Research

Funding: DFG, 215.000 EUR

Project Details:
The early steps of hepatitis C virus (HCV) cell entry involve a complex interplay between the incoming virion and host cell expressed factors. Key host factors in the early phase of HCV cell entry include scavenger receptor class B member 1 (SR-BI), low-density lipoprotein receptor (LDLR) and CD81. Work from the previous funding period has revealed how genetic variation in one host factor, the high-density lipoprotein (HDL) receptor SR-BI, can modulate HCV infection, while highlighting at the same time that to fully understand the mechanisms of early HCV-cell interactions a broader view of the host cell molecules involved is required. In particular, others and we demonstrated that HCV host factors interact with each other and with cholesterol and this critically determines susceptibility. Moreover, we have identified CD81-binding partners calpain-5 (CAPN5) and casitas B-lineage lymphoma proto-oncogene b (CBLB) as novel modulators of HCV entry.
The proposed project for the next funding period has the overarching goal to better characterize how the host factors involved in the early phase of HCV entry interact with the virus and each other, and how these interactions are modulated by genetic and pharmacological factors. The project has four parts: (1) We will evaluate coding SR-BI and CD81 variants in a LDLR/SR-BI negative or - respectively - CD81 negative context for their effect on the HCV replication cycle and especially the early phase of cell entry in vitro. (2) We will determine how selected CD81 variants influence the interaction between CD81 and SR-BI and to what extent this mechanistically explains cell entry phenotypes. Here we will cooperate with project A6 (Pietschmann) which focusesl conversely on variation in SR-BI and membrane cholesterol content. (3) We will investigate how statins and other lipid lowering drugs including the new and highly potent monoclonal antibodies directed at proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of LDLR subcellular localization and function, impact HCV infection. Specifically, we will address the impact on the expression level of SR-BI, LDLR and CD81 and on membrane and cellular cholesterol content of hepatocytes as well as the impact of statin therapy on viral load and hepatic inflammation in patients with chronic hepatitis C. (4) Finally, we will extend our analysis to newly identified CD81 interaction partners CAPN5 and CBLB and their role in HCV cell entry and receptor complex regulation beginning with the generation of human variants to probe whether they impact CD81 and SR-BI interactions as well as HCV infection. Taken together, this work holds the promise of a deeper understanding of the mechanistic role of established and newly discovered HCV entry factors during the early phase of HCV cell entry, its modulation by host genetic variants and non-genetic host factors such as exposure to lipid metabolism-modulating drugs and thus of interindividual variability in the course of chronic hepatitis C.

Cooperation Partners:

Prof. Dr. Thomas von Hahn

Klinik für Gastroenterologie, Hepatologie und Endokrinologie und Institut für Molekularbiologie - Medizinische Hochschule Hannover

Funding: DFG Sonderforschungsbereich 900 "Mirkobielle Persistenz und seine Kontrolle", 215.000 EUR

Project Details:
The early steps of hepatitis C virus (HCV) cell entry involve a complex interplay between the incoming virion and host cell expressed factors. Key host factors in the early phase of HCV cell entry include scavenger receptor class B member 1 (SR-BI), low-density lipoprotein receptor (LDLR) and CD81. Work from the previous funding period has revealed how genetic variation in one host factor, the high-density lipoprotein (HDL) receptor SR-BI, can modulate HCV infection, while highlighting at the same time that to fully understand the mechanisms of early HCV-cell interactions a broader view of the host cell molecules involved is required. In particular, others and we demonstrated that HCV host factors interact with each other and with cholesterol and this critically determines susceptibility. Moreover, we have identified CD81-binding partners calpain-5 (CAPN5) and casitas B-lineage lymphoma proto-oncogene b (CBLB) as novel modulators of HCV entry.
The proposed project for the next funding period has the overarching goal to better characterize how the host factors involved in the early phase of HCV entry interact with the virus and each other, and how these interactions are modulated by genetic and pharmacological factors. The project has four parts: (1) We will evaluate coding SR-BI and CD81 variants in a LDLR/SR-BI negative or - respectively - CD81 negative context for their effect on the HCV replication cycle and especially the early phase of cell entry in vitro. (2) We will determine how selected CD81 variants influence the interaction between CD81 and SR-BI and to what extent this mechanistically explains cell entry phenotypes. Here we will cooperate with project A6 (Pietschmann) which focusesl conversely on variation in SR-BI and membrane cholesterol content. (3) We will investigate how statins and other lipid lowering drugs including the new and highly potent monoclonal antibodies directed at proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of LDLR subcellular localization and function, impact HCV infection. Specifically, we will address the impact on the expression level of SR-BI, LDLR and CD81 and on membrane and cellular cholesterol content of hepatocytes as well as the impact of statin therapy on viral load and hepatic inflammation in patients with chronic hepatitis C. (4) Finally, we will extend our analysis to newly identified CD81 interaction partners CAPN5 and CBLB and their role in HCV cell entry and receptor complex regulation beginning with the generation of human variants to probe whether they impact CD81 and SR-BI interactions as well as HCV infection. Taken together, this work holds the promise of a deeper understanding of the mechanistic role of established and newly discovered HCV entry factors during the early phase of HCV cell entry, its modulation by host genetic variants and non-genetic host factors such as exposure to lipid metabolism-modulating drugs and thus of interindividual variability in the course of chronic hepatitis C.

