Zielstellung: Ziel dieser kumulativen Dissertationsarbeit war die vergleichende Untersuchung der Wirtsantwort in verschiedenen Mauslinien nach Infektion mit Streptobacillus (S.) moniliformis und Rodentibacter (R.) pneumotropicus mit Anzeigeparametern für die Klinik, die Pathologie und die Immunantwort. Es sollten neue erregerspezifische enzyme-linked immunosorbent assays (ELISA) evaluiert und durch die Bestimmung der Immunglobulin G (IgG)-Subklassen mausstammspezifische Unterschiede in der Immunantwort aufgezeigt werden. Darüber hinaus waren Sentinelsysteme zu bewerten. Material und Methoden: Es wurden BALB/c und C57BL/6-Mäuse intranasal mit S. moniliformis- oder R. pneumotropicus infiziert und mit Kontaktsentinels vergesellschaftet. Zusätzlich wurde benutzte Einstreu der Infektionskäfige auf Käfige mit nichtinfizierten CD1-Mäusen (Einstreu-Sentinels) übertragen. Die Infektionsgruppen wurden über 4 Wochen, die Sentinels mindestens 7 Wochen alle 12 Stunden klinisch untersucht und die Verläufe dokumentiert. Am Ende der Experimente bzw. bei Erreichen spezifischer Abbruchkriterien wurden die Mäuse tierschutzgerecht euthanasiert und definierte Organproben für pathohistologische und bakteriologische Untersuchungen gewonnen. Die Erreger wurden dabei massenspektrometrisch sowie mittels polymerase chain reaction (PCR) differenziert und in Proben des Respirationstraktes quantitativ erfasst. Erregerspezifische Antikörper wurden in tracheonasaler Spülflüssigkeit und im Serum in eigens etablierten ELISA‘s auf Basis von Ganzzellextrakten bestimmt. Weiterhin erfolgte die Messung des Verhältnisses der IgG-Subtypen IgG1 und IgG2 im ELISA. Ergebnisse: Der Infektionsversuch mit S. moniliformis bestätigte mit einer Mortalität von 75% die bekannte hohe Infektionsanfälligkeit der C57BL/6-Mäuse im Gegensatz zu BALB/c, die keine Krankheitsanzeichen entwickelten. Die wichtigsten pathologischen Manifestationen waren eitrig-nekrotisierende Lymphadenitiden und Pneumonien in Verbindung mit der Reisolation des Infektionsstammes. Mithilfe des etablierten ELISA‘s gelang der Nachweis erregerspezifischer IgG-Antikörper im Serum der Tiere beider Linien. Bei den Kontaktsentinels konnte, bis auf eine Ausnahme, weder kulturell, noch serologisch eine Infektion nachgewiesen werden. Gleiches gilt für alle Einstreu-Sentinels. Molekularbiologisch wurde aber Erreger-DNA in den Lungen der Sentinels festgestellt. Die Infektion mit einem R. pneumotropicus Stamm, welcher genotypisch positiv für alle drei bekannten RTX-Toxine dieses Erregers war, führte zu einer unerwartet hohen Morbidität und Mortalität in beiden Mauslinien. In frühzeitig euthanasierten Tieren beider Linien konnten katarrhalisch-eitrige bis nekrotisierende Bronchopneumonien sowie eine Dissemination des Belastungsstammes in zahlreiche innere Organe nachgewiesen werden. In überlebenden Tieren beider Linien wurde eine deutliche Kolonisation respiratorischer Schleimhäute mit dem Belastungsstamm trotz z.T. hoher mukosaler IgA-Spiegel und Serokonversion im Blut nachgewiesen. Überlebende C57BL/6 Mäuse zeigten eine signifikant niedrigere Bakterienlast in inneren Organen als BALB/c Mäuse. In allen Kontaktsentinels, aber nicht in einem einzigen Einstreu-Sentinel, konnte kulturell und indirekt serologisch eine Infektion mit R. pneumotropicus nachgewiesen werden. Die Bestimmung der IgG-Subklassen in den Seren der C57BL/6-Mäuse beider Infektionsstudien ergab eine Verschiebung des Verhältnisses IgG2/IgG1 von unter 0,8 vor zu über 1,6 nach Infektion. Dies weist auf eine T-Helferzell (Th) 1-dominierte Immunantwort hin. BALB/c-Mäuse behielten dagegen ein Verhältnis unter 0,8 auch nach der Infektion bei, sodass auf eine Th2- Antwort zu schließen war. Schlussfolgerungen: Sowohl für S. moniliformis als auch für R. pneumotropicus konnten Tiermodelle mit diversen Anzeigeparametern etabliert werden, welche für Folgestudien zur Pathogenese oder Immunprophylaxe genutzt werden können. Für beide Erreger wurden neue sensitive und spezifische ELISA-Protokolle in die Diagnostik eingeführt. Kontaktsentinels, aber nicht Einstreu-Sentinels, sind gut geeignet, um R. pneumotropicus-Infektionen nachzuweisen. Die beobachtete stammspezifische Klinik, Pathologie und Immunantwort der C57BL/6-Mäuse nach experimenteller S. moniliformis-Infektion sprach für eine pathologische Th1-Immunantwort. Im Gegensatz dazu war im R. pneumotropicus – Infektionsversuch die Th1-Immunantwort der C57BL/6-Mäuse mit einer effektiveren Reduktion des Erregers in inneren Organen assoziiert. Die unerwartet hohe Morbidität und Mortalität im R. pneumotropicus –Infektionsversuch weist auf eine besonders hohe Virulenz des eingesetzten Stammes hin, sodass in dieser Arbeit erstmalig ein septikämischer Verlauf in Wildtyp-Mäusen nach intranasaler R. pneumotropicus-Infektion nachgewiesen werden konnte.:Inhaltsverzeichnis (I) Abkürzungsverzeichnis (III) 1 Einleitung (1) 2 Literatur (3) 2.1 Streptobacillus moniliformis (3) 2.1.1 Allgemeine Charakteristika (3) 2.1.2 Differenzierung von Streptobacillus spp.