The low affinity IgE receptor, CD23, is expressed by a wide variety of cells and cleaved from its original 45 kDa size to several smaller soluble CD23 proteins. Soluble CD23 function depends on the form of the protein and its interaction with various ligands. CD23 is believed to play an important role in regulating allergic responses and in inflammation, amongst others. β2 integrins are important in a variety of cell-adhesion reactions during immune-inflammatory mechanisms and the binding of their natural ligands generates outside-in cellular signalling, leading to cell activation. Although the binding of CD23 to β2 integrins contributes to this signalling in monocytes, the interaction site for CD23 is unknown. This study focused on the interaction of three soluble CD23 proteins with the β2 integrins CD11b/CD18 and CD11c/CD18. Differentiated HL60, THP1 and U937 monocytic cells were used to demonstrate the binding of three recombinant CD23 constructs (corresponding to 16, 25 and 33 kDa human soluble CD23) to upregulated CD11b/CD18 and CD11c/CD18. This binding was partially blocked by an antibody specific for the CD11b/CD18 αI domain, demonstrating that αI domains are involved in binding to CD23. Recombinant αI domain proteins of CD11b and CD11c were demonstrated to bind CD23 using ELISA and in surface plasmon resonance spectroscopy. The dissociation constants for CD23-CD11b/CD18 and CD23-CD11c/CD18 are comparable to other integrin ligands. This study has shown that CD23 interacts directly with the αI domains of β2 integrins and that the interaction surface likely spans the lectin domain as well as either the stalk and/or C-terminal tail of CD23. This study also looked at the effect that soluble CD23 proteins had on monocyte biology. It appears that iv sCD23 proteins have little effect on the phagocytic or chemotactic ability of monocytes, while an increase in oxidative burst was shown with the 16 kDa and 25 kDa CD23 proteins. Signalling pathways for the production of reactive oxygen species were investigated and it appears that the CD23 proteins signal mainly through the phosphoinositide-3 kinase pathway, although the mitogen activated protein kinase and Src kinase pathways may also play a role. These data suggest that sCD23 proteins induce outside-in signalling of β2 integrins and are able to change the activation state of CD11b/CD11c by stimulating oxidative burst. This needs to be further investigated by determining how the three sCD23 proteins are binding the CD11 proteins and investigating further leukocyte function and inflammatory responses by the cells.

Both CD23 and the β2 integrins (also known as CD11/CD18) have very important immunological functions, especially during the allergic response where the binding of CD23 to β2 integrins contributes to various types of signalling in monocytes which can result in drastic sensitivities experienced by some allergic individuals. CD23, also known as the low affinity receptor for immunoglobulin E or (FcεRII), is a type II transmembrane glycoprotein which is synthesized by haematopoietic cells and has biological activity in both membrane-bound and freely soluble forms. It acts via a number of receptors, including the β2 integrins. β2 integrins are specifically found on leukocytes and they play important roles in cell–cell or cell–matrix adhesion via their ability to bind multiple ligands. These molecules occur as heterodimers consisting of an alpha (α) and beta (β) subunit. The α-subunits of β2 integrins contain an approximately 200-amino-acid inserted domain or I-domain which is implicated in ligand binding function. There