Results:

https://www.sfb900.de/en/

Cooperation Partners:

Prof. Dr. Thomas von Hahn, Klinik für Gastroenterologie, Hepatologie und Endokrinologie und Institut für Molekularbiologie - Medizinische Hochschule Hannover

Funding: QOL Med LLC,Vero Beach, Florida, USA; Unrestricted Research Grant , 230.000 EUR

Project Details:
Current concepts of genetically-determined carbohydrate malabsorption have implicated homozygous and compound heterozygous mutations in the gene encoding SI as the molecular basis for the onset of this intestinal disorder (Naim et al., J Pediatr Gastroenterol Nutr. 2012 Nov;55 Suppl 2:S13-20. review). The major pathogenic variants in CSID are: V577G in the isomaltase subunit and G1073D, F1745C and R1124X in the sucrase subunit, whereby the G1073D is the mutation with the highest prevalence among CSID patients. We have recently suggested that the symptoms and clinical phenotype in CSID follow a gradient of severity that is directly associated with the cellular trafficking patterns of SI mutants between the ER, Golgi and cell surface (Gericke et al., Biochim Biophys Acta. 2017 Mar;1863(3):817-826). Interestingly, some of the mutations analysed occur as heterozygotes in these patients. Along similar lines is the finding that 5 out of 11 patients in our study by Sander et al. (Hum Mutat. 2006 Jan;27(1):119.) occur as heterozygotes towards mutations of the SI gene and harbor mutations such as G1073D, F1745C and T694P.

Funding: DFG Sonderforschungsbereich 900 "Mirkobielle Persistenz und seine Kontrolle", 430.000 EUR

Project Details:
The early steps of hepatitis C virus (HCV) cell entry involve a complex interplay between the incoming virion and host cell expressed factors. Key host factors in the early phase of HCV cell entry include scavenger receptor class B member 1 (SR-BI), low-density lipoprotein receptor (LDLR) and CD81. Work from the pre-vious funding period has revealed how genetic variation in one host factor, the high-density lipoprotein (HDL) receptor SR-BI, can modulate HCV infection, while highlighting at the same time that to fully under-stand the mechanisms of early HCV-cell interactions a broader view of the host cell molecules involved is required. In particular, others and we demonstrated that HCV host factors interact with each other and with cholesterol and this critically determines susceptibility. Moreover, we have identified CD81-binding partners calpain-5 (CAPN5) and casitas B-lineage lymphoma proto-oncogene b (CBLB) as novel modulators of HCV entry.
The proposed project for the next funding period has the overarching goal to better characterize how the host factors involved in the early phase of HCV entry interact with the virus and each other, and how these interactions are modulated by genetic and pharmacological factors. The project has four parts: (1) We will evaluate coding SR-BI and CD81 variants in a LDLR/SR-BI negative or - respectively - CD81 negative con-text for their effect on the HCV replication cycle and especially the early phase of cell entry in vitro. (2) We will determine how selected CD81 variants influence the interaction between CD81 and SR-BI and to what extent this mechanistically explains cell entry phenotypes. Here we will cooperate with project A6 (Pietsch-mann) which focusesl conversely on variation in SR-BI and membrane cholesterol content. (3) We will inves-tigate how statins and other lipid lowering drugs including the new and highly potent monoclonal antibodies directed at proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of LDLR subcellular locali-zation and function, impact HCV infection. Specifically, we will address the impact on the expression level of SR-BI, LDLR and CD81 and on membrane and cellular cholesterol content of hepatocytes as well as the impact of statin therapy on viral load and hepatic inflammation in patients with chronic hepatitis C. (4) Final-ly, we will extend our analysis to newly identified CD81 interaction partners CAPN5 and CBLB and their role in HCV cell entry and receptor complex regulation beginning with the generation of human variants to probe whether they impact CD81 and SR-BI interactions as well as HCV infection. Taken together, this work holds the promise of a deeper understanding of the mechanistic role of established and newly discovered HCV entry factors during the early phase of HCV cell entry, its modulation by host genetic variants and non-genetic host factors such as exposure to lipid metabolism-modulating drugs and thus of interindividual variability in the course of chronic hepatitis C.