(4) 2.1.3 Serologische Methoden zum indirekten Nachweis einer Streptobacillus moniliformis - Infektion (5) 2.1.4 Epidemiologie der durch Streptobacillus moniliformis hervorgerufenen Zoonose (6) 2.1.5 Klinik und Pathologie der Streptobacillus moniliformis-Infektion bei Nagetieren (8) 2.1.6 Klinik und Pathologie der Streptobacillus moniliformis-Infektion in Menschen und anderen Nebenwirten (9) 2.1.7 Pathogenese und Virulenzfaktoren (10) 2.1.8 Prävalenz in Nagern (11) 2.1.9 Sanierung Streptobacillus moniliformis infizierter Nagetierbestände und Prävention (12) 2.2 Rodentibacter (R.) pneumotropicus und heylii (Pasteurella (P.) pneumotropica Biotyp Jawetz und Heyl) (14) 2.2.1 Allgemeine Charakteristika (14) 2.2.2 Ursprüngliche Einteilung in Biotypen und Reklassifikation zu Rodentibacter spp. (14) 2.2.3 Differenzierung von Rodentibacter spp. (15) 2.2.4 Serologische Methoden zum indirekten Nachweis einer Rodentibacter- Infektion (15) 2.2.5 Übertragung (15) 2.2.6 Klinik und Pathologien der Rodentibacter-Infektion in Nagern (16) 2.2.7 Pathogenese und Virulenzfaktoren (18) 2.2.8 Prävalenz (19) 2.2.9 Sanierung Rodentibacter pneumotropicus infizierter Nagetierbestände und Prävention (20) 2.3 Mäuse als Versuchstiere (22) 2.3.1 Inzucht-Stämme (22) 2.3.1.1 Merkmale, Verwendung und Historie der BALB/c-Wildtypmäuse (22) 2.3.1.2 Merkmale, Verwendung und Historie der C57BL/6-Wildtypmäuse (23) 2.3.1.3 Unterschiede der Immunreaktionen in C57BL/6- und der BALB/c- Mäusen (23) 2.3.2 Auszucht-Stämme (24) 2.3.2.1 Merkmale, Verwendung und Historie der CD1-Wildtypmäuse (24) 2.4 Gesundheitsmonitoring in Labortierhaltungen (25) 2.4.1 Empfehlungen der Federation of Laboratory Animal Science Associations (FELASA) (25) 2.4.2 Sentinelsysteme für das Gesundheitsmonitoring in Labormausbeständen (26) 3 Publikationen (28) 3.1 Fornefett J, Krause J, Klose K, Fingas F, Hassert R, Eisenberg T, Grunwald T, Müller U, Schrödl W, Baums CG. Comparative analysis of clinics, pathologies and immune responses in BALB/c and C57BL/6J mice infected with Streptobacillus moniliformis. Microbes and Infection. 2018;20(2):101-110 (28) 3.2 Fornefett J, Krause J, Klose K, Fingas F, Hassert R, Benga L, Grunwald T, Müller U, Schrödl W, Baums CG. Comparative analysis of humoral immune responses and pathologies of BALB/c and C57BL/6 wildtype mice experimentally infected with a highly virulent Rodentibacter pneumotropicus (Pasteurella pneumotropica) strain. BMC Microbiology. 2018;18(1):45 (39) 4 Übergreifende Diskussion (51) 5 Zusammenfassung (59) 6 Summary (61) 7 Literaturverzeichnis (63) 7.1 Fachliteratur (63) 7.2 Internet (76) 7.3 Gesetzestexte (78) Anhang (79) i Ergänzende Abbildungen (79) ii Ergänzendes Material zu 3.1 “Comparative analysis of clinics, pathologies and immune responses in BALB/c and C57BL/6J mice infected with Streptobacillus moniliformis” (81) iii Ergänzendes Material zu 3.2 “Comparative analysis of humoral immune responses and pathologies of BALB/c and C57BL/6 wildtype mice experimentally infected with a highly virulent Rodentibacter pneumotropicus (Pasteurella pneumotropica) strain” (83) Liste mit weiteren Veröffentlichungen Danksagung / Objective: Aim of this cumulative doctoral thesis was the comparative analysis of the host response in different mice strains infected with Streptobacillus (S.) moniliformis and Rodentibacter (R.) pneumotropicus with readout parameters for clinics, pathology and immune response. New pathogen specific enzyme linked immunosorbent assay’s (ELISA) were evaluated. Differentiation of immunoglobulin (Ig) G subclasses was conducted to reveal differences in the immune response between the two mice strains. Furthermore, sentinel systems were assessed. Materials and methods: BALB/c and C57BL/6 mice were infected intranasally with S. moniliformis or R. pneumotropicus and housed together with contact sentinels. Soiled bedding from infection cages was transmitted to cages with uninfected CD1 mice (bedding sentinels). Infection groups were observed for 4 weeks, sentinels for at least 7 weeks and the clinical course was documented. At the end of the experiments or when predefined termination criteria were reached, animals were humanely killed. Predefined organ samples were collected for pathohistological and bacteriological screenings. Pathogens were differentiated via mass spectrometry and via polymerase chain reaction (PCR). The specific bacterial load was quantified in samples of the respiratory tract. Pathogen-specific antibodies were detected in tracheonasal lavages and sera using newly established ELISAs based on whole cell extracts. Determination of the ratios of the IgG subtypes (IgG1 to IgG2) was conducted using ELISAs. Results: The S. moniliformis experiment confirmed the known high susceptibility of C57BL/6 mice with a mortality of 75%. This was in contrast to BALB/c, which developed no signs of illness. The major pathologies were purulent-necrotizing inflammations of the lymph nodes and the lung associated with detection of the challenge strain. Specific IgG-antibodies were detected in sera of both mice strains by the newly established ELISAs. In contact and bedding sentinels the infection was not detected by culture or indirectly by serology, except for one contact sentinel. However, pathogen DNA was detectable in the lungs of these animals via PCR. The infection with the R. pneumotropicus strain, which is genotypically positive for all 3 known RTX toxins of this pathogen, leaded to an unexpected high morbidity and mortality in both mice strains. In early losses a catharal-purulent to necrotizing bronchopneumonia as well as dissemination of the challenge strain in various inner organs was recorded. Efficient colonization of the respiratory mucosa through the challenge strain was detected in survivors of both lines despite high mucosal IgA levels and seroconversion in the blood. Surviving C57BL/6 mice showed a significant lower bacterial burden in inner organs than BALB/c. All contact sentinels were culturally and serologically positive for R. pneumotropicus infection in contrast to all bedding sentinels. Differentiation of IgG subclasses in sera of C57BL/6 mice of both experiments revealed a shift of the IgG2/IgG1 ratio from 0.8 prior to infection to 1.6 post infection suggesting a T helper (Th) 1-prone immune response. BALB/c mice remained under 0.8 after infection indicating a Th2-prone immune response. Conclusions: New animal models with various readout parameters were established for both S. moniliformis and R. pneumotropicus. These models can be used in future studies on pathogenesis and immunoprophylaxis. Sensitive und specific ELISA-protocols were established for both pathogens. Contact sentinels but not bedding sentinels are appropriate for detection of R. pneumotropicus-infections. The observed distinct clinic, pathology and immune response of C57BL/6 mice experimentally infected with S. moniliformis indicated on the one hand a pathological Th1 immune response. On the other hand, the Th1 response of C57BL/6 mice to R. pneumotropicus infection was associated with a more efficient clearance of the challenge strain in internal organs. The unprecedented high morbidity and mortality in the R. pneumotropicus experiment indicates high virulence of this strain. Accordingly, this work revealed for the first time septicaemia in wildtype mice after intranasal R. pneumotropicus-infection.:Inhaltsverzeichnis (I) Abkürzungsverzeichnis (III) 1 Einleitung (1) 2 Literatur (3) 2.1 Streptobacillus moniliformis (3) 2.1.1 Allgemeine Charakteristika (3) 2.1.2 Differenzierung von Streptobacillus spp.