are four different types of β2 integrins, namely CD11a, CD11b, CD11c and CD11d, all dimers with the common beta subunit, CD18. CD23 and CD11/18 are natural ligands of each other; however the interaction site for CD23 is unknown. It is postulated that the integrin recognizes a tripeptide motif in a small disulfide-bonded loop at the N-terminus of the lectin head region of CD23, which is focussed around Arg172, Lys173 and Cys174 (RKC). This study thus focused on the interaction between the I-domain of CD11 (b and c) and a recombinant 25kDa construct of sCD23. In order to understand the characteristics of ligand binding between the relevant proteins of interest, alanine substitutions on the RKC motif of CD23 were made via site-directed mutagenesis. Consequently, a recombinant form of the I-domain of CD11 (b and c) as well as a wild type (containing the RKC motif) and mutant form (containing an AAC motif) of sCD23 were expressed and purified. The CD11 recombinant proteins were purified via affinity chromatography and the CD23 recombinant proteins via gel filtration chromatography. In addition, synthetic (CD23 derived) peptides, one containing the RKC sequence and the other the AAC sequence, were designed and custom synthesized. The synthetic peptides as well as the recombinant CD23 proteins were then analyzed for their interaction with the CD11 I-domain via ELISA. Subsequent ELISA analyses showed that the native sCD23 and the RKC peptide were able to bind to the integrin α I-domain whereas the mutant sCD23 and the corresponding synthetic AAC peptide failed to bind. This interaction was also analysed via flow cytometry using differentiated U937 cells, yielding similar results. ELISA analyses for the sCD23-CD11b I-domain interaction showed a Kd of 0.36 ± 0.14 μM whereas the RKC-CD11b I-domain interaction yielded a Kd of 1.75 ± 0.58 μM. Similarly, the sCD23-CD11c I-domain interaction yielded a Kd of 0.39 ± 0.09 μM and 1.53 ± 0.72 μM for the RKC-CD11c I-domain interaction. Peptide inhibitory analysis, analysed via ELISA and flow cytometry, reinforced the fact that the RKC motif on sCD23 is a prerequisite for ligand binding of the CD11b/c I-domain.

No description available.

Lee Ka Wai Sharon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 227-260). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.I / ABBREVIATIONS --- p.III / ABSTRACT --- p.VI / 摘要 --- p.XI / CONFERENCE PUBLICATIONS --- p.XVII / TABLE OF CONTENTS --- p.XVIII / Chapter Part I - --- General Introduction / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1. --- The Search of Immunomodulatory Agents --- p.1 / Chapter 1.2. --- Cordyceps sinensis (Dong Cong Xia Cao) as an Immunomodulatory Agent --- p.2 / Chapter 1.2.1. --- General Aspects --- p.2 / Chapter 1.2.2. --- Evidence from the Traditional Chinese Medicine Concepts --- p.2 / Chapter 1.2.3. --- Evidence from the Traditional Chinese Medicine Classics --- p.4 / Chapter 1.2.4. --- Evidence from the Modern Research Literature --- p.4 / Chapter 1.2.4.1. --- lmmunomodulation --- p.4 / Chapter 1.2.4.2. --- Anti-tumor Effects --- p.7 / Chapter 1.2.4.3. --- Other Activities Related to the Immune System --- p.8 / Chapter 1.2.4.4. --- Potential Active Ingredients: Cordycepin and Polysaccharides --- p.8 / Chapter 1.2.5. --- Prescription and Usage: Single Vs Concocted --- p.11 / Chapter 1.2.5.1. --- Single Form as an Immunoactivating Agent --- p.11 / Chapter 1.2.5.2. --- Concocted as an Anti-asthmatic Agent --- p.12 / Chapter 1.3. --- Our Hypothesis and Rationale --- p.13 / Chapter Chapter 2: --- Experimental Design --- p.24 / Chapter 2.1. --- General