dc.contributor.advisor | Sørensen, Karen Kristine | |
dc.contributor.author | Kyrrestad, Ingelin | |
dc.date.accessioned | 2024-02-19T14:34:59Z | |
dc.date.available | 2024-02-19T14:34:59Z | |
dc.date.issued | 2024-03-15 | |
dc.description.abstract | The liver is a major organ in the body's defense against blood-borne pathogens. It acts as a filter for the blood and is a central site for immune responses, and a central hub for various metabolic processes. Within the liver, an extensive network of small blood vessels, the hepatic sinusoids, are key sites for the exchange of nutrients and waste products between the blood circulation and the liver parenchyma, supporting immune functions and metabolic processes. The liver sinusoidal endothelial cells form the delicate lining of the hepatic sinusoids, acting as scavenger cells with a remarkable ability to eliminate waste products from the bypassing blood. The systemic circulation also carries pathogens, like viruses, that can be swiftly taken up by the LSECs, potentially causing infection in these cells. Cytomegaloviruses targets endothelial cells, but the route of uptake and infection in LSECs has not been described. This thesis aims to provide novel knowledge about the mechanisms of how a pathogenic virus enter and mediates infection in LSECs, and how dexamethasone, an immunosuppressive drug, can affect this.
In the first part of the study, we established a protocol to study virus uptake in mouse LSECs by blocking endocytosis function of the cells. For this purpose, we used dynamin-inhibitors and acidification inhibitor, and evaluated the effect of these. Then, we used this method to study the in vitro uptake and infection by cytomegalovirus, a pathogen highly associated with the liver. Also, we aimed to identify a cell surface receptor able to mediate this infection.
The second part of the study provides a comprehensive overview of biological processes and pathways in LSECs affected by dexamethasone, a frequently used anti-inflammatory and immunosuppressive drug. This was investigated by quantitative proteomics, with the observation that dexamethasone suppressed LSEC activation and inflammation and enhanced the survival of cultured cells.
Lastly, we aimed to find if dexamethasone could affect the susceptibility to cytomegalovirus infection in LSECs and the inflammatory response mediated by the cells. In this study, we investigated LSECs isolated from two different mice strains, BALB/c and C57BL/6, as their immune system can respond differently to viral infections. This study aimed to provide insights into how immunosuppressive drugs can affect virus infection in LSECs, and potential differences caused by genetic background of the mice. | en_US |
dc.description.abstract | Leveren er et svært viktig organ i kroppens forsvar mot patogener som fraktes med blodbanen. Organet fungerer som et blodfilter og har en sentral rolle i immunforsvarets funksjon, og kroppens metabolisme. Et omfattende nettverk av små blodkar, leversinusoidene, er nødvendige for utveksling av næringsstoffer og avfallsprodukter mellom blodsirkulasjonen og leverparenkymet, og bistår immunfunksjoner og metabolske prosesser. Endotelcellene som danner den tynne veggen i leversinusoidene kalles LSECs (liver sinusoidal endothelial cells på engelsk) og fungerer som altetende celler med en stor evne til å fjerne avfallsprodukter fra blodet som passerer forbi. Det systemiske kretsløpet bærer også virus, som raskt kan tas opp og elimineres av LSECs, men som i noen tilfeller forårsaker viruinfeksjon i disse cellene. Cytomegalovirus infiserer ofte endotelceller, men opptaksmekanismen og infeksjonsruten i LSECs er ikke kjent. Målet med denne avhandlingen er å bidra med ny kunnskap om hvordan et patogent virus kommer seg inn og forårsaker infeksjon i LSECs, og hvordan dexamethasone, et immundempende legemiddel, kan påvirke dette.
I den første delen av studiet etablerte vi en protokoll for å studere virusopptak i LSECs isolert fra muselever ved å modifisere endocytosefunksjonen til cellene. Til dette formålet brukte vi inhibitorer for å blokkere dynamin, nødvendig for reseptor-mediert endocytose, og en annen inhibitor for å hindre surgjøring av endosomer. Deretter evaluerte vi effekten av disse. Videre brukte vi denne metoden for å studere opptak og infeksjon av cytomegalovirus, et patogen som ofte infiserer leveren og forårsaker latens. Et annet mål var å identifisere en reseptor hos LSECs som kunne mediere denne infeksjonen.
Den andre delen av studiet gir en omfattende oversikt over biologiske prosesser og mekanismer i LSECs som påvirkes av dexamethason, et omfattende brukt legemiddel med antiinflammatorisk og immundempende effekter. Dette ble undersøkt ved kvantitativ proteomikk, hvor vi fant at dexamethason undertrykte cellenes aktivering og inflammasjon og forbedret levedyktigheten til LSECs i cellekultur.
