.00

Abfahrt Bus (pünktlichst!)

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

ABSTRACTS (in alphabetical order of presenting authors)

Conventional and plasmacytoid bone marrow-derived dendritic cells contribute to Toll-like receptor-independent IFN-alpha/beta production in response to inactivated parapoxvirus ovis Sabine Siegemund1, Andrea Hartl2, Franziska Dautel1, Ruediger Raue3, Marina A. Freudenberg4, 2

Mathias

Buettner5,

Gabriele

Koehler6,

Carsten

J.

Kirschning2,

Tim

1

Sparwasser , Gottfried Alber 1

Institute of Immunology, College of Veterinary Medicine, University of Leipzig, Germany;

2

Institute of Microbiology, Technische Universitaet Muenchen, Germany;

3

Pfizer Animal

4

Health, Kent, United Kingdom; Max Planck Institute for Immunobiology, Freiburg, Germany; 5

Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, Oberschleissheim,

Germany;

6

Gerhard-Domagk-Institute

for

Pathology,

Universitaetsklinikum

Muenster,

Germany Parapoxvirus ovis (PPVO) is a member of the Poxviridae family and belongs to the genus Parapoxvirus. It displays only limited homology with orthopoxviruses and has some molecular features such as an unusual high GC content distinct from orthopoxviruses. Inactivated parapoxvirus ovis (iPPVO) has strong immunostimulatory capacities mediating antiviral activity in vivo. The role of dendritic cells and the pattern recognition receptors responsible for recognition of iPPVO are unknown. We demonstrate that bone marrowderived plasmacytoid dendritic cells (BM-pDC) and bone marrow-derived conventional dendritic cells (BM-cDC) secrete IFN-alpha/beta in response to iPPVO. Furthermore, iPPVO induces TNF-alpha and IL-12/23p40 release and MHC-II, MHC-I and CD86 up-regulation by bone marrow-derived dendritic cells (BMDC). After engulfment, iPPVO was located in endosomal compartments and in the cytosol of BMDC. Although iPPVO is a double-stranded DNA virus, the DNA-recognizing toll-like receptor (TLR) 9 is not involved in iPPVO-induced release of IFN-alpha/beta by BMDC. Moreover, we demonstrate that iPPVO elicits IFNalpha/beta by TLR-independent pathways, since IFN-alpha/beta release does not require myeloid differentiation primary response gene 88 (MyD88) or TIR-domain containing adaptor protein inducing interferon (TRIF). In contrast, iPPVO-induced TNF-alpha and IL-12/23p40 release and enhanced expression of MHC-I and CD86 but not MHC-II by BMDC partially depends on MyD88 but not on TLR2, TLR4 or TLR9. These results provide first evidence that iPPVO mediates its immunostimulatory properties by TLR-independent and -dependent pathways and demonstrate an important role of cDC for IFN-alpha/beta production. 11

13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Leishmania amastigote propagation in human host cells Elena Bank 1, Alexander Wenzel1 and Ger van Zandbergen1. 1

Instiute for Medical Microbiology and Hygiene, University Clinic of Ulm

Leishmania major (L. major) is an obligate intracellular parasite elegantly misusing the apoptotic

cell

clearance

system

for

disease

development.

