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The ability of filarial parasites to persist in an immunological competent host, has led to the suggestion that they have evolved specific measures to counter immune defences. Filarial nematodes produce and secrete excretory-secretory (ES) products, some of which have been described to have a potential role in immune evasion. As part of these ES products, two homologues of the mammalian cytokine macrophage-migration inhibitory factor (MIF) have been described from the filarial nematode Brugia malayi, Bm-MIF-1 and Bm-MIF-2. Mammalian MIF is a widely distributed protein constitutively expressed in many immune and non-immune cell types. Although firstly characterised by its ability to stop migration of peritoneal macrophages, it has now been shown to play an important role during different inflammation processes. The main aim of this study is to elucidate the role of Brugia MIF homologues and their relation with the mammalian cytokine. This thesis studies the effect of both filarial and host MIF homologues on two major immune cell types, macrophages and dendritic cells (DC). We found that both Brugia and mouse-MIF synergise with IL-4 to activate macrophages to an alternative phenotype, by enhancing expression of IL-4-induced alternative activation markers Arginase-1, Ym-1 and the macrophage Mannose Receptor. MIF also synergises with IL-4 to render macrophages suppressive, an important outcome during filarial infection. Additionally we found that MIF homologues induce IL-4Ra expression, suggesting a mechanism by which MIF enhances IL-4 activation. We showed that filarial and mouse MIF homologues differ in their capacity to activate bone marrow-derived immature dendritic cells. Mouse-MIF up-regulates MHC-II and CD40 expression and induces pro-inflammatory cytokine production after overnight treatment. On the other hand Bm-MIF-2 induces low levels of cytokine production but does not up-regulate activation markers, and Bm-MIF-1 failed to activate DC. Furthermore, we demonstrate that filarial MIF homologues impair DC differentiation from bone marrow precursors. While bone marrow cells cultured in the presence of GM-CSF, with or without mouse-MIF, differentiate into CD11c+ DC, addition of Bm-MIF-2 to the culture media impairs differentiation arresting the cells in an undifferentiated phenotype characterised by the expression of myeloid and granulocyte markers CD11b and GR1. Finally, using an in vivo model where we implant Brugia malayi parasites in the peritoneal cavity of mice, we observed that host MIF does not play an essential role in the activation of macrophages by adult parasites as macrophages form MIF deficient mice present the same phenotype as their wild type counterparts.

In this thesis I examined the role of circulating monocytes and lung macrophages in the pathogenesis of the early fibrotic, progressive fibrotic and resolution phases of pulmonary fibrosis. Pulmonary fibrosis with destruction of lung architecture and consequent respiratory failure and death represents a massive worldwide health burden. Although idiopathic pulmonary fibrosis (IPF) is the archetypal and most common cause of lung fibrosis, numerous respiratory diseases can progress to pulmonary fibrosis, and this usually signifies a worse prognosis. Importantly, the incidence and prevalence of IPF continue to rise and it remains one of the few respiratory conditions for which there are no effective therapies. The mechanisms resulting in pulmonary fibrosis are controversial. Early work in the 1980s and 1990s suggested that lung macrophages were important. However, at the turn of the 21st century there was a shift to a belief that pulmonary fibrosis resulted from aberrant wound healing as a consequence of repetitive epithelial injury from an as yet unknown cause. However, with the ever expanding knowledge of the importance of macrophages in other fibrotic conditions such as the kidney and liver, the potential importance of macrophages in pulmonary fibrosis has become more pertinent. Using an in vivo depletional strategy in several murine models of lung fibrosis, in conjunction with human studies, I sought to characterise the role of circulating monocytes and lung macrophages in the pathogenesis of pulmonary fibrosis. I have established that circulating monocytes and lung macrophages are not critical for the development of early lung fibrosis. In contrast, circulating monocytes and lung macrophages are important during the progressive fibrotic phase of lung fibrosis. Furthermore, my data suggest that the pro-fibrotic alternatively activated macrophages may be the sub-class of macrophages that mediate this fibrogenic effect. In addition and in contrast, I have established that lung macrophages are required for the resolution of fibrosis. This finding is in keeping with important work performed in the field of liver fibrosis. There is an ever increasing literature examining the role of matrix metalloproteinases (MMPs) during tissue fibrosis and repair. My work has suggested that during lung fibrosis there may be compartmental specific functions of MMPs that regulate lung fibrogenesis, although more work is required before this exciting finding can be properly defined.