Til slutt undersøkte vi om dexamethason kunne påvirke mottakeligheten for infeksjon av cytomegalovirus i LSECs og samtidig studere cellenes immunrespons forårsaket av viruset. I denne studien inkluderte vi celler isolert fra to forskjellige musestammer, BALB/c og C57BL/6, ettersom immunsystemet deres kan reagere forskjellig på virusinfeksjoner. Denne studien hadde som mål å gi innsikt i hvordan immundempende legemidler kan påvirke virusinfeksjon i LSECs, og potensielle forskjeller forårsaket av musenes ulike genetiske bakgrunn. | en_US |
dc.description.doctoraltype | ph.d. | en_US |
dc.description.popularabstract | The liver is a major organ in the body's defense against blood-borne pathogens. It acts as a filter for the blood and is a central site for immune responses, and a central hub for various metabolic processes. Within the liver, an extensive network of small blood vessels, the hepatic sinusoids, are key sites for the exchange of nutrients and waste products between the blood circulation and the liver parenchyma, supporting immune functions and metabolic processes. The liver sinusoidal endothelial cells form the delicate lining of the hepatic sinusoids, acting as scavenger cells with a remarkable ability to eliminate waste products from the bypassing blood. The systemic circulation also carries pathogens, like viruses, that can be swiftly taken up by the LSECs, potentially causing infection in these cells. Cytomegaloviruses targets endothelial cells, but the route of uptake and infection in LSECs has not been described. This thesis aims to provide novel knowledge about the mechanisms of how a pathogenic virus enter and mediates infection in LSECs, and how dexamethasone, an immunosuppressive drug, can affect this.
In the first part of the study, we established a protocol to study virus uptake in mouse LSECs by blocking endocytosis function of the cells. For this purpose, we used dynamin-inhibitors and acidification inhibitor, and evaluated the effect of these. Then, we used this method to study the in vitro uptake and infection by cytomegalovirus, a pathogen highly associated with the liver. Also, we aimed to identify a cell surface receptor able to mediate this infection.
The second part of the study provides a comprehensive overview of biological processes and pathways in LSECs affected by dexamethasone, a frequently used anti-inflammatory and immunosuppressive drug. This was investigated by quantitative proteomics, with the observation that dexamethasone suppressed LSEC activation and inflammation and enhanced the survival of cultured cells.
Lastly, we aimed to find if dexamethasone could affect the susceptibility to cytomegalovirus infection in LSECs and the inflammatory response mediated by the cells. In this study, we investigated LSECs isolated from two different mice strains, BALB/c and C57BL/6, as their immune system can respond differently to viral infections. This study aimed to provide insights into how immunosuppressive drugs can affect virus infection in LSECs, and potential differences caused by genetic background of the mice. | en_US |
dc.identifier.uri | https://hdl.handle.net/10037/32983 | |
dc.language.iso | eng | en_US |
dc.publisher | UiT The Arctic University of Norway | en_US |
dc.publisher | UiT Norges arktiske universitet | en_US |
dc.relation.haspart | <p>Paper I: Kyrrestad, I., Larsen, A. K., Sánchez Romano, J., Simón-Santamaría, J., Li, R., & Sørensen, K.K. (2023). Infection of liver sinusoidal endothelial cells with Muromegalovirus muridbeta1 involves binding to neuropilin-1 and is dynamin-dependent. <i>Frontiers in Cellular and Infection Microbiology, 13</i>, 1249894. Also available in Munin at <a href=https://hdl.handle.net/10037/31829>https://hdl.handle.net/10037/31829</a>.
<p>Paper II: Bhandari, S., Kyrrestad, I., Simón-Santamaría, J., Li, R., Szafranska, K., Smedsrød, B. & Sørensen, K.K. Mouse liver sinusoidal endothelial cell responses to the glucocorticoid receptor agonist dexamethasone. Manuscript.
<p>Paper III: Kyrrestad, I., Sánchez Romano, J., Larsen, A.K., Simón-Santamaría, J., & Sørensen, K.K. Effects of dexamethasone on Muromegalovirus muridbeta1 infection in liver sinusoidal endothelial cells from BALB/c and C57BL/6 mice. Manuscript. | en_US |
dc.rights.accessRights | openAccess | en_US |
dc.rights.holder | Copyright 2024 The Author(s) | |
dc.subject.courseID | DOKTOR-003 | |
dc.subject | LSEC | en_US |
dc.subject | Dexamethasone | en_US |
dc.subject | Cytomegalovirus | en_US |
dc.title | Cytomegalovirus infection and dexamethasone effects in liver sinusoidal endothelial cells | en_US |
dc.type | Doctoral thesis | en_US |
dc.type | Doktorgradsavhandling | en_US |