Amyotrophic lateral sclerosis (ALS) is characterized by motor neuron degeneration resulting in progressive paralysis and death. The only known cause of typical ALS is mutations in SOD1; these predominantly missense mutations produce a toxic gain-of-function in the enzyme Cu/Zn superoxide dismutase (SOD1). The prevailing hypotheses regarding the mechanism of toxicity were a) oxidative damage from aberrant SOD1 redox chemistry, and b) misfolding of the mutant protein. The goal of this thesis was to investigate the molecular mechanisms of the mutant SOD1 (mSOD1) misfolding and toxicity. We proposed that oxidative damage to SOD1 itself could cause its misfolding and aggregation. To investigate this hypothesis, we subjected purified SOD1 in vitro to metal catalyzed oxidation. Oxidation of SOD1 produced aggregates reminiscent of those observed in ALS pathology. Aggregation propensity of zinc-deficient SOD1 and several mSOD1s known to have lower zinc-binding affinity was proportional to partial unfolding. Oxidation of SOD1 caused conversion of several His residues to 2-oxo-histidine. Because oxidation of SOD1 primarily affected the metal-binding His residues, we hypothesized that oxidation of wild-type, holo-SOD1 should lead to aggregation. Increasing the concentration of wild-type SOD1 in oxidation reactions produced aggregates similar to those observed earlier. Both wild-type and mSOD1 aggregation kinetics revealed an initial decrease in particle size rather than a monotonic increase using dynamic light scattering. This was consistent with the conversion of SOD1, normally an obligate homodimer, into monomers prior to aggregation. This observation was confirmed using analytical ultracentrifugation. The common aggregation pathway for wild-type and mSOD1 suggested a mechanism for sporadic ALS caused by SOD1 misfolding. To interrogate the in vivo misfolding pathway of SOD1, we used its high-resolution structure to create an antibody that reacts with monomer/misfolded SOD1 but not the native dimer. Upon verifying the reactivity of this antibody, we showed that monomer/misfolded SOD1 is found in a human case of familial ALS and in transgenic animal models of ALS. Misfolded SOD1 is found primarily in affected cells, motor neurons. Misfolded SOD1 is also initially absent, but appears prior to symptom onset. These observations together suggest a causal role for SOD1 misfolding through a monomeric intermediate in ALS pathogenesis.

Detection and treatment of bacterial kidney disease (BKD) was investigated. Experiments were conducted to evaluate the quantitative, fluorescent antibody technique (QFAT) that is used to detect, identify, and quantify both typical and 'bar form' Renibacterium salmoninarum cells. Smears of kidney tissue from naturally and artificially infected salmonids, both with and without chemotherapy, were quantitatively examined throughout the course of R. salmoninarum infections. Detection and quantification by QFAT has been reported to provide assessments of prevalence and severity of R. salmoninarum of individual fish. These assessments and the occurrence of 'bar forms' of R. salmoninarum have been used as an indication of recovery within a population. 'Bar forms' were observed in kidney tissue smears of fish that survived bacterial challenge when treated with erythromycin. The 'bar form' was also detected when rainbow trout were artificially infected with lower doses of live R . salmoninarum and in fish that were injected with irradiation-inactivated R. salmoninarum cells. By examining R. salmoninarum cultures in vitro by QFAT, it was determined that 'bar forms' did not occur on artificial media even when antibiotics were incorporated into the agar. When QFAT was compared to direct fluorescent antibody technique (DFAT) and quantitative enzyme linked immunosorbent assay (ELISA), it was determined that QFAT had similar sensitivity as ELISA but was more sensitive than DFAT. QFAT was also used to predict minimum mortality. Experiments were also conducted to evaluate drug regimes to treat both artificial and natural R. salmoninarum infections. Erythromycin was administered by intraperitoneal injection in different doses and at selected days post infection. Erythromycin decreased percent mortality and increased mean day to death, but did not completely eradicate R. salmoninarum from infected test animals. Sarafloxacin and erythromycin were incorporated into daily ration of artificially infected test animals. Contrary to erythromycin, sarafloxacin did not decrease mortality or increase mean day to death when tested in vivo against R. salmoninarum. A new drug, A-77143, was tested in vitro to determine if it was bactericidal and its minimum inhibitory concentration. When A- 77143 was compared to other antibiotics, it had a relatively low minimum inhibitory concentration and was shown to be bactericidal against the eight strains of R. salmoninarum tested. / Graduation date: 1993