Aspects of the Human Immune System --- p.24 / Chapter 2.2. --- Designing the In vitro Study on Cell-mediated Immunity --- p.24 / Chapter 2.2.1. --- T Cells --- p.25 / Chapter 2.2.2. --- Macrophages --- p.26 / Chapter 2.3. --- Designing the In vitro and In vivo Study of Anti-tumor Activities --- p.29 / Chapter 2.3.1. --- Tumor Biology --- p.29 / Chapter 2.3.2. --- Tumor and Immunity --- p.29 / Chapter 2.3.2.1. --- T-Cell-Mediated Cytolysis (Tc Cells) --- p.30 / Chapter 2.3.2.2. --- Delayed-Type Hypersensitivity (TDth Cells) --- p.30 / Chapter 2.3.2.3. --- Natural Killer (NK) Cells --- p.30 / Chapter 2.3.2.4. --- Lymphokine-Activated Killer (LAK) Cells --- p.31 / Chapter 2.3.2.5. --- Antibody-Dependent Cell-Mediated Cytotoxic (ADCC) Cells --- p.31 / Chapter 2.3.2.6. --- Activated Macrophages (AMΦ) --- p.31 / Chapter 2.3.3. --- Mechanism of Tumor Engulfment --- p.32 / Chapter 2.3.4. --- The Experimental Plan --- p.33 / Chapter 2.4. --- Designing the In vitro Study and Clinical Trials on Anti-asthmatic Activities --- p.36 / Chapter Part II - --- Methodology / Chapter Chapter 3: --- Materials and Methods / Chapter 3.1. --- List of Materials and Their Origin --- p.39 / Chapter 3.1.1. --- Traditional Chinese Medicine --- p.39 / Chapter 3.1.2. --- Cells for In vitro Experiments --- p.39 / Chapter 3.1.3. --- Mice for In vivo Experiments --- p.40 / Chapter 3.1.4. --- "Medium, Buffer, Supplements and Reagents for Cell Culture" --- p.40 / Chapter 3.1.5. --- Dye for Cellular Staining --- p.40 / Chapter 3.1.6. --- Cell Mitogens and Activator --- p.41 / Chapter 3.1.7. --- Reagents for Flow Cytometric Analysis --- p.41 / Chapter 3.1.8. --- Reagent Kits --- p.41 / Chapter 3.1.9. --- ELISA Kits --- p.42 / Chapter 3.1.10. --- Antibodies --- p.43 / Chapter 3.1.11. --- Reagents for RNA Extraction --- p.44 / Chapter 3.1.12. --- Reagents for Gel Electrophoresis --- p.44 / Chapter 3.1.13. --- Reagents for cDNA Expression Array --- p.44 / Chapter 3.1.14. --- Other Reagents --- p.45 / Chapter 3.1.15. --- Special Equipment and Apparatus --- p.45 / Chapter 3.2. --- Details of Materials --- p.46 / Chapter 3.2.1. --- Traditional Chinese Medicine --- p.46 / Chapter 3.2.1.1. --- Natural Cordyceps sinensis --- p.46 / Chapter 3.2.1.2. --- HERBSnSENSEŚёØ Cordyceps --- p.46 / Chapter 3.2.1.3. --- Wheeze-Relief Formula --- p.46 / Chapter 3.2.2. --- "Media, Supplements and Reagents for Cell Culture" --- p.47 / Chapter 3.2.2.1. --- Cell Culture Media --- p.47 / Chapter 3.2.2.2. --- Serum Supplements --- p.47 / Chapter 3.2.2.3. --- Anti-CD16 Magnetic Microbeads --- p.47 / Chapter 3.2.2.4. --- Fico´HёØ-Paque Plus Solution --- p.47 / Chapter 3.2.2.5. --- PercolĺёØ Solution --- p.48 / Chapter 3.2.2.6. --- Phosphate Buffered Saline (PBS) --- p.48 / Chapter 3.2.2.7. --- Water --- p.48 / Chapter 3.2.3. --- Dye for Cellular Staining --- p.48 / Chapter 3.2.3.1. --- HemacoloŕёØ for Microscopy --- p.48 / Chapter 3.2.3.2. --- Trypan Blue Dye --- p.49 / Chapter 3.2.4. --- Reagents for Flow Cytometry --- p.49 / Chapter 3.2.4.1. --- FACS Flow Sheath Fluid --- p.49 / Chapter 3.2.4.2. --- FACS Wash Medium --- p.49 / Chapter 3.2.4.3. --- Paraformaldehyde --- p.49 / Chapter 3.2.5. --- Special Equipments and Apparatus --- p.49 / Chapter 3.2.5.1. --- Magnetic Cell Sorting System (MACS) --- p.49 / Chapter 3.3. --- Human Subjects --- p.51 / Chapter 3.3.1. --- Inclusion Criteria --- p.51 / Chapter 3.3.2. --- Exclusion Crtieria --- p.51 / Chapter 3.3.3. --- Medication --- p.52 / Chapter 3.3.4. --- Informed Consent and Patient Information --- p.52 / Chapter 3.4. --- Animals --- p.53 / Chapter 3.4.1. --- Maintenance --- p.53 / Chapter 3.4.2. --- Survival Experiment Using Erhlich Ascites Tumor Bearing ICR Mice --- p.53 / Chapter 3.4.3. --- Experiments of Immunomodulatory activity in Sarcoma 180 Bearing BALB/c Mice --- p.54 / Chapter 3.5. --- Methodology --- p.55 / Chapter 3.5.1. --- Preparation of the Traditional Chinese Medicine --- p.55 / Chapter 3.5.1.1. --- Hot Water Extraction of Water Soluble Fraction of Natural Cordyceps sinensis --- p.55 / Chapter 3.5.1.2. --- Hot Water Extraction of Water Soluble Fraction of HERBSnSENSEŚёØ Corydceps and the Wheeze-relief Formula for In vitro Experiments --- p.55 / Chapter 3.5.1.3. --- HERBSnSENSEŚёØ Corydceps for the In Vivo Experiments --- p.56 / Chapter 3.5.1.4. --- Extraction Efficiency of the Hot Water Extracts --- p.56 / Chapter 3.5.2. --- Limulus Ameobocyte Lysate Test --- p.56 / Chapter 3.5.3. --- Cell Preparation --- p.57 / Chapter 3.5.3.1. --- "Isolation of Human Peripheral Blood Mononuclear Cells, Lymphocytes and Monocytes" --- p.57 / Chapter 3.5.3.2. --- Isolation of Eosinophils --- p.58 / Chapter 3.5.3.3. --- Isolation of Spleen Cells from BALB/c Mice --- p.58 / Chapter 3.5.3.4. --- "Murine Ehrlich Ascites Tumor (EAT), PU5-18, and Sarcoma 180 (SC-180) Cell Lines" --- p.59 / Chapter 3.5.3.5. --- Human Eosinophilic Leukemic Cell Line (EoL-1) --- p.59 / Chapter 3.5.3.6. --- Human Hepatocarcinoma Hep-3B Cell Line --- p.59 / Chapter 3.5.3.7. --- Human Leukemic Cell Line (HL-60) --- p.59 / Chapter 3.5.3.8. --- Human Mast Cell Line (HMC-1) --- p.60 / Chapter 3.5.4. --- Collection of Mouse Serum and Human Plasma --- p.60 / Chapter 3.5.5. --- Collection of Culture Supernatant --- p.60 / Chapter 3.5.6. --- The Trypan Blue Exclusion Assay --- p.61 / Chapter 3.5.7. --- Colorimetric 5-bromo-2'-deoxyuridine (BrdU) Cell Proliferation Enzyme Linked Immunosorbent Assay (ELISA) --- p.61 / Chapter 3.5.8. --- Immunophenotyping --- p.62 / Chapter 3.5.9. --- The Cytometric Bead Array (CBA) Kits --- p.62 / Chapter 3.5.10. --- Intracellular Florescence Staining for Reactive Oxygen Species --- p.63 / Chapter 3.5.11. --- The Intracellular Zymosan Florescence Assay --- p.64 / Chapter 3.5.12. --- Total Cellular RNA Extraction --- p.64 / Chapter 3.5.13. --- Gel Electrophoresis of RNA Integrity --- p.65 / Chapter 3.5.14. --- cDNA Expression Array --- p.65 / Chapter 3.5.15. --- Cell Staining Using Cytospin --- p.66 / Chapter 3.5.16. --- Annexin V-FITC/Propidium Iodide Apoptosis Detection --- p.66 / Chapter 3.5.17. --- Weighing the Spleen and Tumor --- p.67 / Chapter 3.5.18. --- Preparing Samples for the Eosinophilic Cationic Protein Fluoroenzymeimmunoassay --- p.67 / Chapter 3.5.19. --- Statistical Analysis --- p.67 / Chapter Part III - --- Results: Pre-functional Assays / Chapter Chapter 4: --- "Extraction, Endotoxin Measurement, In vitro Cytotoxicity Testing, and the Selection of Optimal Concentration" / Chapter 4.1. --- Extraction efficiency --- p.68 / Chapter 4.1.1. --- Introduction --- p.68 / Chapter 4.1.2. --- Results --- p.68 / Chapter 4.2. --- Endotoxin Level --- p.69 / Chapter 4.2.1. --- Introduction --- p.69 / Chapter 4.2.2. --- Results and Interpretation --- p.69 / Chapter 4.3. --- Cytotoxicity --- p.70 / Chapter 4.3.1. --- Introduction --- p.70 / Chapter 4.3.2. --- Results and Interpretation --- p.71 / Chapter 4.3.2.1. --- Peripheral Blood Mononuclear Cells (PBMC) --- p.71 / Chapter 4.3.2.2. --- Eosinophils --- p.72 / Chapter 4.4. --- The Optimal Concentration (OC) --- p.76 / Chapter 4.4.1. --- Introduction --- p.76 / Chapter 4.4.2. --- Results and Interpretation --- p.76 / Chapter Part IV- --- Results: Immunomodulatory Activities of Cordyceps sinensis as