(4) 2.1.3 Serologische Methoden zum indirekten Nachweis einer Streptobacillus moniliformis - Infektion (5) 2.1.4 Epidemiologie der durch Streptobacillus moniliformis hervorgerufenen Zoonose (6) 2.1.5 Klinik und Pathologie der Streptobacillus moniliformis-Infektion bei Nagetieren (8) 2.1.6 Klinik und Pathologie der Streptobacillus moniliformis-Infektion in Menschen und anderen Nebenwirten (9) 2.1.7 Pathogenese und Virulenzfaktoren (10) 2.1.8 Prävalenz in Nagern (11) 2.1.9 Sanierung Streptobacillus moniliformis infizierter Nagetierbestände und Prävention (12) 2.2 Rodentibacter (R.) pneumotropicus und heylii (Pasteurella (P.) pneumotropica Biotyp Jawetz und Heyl) (14) 2.2.1 Allgemeine Charakteristika (14) 2.2.2 Ursprüngliche Einteilung in Biotypen und Reklassifikation zu Rodentibacter spp. (14) 2.2.3 Differenzierung von Rodentibacter spp. (15) 2.2.4 Serologische Methoden zum indirekten Nachweis einer Rodentibacter- Infektion (15) 2.2.5 Übertragung (15) 2.2.6 Klinik und Pathologien der Rodentibacter-Infektion in Nagern (16) 2.2.7 Pathogenese und Virulenzfaktoren (18) 2.2.8 Prävalenz (19) 2.2.9 Sanierung Rodentibacter pneumotropicus infizierter Nagetierbestände und Prävention (20) 2.3 Mäuse als Versuchstiere (22) 2.3.1 Inzucht-Stämme (22) 2.3.1.1 Merkmale, Verwendung und Historie der BALB/c-Wildtypmäuse (22) 2.3.1.2 Merkmale, Verwendung und Historie der C57BL/6-Wildtypmäuse (23) 2.3.1.3 Unterschiede der Immunreaktionen in C57BL/6- und der BALB/c- Mäusen (23) 2.3.2 Auszucht-Stämme (24) 2.3.2.1 Merkmale, Verwendung und Historie der CD1-Wildtypmäuse (24) 2.4 Gesundheitsmonitoring in Labortierhaltungen (25) 2.4.1 Empfehlungen der Federation of Laboratory Animal Science Associations (FELASA) (25) 2.4.2 Sentinelsysteme für das Gesundheitsmonitoring in Labormausbeständen (26) 3 Publikationen (28) 3.1 Fornefett J, Krause J, Klose K, Fingas F, Hassert R, Eisenberg T, Grunwald T, Müller U, Schrödl W, Baums CG. Comparative analysis of clinics, pathologies and immune responses in BALB/c and C57BL/6J mice infected with Streptobacillus moniliformis. Microbes and Infection. 2018;20(2):101-110 (28) 3.2 Fornefett J, Krause J, Klose K, Fingas F, Hassert R, Benga L, Grunwald T, Müller U, Schrödl W, Baums CG. Comparative analysis of humoral immune responses and pathologies of BALB/c and C57BL/6 wildtype mice experimentally infected with a highly virulent Rodentibacter pneumotropicus (Pasteurella pneumotropica) strain. BMC Microbiology. 2018;18(1):45 (39) 4 Übergreifende Diskussion (51) 5 Zusammenfassung (59) 6 Summary (61) 7 Literaturverzeichnis (63) 7.1 Fachliteratur (63) 7.2 Internet (76) 7.3 Gesetzestexte (78) Anhang (79) i Ergänzende Abbildungen (79) ii Ergänzendes Material zu 3.1 “Comparative analysis of clinics, pathologies and immune responses in BALB/c and C57BL/6J mice infected with Streptobacillus moniliformis” (81) iii Ergänzendes Material zu 3.2 “Comparative analysis of humoral immune responses and pathologies of BALB/c and C57BL/6 wildtype mice experimentally infected with a highly virulent Rodentibacter pneumotropicus (Pasteurella pneumotropica) strain” (83) Liste mit weiteren Veröffentlichungen Danksagung

Die von T-Helfer (Th) -Zellen produzierten Zytokine spielen eine entscheidende Rolle bei der Einleitung, der Aufrechterhaltung und der Regulation von Immunantworten. Bei der Untersuchung von Immunantworten hat sich eine vereinfachte Einteilung der Th-Zellen in zwei Klassen als hilfreich erwiesen: Th1 und Th2. Stabil differenziell exprimierte Oberflächenmoleküle werden benötigt, um lebende Th1- und Th2-Zellen identifizieren, auf Einzelzellebene charakterisieren und möglicherweise die von ihnen erzeugten Immunantworten modulieren zu können. Auf der Suche nach solchen Molekülen wurde in Zusammenarbeit mit der Firma Millennium Pharmaceuticals das Oberflächenmolekül TIM-3 entdeckt. Die Ergebnisse der vorliegenden Arbeit belegen, dass TIM-3 nicht nur von CD4+ Th-Zellen, sondern auch von CD8+ T-Zellen, gamma/delta-T-Zellen, sowie einigen Makrophagen und der Mehrheit der dendritischen Zellen in der Milz von Mäusen auf der Zelloberfläche exprimiert wird. Die Expression von TIM-3 auf Th-Zellen ist klar mit einem aktivierten Phänotyp assoziiert. TIM-3 wird unter polarisierenden Bedingungen in vitro im Vergleich zu Th2-Zellen bevorzugt, jedoch nicht ausschließlich von Th1-Zellen exprimiert. Erstmals wurde auf Einzelzellebene die Zytokinproduktion TIM-3 exprimierender Th-Zellen untersucht. Die Analyse von Th0-Zellen, welche unter nichtpolarisierenden Bedingungen in vitro hergestellt wurden, ergab keine bevorzugte Produktion von Th1-Zytokinen und keine verminderte Expression von Th2-Zytokinen durch TIM-3 exprimierende Th-Zellen. Aufgrund der in dieser Arbeit erhaltenen Ergebnisse erlaubt die Expression von TIM-3 allein daher nicht die Identifizierung von Th1-Zellen. Nach einer Infektion mit Toxoplasma gondii lag jedoch eine bevorzugte Assoziation zwischen der Expression von TIM-3 und der pathogenspezifischen Produktion von Interferon (IFN)-gamma, Interleukin (IL)-2 und