The L1 region of the porcine adenovirus (PAdV)-3 genome encodes a protein of 622 amino acids named IIIa. Although it binds a neighboring group of nine (GON) hexons at the capsid level and cement the icosahedral shell that contains the viral DNA, little is known regarding its function with respect to viral life cycle. Moreover, the known location of IIIa protein in the capsid may help to express targeting ligands for altering the tropism of PAdV-3. The objective of this study was to characterize the IIIa protein of porcine adenovirus Type 3 (PAdV-3). <p> In order to characterize the IIIa protein, polyclonal antisera were raised in rabbits against different regions of IIIa. Anti-IIIa sera detected a specific protein of 70 kDa in PAdV-3 infected cells using Western blot assay. Immunofluorescence studies indicated that IIIa is predominantly localized in the nucleus of PAdV-3 infected cells. Analysis of PAdV-3 IIIa using antibodies specific for N- and C- terminal domains of the protein suggested that although the N-terminus and C-terminal domains of IIIa are immunogenic, they are not exposed on the surface of PAdV-3 virions. These results were further confirmed by our inability to isolate a chimeric PAdV-3 virion containing a heterologous protein fused to the N-terminus or C-terminus of IIIa. <p>Functional analysis suggested that IIIa may transactivate the major late promoter and down regulate the early region (E) 1A promoter. In order to locate the domains of IIIa responsible for different functions, in-frame deleted/truncated forms of IIIa were constructed. Analysis of the deleted/truncated forms of IIIa suggested that a) the sequences located between amino acids 273-410 and between amino acids 410-622b) affect the nuclear localization and transactivation function respectively.<p>Since protein- protein interactions are important for the biological functions of the protein, we determined the interaction of PAdV-3 IIIa with other viral proteins. IIIa was found to interact with DNA binding protein (DBP), E3 13.7 kDa protein, hexon, fiber, and pIX. These results suggest that PAdV3 IIIa may do more in the viral life cycle than merely act as cement between the hexons to maintain capsid stability and may actually be involved in regulating early to late gene transcription at appropriate stages during viral infection.

TGF-β negatively affects the maintenance and expansion of hematopoietic stem cells ex vivo and its inhibition has been widely studied as a treatment for numerous hematopoietic disorders and cancers. Current inhibitory strategies (small molecule ATP competitors and neutralizing antibodies) are compared to a novel cell-permeable peptide-based inhibitor of TGF-β RI. Multiple levels of assay from biochemical to functional are utilized with the aim of applying the most successful inhibitor to hematopoietic stem cell culture. The neutralizing antibody proved ineffective in the short-term biochemical assay but was extremely effective at neutralizing TGF-β signalling in proliferation and hematopoietic colony-forming cell assays with no evidence of toxicity. The small molecule inhibitors (SD-208 and Pyrazole TGF-β RI inhibitor) were equally effective at micromolar levels in all forms of assay, with SD-208 being slightly more potent. The novel peptide inhibitor proved ineffective in all assays, which is likely a result of its rapid degradation in live cells.