a Single Herb / Chapter Chapter 5: --- Mitogenic Activity --- p.80 / Chapter 5.1. --- Introduction --- p.80 / Chapter 5.2. --- Results --- p.80 / Chapter 5.3. --- Discussion --- p.81 / Chapter Chapter 6: --- Cytokines and Cytokine Receptors --- p.84 / Chapter 6.1. --- Introduction --- p.84 / Chapter 6.2. --- Results --- p.84 / Chapter 6.2.1. --- Effects of Natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on the Induction of Cytokines from Lymphocytes --- p.84 / Chapter 6.2.1.1. --- TNFa --- p.84 / Chapter 6.2.1.2. --- IL-6 --- p.85 / Chapter 6.2.1.3. --- IL-10 --- p.85 / Chapter 6.2.2. --- Effects of Natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on the Induction of Cytokines from Monocytes --- p.92 / Chapter 6.2.2.1. --- IL-1β --- p.92 / Chapter 6.2.2.2. --- IL-6 --- p.92 / Chapter 6.2.2.3. --- IL-10 --- p.97 / Chapter 6.2.2.4. --- TNFα --- p.97 / Chapter 6.2.3. --- Effects of Natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on the Expression of Cytokine Receptor --- p.102 / Chapter 6.2.4. --- Effects of Natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on the Gene Expression of Cytokines and Cytokine Receptors in Peripheral Blood Mononuclear Cells --- p.105 / Chapter 6.3. --- Discussion --- p.112 / Chapter Chapter 7: --- Macrophage Functions: Phagocytosis and Release of Reactive Oxygen Species (ROS) --- p.116 / Chapter 7.1 --- Introduction --- p.116 / Chapter 7.2. --- Results --- p.117 / Chapter 7.2.1. --- Phagocytosis --- p.117 / Chapter 7.2.2. --- Release of Reactive Oxygen Species (ROS) --- p.117 / Chapter 7.3. --- Discussion --- p.124 / Chapter Chapter 8: --- Apoptosis of Selected Cancer Cell Lines --- p.126 / Chapter 8.1. --- Introduction --- p.126 / Chapter 8.2. --- Results --- p.127 / Chapter 8.2.1. --- Differential Cytotoxic Effects of natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on Various Cancer Cell Lines In vitro --- p.127 / Chapter 8.2.2. --- Differential Anti-Proliferative Effects of natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on Various Cancer Cell Lines In vitro --- p.129 / Chapter 8.2.3. --- Differential Apoptotic Effects of Natural Cordyceps sinensis and HERBSnSENSEŚёØ Cordyceps on Various Cancer Cell Lines In vitro --- p.131 / Chapter 8.2.3.1. --- Peripheral Blood Mononuclear Cells --- p.131 / Chapter 8.2.3.2. --- Hepatocarcinoma Hep-3B --- p.131 / Chapter 8.2.3.3. --- Human Eosinophilic Leukemic Cell Line --- p.134 / Chapter 8.2.3.4. --- Human Mast Cell Line --- p.134 / Chapter 8.2.3.5. --- Human Leukemic Cell Line (HL-60) --- p.138 / Chapter 8.2.3.6. --- Murine Macrophages/Monocytes Cell Line PU5-18 --- p.138 / Chapter 8.2.3.7. --- Murine Erhlich Ascites Tumor (EAT) --- p.142 / Chapter 8.2.3.8. --- Murine Sarcoma 180 (SC-180) --- p.142 / Chapter 8.3. --- Discussion --- p.145 / Chapter Part V- --- Results: Immunomodulatory Activities of Cordyceps sinensis in Concoction / Chapter Chapter 9: --- The In vivo Animal Model --- p.147 / Chapter 9.1. --- introduction --- p.147 / Chapter 9.2. --- Results --- p.148 / Chapter 9.2.1. --- The ICR Mice Model --- p.148 / Chapter 9.2.1.1. --- In vivo Effects of Natural C. sinensis and HERBSnSENSEŚёØ Cordyceps on the Ascitic Fluid Production of ICR Mice --- p.148 / Chapter 9.2.1.2. --- Effects of Natural C. sinensis and HERBSnSENSEŚёØ Cordyceps on the Survival of Tumor-bearing ICR Mice --- p.149 / Chapter 9.3. --- The BALB/c Mice Model --- p.153 / Chapter 9.3.1. --- In vivo Effects of HERBSnSENSEŚёØ Cordyceps on Spleen and Tumor Weight --- p.153 / Chapter 9.3.2. --- Effects of HERBSnSENSEŚёØ Cordyceps on the Mitogenic Activities of Spleen Cells --- p.154 / Chapter 