Tumor Nekrose Faktor (TNF)-alpha vor. Somit korreliert die TIM-3 Expression auf Th-Zellen nur unter bestimmten Bedingungen mit einem Th1-Phänotyp. / The cytokines that are produced by T helper (Th) cells are decisive for the initiation, the maintenance and the regulation of immune responses. A simplified classification of Th cells has proven to be useful for the analysis of immune responses: Th1 and Th2. Stably and differentially expressed surface molecules are required for the identification of live Th1- and Th2-cells, their characterisation at the single cell level and the possible modulation of the immune responses that they induce. On the search for such molecules the surface molecule TIM-3 was discovered in collaboration with Millennium Pharmaceuticals. The present work shows that TIM-3 protein is not only expressed on the cell surface by CD4+ Th cells but also by CD8+ T cells and gamma/delta T cells as well as by some macrophages and the majority of the dendritic cells in the murine spleen. TIM-3 expression on Th cells is clearly associated with an activated phenotype. Under polarising conditions in vitro TIM-3 is expressed preferentially albeit not exclusively by Th1 cells compared to Th2 cells. For the first time, the cytokine production of TIM-3 expressing Th cells has been analysed at the single cell level. The analysis of Th0 cells, generated under non-polarising conditions in vitro showed no preferential production of Th1-cytokines and no diminished production of Th2-cytokines by TIM-3 expressing Th-cells. The results obtained in this work lead to the conclusion that expression of TIM-3 does not permit the identification of Th1-cells. However upon infection with Toxoplasma gondii a positive association between the expression of TIM-3 and the pathogen-specific production of Interferon (IFN)-gamma, Interleukin (IL)-2 and Tumor Necrosis Factor (TNF)-alpha was observed. Therefore the expression of TIM-3 on Th-cells only correlates under specific conditions with a Th1-phenotype.

Im ersten Teil dieser Dissertation wurde der Einfluss des mitochondrialen Proteins TCAIM (T cell activation inhibitor, mitochondrial) auf die T-Zellaktivierung untersucht. Hierzu wurde eine transgene Mauslinie mit einem T-zellspezifischen knock-in (KI) von Tcaim in den Rosa26 Lokus generiert. Die Tcaim-Überexpression beeinflusste die Fission und Umverteilung von Mitochondrien und reduzierte die T-Zellrezeptor (TZR)-induzierte Bildung mitochondrialer, radikaler Sauerstoffspezies. In vitro stimulierte CD4+ Tcaim KI T-Zellen zeigten eine geringere Aktivierung, Proliferation und IL-2 Sekretion als Kontrollzellen. T-Zellen aus Tcaim KI Mäusen, die in Rag-1 knock-out Mäuse transferiert wurden, waren nicht fähig ein allogenes Haut-Transplantat abzustoßen und behielten einen naiven Phänotyp. Diese Ergebnisse zeigen, dass TCAIM als mitochondriales Protein wichtige Schritte in der Zellaktivierung und der Bildung von Gedächtnis-T-Zellen beeinflusst. Der zweite Teil der Dissertation beschäftigte sich mit dem Einfluss der CD44-Oberflächenexpression auf die Differenzierung von T-Helfer (TH)-Zellen. Eine hohe CD44-Expression unterscheidet Effektor- von naiven T-Zellen. Durch die allogene Stimulation von CD4+ T-Zellen bildeten sich drei verschiedene Populationen: CD44+, CD44++ und CD44+++. Sowohl in vitro als auch in vivo generierte alloreaktive TH17-Zellen wurden in der CD44+++ Population, TH1-Zellen hingegen in der CD44++ Population, detektiert. Es wurde beschrieben, dass sowohl eine geringe TZR- als auch eine geringe CD28-Stimulation eher die Bildung von TH17- als TH1-Zellen unterstützen. Unter genau diesen Bedingungen kann CD44 als kostimulatorisches Molekül die Signaltransduktion verstärken. Tatsächlich zeigten allogenreaktive CD44+++ TH-Zellen eine höhere ZAP-70-Phosphorylierung als CD44++ TH-Zellen. Diese Ergebnisse unterstützen die Annahme, dass CD44 durch die Verstärkung der Signaltransduktion die TH17-Differenzierung fördern kann. / Within the first part of this thesis, the influence of the mitochondrial Protein TCAIM (T cell activation inhibitor, mitochondrial) on T cell activation was investigated. Tcaim expression correlated negatively with the rejection of allografts and it is down-regulated during T cell activation. To study effects of TCAIM during T cell activation, we generated a T cell-specific mouse strain with a Tcaim knock-in (KI) targeted to the Rosa26 locus. Tcaim overexpression changed the mitochondrial morphology and reduced the T cell receptor (TCR)-induced mitochondrial reactive oxygen species production. In vitro activation of Tcaim KI CD4+ T cells resulted in a decreased activation, proliferation and cytokine release. Importantly, Rag-1 knock-out mice, reconstituted with Tcaim KI T cells, tolerated allogeneic skin grafts. Thus, by regulating TCR-induced mitochondrial distribution and ROS production, TCAIM controls important steps during T cell activation and memory formation. The second part dealt with the influence of CD44 surface expression level for T helper cell (Th cell) differentiation. By association with lymphocyte-specific protein kinase (LCK) it can enhance T cell signaling. Allogeneic stimulation of CD4+ T cells resulted in the formation of three distinguishable populations: CD44+, CD44++ and CD44+++. In vitro and in vivo generated allo-reactive TH17 cells were mainly CD44+++. This is in contrast to TH1 cells which were dominantly CD44++. Titration experiments revealed that low TCR- and co-stimulation supports TH17 rather than TH1 development. Under exactly these conditions it was reported that CD44 can act as co-stimulatory molecule and replace CD28. Indeed, CD44+++CD4+ T cells contained already more phosphorylated ZAP-70 as compared to CD44++ cells. Our results support the notion that CD44 enhances TCR signaling strength by delivering LCK, which is required to support TH17 development.