This

parasite

enters

polymorphonuclear neutrophil granulocytes (PMN) in its promastigote form. Hiding inside Annexin A5 (AnxA5)-positive PMN the parasite transfers into macrophages (MF), where it multiplies in its amastigote form. We found that the presence of AnxA5-binding population of promastigotes is responsible for the survival and infectivity of viable promastigotes inside PMN. Still relatively little is known about macrophage infection by the amastigote form of L. major propagating the disease. We developed a novel in vitro method to culture the amastigote form of L. major and compared these amastigotes with promastigotes We found them to be higly infectious for different types of human MF. To study amastigote development and propagation in more detail, we generated eGFP expressing L. major. The eGFP marker is upregulated in the amastigotes stage. Using these transfectants we infected type I (inflammatory) and typ II (anti-inflammatory) human MF. We found that type II MF take up more parasites as compared to type I MF. Using FACS analyses we could detect the development of amastigotes by a higher expression level of eGFP as compared to the eGFP expression of intraphagocytic promastigotes. Focussing on amastigote uptake using timelapse imaging we found that dying eGFP-negative and AnxA5-positive amastigotes enter MF first followed by viable eGFP-positive parasites. These new tools will enable us to examine L. major amastigote propagation in human host cells.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Apoptotic Leishmania major mediate a Th2 response in BALB/c mice Julia Barthelmann, Juergen Westermann, Kathrin Kalies Institute of Anatomy, University of Luebeck It has recently been reported that the virulent inoculum of Leishmania major (L. major) promastigotes conventionally used for infection experiments contains about 50% of apoptotic parasites. The depletion of apoptotic parasites lead to a reduced infectivity in BALB/c mice in vivo. In order to analyse the detrimental effect of apoptotic leishmania on the immune response in the lymph node, we separated viable and apoptotic L. major by magnetic cell separation. We studied T-cell proliferation and cytokine mRNA expression in the draining lymph node after infection of susceptible BALB/c mice with viable L. major. We found that the lack of apoptotic parasites in the inoculum leads to a delay of disease progression and decreased IL-4 and IL-10 mRNA levels 6 weeks after infection, while IFN-gamma levels remain unchanged. Furthermore, Th2-associated total serum IgG1 levels are reduced. Disease, cytokine mRNA production and total serum IgG1 after 6 weeks could be restored by adding apoptotic leishmania to the inoculum, thereby indicating that apoptotic L. major support the establishment of a Th2 immune response. Although the initial composition of the inoculum determines the disease development, the response in the lymph node is not defined 3 days after infection: Time point and magnitude of initial T-cell proliferation do not differ compared to conventional L. major infections and the cytokine pattern does not correlate with the final disease outcome. Overall, the removal of apoptotic parasites in the inoculum decreases the Th2 response, but does not explicitly support the establishment of a Th1 phenotype in susceptible BALB/c.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

IL-17 maintains protective immunity during Mycobacterium tuberculosis infection Jochen Behrends,1 Dominik Rueckerl,1 Manuela Heßmann,1 Uwe Mueller,2 Gottfried Alber,2 Yoichiro Iwakura,3 Stefan Ehlers4,5 & Christoph Hoelscher1 1

Infection Immunology, Research Center Borstel, Germany; 2University of Leipzig, Germany;

3

University of Tokyo, Japan; 4Microbial Inflammation Research, Research Center Borstel,

Germany; 5Molecular Inflammation Medicine, Christian-Albrechts-University, Kiel, Germany Because a variety of autoimmune disorders have now been shown to depend on interleukin (IL)-17-producing T helper (TH)17 cells, therapeutic blockade of TH17 development may provide a novel approach to avoid adverse consequences of anti-inflammatory strategies such as reactivation of latent tuberculosis (TB). To evaluate the potential risk of interfering with IL-17-dependent inflammation, we analyzed the outcome of experimental TB in IL-17deficient (-/-) mice after infection with Mycobacterium tuberculosis (Mtb). IL-17 was important for the induction of neutrophil chemokines after Mtb infection, but was not involved in granuloma formation and protection during the first three months of Mtb infection. Mtbinfected IL-17-/- mice efficiently generated interferon-gamma (IFN
)-producing T cells and IFNgamma-dependent effector responses. However, IL-17-/- mice were not able to control mycobacterial replication during the chronic phase of experimental TB and died significantly earlier than corresponding wildtype mice. This breakdown of immune protection in IL-17-/mice was associated with a drop in the frequency of IFN
-producing CD4+ T cells. Our findings reveal that IL-17 is essential for maintaining CD4+ T cell-dependent protection during chronic stages of TB. Hence, interfering with IL-17-dependent pathways as an antiinflammatory therapeutic approach will possibly incur the danger of reactivating latent TB. (Supported by the Inflammation Research Excellence Cluster)

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

The visualization of IFN-beta producing cells versus their infection state in time course studies during of MCMV infection Stephanie Borkens1, Vu Thuy Khanh Le2, Stefanie Scheu1 1