TGF-β negatively affects the maintenance and expansion of hematopoietic stem cells ex vivo and its inhibition has been widely studied as a treatment for numerous hematopoietic disorders and cancers. Current inhibitory strategies (small molecule ATP competitors and neutralizing antibodies) are compared to a novel cell-permeable peptide-based inhibitor of TGF-β RI. Multiple levels of assay from biochemical to functional are utilized with the aim of applying the most successful inhibitor to hematopoietic stem cell culture. The neutralizing antibody proved ineffective in the short-term biochemical assay but was extremely effective at neutralizing TGF-β signalling in proliferation and hematopoietic colony-forming cell assays with no evidence of toxicity. The small molecule inhibitors (SD-208 and Pyrazole TGF-β RI inhibitor) were equally effective at micromolar levels in all forms of assay, with SD-208 being slightly more potent. The novel peptide inhibitor proved ineffective in all assays, which is likely a result of its rapid degradation in live cells.

Amyotrophic lateral sclerosis (ALS) is characterized by motor neuron degeneration resulting in progressive paralysis and death. The only known cause of typical ALS is mutations in SOD1; these predominantly missense mutations produce a toxic gain-of-function in the enzyme Cu/Zn superoxide dismutase (SOD1). The prevailing hypotheses regarding the mechanism of toxicity were a) oxidative damage from aberrant SOD1 redox chemistry, and b) misfolding of the mutant protein. The goal of this thesis was to investigate the molecular mechanisms of the mutant SOD1 (mSOD1) misfolding and toxicity. We proposed that oxidative damage to SOD1 itself could cause its misfolding and aggregation. To investigate this hypothesis, we subjected purified SOD1 in vitro to metal catalyzed oxidation. Oxidation of SOD1 produced aggregates reminiscent of those observed in ALS pathology. Aggregation propensity of zinc-deficient SOD1 and several mSOD1s known to have lower zinc-binding affinity was proportional to partial unfolding. Oxidation of SOD1 caused conversion of several His residues to 2-oxo-histidine. Because oxidation of SOD1 primarily affected the metal-binding His residues, we hypothesized that oxidation of wild-type, holo-SOD1 should lead to aggregation. Increasing the concentration of wild-type SOD1 in oxidation reactions produced aggregates similar to those observed earlier. Both wild-type and mSOD1 aggregation kinetics revealed an initial decrease in particle size rather than a monotonic increase using dynamic light scattering. This was consistent with the conversion of SOD1, normally an obligate homodimer, into monomers prior to aggregation. This observation was confirmed using analytical ultracentrifugation. The common aggregation pathway for wild-type and mSOD1 suggested a mechanism for sporadic ALS caused by SOD1 misfolding. To interrogate the in vivo misfolding pathway of SOD1, we used its high-resolution structure to create an antibody that reacts with monomer/misfolded SOD1 but not the native dimer. Upon verifying the reactivity of this antibody, we showed that monomer/misfolded SOD1 is found in a human case of familial ALS and in transgenic animal models of ALS. Misfolded SOD1 is found primarily in affected cells, motor neurons. Misfolded SOD1 is also initially absent, but appears prior to symptom onset. These observations together suggest a causal role for SOD1 misfolding through a monomeric intermediate in ALS pathogenesis.

Background: As a part of a national health control program, Statens VeterinärmedicinskaAnstalt performs diagnostics to screen flocks for certain pathogens causing high mortality,morbidity and/or serious economical losses. There are several viruses in the programincluding IBDV (infectious bursal disease virus), IBV (infectious bronchitis virus) and NDV(Newcastle disease virus). Method: 96 serum samples were collected from different poultryflocks in Sweden and analyzed by ELISA, which are currently used in the health controlprogram as well as by a commercial prototype of a multiplex immunoassay manufactured byLuminex Corp., which is currently under evaluation at the United States Department ofAgriculture USDA. This 4-plex assay detects antibodies for the three above-mentionedviruses as well as antibodies of avian reovirus. In the context of this study the ELISAs run inroutine diagnostics as well as a REO ELISA were used as the standard for comparison.Result: The antibody concentration in serum from vaccinated chickens was high while theantibody concentration level in serum from not vaccinated chickens was low. There was agood correlation between the multiplex assay and ELISA. Conclusion: The results obtainedin this study indicate that the Luminex multiplex assay tested has the potential to be usedroutinely for screening flocks.