In der Pathogenese der Multiplen Sklerose (MS) wird autoantigenspezifischen proinflammatorischen T-Helferzellen eine entscheidende Rolle zugeschrieben. Das am meisten untersuchte Autoantigen ist das Myelin Basic Protein (MBP). Bisher waren zum Nachweis autoantigenspezifischer T-Zellen deren Kultur über Tage bis Monate unumgänglich. In dieser Arbeit wurden Methoden zum direkten ex vivo-Nachweis autoreaktiver T-Helferzellen etabliert, die die reaktive Sekretion der proinflammatorischen Zytokine Interferon gamma und Tumor Nekrose Faktor alpha nach sechsstündiger Stimulation nachweisen. Die durchflusszytometrische Analyse antigenreaktiver Zytokinexpression in fixierten Zellen wies eine Sensitivität von 1/10.000 in mononukleären Zellen des peripheren Blutes (PBMC) auf. Es konnten damit bei 34 untersuchten MS-Patienten und 25 gesunden Kontrollpersonen keine MBP-reaktiven T-Helferzellen detektiert werden, während sich die Reaktion auf die beiden Kontrollantigene Tetanus Toxoid und Cytomegalie Virus-Antigen in den beiden Gruppen nicht relevant unterschied. Deshalb wurde in einer anderen Methode reaktiv sezerniertes Zytokin extrazellulär auf lebenden Zellen gebunden und durch einen anschließenden magnetischen Anreicherungsschritt die Sensitivität auf 2/100.000 erhöht. Bei einem von acht MS-Patienten wurde so eine Population MBP-spezifischer Zellen mit einer Ausgangsfrequenz von 2,15/100.000 nachgewiesen. Im Liquor von drei MS-Patienten ließen sich keine MBP-reaktiven proinflammatorischen T-Helferzellen detektieren. Diese Ergebnisse implizieren, dass die Frequenz MBP-spezifischer T-Helferzellen im peripheren Blut und im Liquor der meisten MS-Patienten und Kontrollpersonen geringer ist als die Sensitivität der etablierten Methoden, diese Zellen jedoch bei einigen Patienten in höheren Frequenzen nachgewiesen werden können. / Autoantigen-specific proinflammatory T-helper cells are assumed to play an important role in the pathogenesis of Multiple Sclerosis (MS). The most extensively studied autoantigen is Myelin Basic Protein (MBP). To detect autoantigen-specific T-cells, so far these had to be cultured for several days or months. In this work methods for the direct ex vivo detection of autoreactive T-helper cells have been established by detecting the reactive secretion of the proinflammatory cytokines Interferon gamma and Tumor Necrosis Factor alpha after six hour stimulation. The flow cytometric analysis of antigen-reactive cytokine expression in fixed cells showed a sensitivity of 1/10.000 in peripheral blood mononuclear cells (PBMC). With this method there could not be detected any MBP-reactive T-helper cells in 34 MS-patients and 25 healthy controls, whereas the reaction after stimulation with the two control antigens Tetanus Toxoid and Cytomegalovirus antigen did not differ relevantly between the two groups. Therefore in another method the reactively secreted cytokine was bound on the surface of living cells and the sensitivity was then increased to 2/100.000 by following magnetic enrichment. With that, there could be detected a population of MBP-specific cells in one of eight MS-patients with a frequency of 2,15/100.000 in PBMC. There could not be found any MBP-reactive proinflammatory T-helper cells in the cerebrospinal fluid of three MS-patients. Our results suggest that the frequency of MBP-specific T-helper cells in peripheral blood and cerebrospinal fluid is below the employed methods' detection limit in most MS-patients, but seldom these cells can be detected in higher frequencies.