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Anatomical Sciences. / Due to paucity of free respiratory macrophages (FRMs), compared with mammals, birds have been alleged to be more susceptible to pulmonary infections and affliction. The goal of this study was to question or validate this speculation. Twenty-two mature healthy chickens, 24 domestic ducks and 20 rats were used in various experiments. After pulmonary lavage, FRMs were stained with trypan blue for cell count and with neutral red and trypan blue to assess cell longevity. The cell dynamics was determined by counts made on serial lavages. The morphological attributes of the FRMs and that of the respiratory “phagocytic epithelium” were quantified stereo logically. The rat had a significantly greater number of macrophages and the surface density of the filopodia of the FRMs was higher than that of the birds. The volume density of the vesicular bodies of the macrophages in the three groups of animals was not significantly different. Putative cell flux onto the respiratory surface was observed in the birds and not in the mammal. The surface area of the “phagocytic epithelium” of the birds was very extensive. Compared with mammals, in general, FRMs are fewer in birds. Despite this, the pulmonary defensive status in birds may not necessarily be compromised: functionally, avian FRMs appear to be more efficient. Moreover, their defense function is complimented particularly by the phagocytic activity of the epithelium immediate to the blood-gas barrier, the most vulnerable site of the lung-air sac system. / WHSLYP2017

by Chan Chun-wai, Francis. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 105-116). / Abstract --- p.I / Acknowledgments --- p.III / Abbreviations --- p.IV / Objectives --- p.VI / Content --- p.VII / Chapter Section 1 --- Introduction / Chapter I. --- Preamble --- p.1 / Chapter II. --- Characteristics of Cell Death Process --- p.1 / Chapter II.1. --- Necrosis --- p.1 / Chapter II.2. --- Apoptosis-Programmed Cell Death --- p.5 / Chapter III. --- Triggering of Programmed Cell Death --- p.10 / Chapter IV. --- DNA Fragmentation and Activation of Endogenous Endonuclease --- p.12 / Chapter V. --- Signal Transduction Leading to Programmed Cell Death --- p.14 / Chapter V.1. --- Role of Calcium Ion --- p.14 / Chapter V.2. --- Role of Protein Kinase C --- p.15 / Chapter V.3. --- Protein Dephosphorylation by Phosphatases --- p.16 / Chapter V.4. --- Role of Adenosine 3':5'-cyclic Monophosphate --- p.17 / Chapter V.5. --- Other Signaling Mechanisms --- p.17 / Chapter VI. --- Gene Regulation in Programmed Cell Death --- p.19 / Chapter VI. 1. --- Gene Expression in Programmed cell death --- p.19 / Chapter VI. 1.1 . --- Tissue Transglutaminase --- p.19 / Chapter VI. 1.2. --- Poly (ADP-ribose) Polymerase --- p.20 / Chapter VI. 1.3. --- Testosterone-Repressed Prostate Message-2 Gene --- p.20 / Chapter VI. 1.4. --- Other Programmed Cell Death Associated Gene Expressions --- p.21 / Chapter VI.2. --- Protooncogene Regulation in Programmed Cell Death --- p.22 / Chapter VI.2.1. --- bcl-2 Expression --- p.22 / Chapter VI.2.2. --- c-myc Expression --- p.23 / Chapter VII. --- Concanavalin A and succinylated Concanavalin A --- p.25 / Chapter VII. 1. --- Physiochemical Characterization --- p.25 / Chapter VII.2. --- Cellular Response to Concanavalin A --- p.29 / Chapter VIII. --- Features of Murine Macrophage Cell Line PU5-1.8 and Normal Macrophages --- p.32 / Chapter Section 2 --- Materials and Methods / Chapter I. --- Materials --- p.33 / Chapter II. --- Cell Culture --- p.33 / Chapter III. --- [Methyl-3H]-Thymidine Incorporation Assay --- p.34 / Chapter IV. --- [Methyl-3H]-Thymidine Release Assay --- p.34 / Chapter V. --- "3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT ) Cell Death Assay" --- p.35 / Chapter VI. --- Identification of Cell Death using DNA Chelating Fluorescence Probes´ؤFluorescent Microscopy and Confocal Laser Microscopy --- p.35 / Chapter VII. --- Analysis of DNA Fragmentation --- p.37 / Chapter VIII. --- Determination of Fluxes by Confocal Laser Microscopy --- p.38 / Chapter IX. --- Determination of PKC Activation by Western Blotting and Immunocytochemistry --- p.39 / Chapter X. --- Statistical Analysis --- p.41 / Chapter Section 3 --- Results / Chapter