Studies were performed on two types of infection of teleost fish where viruses have been observed by electron microscopy: erythrocytic infections in the Atlantic Cod (Gadus morhua) and the Common Blenny (Blennius hpo lis) and lymphcystis disease., Searches were made for new, isolations of these infections Ja British coastal waters and on shores chiefly in the vicinity of Plymouth and Aberystwyth. In the absence of disease symptoms, the blood of fish was, screened for the presence of viral inclusion bodies by standard haematological methods. PEN in cod was found in the North Sea-. and in the Celtic Sea off southern Eire, thus extending the previous distribution data from the Atlantic-coastal waters. of North America. The blenny infection was also found in new sites on shores in the vicinity of Plymouth. Moreover, the cytology of these infectionswas as had been previously described. Collection data for the PEN infections showed an inverses; - relationship of infection incidence-with age for cod sample populations but no correlation was found for blenny sample populations. In addition, no external disease symptoms were observed in either type of infection. Concerning the recognition of the blenny infection, observations from maintaining blennies suggested the length of the natural infection might be inversely related to temperature; non-experimental longevities are quoted in this connection. The degree of infection in individual fish was estimated by light microscopy and the estimates for both erythrocytic infections cover the range 1-60% infection. Attempts were made to propagate the viruses in vitro using fish cell and organ cultures. Primary cell cultures were originated from tissues of the Blenny, Flounder, Plaice and Dab using the protocol in the literature for marine fish cell culture. Vigorous cell outgrowth was observed in the flounder cultures and in these the time to confluence was only 3-5 days. However, established secondary cultures could not be derived from tissues of either species. Plaice and dab cultures were used for virus inoculation but the virus from the blenny infection and lymphocystis virus could not be propagated. , Organ cultures were set up using skin blocks from the Flounder. With tris-buffered maintenance medium such cultures maintained histological integrity for 15 days. However, one - trial inoculation with lymphocystis virus showed no-integration or multiplication of the virus in the tissue. In connection with attempts to induce the blenny infection, the. effect of high temperature-in the Blenny was investigated. The infection was not induced over a9 day holding period but lytic effects on the erythrocyte nuclei were observed. The effect of the drug acetylphenylhydrazine (APH) in the Blenny was also investigated with the aim of reproducing its reported action of anaemia induction and ensuing erythropoiesis. Marked anaemia was produced but not erythropoiesis. However, this result could not nesessarily be interpreted as the effect of APH alone. The viruses were identified and characterized with emphasis on their mophology, using ultrathin sectioning, negative staining and shadowing methods. It was concluded that the virus from the Blenny and lymphocystis virus conform to the structural measurements in the literature but negative staining indicated that both viruses display unique core structures. These are discussed in the light of the knowledge of other DNA virus cores. The position of these viruses is further considered with respect to their classification in the virus family Iridoviridae.