"Soaring stress hormones hit fertility" (Hohe Spiegel an Stresshormonen mindern die Fertilität) titelt die British Broadcasting Corporation (BBC) online im Juni 2001. Stress ist als schwangerschaftsgefährdendes Element vielfach in klinischen Studien untersucht worden. Gegenstand dieser Arbeit war es, die durch Stress ausgelöste Abortkaskade immunologisch mit anderen Abortstimuli zu vergleichen und zu untersuchen, ob eine gemeinsame abortive "Endstrecke" über die Prothrombinase fibrinogen like protein 2 (fgl2) existiert. In den Versuchen im Mausmodell zeigte sich, dass der pathophysiologische Mechanismus, der zum Abort führt, entscheidend von dem Abort auslösenden Stimulus abhängt. So scheint Stress einen Abort primär über TNF-alpha und Apoptose zu vermitteln. Stark inflammatorische Reize, wie sie bei mikrobiellen Infektionen mit erhöhter Expression von LPS und erhöhten Werte an IL-12 auftreten, induzieren eine Koexpression von TNF-alpha und IFN-gamma. Die Ko-Expression dieser beiden Th1-Zytokinen scheint notwendig zu sein, um die Prothrombinase fgl2 heraufzuregulieren. Die klinischen Daten dieser Arbeit, die an Plazentagewebe von Patientinnen mit Spontanabort beziehungsweise einer Präeklampsie erhoben wurden, zeigen einen deutlichen, lokalen Anstieg des Th1-Zytokin TNF-alpha und eine vermehrte Expression von fgl2 Protein im Gefäßendothel im Vergleich zu Plazentagewebe von unkomplizierten Schwangerschaften. Gleichzeitig konnte eine deutliche Fibrinablagerung beobachtet werden. Eine solche Immunkonstellation könnte durchaus die erfolgreiche Implantation und die ausreichende Ernährung des heranwachsenden Embryos/Fötus einschränken und wichtige, pathophysiologische Grundlage für die Manifestation eines Spontanaborts oder einer Präeklampsie sein. / "Soaring stress hormones hit fertility" is the headline of the British Broadcasting Cooperation online in June 2001. Stress is known to be harmful during pregnancy as many clinical studies demonstrated. The aim of this work was to compare the immunological mechanism of a stress-induced abortion with other abortive stimuli and whether there exists a shared final route via up-regulation of fibrinogen-like protein 2 (fgl2). In the experiments in mice it turned out that the pathophysiological mechanism by which the abortion is mediated depend on the abortive stimuli. It has been demonstrated that stress induces the mRNA expression of TNF-alpha and increases apoptosis. Strong inflammatory stimuli as represented by the injection of IL-12, which is normally upregulated by bacterial LPS, induces the mRNA co-expression of TNF-alpha and IFN-gamma in comparison to normal pregnancies in mice. It seems that this co-expression of TNF-alpha and IFN-gamma is needed for induction of the novel prothrombinase fgl2. The clinical data of this work show an up-regulation of TNF-alpha as well as fgl2 in the pregnancy complications, spontaneous abortion and pre-eclampsia, especially in endothelial cells. This up-regulation was associated with an increase in fibrin deposition. Such an immune constellation might interfere with successful implantation as well as sufficient nutrition of the growing embryo/fetus. This could be one of the pathophysiological trigger for the manifestation of a spontaneous abortion or a pre-eclampsia.

CD4+ T-Helferzellen (Th) entwickeln sich zu Th1 und Th2 Zellen, die nach ihrer Funktion und Zytokinexpression eingeteilt werden. Die differentielle Induktion von Th Zellen, die Th1 oder Th2 Zytokine exprimieren, ist der Schlüssel zur Regulation von Immunantworten bei Infektionskrankheiten, Allergien und Autoimmunerkrankungen. Daher können stabil exprimierte Oberflächenmoleküle, die spezifisch für die funktionell unterschiedlichen Th Zellen sind, von besonderer Bedeutung für die Analyse und selektive funktionelle Modulation von Th Subtypen sein und erlauben es neue therapeutische Strategien für die Behandlung von allergischen und Autoimmunerkrankungen zu etablieren. TIM-3 wurde kürzlich identifiziert als ein Molekül, welches selektiv auf der Oberfläche von Th1 Zellen exprimiert wird und welches möglicherweise eine Rolle bei der Induktion von Autoimmunerkrankungen spielt. Um monoklonale Antikörper gegen humanes TIM-3 zu produzieren, wurde die humane TIM-3 cDNA von in vitro generierten dendritischen Zellen kloniert. Der extrazelluläre Teil des Gens wurde in den prokaryotischen Expressionsvektor pQE100S insertiert und in E.coli BL21(DE3) exprimiert. Die gesamte codierende Sequenz wurde in den eukaryotischen Expressionsvektor pIRES2EGFP subkloniert und auf der Oberfläche von Säugetierzellen exprimiert. Stabile Transfektanten der CHO-K1 und HEK293 Zelllinie wurde etabliert. Die Balb/c Mäuse wurden mit löslichem und unlöslichem rekombinanten humanem TIM-3 sowie mit stabilen Transfektanten für humanes TIM-3 immunisiert. Milzzellen dieser Tiere wurden mit der Myelomzelllinie P3 X 63 Ag8.653 fusioniert. Die entwickelten Hybridome wurden im ELISA und mittels FACS auf Spezifität gegen humanes TIM-3 hin untersucht. Ein Klon der generierten Hybridome war positiv im ELISA zeigte jedoch kein Signal gegen TIM-3 auf der Oberfläche von Zellen. / CD4+ T helper (Th) cells develop into effector Th1 and Th2 cells, which are frequently categorized according to their function and cytokine expression. The differential induction of Th cells expressing Th1 or Th2 cytokines is key to the regulation of immune responses by infectious diseases, allergies and autoimmnune diseases. Thus, stably expressed surface molecules, significant for functionally different types of Th cells could be of utmost importance for the analysis and selective functional modulation of Th subsets and provide new therapeutic strategies for the trestment of allergic or autoimmune diseases. TIM-3 was recently identified as a molecule that is selectively expressed on the surface of Th1 cells and that may have a role in the induction of autoimmune disease. To produce monoclonal antibody of human TIM-3, the human TIM-3 cDNA was cloned from in vitro generated dendritic cells. The extracellular domain of human TIM-3 was inserted into prokaryotic expression vector pQE100S and expressed in E.coli BL21(DE3). The whole coding region was subcloned into eukaryotic expression vector pIRES2EGFP and expressed on the surface of mammalian cells. The stable transfectants of CHO-K1 and HEK-293 cell line was established. The BALB/c mice were immunized with soluble and insoluble recombinant human TIM-3 and also with stable transfectants. Splenocytes were fused with P3 X 63 Ag8.653 myeloma cells. The generated hybridomas were tested in ELISA and FACS for specificity against human TIM-3. A generated clone was positive in ELISA but did not respond to the TIM-3 molecule on the cell surface.