Institute of Medical Microbiology and Hospital Hygiene, University of Duesseldorf

2

Institute of Virology, University of Duesseldorf

Type I interferons are a family of multiple IFN-alphas and a single IFN-beta which were initially identified on the basis of their antiviral activities. Previous findings identified pDCs as the major IFN-beta producing cells in the spleen. However, which cells are actually infected with MCMV remains unclear, although it has been suggested that at certain stages of infection MCMV can actively replicate in macrophages and conventional DCs. For a detailed analysis of the initial phase of MCMV infection, we used a MCMV strain which expresses EGFP under the immediate-early promoter (MIEP) to infect IFN-beta/YFP reporter knockin mice. This experimental approach allows for the simultaneous visualization of the IFN-beta response and the infection status of MCMV in vivo. In initial analyses at 24h post infection. we identified splenic pDCs as well as few CD11b+ cells expressing IFN-beta. Furthermore, we could show that the IFN-beta producing pDCs are not directly infected with MCMV and that mainly CD11b+/c+ cells expressed EGFP as a marker for MCMV infection. Current studies aim at the clarification of IFN-beta-production versus the infection status of individual cells in this simultaneous analysis during several time points of infection.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Immune regulatory functions of alveolar type II epithelial cells Marcus Gereke, Harro Frauendorf, Dunja Bruder Immune regulation group, Helmholtz Center for Infection Research, Braunschweig Whereas the lung epithelium was long time related primarily with physical barrier and gas exchange functions, the contribution of alveolar type II epithelial cells (AECII) in respiratory immune regulation has become increasingly appreciated. However, their precise function in the induction and regulation of T cell reactivity to self antigen remains poorly understood. Utilizing a transgenic mouse model for CD4+ T cell mediated pulmonary inflammation we found that MHC class II expressing AECII present self-antigen to CD4+ T cells resulting in functional activation of lung-reactive T cells and finally autoimmunity. Importantly, we unravelled a previously unknown immunological attribute of AECII in re-establishment of peripheral T cell tolerance in the lung. Upon inflammation, AECII secrete a broad variety of soluble factors including transforming growth factor-beta (TGF-beta), Platelet Factor-4 and Surfactant Protein-A and -D, which suppress T cell proliferation and induce in a partially TGF-beta dependent mechanism Foxp3 expression in lung-reactive CD4+ T cells. As a part of the innate immune system AECII thus exhibit so far underestimated immune regulatory function and synergize with adaptive immune mechanisms to re-establish tolerance to selfantigen in the lung. Preliminary data suggest that upon influenza infection alveolar self antigen recognition by CD4+ T cells does not result in increased abundance of Foxp3 expressing regulatory T cells thus indicating that the capability to respond to and to eradicate a pathogen dominates about the necessity to protect against potentially harmful autoimmune reactions. Currently we are investigating the contribution of AECII in balancing tolerogenic and pathogen-specific immunity in the lung.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Murine 65 kDa GBPs: important effector molecules in Toxoplasma infection. Daniel Degrandi, Carolin Konermann, Cornelia Beuter-Gunia, Sarah Lahme, Anna Fischer, Elisabeth Kravets, Klaus Pfeffer Medizinische Mikrobiologie und Krankenhaushygiene. Heinrich-Heine-Universität Düsseldorf The 65 kDa guanylate-binding proteins comprise a growing family of highly conserved GTPases, found in mice, humans, and many other species. In mice, 11 members of the GBP family have been described. In recent studies, we could show that several members of the mGBP family colocalize with the parasitophorous vacuole (PV) of avirulent Toxoplasma gondii (Tg) strains, suggesting a direct antiparasitic function of the mGBP proteins. Interestingly, highly virulent Tg strains are able to modulate the cellular response to the infection and suppress the recruitment of mGBP proteins to the PV. The mechanisms involved in the recruitment of mGBP proteins to the PV and their molecular and biochemical activity are the major focus of our current studies. First results indicate, that GTP-binding and hydrolysis are needed for normal localization of the proteins in infected and uninfected cells. Furthermore, the recruitment of mGBP proteins towards the Toxoplasma PV is dependent on the microtubular network, since cells treated with Paclitaxel and other microtubule interacting drugs showed no colocalization of mGBPs with the PV. Studies in mGBP2-/- mice showed an increased susceptibility towards infections with Tg. Also, mGBP2 deficient cells show a significantly reduced capability to control Tg growth in vitro. These data indicate, that the family of 65 kDa mGBPs play crucial roles in the cell autonomous defense against intracellular pathogens.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Protective effect of filarial infection inhibiting malaria outcome in mice Susanne Deininger1, Daniel Fernández-Ruiz1, Gwydion Brennan1, Bettina Dubben1, Achim Hoerauf1, Sabine Specht1 1

Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn,

Bonn, Germany Malaria is a serious tropical disease with a high risk of mortality to date. Chronic helminth infections and often co-endemic with malaria and both might alter the immune response against another. By use of a co-infection model of the filarial nematode Litomosoides sigmodontis and the malaria pathogen Plasmodium berghei ANKA in Balb/c mice we discovered that a preceding filarial infection inhibited a subsequent infection with P. berghei sporozoites in one-third of mice. Interestingly, this sterile protection was correlated with presence of microfilariae, which are the first stage larvae of the filarial parasite. We observed increased levels of activated T cells in spleen and liver of microfilaremic mice. Furthermore, phagocytotic cells were increased in the spleens of these mice. In order to investigate the underlying mechanism, we analysed cytokine profiles in these mice. We found that worminfected mice produced higher levels of IL-10, IFN-gamma and granzyme B and their CD4+ and CD8+ T cells were found to be in an activated status (CD69+) secreting IFN-gamma, perforin and granzyme B. Both candidates the cytotoxic T cells and the phagocytotic cells may contribute to the mechanisms responsible for blocking parasitaemia of malaria pathogens in a part of filarialinfected mice. A better knowledge about the protective mode of a patent filarial infection on the outcome on malaria may provide some tools to influence the course of malaria in favour for the host.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

The regulatory T cell response during acute viral infection is locally defined and controls the magnitude and duration of the virus-specific cytotoxic T cell response Kirsten Dietze1, Gennadiy Zelinskyy1, Ulf Dittmer1 1

Institut fuer Virologie, Universitaetsklinikum Essen

Cytotoxic T-cells (CTL) facilitate control of acute viremia in many viral infections, including retroviruses like HIV or HTLV. However, viruses that establish chronic infections have developed mechanisms to evade destruction by CTL. We have used the Friend Virus (FV) model to investigate these mechanisms. In the acute infection FV induces a strong CTL response but the mice become persistently infected. However, regulatory CD4+ T cells (Treg) that expand in the spleen of infected mice suppress the production of cytotoxic molecules in CD8+ T cells and the cytotoxic function of CTL. The aim of our current work was to analyse the compartmentalisation of the Treg response and the subsequent local suppression of CD8+ T cells by Tregs during an ongoing retroviral infection. We found, that expansion of effector CD8+ T cells, production of cytotoxic molecules and degranulation was directly linked to viral loads in lymphatic organs. Consequently the expansion of induced Treg correlated with the number and function of virus-specific CD8+ T cells. For the expansion of Treg the presence of CTL was obligatory, what was shown by CD8 depletion experiments. Furthermore, depleting Treg in DEREG mice resulted in enhanced expansion of effector CD8+ T cells and improved the production of cytotoxic molecules leading to reduced viral loads in lymphatic organs. In summary, during acute retroviral infection Treg downregulated the expansion and function of virus-specific CTL. The immunosuppressive activity of Tregs was locally defined to the organs in which efficient viral replication followed by a strong CD8+ effector cell response took place.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Molecular mechanisms involved in aberrant type I interferon-induction by S. aureus protein A Isabelle Bekeredjian-Ding1, Sibel Durlanik1, Marijo Parcina1, Sandra Ammann1, Wulf Schneider-Brachert2 Klaus Heeg1 1

Hygiene-Institute, Dept. of Med. Microbiology and Hygiene, UniversityHospital Heidelberg