9.3.3. --- "In vivo Effects of HERBSnSENSEŚёØ Cordyceps on the Cell Surface Expression of CD3, CD4, and CD8" --- p.157 / Chapter 9.3.4. --- Effects of HERBSnSENSEŚёØ Cordyceps on the Cytokine Release from Cultured Spleen Cells --- p.161 / Chapter 9.3.4.1. --- TNFα --- p.161 / Chapter 9.3.4.2. --- IFNγ --- p.163 / Chapter 9.3.4.3. --- IL-2 --- p.163 / Chapter 9.3.4.4. --- IL-4 --- p.163 / Chapter 9.3.4.5. --- IL-6 --- p.167 / Chapter 9.3.4.6. --- IL-10 --- p.167 / Chapter 9.3.4.7. --- IL-12p70 --- p.167 / Chapter 9.3.4.8. --- Monocyte Chemoattractant Protein(MCP)-1 --- p.167 / Chapter 9.3.5. --- In vivo Effects of HERBSnSENSEŚёØ Cordyceps on the Cytokine Synthesis --- p.172 / Chapter 9.4. --- Discussion --- p.174 / Chapter Chapter 10: --- In vitro Studies on Eosinophils and Peripheral Blood Mononuclear Cells --- p.178 / Chapter 10.1. --- Introduction --- p.178 / Chapter 10.2. --- Results --- p.180 / Chapter 10.2.1. --- In vitro Effects of Wheeze-Relief Formula on the Survival of IL-5 Enhanced Eosinophils --- p.180 / Chapter 10.2.2. --- In vitro Effects of Wheeze-Relief Formula on the Degranulation of Eosinophils --- p.180 / Chapter 10.2.3. --- In vitro Effects of Wheeze-Relief Formula on the Surface Expression of Adhesion Molecules and Chemokine Receptors on Eosinophils --- p.183 / Chapter 10.2.4. --- In vitro Effects of Wheeze-Relief Formula on the Surface Expression of Adhesion Molecules on Eosinophils --- p.183 / Chapter 10.2.5. --- In vitro Effects of Wheeze-Relief Formula on the Cytokine Release from Peripheral Blood Mononuclear Cells --- p.187 / Chapter 10.2.6. --- In vitro Effects of Wheeze-Relief Formula on the Gene Expression Profile of Cytokines and Cytokine Receptors of Peripheral Blood Mononuclear Cells --- p.187 / Chapter 10.3. --- Discussion --- p.196 / Chapter Chapter 11: --- The Clinical Trial: Analysis of Serological Markers --- p.200 / Chapter 11.1. --- Introduction --- p.200 / Chapter 11.2. --- Results --- p.202 / Chapter 11.2.1. --- Demographic Data and Drop-out Cases --- p.202 / Chapter 11.2.2. --- Lung Function Test --- p.202 / Chapter 11.2.3. --- Steroid Dosage --- p.202 / Chapter 11.2.4. --- Serological Markers --- p.205 / Chapter 11.3. --- Discussion --- p.215 / Chapter Part VI - --- Conclusion / Chapter Chapter 12: --- Concluding Remarks and Future Perspectives --- p.217 / Chapter Part VII- --- Appendix / Parent Information Sheet --- p.222 / 家長資訊 --- p.223 / Consent Form --- p.224 / Licence to Conduct Animal Experiments --- p.225 / Bibliography --- p.227

The immune systems of various teleost fish have been studied in some detail for the past several decades. One aspect of fish immunity, that of endogenously produced modulating factors, has recently received a great deal of attention. Understanding the functions and roles of endogenous factors that regulate fish immunity is paramount to expanding the fields of fish immunology and vaccinology. It is know that several lymphoid cell derived factors are detectable in in vitro cell culture systems and exhibit immune modulating effects similar to well studied proteins in mammals. However in comparison, few genes or gene products involved in the modulation of the trout immune responses have been isolated, cloned and characterized. The studies described herein were designed to isolate specific genes from rainbow trout (0ncorhynchus mykiss) and characterize their involvement in the modulation and regulation of the trout immune system. Two distinct genes were isolated cloned and sequenced. The first, non-specific cytotoxic cell enhancement factor (NCEF) gene is closely related to a human gene termed "natural killer enhancement factor" (NKEF) which is important in the modulation of human natural killer cell activity. The second gene is closely related to a group of recently characterized mammalian genes involved in the signal transduction of cytokines termed "STATs". The role of these genes and their respective protein products will be examined and discussed. The antigenic structures of the fish proteins (NCEF and STAT5) were examined by western blot and immunohistochemistry. Monoclonal antibodies derived against the respective human proteins were found to cross react with the corresponding trout proteins, demonstrating antigenic relatedness. The monoclonal regents were also used to analyze the expression of these proteins in fish cells of lymphoid and non lymphoid origin. In vitro cell culture analysis was used to determine the effects and roles of NCEF and STAT5 gene products in the trout immune system. The cytolytic and apoptotic killing activities of spleen, head kidney and peripheral blood leukocytes were found to be enhanced by NCEF. Mitogenic stimulation of peripheral blood lymphoid cells resulted in the trout STAT5 protein binding to a know sequences contained with in the promoters of genes transcriptionally activated in response to cytokine exposure. / Graduation date: 1996

No description available.

Prophylactic administration of the immunosuppressive drug cyclosporine A protects Balb/c mice from fatal Leishmania major infections. It is believed that distinct subpopulations of CD4+ T lymphocytes and their distinctive cytokines may determine susceptibility and resistance to leishmaniasis among inbred strains of mice. CsA may enhance disease resistance in Balb/c mice by modulating these T cell subsets and/or their cytokines. We have measured lymphoid cell production of IL-2, IL-4, and TNF-a in naturally resistant C57/Bl/6, CsA-treated Balb/c, and nontreated Balb/c mice during the course of L. major infection. CsA treatment inhibited IL-2 and IL-4 production for the first week of infection. Thereafter the cytokine production of all three groups of mice did not differ greatly except in week two when the treated mice produced significantly enhanced levels of IL-4. C57B1/6 mice did produce slightly more TNF-a than either group of Balb/c mice, but as the CsAprotected and diseased Balb/c mice produced similar amounts of this cytokine, the elevation in C57B1/6 animals probably reflects a strain-related difference rather than disease resistance. / Department of Biology

If used early in infection, prophylactic treatment with the immunomodulatory drug cyclosporin A of Leishmania ma'or infected Balb/c mice has been shown to enhance resistance of these mice to serious disease. It is thought that CsA treatment affects disease progression by altering the balance of specific T lymphocyte populations as well as the secretion of various cytokines. We have followed the levels of L3T4+ T cells, Ly-2+ T cells, and total T and B lymphocytes, as well as IL-4 in susceptible Balb/c mice, CsA-treated Balb/c mice, and naturally resistant C57B1/6 mice during the course of L. ma'or infection. The CsA-treated mice displayed a disease pattern similar to that of the C57B1/6 group throughout infection. Most importantly, CsA treatment appeared to inhibit IL-4 production early post infection in both spleen and lymph node, and also appeared to inhibit the dramatic early increase of L3T4+ (CD4+) T cells which is characteristic of the susceptible Balb/c mice. / Department of Biology