Funding: NIH, 318.177 EUR

Project Details:
To achieve a comprehensive mapping of the detailed autonomic, sensory and intrinsic innervation of the colon we have brought together a multidisciplinary team of world experts who have developed breakthrough methodological approaches to assess intrinsic and extrinsic innervation as well as functional circuitry. These recent advanced technologies include the use of tissue clearing (CLARITY), optogenetics, viral tracing, and a miniaturized microelectrode array device capable of a wide range of stimulation parameters, high-resolution microscopy and fiber-optic manometry catheter, as well as laser capture microdissection combined with NanoString nCounter techniques to map the molecular profiling of enteric neurons. These approaches will be applied to define molecular identity of ENS neurons, functional connectivity, detailed autonomic and sensory neuroanatomy, identification of ENS neurons projecting to target colonic cells and influence of different type of electrical stimulation on colonic function (secretion, permeability, motility, afferent nerve modulation). This will provide the foundation of the physiological mechanisms regulating the large intestine and the basis for a strategic development of efficacious treatment for the many intractable colonic disorders.

Cooperation Partners:

Flinders University (AU), University of California Los Angeles (USA), University of Nevada School of Medicine (USA) and Technical University of Munich (DE)

Funding: EU , 330.000 EUR

Project Details:
Full proposal for the call identifier SFS-14-2016 - Research and Innovation Action
"Understanding host-pathogen-environment interactions"

The problem being addressed is the major economic losses to the pig production industry worldwide due to Streptococcus suis (S. suis). This pathogen can cause invasive disease in pigs with symptoms such as acute sepsis, meningitis, endocarditis, pneumonia and arthritis often being reported. Almost 100% of pig farms world-wide have carrier animals (based on consultation with national farming associations veterinary practitioners and scientific researchers). S. suis is also frequently associated with porcine respiratory disease complex which is one of the major causes of mortality in pigs. In polymicrobial respiratory infections S. suis is considered as an opportunist invader and the interactions with other pathogens and the effects on the host?s immune system are not well understood. S. suis is also a zoonotic pathogen and human infections worldwide have increased significantly in the past years, with most cases originating in Southeast Asia . Currently, no efficacious, cross-protective vaccines exist for S. suis and resistance to macrolides, lincosamides, tetracyclines, and sulphonamides has been reported for up to 85% of S. suis isolates in many countries.S. suis is reported to be the most serious pathogen in piglets between the ages of 4 and 12 weeks and a leading cause of mortality in suckling pigs. Reports describing difficulty in disease control and management, especially "failure of bacterin vaccines" are common. Apart from economic losses due to mortality, S. suis infections depress both food conversion efficiency and daily life weight gain, thereby increasing unit production costs. Control is a priority target for the pig production and animal health industry due to the lack of cross-protective vaccines, increasing antibiotic resistance and endemic carriage in pig herds worldwide. Furthermore, there is recent concern about the emergence of hyper-virulent strains able to cause more rapid and severe infections of pigs and humans. The goal of PIGSs is to increase our understanding of the host-pathogen-environment interactions in S. suis infections in pigs, and thereby strengthening the evidence base for new innovations and effective prevention and control strategies. These include policy advice to stakeholders (e.g. farming practices), new diagnostics for virulent strains, subunit protein vaccines and other interventions to manipulate the host's protective microbiota and natural defense/immunity.

Results:

https://onlinelibrary.wiley.com/doi/10.1002/mbo3.1234; https://www.nature.com/articles/s41598-022-18227-3; https://www.mdpi.com/2076-2607/9/2/366; https://www.mdpi.com/2076-0817/13/1/4

Cooperation Partners:

Jerry Wells (NL), Koordinator

Funding: Boehringer Ingelheim Vetmedica GmbH, 16.666 EUR

Project Details:
Zeitgleiche Isolierung und Charakterisierung von S. suis und PRRSV aus Organsystemen sezierter Schweine. Charakterisierung der Effizienz der Immunausweichmechanismen von S. suis Isolaten.