2

Institute for Med. Microbiology und Hygiene, University of Regensburg

Protein A (SpA), an immunoglobulin (Ig)-binding protein, is a major virulence factor of Staphylococcus aureus and well-known as an immunostimulatory protein. We previously observed that certain strains of S. aureus induce IFN-alpha secretion from plasmacytoid dendritic cells (pDC). The aim of the project presented was therefore, to investigate the role of SpA in type I interferon induction from pDC. Remarkably, IFN-a induction correlated with bacterial levels of SpA expression, and subsequent experiments showed that recombinant SpA induces IFN-alpha secretion from pDC. Moreover, IFN-I induction could be blocked by saturating Ig or Fc fragments, indicating that the Ig-binding domain may be essential for IFN-I induction. Most importantly, DNAse and RNAse digestion of recombinant SpA did not alter its ability to induce IFN-I. Recently, SpA has been shown to bind TNFR1 on respiratory epithelial cells. Here we show that anti-TNF-R mAb neutralisation can inhibit the SpAinduced type I interferon secretion. We further show that SpA colocalizes with the TNF-R2 in transfected HEK293 cells. Thus, SpA may represent a novel TLR-independent stimulus for pDC activation.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

In E. coli Nissle 1917 monocolonized Rag1 deficient mice CD4+ T cells are essential for the protection against dissemination and septic shock. Ute Eberle* 1, Kerstin Fink*1, Martina Müller1, Frank Leithäuser2, Thomas A. Ölschläger3, Ingo B. Autenrieth1, Julia-Stefanie Frick1 1

Institute of Medical Microbiology and Hygiene, University of Tuebingen, Germany

2

Institute of Pathology University of Ulm, Germany

3

Institute of Molecular Biology of Infection, University of Wuerzburg, Germany

*

equal contribution

E. coli Nissle 1917 (EcN) is a well defined probiotic E. coli strain, which is effective in maintaining remission in ulcerative colitis. The aim of this study was to explore safety aspects of this frequently used probiotic strain. Therefore, germfree Rag1-/- mice were monocolonized with EcN. Upon CD4+ T cell transfer germfree Rag1-/- mice showed a high mortality rate due to dissemination of EcN. In peripheral organs high bacterial loads of EcN were detected correlated with high levels of TNF in the serum. In contrast, SPF Rag1-/- mice colonized with EcN showed no dissemination of EcN in peripheral organs even though the numbers of bacteria in the intestine did not differ. Furthermore, EcN monocolonized C57Bl/6 mice showed no increased mortality rate, indicating that CD4+ T cells were essential either for the inhibition of translocation or for the clearance of EcN from the peripheral organs. The translocation and dissemination are an EcN specific effect, as it was not observed in germfree Rag1-/- mice monocolonized with E. coli mpk, a commensal E. coli stain isolated from the murine intestine. Additionally, the dissemination of EcN in monocolonized Rag1-/mice was not flagella dependent. As the translocation of EcN Dflic and DflgE to peripheral organs was comparable to the translocation of wildtype EcN. Therefore, an unknown bacterial factor seems to account for the dissemination of EcN in monocolonized Rag1-/mice, and both the immature intestinal barrier and the immature mucosa associated immune system of germfree animals seem to be essential for the translocation of EcN.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Increased susceptibility to infection with Aspergillus fumigatus in graft-versus-host disease is not due to impaired pathogen clearance Bernd Echtenacher1, Kristina Doser 2, Matthias Edinger2 and Petra Hoffmann2 1

Institute of Immunology, University Regensburg and

2

Dept. of Hematology and Oncology,

University Hospital Regensburg, Regensburg, Germany Graft-versus-host disease (GvHD) is a frequent and life-threatening complication after allogeneic bone marrow transplantation (alloBMT) that is initiated by mature alloreactive T cells within the graft. These show excessive proliferation and pro-inflammatory cytokine secretion upon interaction with host antigen-presenting cells, which leads to a dysregulated cytokine milieu and finally results in tissue damage and target organ destruction (gut, liver and skin).