I. --- Concanavalin A was a Cell Death Causing Agent in PU5-1.8 cells --- p.42 / Chapter I.1 --- Con A Reduced the Cell Proliferation in PU5-1.8 cells --- p.42 / Chapter I.2. --- Con A Exhibited Cytotoxic Effect to PU5-1.8 cells --- p.44 / Chapter I.3. --- Con A Exhibited Cytotoxic Effect on Normal Peritoneal Macrophages --- p.46 / Chapter I.4. --- Succinylated Concanavalin A Showed a Weaker Cytotoxic Effect in the PU5-1.8 cells --- p.46 / Chapter I.5. --- α-D-Methylmannopyranoside Inhibited the Cytotoxic Effect of Con A in PU5-1.8 cells --- p.50 / Chapter I.6. --- FCS Inhibited the Con A-induced cell death of PU5-1.8 cells --- p.52 / Chapter II. --- Concanavalin A was an Apoptosis Causing Agentin PU5-1.8 cells --- p.57 / Chapter II. 1. --- Con A Induced Apoptosis in PU5-1.8 cells --- p.57 / Chapter II. 2. --- Con A Enhanced the Release of DNA in PU5-1.8 cell --- p.63 / Chapter II. 3. --- Con A Induced DNA fragmentation in PU5-1.8 cells --- p.63 / Chapter II.4. --- Cycloheximide Inhibited the Con A-Induced Cell Death in PU5-1.8 cells --- p.67 / Chapter II.5. --- Nicotinamide Inhibited the Con A-Induced Cell Death in PU5-1.8 cells --- p.71 / Chapter III. --- Signaling elicited by Concanavalin A --- p.74 / Chapter III.1. --- Con A Increased Intracellular Free Calcium Ion Concentration of PU5-1.8 cells --- p.74 / Chapter III. 1.1. --- Con A Induced Ca2+ Mobilization in PU5-1.8 cells --- p.74 / Chapter III. 1.2. --- Con A Induced the Ca2+ Influx and Intracellular Ca2+ Mobilization --- p.78 / Chapter III. 1.3. --- BAPTA-AM Inhibited the Ca2+ Mobilization in PU5-1.8 cells Stimulated by Con A --- p.80 / Chapter III.2. --- Role of Protein kinase C --- p.86 / Chapter III.2.1. --- Con A Increased the amount of PKC in PU5-1.8 cells --- p.86 / Chapter III.2.2. --- Con A translocated the Protein Kinase C from Cytosol into Subnuclear Region --- p.86 / Chapter III.2.3. --- The Cell Death Induced by Con A Is Partially Inhibited by PKC Depletion But not by Staurosporine --- p.89 / Chapter Section 4 --- Discussions / Chapter I. --- PU5-1.8 cells as a Model for the Study of Cell Deathin Macrophages --- p.94 / Chapter II. --- Concanavalin A caused Cell Death in PU5-1.8 cells --- p.95 / Chapter III. --- Concanavalin A induced Programmed Cell Death in PU5-1.8 cells --- p.97 / Chapter IV. --- Increase in Intracellular Calcium was not Required in Con A-induced Cell Death --- p.100 / Chapter V. --- Activation of Protein Kinase C was Partially Required for Con A-induced Cell Death --- p.101 / Chapter VI. --- General Discussions --- p.102 / Chapter Section 5 --- Bibliography --- p.104 / Reference --- p.104

by Tsui Kai Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1992. / Includes bibliographical references (leaves 100-112). / Abstract --- p.i / Acknowledgements --- p.iii / List of Abbreviations --- p.iv / Contents --- p.v / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter Chapter 2 --- The Effect of In Vivo Methimazole Treatment on the Functions of Macrophages --- p.10 / Introduction --- p.10 / Materials and Methods --- p.14 / Results --- p.27 / Discussion --- p.38 / Chapter Chapter 3 --- The Effect of In Vivo Methimazole Treatment on the Function of Lymphocytes --- p.41 / Introduction --- p.41 / Materials and Methods --- p.44 / Results --- p.50 / Discussion --- p.60 / Chapter Chapter 4 --- The Lack of Demonstrable Effect of In Vitro Methimazole Treatment on the Functions of Macrophages and Lymphocytes --- p.62 / Introduction --- p.62 / Materials and Methods --- p.63 / Results --- p.66 / Discussion --- p.74 / Chapter Chapter 5 --- Effect of Thyroid Hormone Replacement on the Immune Response of Methimazole-Treated Mice --- p.76 / Introduction --- p.76 / Materials and Methods --- p.78 / Results --- p.82 / Discussion --- p.91 / Chapter Chapter 6 --- General Discussion --- p.95 / References --- p.99