Project Details:
Respiratory multifactorial diseases cause problems in swine populations worldwide. Pathogens as porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (M. hyopneumoniae)may be involved in disease development in combination with management, husbandry, and environmental factors. In a conventional farm, where piglets were not vaccinated against PCV2, it will be examined to what extent the introduction of vaccination against PCV2 has an effect on animal health. In addition the effect of the used combinaory vaccine (PCV2+M.hyopneumoniae) will be evaluated in comparison to simultaneously administered mono- vaccines against PCV2 and M. hyopneumoniae.
In a two-phase trial, 524 (phase 1) or 521 (phase 2) clinically healthy piglets are included at the first week of life. In the first phase, performance parameters will be compared in animals vaccinated against M. hyopneumoniae only (group A) or vaccinated against PCV2 and M. hyopneumoniae (group B). In phase 2, vaccinations against PCV2 and M. hyopneumoniae with different vaccines are compared (groups C and D). Performance parameters recorded will include total losses, daily weight gains during suckling, rearing, and fattening, and pathogen loads in serum (PCV2) or tracheobronchial secretions (M. hyopneumoniae). In addition, lungs are assessed at slaughter.

Funding: Deutsche Forschungsgemeinschaft (DFG), 199.450 EUR

Project Details:
Der Respirationstrakt ist eine häufige Eintrittspforte für Krankheitserreger. Das Hundestaupevirus (CDV) sowie das nahverwandte Masernvirus müssen die Barriere des Atemwegsepithels überwinden, um zu ihren Zielzellen, den Immunzellen, zu gelangen. Nectin-4, der einzige bekannte Rezeptor für beide Viren auf Epithelzellen, ist ein basolaterales Protein. Nach Aufnahme werden die Morbilliviren von polarisierten Zellen des respiratorischen Epithels über die apikale Membran freigesetzt, gelangen in die Luftwege und können so den Wirt verlassen. Es ist bislang nicht bekannt wie das CDV im Anfangsstadium der Infektion die Barriere des Atemwegsepithels überwindet und in den Wirt eindringt. In dem geplanten Projekt soll daher mittels Präzisionslungenschnitten und Air-liquid-interface-Kulturen differenzierter respiratorischer Zellen analysiert werden, wie CDV das respiratorische Epithel überwindet und subepitheliale Zielzellen infiziert. Hierbei werden die infizierten Zelltypen, der Infektionsverlauf, zytopathogene Effekte und die Regeneration des Epithels in beiden Kultursystemen näher charakterisiert. Der Einsatz von CDV-Mutanten, die Defekte in der Rezeptorerkennung aufweisen (SLAM-blinde und Epithelzell-Rezeptor-blinde CDV), ermöglicht hierbei gezielte Aussagen über das Spektrum der infizierbaren Zellen und die Effizienz der Infektion. Als zweite Möglichkeit des Überwindens der Epithelbarriere wird untersucht, ob CDV über die parazelluläre Route eindringen kann. Außerdem wird der Einfluss verschiedener Umweltfaktoren, von denen bekannt ist, dass sie die Verbindung zwischen Epithelzellen (tight junctions) öffnen, auf den Infektionsverlauf ermittelt. Zusätzlich soll geklärt werden, ob infizierte Makrophagen oder dendritische Zellen bei der Überwindung der Epithelzellbarriere als Vektoren fungieren und so bei der Ausbreitung der Infektion behilflich sind. In weiteren in vitro-Experimenten wird mittels Zytokinexpressionsanalysen bestimmt, welche Auswirkung die CDV-Infektion auf immunologische Funktionen in der Lunge hat. Im Rahmen der CDV-Infektion des Atemwegepithels soll außerdem der Einfluss einer Co-Infektion (Bordetella bronchiseptica) untersucht werden. Das Projekt wird entscheidend für das Verständnis der Pathogenese der CDV-Infektion beitragen. Es wird auch hilfreich sein für das Verständnis anderer Viren, die den Respirationstrakt als Durchgangsstation benutzen, um in ihren Wirt einzudringen.

Funding: Bundesministerium für Ernährung und Landwirtschaft, 682.563 EUR

Project Details:
Unter standardisierten Versuchsbedingungen mit Einzeltierhaltung werden Akzeptanz und Verdaulichkeit sowie Auswirkungen auf die Magen-Darm-Gesundheit junger Mastschweine geprüft, in deren Mischfutter die Komponente Weizen (ca. 70 %) in zunehmenden Anteilen durch Roggen ersetzt wurde. Damit wird eine vergleichende Bewertung der beiden Schwergetreidearten in der Mastschweinefütterung ermöglicht.

Cooperation Partners:

Institut für Tierernährung, Freie Universität Berlin

Institut für Tierernährung, Universität Bonn

KWS LOCHOW GmbH, Bergen/Wohlde