Patients after alloBMT are severely immunocompromised and therefore

particularly prone to opportunistic bacterial and fungal infections. While immunosuppressive medication for GVHD prophylaxis clearly raises the risk of infection, the contribution of GVHD itself to this increased susceptibility is much less understood. To evaluate the impact of GVHD on the host's defence against fungal infections, allo-transplanted BALB/c mice with or without GVHD were infected intratracheally

or intravenously with the clinically relevant

pathogen Aspergillus fumigatus. Mortality was significantly higher in GVHD animals (only 20% survival after 2wks) as compared to the non-GVHD group (75% survival for more than 5wks). Interestingly, clearance of the fungus from the lung after i.t. infection, or from spleen and liver after i.v. infection, was rapid and comparable in both groups and no live fungus was detectable in moribund animals. However, when lymphocytes isolated from spleen and liver of infected animals were restimulated in vitro with germinating conidia, cells from GVHD animals secreted significantly more pro-inflammatory TNF and IL-6 than those from control mice. This suggests that an uncontrolled inflammatory immune response contributes to the high morbidity and mortality of opportunistic infections in GVHD.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Modulation of host macrophage apoptosis by leishmania infection Stefanie Enzenmüller1, Cordula Schropp2, Simone Fulda1, Ger van Zandbergen2 and Silke Fischer1,2 1

University Children's Hospital, Ulm.

2

Institute for Medical Microbiology and Hygiene,

University Clinic of Ulm Leishmania are obligate intracellular parasites which undergo a promastigote flagellated stage in the sandfly and an aflagellated amastigote stage in vertebrate hosts. They cause a spectrum of human diseases, ranging from self-limiting cutaneous infections to visceral leishmaniasis. The infection of mammalian hosts is initiated by promastigotes that are phagocytosed by macrophages either directly or after infection of neutrophils initially recruited to the sandfly bite. In host cells Leishmania replicate and differentiate to amastigotes. Like all intracellular parasites, Leishmania have evolved specialized strategies to evade immune destruction and to interact with multiple apoptotic systems to complete their life cycle. The repression of host cell apoptosis is one type of strategy to protect the host macrophage in which the intracellular parasites replicate and persist. Our main research interest is focused on how Leishmania major interferes with the host cell apoptotic machinery in infected cells. Therefore we investigate how Leishmania modulate the different signalling pathways of apoptosis. We used two different cell lines (monocyte-derived macrophages THP1 and murine macrophage-like Raw 264.7). Cells were infected with L. major in vitro and subsequently treated with external apoptosis-inducing stimuli such as UVlight or staurosporine. First results are indicating that L. major inhibits caspase activation, cytochrome c release from mitochondria and modulates the level of BH3-only proteins within the infected macrophage cells.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

The

IL-23/IL-17

axis

is

required

for

protective

immune

responses

against

Trypanosoma cruzi infection Hanna Erdmann,1 Caroline Rossnagel,1 Nico Ghilardi,2 Yoichiro Iwakura,3 Thomas Jacobs,4 Christoph Hoelscher1 1

Infection Immunology, Research Center Borstel, Germany;

Francisco CA USA;

3

2

Genentech, South San

Center for Experimental Medicine, Institute of Medical Science,

University of Tokyo, Japan; 4Bernhard-Nocht-Institute for Tropical Medicine and Hygiene, Hamburg, Germany Interleukin (IL)-12 is a potent inducer of interferon-gamma (IFN
)-producing T helper (TH)1 cells and promotes a protective cell-mediated immune response after infection with the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. IL-23 is structurally closely related to IL-12 and shares the IL-12/23p40 subunit and the corresponding IL-12 receptor
1 subunit. However, IL-23 is not as potent as an inducer of IFN
-production than IL-12. Instead IL-23, but not IL-12, promotes the proliferation of IL-17producing TH17 cells. To analyze the role of IL-23 for protective immune responses during experimental Chagas disease, IL-23p19 deficient (-/-) mice were infected with T. cruzi. Compared to wild-type mice, IL-23p19-/- mice developed a higher parasitemia and an increased mortality. However, this susceptibility was not due to an impaired TH1 immune response. Because IL-23 supports the development of IL-17-secreting TH17 cells, we infected IL-17-/- mice with T. cruzi to study the relevance of IL-17 for protective immune responses. Like IL-23-/- mice, IL-17-/- mice exhibited a higher parasitemia, an elevated mortality and an altered liver pathology. Moreover, TH1 immune responses were not affected by the absence of endogenous IL-17. Together, we suggest here that in addition to TH1 cells, IL-23-dependent TH17 cells are required for a successful resolution of T. cruzi infection. One important effector cytokine that mediates this IFN
-independent arm of the protective immune response during experimental Chagas disease appears to be IL-17. Downstream effector mechanisms induced by IL-17 are currently under investigation. (Supported by the Inflammation Research Excellence Cluster).