background The extracellular matrix receptor integrin ανβ6 is known to potentiate breast cancer (BrCa) cell invasion, metastasis and tumour-trophic growth factor receptor crosstalk during tumourigenesis. Monoclonal antibody blockade of ανβ6 diminishes invasion in vitro and arrests BrCa tumour growth and metastasis in vivo. Aberrant integrin activation status has been implicated in progression to metastatic disease in BrCa; with differential internalisation and endocytic trafficking kinetics reported for active versus inactive integrin species in malignant disease. Despite its emerging potential for targeted therapy, little is known regarding regulation of integrin ανβ6-mediated activation and signalling during progression to an invasive, metastatic state. It is hypothesised that the aetiopathological significance of integrin ανβ6 during neoplastic transformation and malignant progression in BrCa is dependent specifically upon its activation status and associated conformation, since this active state will permit establishment of known integrin-mediated oncogenic signalling underpinning acquisition of a malignant phenotype, including activation of invasion and metastasis. results Canonical integrin activation studies using divalent cations and cognate ligand stimulation indicated antibodies 6.2E5 and 6.2G2 recognise activation-associated epitopes, which are also ligand-induced binding sites (LIBS) in live-labelled cells by FCM and IMF. However, their utility to discriminate the active fraction distinct from the total or inactive fractions of ανβ6 by IHC in primary BrCa samples could not be robustly established. Evaluation of the 6.2E5 and 6.2G2 epitopes in the MCF10 isogenic model revealed that relative surface abundance of these active epitopes determined by FCM was not significantly altered; but their subcellular redistribution upon neoplastic transformation and malignant progression was observed by IMF, implicating derailed internalisation and trafficking of active ανβ6 during breast tumourigenesis and metastatic disease progression. Proteomic interrogation and network analysis of the 2D-enriched adhesion assays identified 7 novel putative molecular regulators of a ligand-engaged, activated ανβ6-mediated adhesion environment (DMBT-1, MARCKS, MXRA5, SEPT6, SEPT9, MYH9, MYH10) in the BT-20 TNBC cell line. Functional validation of these candidate mediators of the "β6 adhesome" by siRNA strategies was not achieved due to inconsistent stable knockdown. Phosphoproteomic definition of LAP ligand-engaged, active ανβ6-mediated signalling ("β6 kinome") during receptor-ligand internalisation revealed EGFR-dependency for downstream ERK1/2 signal activation in BT-20 and SUM159, but not MDA-MB-468 TNBC cells. Kinase substrate enrichment analysis (KSEA) identified 5 novel putative mediators of downstream ανβ6 signalling (COT, MAPKAPK2, PDPK1, Nuak1, TBK1) and implicated Akt1 isoform-specific activation downstream of ανβ6-LAP internalisation. Following LAP-induced ανβ6 activation and internalisation, EGFR underwent phosphorylation at multiple known activation sites, including a residue (Thr693) critical for EGFR receptor internalisation; suggesting integrin ανβ6-EGFR reciprocity during respective receptor activation and internalisation. conclusion The active conformer of integrin ανβ6 may be studied using antibodies 6.2E5 and 6.2G2 in live-labelled cells by FCM and IMF. Subcellular redistribution of activation-associated epitopes during BrCa progression implicates derailed internalisation and intracellular trafficking kinetics of active ανβ6 during tumourigenesis, while protein expression studies identified 7 putative molecular regulators of ligand-engaged, active ανβ6-mediated adhesion. Integrin ανβ6-mediated signalling during internalisation revealed an ανβ6-EGFRAkt1 signalling axis during breast tumourigenesis and disease progression, while further understanding of integrin biology and growth factor receptor crosstalk may provide additional rationale for potential combination therapies in breast cancer.

The Hippo Pathway is a highly conserved regulator of tissue growth and size determination, limiting the activity of the transcriptional co-activator Yorkie (Yki), which promotes proliferation and inhibits apoptosis. Hippo signalling integrates and transduces cell polarity and cell-cell adhesion inputs thereby responding to the state of tissue architecture. The transmembrane apical polarity protein Crumbs (Crb) controls the activity of Yki by regulating Expanded (Ex), a protein that promotes Hippo signalling through kinase-dependent and -independent mechanisms to robustly inhibit Yki activity. Crb plays a dual role in the regulation of Ex by controlling its apical localisation, facilitating Yki inhibition, and by promoting Ex degradation, thus activating Yki. Crb regulates the stability of Ex by stimulating a phosphorylation-dependent ubiquitylation and proteasomal degradation. Characterisation of the precise mechanisms by which Crb regulates Ex has been the focus of this thesis. Based on candidates identified by mass spectrometry and from literature, the Casein Kinase 1 (CK1) family of kinases, and the deubiquitylating enzyme (DUB) Usp2 have both been identified as novel regulators of Ex stability. CK1s promote Ex phosphorylation and degradation, acting as Ex inhibitors, while Usp2 promotes Ex function by promoting its stabilisation. Furthermore, in a screen to identify DUBs that regulate Drosophila adult wing size, CG10889 has been established as a novel regulator of growth that interacts with members of the Hippo pathway.

The lymphatic vasculature is a key player in progression of many cancers, with lymphangiogenesis at the primary tumour and tumour-draining lymph nodes (TDLNs) associated with poor patient prognosis. As well as providing a highway for metastatic tumour cells, recent reports propose lymphatics as modulators of immunity, highlighting a need for greater understanding of immune regulation by lymphatics. The specific role of lymphatic endothelial cells (LECs) in this context, particularly in TDLNs, is unknown. As TDLNs are immune hubs, yet anti-tumour immune responses are often ineffective, this thesis aimed to investigate functional changes to lymphatics in TDLNs and the role of TDLN-derived LECs in anti-tumour immunity. I hypothesised that factors from the tumour microenvironment alter functionality of TDLN-LECs from early stages of tumour development. I further hypothesised that these changes would promote immune tolerance, with this thesis exploring specific impact on dendritic cell (DC) mediated immunity. Using the B16-F10 melanoma model, this work confirmed expansion of TDLN-LECs prior to metastasis and demonstrated transcriptional reprogramming of immune-associated pathways in LECs isolated from early TDLNs. This was accompanied by differentially localized migratory DCs, clustered at lymphatic subcapsular sinuses. In vitro using co-culture assays revealed mature DCs undergo prolonged interactions with LECs conditioned with B16-F10 tumour-conditioned media, suggesting a change in the physical interactions occurring in vivo in early TDLNs. Additionally, we investigated possible mechanistic contributors, demonstrating using in vitro and in vivo blockade and knockout models, a role for lymphatic expressed Podoplanin in DC interactions and migration. Prolonged physical interactions were further found to facilitate antigen transfer from ovalbumin-loaded LECs to DCs yet inhibit DC priming of T-cells, with DCs found capable of acquiring TDLN-LEC archived antigen in vivo. These results show that in lymph nodes conditioned by factors derived from the tumour microenvironment, prolonged physical interactions between LECs and DCs impact DC migration and T-cell priming. As immune tolerance is a key feature of the tumour microenvironment, this work has highlighted lymphatics as key modulators of the anti-tumour immune response. Furthermore, this work provides new insight into lymphatic involvement during tumour development, identifying lymphatics as a potential target for early intervention therapies.

