The Effect of Lipids from Mycobacterium Bovis on Bovine
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The Effects of Lipids from Mycobacterium bovis on Bovine Innate and Acquired Immune Responses By Christopher Pirson A thesis submitted to the University of Birmingham for the Degree of Doctor of Philosophy Bovine Tuberculosis Research Team Animal Health & Veterinary Laboratories Agency & School of Biosciences University of Birmingham September 2014 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Declaration The work presented in this thesis was carried out in the Bovine TB Research Team at the Animal Health and Veterinary Laboratories Agency KT15 3NB, during the period September 2009 to September 2014. The work in this thesis is original except where acknowledged by references. No portion of the work is being, or has been submitted for a degree, diploma or any other qualification at any other University. ii Published Work Declaration This thesis contains work which has been accepted to and / or published in peer - reviewed journals. Any publications arising from the work presented in this thesis were written and prepared by Christopher Pirson who is listed as the publications primary author and the contributions of other authors to the text in this thesis are not substantial. Thesis content which is similar to that contained in associated peer - reviewed publications is listed below: Pirson et al., (2012) “Differential effects of Mycobacterium bovis - derived polar and apolar lipid fractions on bovine innate immune cells” Veterinary Research 43:54 • Chapter One: pages 6, 10 and 31 • Chapter Two sections: o Preparation of Bacterial Isolates for Lipid Extraction o Extraction of Crude Free Mycobacterial Lipids o Analysis of Lipid Fractions by 2D Thin Layer Chromatography o Preparation of Lipid Antigen Suspensions o Uninfected Cattle o Isolation of Bovine PBMC from Whole Blood + o Isolation of CD14 Monocytes from Bovine PBMC o Generation of Bovine Cultured Monocytes and MDDC o Multiplex Measurement of Cytokine Production o Innate Cell Labelling & Analysis by Flow Cytometry o Mixed Lymphocyte Reaction • Chapter Three, Discussion: page 70 • Chapter Four sections: o Results o Discussion iii Pirson et al., (2015) “Highly purified mycobacterial phosphatidylinositol mannosides drive cell mediated responses and activate NKT cells in cattle” Clinical and Vaccine Immunology 22:2 • Chapter Two sections: o Preparation of Lipid Antigen Suspensions o M. bovis Infected Cattle o Isolation of Bovine PBMC from Whole Blood TM o Measurement of IFNγ by Bovigam ELISA o Lymphocyte Transformation Assay o Lymphocyte Labelling & Analysis by Flow Cytometry • Chapter Six: pages 130, 131 and 137 - 138 Signed: C. Pirson H. M. Vordermeier iv Abstract The interaction between the host and the pathogen is critical in defining the outcome of an infection. For cattle with bovine tuberculosis (BTB), this interaction is likely to occur between antigen presenting cells in the lung and the lipid rich surface of the causative agent Mycobacterium bovis (M. bovis). It is well documented that lipid molecules from mycobacteria are capable of modulating immune responses however previous work has made use of model animal systems or lipids from avirulent bacteria. The aim of this study was to extract lipids from virulent M. bovis and assess any immunomodulatory ability of these molecules in cattle with a view to aiding in the development of control measures for BTB. To this end, lipids were extracted from M. bovis AF 2122/97 and AN5 and the fractions characterised. Upon thin layer chromatography analysis, polar and apolar fractions from both bacterial strains were found to be broadly similar in their lipid constitution although quantitative differences were noted. Lipopeptide was also identified in both polar fractions. Stimulation of bovine antigen presenting cells with the lipid fractions showed polar lipids mediated increases in IL - 10 and IL - 12 production and reductions in cell surface expression of MHCII and CD1b. Further investigation of the polar lipid fraction was performed by subfractionation but no individual lipid could be found responsible for the responses of antigen presenting cells to these subfractions. The ability of the polar and apolar lipid fractions to be recognised by cells of the adaptive immune system was assessed and the polar fraction was found to drive production of IFNγ and strong proliferation of bovine lymphocytes. The role of lipopeptide in the polar fraction was evaluated by enzymatic degradation with Proteinase K and blockade of either MHCII or CD1. While lipopeptide was found to play a role in the generation of lymphocyte responses, these treatments did not abrogate the effects completely suggesting a lipid mediated component as well. Screening of highly purified individual lipid molecules led to the selection of one molecule (AcPIM6), which was found to be capable of driving antigen specific proliferation of NKT cells. v Dedication For the cows… vi Acknowledgements First and foremost, I would like to thank my supervisor at AHVLA, Prof Martin Vordermeier. Martin provided me with both the inspiration and the self - belief that enabled me to undertake this PhD and without his constant support I would not be where I am today. Rarely will you meet a man of such wisdom and international repute who gives their time and knowledge so freely. I also want to recognise the indefatigable encouragement from Dr Gareth Jones, who may not have signed up to supervise a PhD but took on the responsibility with good grace and humour. His scientific knowledge, rigour and attention to detail are aspirational and he helped hammer both the experiments and this thesis into shape. I must also thank Prof Del Besra and his staff at the University, particularly Dr Sid Gurcha who provided much support during my time in Birmingham and without whom the completion of this project would not have been possible. I would also like to express my gratitude to my professional collaborators; particularly Prof Otto Holst from the Research Centre Borstel for supplying both reagents and good advice in equal measure, and Dr Arun Mishra (who I met in Birmingham but is now at NIMR) who provided me with many of his methods for lipid purification. I would be remiss if I didn’t thank Dr Max Bastian who lent his technical assistance and his expertise as well as the methods for Proteinase K digestion of the lipid fractions. My thanks also go to Prof Mark Chambers and the former Tuberculin Production Unit at AHVLA Weybridge for the pellicle of AN5 which enabled this much of the work in this project. vii I am indebted to my colleagues, past and present, at AHVLA Weybridge for their support and (occasionally unenthusiastic) help. To Adam, Bernardo, Phil, Tom, Laura, Ilaria, Gareth, Carmen, Jim, Shelley, Gilly, Stefan, Paul W, Mick, Roland, Paul A, Sonya, Daryan, Emma, Peter, Karen, Krista, Richard, Elihu, Holly, Margot and Penny I offer my heartfelt thanks. Much has happened in the past few years and I wouldn’t have made it through without their friendship, support and (mostly) friendly abuse. A special thanks is reserved for Dr Paul Wheeler whose peace and quiet I shattered by moving into his lab to perform my lipid analysis work and whose brain I picked on a regular basis. Over the past few years I have garnered much support via Twitter. The #PhDchat hashtag has proven a valuable resource and several users have provided me with advice, support and silly things to laugh at. @LunaLevitt, @PayalYokota, @curexcomplex, @jamimmunology, @psyoureanidiot, @_MaddieHoward, @CS_Diamond, @Carly0308 and @Gemgemloulou have all been more helpful than they probably realise. It really only remains for me to thank my future wife Julia and my family; their support and belief has meant a great deal to me and I hope to return the favour one day. viii Table of Contents Declaration ......................................................................................................................................... ii Published Work Declaration .............................................................................................................. iii Abstract .............................................................................................................................................. v Dedication ......................................................................................................................................... vi Acknowledgements .......................................................................................................................... vii Table of Contents .............................................................................................................................. ix List of Figures ................................................................................................................................... xii List of Tables ..................................................................................................................................... xv Publications Associated