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

The contribution of the innate, placental immune system to defend the fetus from infections Diana Friedrich, André Gessner, Daniela Klaffenbach, Jörg Dötsch, and Markus Schnare Institut für Mikrobiologie - Klinische Mikrobiologie, Immunologie und Hygiene des Universitätsklinikums Erlangen, Wasserturmstr. 3-5, 91054 Erlangen The placenta establishes an anatomical barrier between the maternal side and the developing fetus. Nevertheless, it is a potential origin where pathogens coming from the maternal tissue might traverse to the fetal itssue. Therefore, we hypothesized that the placenta upon pathogen encounter is able to orchestrate an immune response by releasing inflammatory chemokines and cytokines. Furthermore the placenta might be able to express a broad repertoire of antimicrobial effector proteins to directly fight against the incoming bacterial threat. The stimulation of isolated placental cells with TLR-ligands or complete bacteria enhanced the secretion of the chemokine IL-8, the proinflammatory cytokines IL-6 and TNF as well as the anti-inflammatory cytokine IL-10 in a stimulus dependent manner. In addition purified placental cells expressed the antimicrobial effector proteins bactericidal/permeabilityincreasing (BPI), beta-defensin 2, secretory leucocyte protease inhibitor and acyloxyacyl hydrolase. Group B streptococci were potent stimulators of these products. Because the synthesized spectrum of AMPs and cytokines identified from isolated placenta cells is similar to what can be observed from neutrophilic granulocytes, we separated trophoblasts from lymphocytes by MACS. Indeed by flow cytometry we could demonstrate that granulocytes were present in the isolated trophoblast fraction. After the separation no lymphocytes could be detected in the purified cell fraction. Via confocal scanning laser microscopy we were able to detect intracellular expression of BPI in purified trophoblasts. This separation step will enable us to determine the specific contribution of the purified trophoblasts and the associated hematopoietic cells for the expression of the cytokines or antimicrobial effector proteins.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Corneal inflammation in response to filarial antigens Katrin Gentil1, Eric Pearlman2, Achim Hoerauf1 1

Institute for Medical Microbiology, Immunology and Parasitology, University Clinic Bonn

2

Department of Ophthalmology and Center for Global Health and Diseases, Case Western

Reserve University, Cleveland, OH, USA River blindness caused by the filarial nematode Onchocerca volvulus is the second leading cause of blindness in the developing world. Infections with O. volvulus cause corneal inflammation eventually leading to sclerosing keratitis and blindness. Our group has been using a mouse model of filarial infection to investigate the mechanisms of neutrophil migration to the cornea. We were investigating the role of Toll-like receptors (TLRs) in the generation of adaptive immune responses and migration of granulocytes to the corneal stroma. We found decreased IFNgamma production by splenocytes of immunized TLR2-/- mice when compared with immunized C57BL/6 mice. Similarly, we found decreased CXC chemokine production in the cornea and decreased neutrophil infiltration into the corneal stroma in TLR2-/- mice. In contrast, IL-5 production and eosinophil migration were unaffected in TLR2-/- mice. Further analysis revealed decreased neutrophil migration in IFNgamma-/- mice. We could demonstrate that IFNgamma primes macrophages for activation by filarial extracts by upregulation of TLR2 expression on the cell surface leading to increased production of proinflammatory cytokines. These in turn induce CXC chemokine production by corneal fibroblasts that attract neutrophil migration to the cornea. These findings demonstrate that although parasites typically induce strong Th2 responses, the low levels of Th1 responses present during filarial infection are potent inducers of neutrophil migration and corneal inflammation.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Antiretroviral effects of Toll-like receptor ligands Kathrin Gibbert1, Ulf Dittmer1 1