Induction of apoptosis is the most studied cell death process and it is a tightly regulated physiological event that enables elimination of damaged and unwanted cells. Apoptosis can be induced via activation of either the intrinsic or the extrinsic signalling pathway. The intrinsic pathway involves activation of the mitochondria by stress stimuli, whereas the extrinsic pathway is triggered by ligand induced activation of death receptors such as Fas. Apoptosis induction via Fas activation plays an important role in the function of cytotoxic T lymphocytes and in the control of immune cell homeostasis. Several studies have shown that anticancer therapies require functional cell death signalling pathways. Irradiation based therapy has been successful in treatment of several malignancies but the usage of high doses has been associated with side effects. Therefore, low dose therapies, that either is optimized for specific delivery or administrated in combination with other treatments, are promising modalities. However, in order to achieve high-quality effects of such treatments, the death effector mechanisms involved in tumour eradication needs to be further explored. Importantly, tumour cells frequently acquire resistance to apoptosis, which consequently allows tumour cells to escape from elimination by the immune system and/or treatment. Interferons constitute a large family of pleotrophic cytokines that are important for the immune response against viruses and other microorganisms. The interferon signalling pathway mediates transcriptional regulation of hundreds of genes, which result in mRNA degradation, decreased protein synthesis, cell cycle inhibition and induction of apoptosis. Interferon has successfully been used in therapy against some tumours. However, several drawbacks have been reported, such as reduced sensitivity to interferon during treatment. The aim of this thesis was to elucidate mechanisms that mediate resistance to death receptor or interferon induced apoptosis in human tumour cell models, as well as investigate what molecular events that underlie cell death following radiation therapy of tumour cells. In order to elucidate mechanisms involved in acquired resistance to Fas- or interferon-induced apoptosis, a Fas- and interferon-sensitive human cell line, U937, was subjected to conditions where resistance to either Fas- or interferon induced apoptosis was acquired. Characterization of the Fas resistant cells showed that multiple resistant mechanisms had been acquired. Reduced Fas expression and increased cFLIP expression, which is an inhibitor of death receptor signalling, were two important changes found. To further examine the importance of these two alterations, clones from the Fas resistant population were established. The reduced Fas expression was determined to account for the resistant phenotype in approximately 70% of the clones. In the Fas resistant clones with normal Fas expression, the importance of an increased amount of the cFLIP protein was confirmed with shRNA interference. A cross-resistance to death receptor induced apoptosis was detected in the interferon resistant variant, which illustrates that a connection between death receptor and interferon induced apoptosis exists. Notably, interferon resistant cells also contained increased cFLIP expression, which were determined to mediate resistance to both interferon and death receptor mediated apoptosis. Finally, when cell death induced by irradiation treatment was investigated in HeLa Hep2 cells we could demonstrate that cell death was mediated by centrosome hyperamplification and mitotic aberrations, which forced the cells into mitotic catastrophes and delayed apoptosis. In conclusion, we have described model systems where selection for resistance to Fas or interferon induced apoptosis generated a heterogeneous population, where several signalling molecules were altered. Furthermore, we have shown that a complex cell death network was activated by irradiation based therapy.