by Suen Yick-keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Bibliography: leaves 163-170. / Abstract --- p.i / Acknowledgements --- p.v / Abbreviations --- p.vi / Objective of the study --- p.vii / Contents --- p.viii / Chapter Section 1 --- Introduction / Chapter 1. --- Roles of macrophges in immune system --- p.3 / Chapter 2. --- Special features of macrophages --- p.6 / Chapter 3. --- Transmembrane signalling in mammalian cells --- p.9 / Chapter 4. --- Transmembrane signalling in macrophages --- p.32 / Chapter 5. --- Choice of the macrophages for the study --- p.40 / Chapter Section 2 --- Materials and Methods / Materials / Chapter 1. --- Animals --- p.44 / Chapter 2. --- Chemicals --- p.44 / Chapter 3. --- Reagents --- p.45 / Methods / Chapter 1. --- pell culture --- p.47 / Chapter 2. --- 3H-thymidine incorporation --- p.48 / Chapter 3. --- Cytosolic free calcium determination --- p.48 / Chapter 4. --- Intracellular pH mesurement --- p.50 / Chapter 5. --- Determination of membrane potential --- p.50 / Chapter 6. --- Determination of phagocytic activity --- p.51 / Chapter 7. --- Cell adhesion assay --- p.52 / Chapter 8. --- Statistical analysis --- p.52 / Chapter Section 3 --- Results / Chapter 1. --- Effect of membrane potential on cell proliferation in PU5-1.8 cells and bone marrow-derived macrophages / Evidence for induction of cell proliferation mediated by membrane depolarization in PU5-1.8 cells --- p.53 / Evidence of an array of agonists on cell proliferation and membrane potential in PU5-1.8 cells --- p.57 / Interrelationship between membrane potential and FCS-mediated proliferation in PU5-1.8 cells --- p.61 / Cytosolic alkalinization induces membrane depolarization in PU5-1.8 cells --- p.64 / Suppression of membrane depolarization and cell proliferation by protein kinase C activation --- p.66 / Effect of membrane potentials on cell proliferation in bone marrow-derived macrophages --- p.68 / Chapter 2. --- Intracellular signals for the regulation of phagocytosis in PU5-1.8 cells / Phagocytosis of unopsonized yeast in PU5-1.8 cells --- p.71 / Effect of membrane potential on phagocytosis in PU5-1.8 cells --- p.73 / Changes in phagocytic activities in PU5-1.8 cells by activation of protein kinase C --- p.82 / Effects of protein kinase C on membrane potential- induced enhancement of phagocytosis in PU5-1.8 cells --- p.84 / Phagocytosis in PU5-1.8 cells requires assembly of microtubule --- p.90 / Effects of intracellular calcium and cAMP on phagocytosis in PU5-1.8 cells --- p.93 / Acidic intracellular pH enhances phagocytosis in PU5-1.8 cells --- p.98 / Chapter 3. --- Effects of various agonists on phagocytosis of yeast in PU5-1.8 cells / Effect of chemotactic peptide N-formyl- methionyl-leucyl-phenylalanine (FMLP) on phagocytosis in PU5-1.8 cells --- p.100 / Effects of lipopolysaccharide (LPS) on phagocytosis in PU5-1.8 cells --- p.105 / Effects of concanavalin A (Con A) on phagocytosis in PU5-1.8 cells --- p.109 / Effect of complement components on phagocytosis in PU5-1.8 cells --- p.113 / Chapter 4. --- Signal pathways for the regulation of cell adhesion on plastic surface in PU5-1.8 cells / Adhesion of PU5-1.8 cells on plastic surface --- p.119 / Effects of membrane potential on cell adhesion on plastic surface in PU5-1.8 cells --- p.121 / Effects of activation of protein kinase C on cell adhesion on plastic surface in PU5-1.8 cells --- p.125 / Effects of intracellular calcium and cAMP on adhesion on plastic surface in PU5-1.8 cells --- p.129 / In vivo cell adhesion of PU5-1.8 cells in Balb/c mice --- p.133 / Chapter 5. --- Effects of various agonists on the cell adhesion on plastic surface in PU5-1.8 cells / Dose dependent of various agonists against the cell adhesion ability of PU5-1.8 cells --- p.141 / Chapter 6. --- Cell adhesion to plastic surface in bone marrow-derived macrophages / Membrane potentials control the adhesiveness of bone marrow-derived macrophages (BMDM0) to plastic surface --- p.143 / Effects of phorbol ester PMA on cell adhesion to plastic surface in bone marrow-derived macrophages --- p.143 / "Effects of cAMP, [Ca2+ ]i and microtubule assembly on cell adhesion to plastic surfacein bone marrow-derived macrophages" --- p.146 / Chapter Section 4 --- Discussion / Chapter 1. --- Effects of membrane potential on cell proliferation in PU5-1.8 cells and bone marrow-derived macrophages --- p.148 / Chapter 2. --- Intracellular signals for the regulation of phagocytosis in PU5-1.8 cells --- p.151 / Chapter 3. --- Signal pathways for the regulation of cell adhesion on plastic surface in PU5-1.8 cells and bone marrow-derived macrophages --- p.158 / Chapter 4. --- General discussion --- p.161 / Chapter Section 5. --- Bibliography / References --- p.163