Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection
| dc.contributor.advisor | Guler, Reto | |
| dc.contributor.advisor | Ozturk, Mumin | |
| dc.contributor.advisor | Brombacher, Frank | |
| dc.contributor.author | Kieswetter, Nathan Scott | |
| dc.date.accessioned | 2021-08-24T01:37:47Z | |
| dc.date.available | 2021-08-24T01:37:47Z | |
| dc.date.issued | 2021 | |
| dc.date.updated | 2021-08-24T01:07:45Z | |
| dc.description.abstract | Tuberculosis (TB) has emerged as the world’s most deleterious infectious disease. The etiological agent of TB, Mycobacterium tuberculosis (Mtb), has evolved the ability to evade the host immune system using several mechanisms; emphasising the need for novel treatment strategies. Peptidoglycan (PG) is an important immunomodulatory heteropolysaccharide structure that can be shed during mycobacterial infection with immunological consequences and as such, changes in PG structure are expected to have important implications on disease progression and host responses. Mycobacterial amidases have been shown to have important roles in the remodelling of PG during cell division in M. smegmatis and are implicated in sensitivity to antibiotic treatment. However, their roles in modulating host immunity remain unknown. Herein, we assess the immune responses to Mtb mutants defective for either one of two amidases, Ami1 and Ami4, in bone marrow-derived macrophages (BMDM) and the C57BL/6 murine models of tuberculosis. Both Ami1 and Ami4 deletion resulted in increased pro-inflammatory response in BMDM. Infection with the Mtb Δami1 mutant in mice resulted in differential induction of proinflammatory cytokines and certain chemokines during the acute phase of the infection, an eff ect that was abrogated in chronic phase infection. The Δami1mutant was found to be susceptible to antibiotics in liquid growth culture but this sensitivity was negated in macrophages and reversed to a tolerant phenotype in mice. The Δami4 mutant, by contrast, did not display differential antibiotic susceptibility and did not significantly alter cytokine and chemokine responses relative to the wildtype control in mice. These findings suggest that Ami1 and Ami4 in Mtb play a nonoverlapping role in antibiotic sensitivity and modulating host immunity during tuberculosis. Additionally, the specific epigenetic alterations which occur during host-Mtb infection that contribute to immune evasion remain unknown. Here, we propose a method to elucidate transcriptomic changes in both human primary monocyte-derived macrophages (MDM) and the Mtb bacillus with which they were infected. In this study, we exhibit a dual-RNA-seq proof-of-concept methodology where, from a single donor, we successfully sequence host RNA from infected MDMs as well as Mtb RNA enriched from those same infected MDMs. Utilizing this optimised methodology, we aim to discover and model epigenetic and transcriptional alterations as well as their effector proteins in primary human macrophages following Mtb infection. Further, we aim to identify novel and annotated ncRNAs which are correlated with these epigenetic modifications. | |
| dc.identifier.apacitation | Kieswetter, N. S. (2021). <i>Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection</i>. (). ,Faculty of Health Sciences ,Institute of Infectious Disease and Molecular Medicine. Retrieved from http://hdl.handle.net/11427/33815 | en_ZA |
| dc.identifier.chicagocitation | Kieswetter, Nathan Scott. <i>"Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection."</i> ., ,Faculty of Health Sciences ,Institute of Infectious Disease and Molecular Medicine, 2021. http://hdl.handle.net/11427/33815 | en_ZA |
| dc.identifier.citation | Kieswetter, N.S. 2021. Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection. . ,Faculty of Health Sciences ,Institute of Infectious Disease and Molecular Medicine. http://hdl.handle.net/11427/33815 | en_ZA |
| dc.identifier.ris | TY - Doctoral Thesis AU - Kieswetter, Nathan Scott AB - There are so many people who I would like to thank. If it takes a village to raise a child, it certainly takes a city to train a scientist. Firstly, I would like to thank my supervisors, A/Prof Reto Guler, Prof Frank Brombacher and Dr Mumin Ozturk for allowing me to further my studies and allowing me to work on several interesting projects. Specifically, I would like to take this opportunity to thank A/Prof Reto Guler for his insightful patient advice, training and ever willingness to talk about my work. His brilliant example has made me a better scientist. Further, I would also like to thank Dr Mumin Ozturk for his constant, patient mentorship, help, advice and friendship. His influence, guidance and example have affected me more than he'll ever know. Lastly, but certainly not least, I would like Professor Bavesh Kana and for all his advice and support. I would also like to express my gratitude to my labmates from the Brombacher group. All the conversations, laughs, celebrations and commiserations have made this journey undeniably easier. In particular, I would like to thank Shelby-Sara Jones for her constant willingness to help with lab work whilst chatting about everything under the sun. To my friends and family, there are no words to express my unending gratitude. Without their love and support along the way, I would never have gotten to this stage in my life. To my parents and sister, I would like to say a huge thank you for their constant support and love during my academic career so far. You guys have been wonderful. A huge thank you to Daniela de Almeida and the French's for their support and love from afar– you guys have been great. I would like to say a special thank you to Dustin Fischer who has always been there for a beer and good old-fashioned rant. I can only hope that my friendship and advice have been even the smallest bit as helpful to him as he has been to me during our long trek through academia. To the Cunniffes, thank you for all your support down this long road and truly making me feel like one of the family. Last but by no means least, I would like to thank my partner, Teagan Cunniffe, whose effortless grace, wit, humour, friendship and constant love have been the single greatest gifts I have ever received. I look forward to our adventures to come. Thank you for being there every step of the way and keeping me sane - This dissertation is dedicated to you. DA - 2021_ DB - OpenUCT DP - University of Cape Town KW - Clinical Science and Immunology LK - https://open.uct.ac.za PY - 2021 T1 - Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection TI - Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection UR - http://hdl.handle.net/11427/33815 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/33815 | |
| dc.identifier.vancouvercitation | Kieswetter NS. Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection. []. ,Faculty of Health Sciences ,Institute of Infectious Disease and Molecular Medicine, 2021 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/33815 | en_ZA |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Institute of Infectious Disease and Molecular Medicine | |
| dc.publisher.faculty | Faculty of Health Sciences | |
| dc.subject | Clinical Science and Immunology | |
| dc.title | Remodelling of Mycobacterial Peptidoglycan During Cell Division and the Epigenetics of Macrophages during M. tuberculosis infection | |
| dc.type | Doctoral Thesis | |
| dc.type.qualificationlevel | Doctoral | |
| dc.type.qualificationlevel | PhD |