In order to further elucidate the interaction between CD23 and β2 integrins (CD11b/CD18) the following objectives were established: Expression and purification of CD11b I-domain as a GST-fusion protein using Escherichia coli; Cloning, synthesis and expression of CD18 I-Like domain.CD11b I-domain has previously been expressed as a GST-fusion protein (Daniels, 2010) and consequently led to comparable expression of CD18 I-like domain as a GST-fusion protein; Preparation of two site-directed mutants of CD18 I-Like domain in order to study the function of the serine residue involved in the S116P mutation. The serine was mutated to proline, as in LAD patients, as well as alanine, a non-polar alternative, in order to contrast and compare binding characteristics.  Expression, refolding and purification of sCD23, and a double mutatedsCD23 (RKΔAA) from E. coli; This was performed according to the method described by Daniels et al. (2005); Investigation of the CD23-CD11b I-like domain interaction through surface plasmon resonance spectroscopy.

Earlier studies have demonstrated that nitrosoureas such as 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) and chlorozotocin (CLZ) can cure almost 100% of C57BL/6 mice bearing syngeneic LSA tumor. In contrast, similiar or higher doses of streptozotocin (STZ) completely failed to cure LSA-bearing mice. Further studies revealed that the efficacy of nitrosoureas may depend on their immunomodulating properties. In the current study, therefore, attempts were made to investigate the effects of these nitrosoureas on the immune system of normal and LSA tumor-bearing mice. Treatment of normal C57BL/6 mice with 5 intraperitoneal injections of 20 mg/kg body weight of BCNU or CLZ caused an increase in the percentage of CD4⁻ CD8⁻ T cells and a decrease in the percentage of CD4⁺CD8⁺ T cells in the thymus. In addition, such treatment also caused an increase in the percentage of CD4⁺ T cells without significantly affecting the CD8⁺ T cells in the thymus. However, when total cellularity of the thymus was studied, BCNU and CLZ were found to decrease the total number of CD4⁺CD8⁺ T cells without significantly affecting the other subsets. In contrast, similiar or higher (100mg/kg body weight) doses of STZ had no significant effect on the total number and percentages of T ceil subsets in the thymus. Also, BCNU and CLZ but not STZ-treatment caused a 50% decrease in the total number of CD4⁺ and CD8⁺ T cells in the spleen. Interestingly in tumor-bearing mice, BCNU treatment was followed by a ten-fold increase in the percentage of CD4⁺ T cells found in the peritoneal cavity. The percentages of CD8⁺ cells increased also, but to a lesser degree. These changes were limited to the peritoneal cavity which is the site of tumor growth. When T cells in the spleens of nitrosourea-treated normal mice were functionally analyzed, it was observed that BCNU and CLZ caused a dramatic decrease in the T cell responsiveness to Con A, anti-CD3, and PMA + calcium ionophore stimulation. In contrast, STZ treatment failed to significantly inhibit the T cell responsiveness to these activation signals. Using the accessory cell-dependent and independent assays, BCNU and CLZ were found to suppress the functions of both T cells and macrophages in normal mice. BCNU and CLZ also suppressed the B cell responsiveness to lipopolysaccharide (LPS). Also, addition of growth factors such as IL-1, IL-2, IL-4 and IL-6 failed to reconstitute the defective responsiveness of BCNU and CLZ-treated T cells and macrophages. Together these data suggest that nitrosoureas have varying immunomodulating properties and this may in turn determine their efficacy in the treatment of cancer. / Master of Science