Institut für Virologie; Universitaetsklinikum Essen

The Toll-like receptor (TLR) system plays an important role in the recognition of infectious pathogens and their signals induce the coordinated activation of innate and adaptive immune response. Nothing was known about the simultaneous activation of the TLR 3, 7 and 9 ligands which induce various cytokines like Type I Interferons or Interleukin-12 in acute retroviral infection. In the current study, we analyzed the expression of inflammatory cytokines by BM-derived DCs stimulated with different combinations of TLR ligands. A simultaneous incubation with the TLR 3 ligand Poly I:C and the TLR 7 ligand Resiquimod (R848) led to a stronger induction of IL-12 compared to the stimulation with just one of those ligands. We used the Friend retrovirus model to get more insight into the role of the combined TLR ligand stimulation in an acute retroviral infection. Treatment of FV-infected mice with Poly I:C and R848 alone or in combination led to a strong reduction in viral loads in the blood and the spleen. An expansion of NK cells and a strong activation of B cells was found in the TLR ligand treated animals. We could show that the depletion of CD8+ T cells in Poly I:C-treated, FV-infected animals led to an increase of viral loads in the spleen and the bone marrow whereas the depletion of NK cells resulted in higher viral loads in the bone marrow but not in the spleen. In summary Poly I:C and R848 showed a very strong antiviral activity in vivo. Thus, the use of TLR ligands with strong antiviral activity might be a good feature for the treatment of retroviral infections.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

Bacterial DRiPs, Yes or No? Silke Grauling-Halama and Gernot Geginat Institut für Medizinische Mikrobiologie und Hygiene, Fakultät für Medizin Mannheim der Universität Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim The rapid recognition of infected cells by CD8 T cells requires fast processing of pathogenderived antigens in the cytoplasm of the host cell followed by subsequent presentation of antigenic peptides in the context of MHC class I molecules on the surface of infected cells. A still unsolved paradox is the discrepancy between a rather long half-live of antigens in the presence of rapid presentation of pathogen-derived antigenic peptides. Studies with virally infected cells suggest that instable structurally altered, so-called defective ribosomal products “DRiPs” are the main source of antigen in infected cells. As viral DRiPs can’t be studied independent of host cells we took advantage of the facultative intracellular bacterium Listeria monocytogenes which enabled us to characterize T cell antigens in infected cells as well as independent of host cells. Our data indicate that similar to virally infected cells the rapid processing of L. monocytogenes derived T cell antigens also depends on an instable form of antigen. In contrast to viral DRiPs, however, the instable form of antigen is not defined by structural alterations of antigens but is a temporary state that antigens are exposed to in their statu nascendi. In summary, our studies suggest a general antigen processing model that does not necessitate the assumption of defective protein synthesis as basis of rapid antigen processing and presentation of stable T cell antigens.

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13. Symposium "Infektion und Immunabwehr" Burg Rothenfels, 12. – 14. März 2009

The role of Natural killer (NK) T cells for protection against Leishmania major infection Klaus Griewank, Beate Lorenz, Michael Fischer, Susanna Lopez Kostka, Esther von StebutBorschitz Dept of Dermatology, Johannes Gutenberg-University, Mainz Leishmaniasis is a serious disease affecting 12 million people worldwide and causing tens of thousands of deaths every year. Infection with Leishmania is also a classic immunological model with resistant mouse strains developing Th1 immunity and susceptible strains initiating a Th2 response leading to failure to contain the infection and eventually death. Here we studied the influence of NKT cells on the development of immunity against L. major using a physiological low dose infection model. Our initial results showed that NKT cell-deficient (CD1d-/- or Ja18-/-) C57BL/6 mice were better able to contain Leishmania infections than their wildtype counterparts. Lesions and parasite burdens in CD1d-/- mice were at least 2fold smaller than in C57BL/6 mice (lesions ~2-fold difference wk3, 5 and 8, p