Being the most aggressive human skin cancers, melanoma has always occurred with a poor prognosis. It is responsible for 80% of skin cancer. Treatments for melanoma include surgical removal, and radio- and chemotherapy, which are not effective toward the advanced stages of the disease. Only three chemotherapy drugs, hydroxyurea, dacarbazine and interleukin-2, are currently approved by the Food and Drug Administration for metastatic melanoma, and the therapeutic response rate is only 5%-20%. Thus, there is a need for novel therapies that can target tumours, especially when the tumour cells become refractory to chemotherapy. ELR–CXC chemokines with a Glutamine – leucine – arginine (ELR) motif (for example, interleukin-8/CXCL8) are able to chemoattract neutrophils during inflammation responses via their receptors, CXCR1 and CXCR2, which can be expressed by human malignant tumour cells, keratinocytes, endothelial cells, and fibroblasts. CXCR1 and CXCR2 play very important roles in melanoma by promoting tumour cell proliferation, angiogenesis, and metastasis. They are also involved in the tumour’s becoming refractory to chemotherapy. An ELR–CXC chemokine antagonist developed by our lab, CXCL8(3-72)K11R/G31P (G31P), effectively blocks CXCR1- and CXCR2- induced inflammatory responses, and further antagonizes the functions of heterologous G protein–coupled receptor’s (GPCR). The tumour–associated GPCRs, along with ELR–CXC chemokines and their receptors, have been shown to simultaneously increase in several tumour models, including melanoma. Thus, given the knowledge regarding the importance of the ELR-CXC chemokines and heterologous GPCRs’ in melanoma and G31P’s ability to block ELR-CXC chemokines and at least some heterologous GPCRs, we hypothesize that G31P is a viable therapeutic option for melanoma cancers by virtue of its success in blocking tumour progression in mouse models. Our data indicated that ELR-CXC chemokine antagonism with G31P had no significant impact on tumour growth or tumour-induced angiogenesis, which suggested that blockade of CXCR1 and CXCR2 alone was insufficient to block tumour development in this melanoma mouse model. Evaluation of other tumour-related parameters (e.g., angiogenic patterns and stress protein level) are recommended as a means of determining what parameters beyond CXCR1 and CXCR2 signaling are important in tumour progression in our matrigel model.

No description available.

No description available.

(1) Human neuron specific enolase (NSE) was purified from human brain tissue and used as an immunogen in the production of murine monoclonal antibodies. It was also used as a standard preparation of NSE in the screening of monoclonal antibodies and in the investigations of an enzyme-linked immunosorbent assay (ELISA) for NSE. (2) Four monoclonal antibodies were raised to NSE. These did not cross react with the alpha isoenzyme of enolase (NNE). Approximately 76% of positive well supernatants reacted with both NSE and NNE. (3) All four monoclonal antibodies reacted in an ELISA but only two of the four reacted on an immunoblot. (4) The monoclonal antibodies were purified by precipitation by ammonium sulphate and by Protein A-affinity column chromatography. The latter resulted in immunoglobulin which was pure by SDS-PAGE. (5) The purified monoclonal antibodies were labelled with horseradish peroxidase by the periodate oxidation method, with ¹²⁵I using the Chloramine T and the Bolton-Hunter methods, and with biotin. (6) Labelling with biotin was the most effective method. (7) The labelled monoclonal antibodies were used in the investigation of a sandwich ELISA for NSE. These experiments showed that high binding occurred with no antigen present. It was surmised that monoclonal antibody-monoclonal antibody binding may be occurring. (8) The high no-antigen control was investigated in a number of ways including altering the assay pH, the detergent concentration, the type of solid support and by using Fab fragments in the assay instead of whole molecule.

This work describes 5 groups of tumours seen in routine neuropathological practice in Southampton between 1980 and 1986. The clinical and light microscopic findings in a total of 44 tumours are described. A panel of monoclonal and polyclonal antibodies was used in immunohistochemical studies on each group, and this made important contributions to the diagnosis and characterisation of these tumours. Six primary central nervous system lymphomas were shown to be 5 follicle centre cell lymphomas (Kiel-classification) and 1 T-cell lymphoma. 15 lymphomas causing spinal cord compression were typed as 11 follicle centre cell lymphomas, 3 T-cell lymphomas and 1 lymphoblastic lymphoma. T-cell lymphomas appear to be more likely to be localised in the spine and to have a better prognosis. In all these tumours admixed reactive cell populations were also identified immunohistochemically. Ten primitive neuroectodermal tumours of the cerebrum were examined and immunohistochemistry assisted in their distinction from lymphoma and metastatic carcinoma. It also showed evidence of differentiation in apparently poorly differentiated parts of the tumours. Immunohistochemical studies facilitated the distinction of pleomorphic xanthoastrocytoma from a monstrocellular astrocytoma and a meningeal malignant fibrous histiocytoma. The recognition of this first entity has important prognostic implications. In 10 cerebellar haemangioblastomas a panel of antibodies was used to investigate the histogenesis of the stromal cell component of these tumours. Endothelial and stromal cells were found to be antigenically distinct and neurone specific enolase activity was found in the latter. The implications of this finding are discussed. The studies confirm the important and increasing role played by immunohistochemistry in our understanding of central nervous system neoplasia.