The socio-economic and geographical distribution of malaria overlaps with that of many parasitic helminths and in these areas co-infections are common. Co-infection with helminths can influence disease outcome causing either exacerbation or amelioration of malaria. Understanding the complex host-parasite interactions that lead to these different disease outcomes is important for the success of control programmes aimed at these parasites. The immune system has evolved diverse types of response (e.g. T-helper 1 (Th1) and T-helper 2 (Th2)) to efficiently combat infection with ‘microparasites’ and helminths respectively. When faced with co-infection however, the need for the host to multitask means it must manage these counter-regulatory responses. In this study a murine model of malaria-hookworm (Plasmodium chabaudi- Nippostrongylus brasiliensis) co-infection was utilised to investigate how changes in T-helper bias affect malaria disease outcome. Antibody isotypes were used as indicators of Th1/Th2 bias and revealed that helminth co-infection reduced the malaria-specific Th1 response. Counter-intuitively this resulted in ‘protection’ from malaria with co-infected mice having reduced peak P. chabaudi parasitaemia and suffering less severe anaemia. In addition to providing a measure of Th1/Th2 bias, analysis of antibody responses revealed the occurrence of cross-reactive antibodies. The potential for these crossreactive antibodies to influence disease outcome was investigated but in this murine model resource-mediated mechanisms of parasite regulation appear to be responsible for the ‘protection’ that co-infection affords. The question of why cross-reactive antibodies are produced has important immunological and ecological implications. Cross-reactive responses may arise through some physiological constraint on the immune mechanisms that usually result in antibody-specificity. However experiments designed to investigate if the specificity of antibodies is constrained by availability of antigen suggest that this is not the case in the model system used here. There is also the possibility that production of cross-reactive antibodies represents an evolutionary optimal strategy for a host faced with unpredictable exposure to a variety of parasites. However a major finding of this study indicates these two taxonomically distinct parasite species share antigens, which in itself is crucial to understanding host-parasite interactions in a co-infection setting. The main findings of this thesis are relevant to co-infection studies in general and the implications for both evolutionary and applied biology are discussed.

Bacillus anthracis produces lethal toxin (LT) and edema toxin (ET) and they suppress the function of LPS-stimulated dendritic cells (DC). Because DCs respond differently to various microbial stimuli, we compared toxin effects in bone marrow DCs stimulated with either LPS or Legionella pneumophila (Lp). DCs were enriched with GM-CSF for 9 days, purified by positive selection, and treated with toxins for 6h; cells were then stimulated with either LPS or Lp-infection for 24h. DC cytokine production and maturation marker expression varied depending upon cell stimulus and the mouse strain used. LT but not ET was more toxic for cells from BALB/c than from C57BL/6 (B6) as measured by 7-AAD uptake; however, ET suppressed CD11c expression. LT suppressed IL-12, IL-6, and TNF-a in cells from BALB/c and B6 mice but increased IL-1ß in LPS-stimulated cultures. ET also suppressed IL-12 and TNF-a but increased IL-6 and IL-1ß in Lp-stimulated cells from B6. Regarding maturation marker expression, LT increased MHCII and CD86 while suppressing CD40 and CD80; ET, on the other hand, generally decreased marker expression across all groups. We conclude that the modulation of cytokine production by anthrax toxins is dependent on variables including the source of the DCs, the type of stimulus and cytokine measured, and the individual toxin tested. However, LT and ET enhancement or suppression of maturation marker expression is more related to the marker studied than the cell stimulus or cell source. Anthrax toxins are not uniformly suppressive of DC function but instead can increase function under defined conditions.

SerpinB2 (aka plasminogen activator type 2) is well described as an extracellular inhibitor of urokinase-type plasminogen activator (uPA). However, the majority of SerpinB2 is retained intracellularly, and many uPA-independent activities have been reported for SerpinB2 suggesting an alternate function. This thesis explores the role of SerpinB2 in epithelial tumour cell lines, highlights the problems associated with various expression systems and argues that SerpinB2 has no role in growth or apoptosis of tumour cells. A potential role for immune modulation and angiogenesis is suggested in in vivo models. Previous research using SerpinB2 transfected, clonally selected tumour cell lines suggested that SerpinB2 regulates the retinoblastoma tumour suppressor protein (Rb) by binding and protecting Rb from degradation. Despite the use of two techniques under numerous conditions and positive controls, no significant interaction between SerpinB2 and Rb was found. SerpinB2 was reported to bind Rb through a PENF homology motif located within the SerpinB2 C-D interhelical loop region. The PENF homology motif was postulated to represent the motif responsible for binding to the C-pocket of Rb. Epstein Barr Virus nuclear antigen 6 (EBNA6) is a known Rb binding protein, which contains two predicted PENF homology motifs. However, mutation of the two PENF homology motifs within EBNA6 did not reduce Rb binding. Furthermore, the SerpinB2 PENF homology motif is actually not well conserved between SerpinB2 proteins from multiple species, whereas other regions of the SerpinB2 C-D loop show a high level of conservation. These data do not support a role for SerpinB2 and the PENF homology motif in Rb binding. SerpinB2 has been proposed to have a role in regulating growth and apoptosis. To further investigate this proposed phenotype of SerpinB2, SerpinB2 was expressed in a range of epithelial tumour lines using transient transfection. No change in growth, apoptosis or Rb levels were found. After ≈2-3 month antibiotic selection for the SerpinB2-expressing plasmid, SerpinB2 protein was lost without the loss of the transgene, indicating selective pressure against long-term SerpinB2 protein expression. To further investigate long-term SerpinB2 expression adenovirus and lentivirus vectors were used. Infection of tumour cell lines with adenovirus vectors expressing SerpinB2 resulted in reduced cell growth, characterised by increased p53 (but not Rb) levels and G2 arrest or apoptosis. When SerpinB2 expressing lentivirus vectors were used to transduce the same tumour cell lines, high levels of long-term expression of functional SerpinB2 was achieved. However, SerpinB2-expressing cell lines showed no differences in growth, proliferation, Rb levels, or apoptosis induced by a range of agents. Growth and apoptosis observed with adenovirus SerpinB2 had all the characteristics of adenovirus-associated toxicity, which has been reported previously for specific proteins. These experiments highlighted the problems associated with SerpinB2 expression systems and suggest that SerpinB2 expression per se is not toxic nor has a role in regulating Rb, growth and apoptosis. Screening of a number of tumour cell lines identified the HPV16 transformed cervical cancer line as expressing high levels of SerpinB2. SerpinB2 was located both extracellularly and intracellularly with a cytoplasmic and nuclear distribution. A high molecular weight SerpinB2 species was identified in CaSki cells and was shown to be the N-linked glycosylated species. Sequencing showed the protein to be Type A SerpinB2 and the protein was shown to form an inhibitory complex with uPA. An abundant low molecular weight SerpinB2 species was also identified in CaSki cell supernatants and appeared to be a proteolytic fragment of SerpinB2. Treatment of CaSki with PMA, TNFα and IFNγ increased SerpinB2 levels. Lentiviral based shRNA failed to significantly down regulate SerpinB2 expression and increasing SerpinB2 levels with lentiviral expression did not change growth, apoptosis, Rb levels or E7 transcription. Lentiviral expression of SerpinB2 in (normally SerpinB2 negative) HPV16 transformed SiHa cells, also failed to show changes in Rb levels or E7 transcription. CaSki thus express wild-type and functional SerpinB2, but no evidence could found that SerpinB2 effects HPV16 E7 transcription or Rb levels. The data presented identifies CaSki as valuable source of biologically functional SerpinB2. SerpinB2 expression in breast cancer cells has been associated with positive prognosis. Tubo, a SerpinB2-negative murine breast carcinoma cell line, was transduced with lentivirus expressing SerpinB2 and grown subcutaneously in BALB/c mice. SerpinB2 expressing tumours appeared red and were larger than control tumours. Furthermore, SerpinB2 expressing tumours had a ≈2 fold higher density of blood vessels when compared to Tubo and Tubo expressing EGFP. Mice carrying tumours expressing SerpinB2 also showed reduced anti-tumour IgG2 responses. These data suggest that a role for SerpinB2 in regulating angiogenesis and antitumour immunity. In conclusion, this thesis challenges the notion that SerpinB2 regulates Rb, cell cycle, and apoptosis and suggests a potential role for SerpinB2 in tumour angiogenesis and immunity.

SerpinB2 (aka plasminogen activator type 2) is well described as an extracellular inhibitor of urokinase-type plasminogen activator (uPA). However, the majority of SerpinB2 is retained intracellularly, and many uPA-independent activities have been reported for SerpinB2 suggesting an alternate function. This thesis explores the role of SerpinB2 in epithelial tumour cell lines, highlights the problems associated with various expression systems and argues that SerpinB2 has no role in growth or apoptosis of tumour cells. A potential role for immune modulation and angiogenesis is suggested in in vivo models. Previous research using SerpinB2 transfected, clonally selected tumour cell lines suggested that SerpinB2 regulates the retinoblastoma tumour suppressor protein (Rb) by binding and protecting Rb from degradation. Despite the use of two techniques under numerous conditions and positive controls, no significant interaction between SerpinB2 and Rb was found. SerpinB2 was reported to bind Rb through a PENF homology motif located within the SerpinB2 C-D interhelical loop region. The PENF homology motif was postulated to represent the motif responsible for binding to the C-pocket of Rb. Epstein Barr Virus nuclear antigen 6 (EBNA6) is a known Rb binding protein, which contains two predicted PENF homology motifs. However, mutation of the two PENF homology motifs within EBNA6 did not reduce Rb binding. Furthermore, the SerpinB2 PENF homology motif is actually not well conserved between SerpinB2 proteins from multiple species, whereas other regions of the SerpinB2 C-D loop show a high level of conservation. These data do not support a role for SerpinB2 and the PENF homology motif in Rb binding. SerpinB2 has been proposed to have a role in regulating growth and apoptosis. To further investigate this proposed phenotype of SerpinB2, SerpinB2 was expressed in a range of epithelial tumour lines using transient transfection. No change in growth, apoptosis or Rb levels were found. After ≈2-3 month antibiotic selection for the SerpinB2-expressing plasmid, SerpinB2 protein was lost without the loss of the transgene, indicating selective pressure against long-term SerpinB2 protein expression. To further investigate long-term SerpinB2 expression adenovirus and lentivirus vectors were used. Infection of tumour cell lines with adenovirus vectors expressing SerpinB2 resulted in reduced cell growth, characterised by increased p53 (but not Rb) levels and G2 arrest or apoptosis. When SerpinB2 expressing lentivirus vectors were used to transduce the same tumour cell lines, high levels of long-term expression of functional SerpinB2 was achieved. However, SerpinB2-expressing cell lines showed no differences in growth, proliferation, Rb levels, or apoptosis induced by a range of agents. Growth and apoptosis observed with adenovirus SerpinB2 had all the characteristics of adenovirus-associated toxicity, which has been reported previously for specific proteins. These experiments highlighted the problems associated with SerpinB2 expression systems and suggest that SerpinB2 expression per se is not toxic nor has a role in regulating Rb, growth and apoptosis. Screening of a number of tumour cell lines identified the HPV16 transformed cervical cancer line as expressing high levels of SerpinB2. SerpinB2 was located both extracellularly and intracellularly with a cytoplasmic and nuclear distribution. A high molecular weight SerpinB2 species was identified in CaSki cells and was shown to be the N-linked glycosylated species. Sequencing showed the protein to be Type A SerpinB2 and the protein was shown to form an inhibitory complex with uPA. An abundant low molecular weight SerpinB2 species was also identified in CaSki cell supernatants and appeared to be a proteolytic fragment of SerpinB2. Treatment of CaSki with PMA, TNFα and IFNγ increased SerpinB2 levels. Lentiviral based shRNA failed to significantly down regulate SerpinB2 expression and increasing SerpinB2 levels with lentiviral expression did not change growth, apoptosis, Rb levels or E7 transcription. Lentiviral expression of SerpinB2 in (normally SerpinB2 negative) HPV16 transformed SiHa cells, also failed to show changes in Rb levels or E7 transcription. CaSki thus express wild-type and functional SerpinB2, but no evidence could found that SerpinB2 effects HPV16 E7 transcription or Rb levels. The data presented identifies CaSki as valuable source of biologically functional SerpinB2. SerpinB2 expression in breast cancer cells has been associated with positive prognosis. Tubo, a SerpinB2-negative murine breast carcinoma cell line, was transduced with lentivirus expressing SerpinB2 and grown subcutaneously in BALB/c mice. SerpinB2 expressing tumours appeared red and were larger than control tumours. Furthermore, SerpinB2 expressing tumours had a ≈2 fold higher density of blood vessels when compared to Tubo and Tubo expressing EGFP. Mice carrying tumours expressing SerpinB2 also showed reduced anti-tumour IgG2 responses. These data suggest that a role for SerpinB2 in regulating angiogenesis and antitumour immunity. In conclusion, this thesis challenges the notion that SerpinB2 regulates Rb, cell cycle, and apoptosis and suggests a potential role for SerpinB2 in tumour angiogenesis and immunity.