The L1 region of the porcine adenovirus (PAdV)-3 genome encodes a protein of 622 amino acids named IIIa. Although it binds a neighboring group of nine (GON) hexons at the capsid level and cement the icosahedral shell that contains the viral DNA, little is known regarding its function with respect to viral life cycle. Moreover, the known location of IIIa protein in the capsid may help to express targeting ligands for altering the tropism of PAdV-3. The objective of this study was to characterize the IIIa protein of porcine adenovirus Type 3 (PAdV-3). <p> In order to characterize the IIIa protein, polyclonal antisera were raised in rabbits against different regions of IIIa. Anti-IIIa sera detected a specific protein of 70 kDa in PAdV-3 infected cells using Western blot assay. Immunofluorescence studies indicated that IIIa is predominantly localized in the nucleus of PAdV-3 infected cells. Analysis of PAdV-3 IIIa using antibodies specific for N- and C- terminal domains of the protein suggested that although the N-terminus and C-terminal domains of IIIa are immunogenic, they are not exposed on the surface of PAdV-3 virions. These results were further confirmed by our inability to isolate a chimeric PAdV-3 virion containing a heterologous protein fused to the N-terminus or C-terminus of IIIa. <p>Functional analysis suggested that IIIa may transactivate the major late promoter and down regulate the early region (E) 1A promoter. In order to locate the domains of IIIa responsible for different functions, in-frame deleted/truncated forms of IIIa were constructed. Analysis of the deleted/truncated forms of IIIa suggested that a) the sequences located between amino acids 273-410 and between amino acids 410-622b) affect the nuclear localization and transactivation function respectively.<p>Since protein- protein interactions are important for the biological functions of the protein, we determined the interaction of PAdV-3 IIIa with other viral proteins. IIIa was found to interact with DNA binding protein (DBP), E3 13.7 kDa protein, hexon, fiber, and pIX. These results suggest that PAdV3 IIIa may do more in the viral life cycle than merely act as cement between the hexons to maintain capsid stability and may actually be involved in regulating early to late gene transcription at appropriate stages during viral infection.

The groupers are vital fish in the market of over 350 million dollars, while grouper nervous necrosis virus (NNV) has caused mass mortality at about 100% in larvae and juveniles, which impacts on economic of marine cultured fish. The monoclonal antibody is one of the best methods to identify the epitopes on the 3D structure. For evaluation, the Balb/c mice were injected with DGNNV and virus-like particles (VLPs) in this study. The results showed that ascite of mAb-cells produced 1200 times higher than the cell secretion in the medium whereas our best clone hAb_VLP8 can only produced 100 times less antibody than the cell secretion. In the meantime before the monoclonal producer is established, the hAb_VLP8 could be used for ascite production to gain high antibody production.

The groupers are vital fish in Taiwan, the market of grouper fry over 300 million dollars. While grouper nervous necrosis virus (NNV) has caused mass mortality, especially 100% in larvae and juveniles, which economically impacts on culture of marine fish. The vaccination is one of the best methods to against viral diseases. The dragon grouper (Epinephelus lanceolatus), malabar grouper (E. malabaricus) and brown-marbled grouper (E. fuscoguttatus) were injected with different dosages and injection frequencies of virus-like particles (VLPs) of DGNNV, which is by the first claimed. The anti-sera of vaccinated fish were analyzed with eight kinds of immunology methods, among which antigen-capture ELISA was the best choice for qualitative and quantitative assays. The signal of antibodies in the vaccinated fish was detected in all groupers in one week after primary immunization, and the antibody titers increased markedly in one month. In dragon grouper, fish was injected with 10 £gg of VLPs, the antibody titer reached 1.05. To given booster injection once, antibody titers were raised to 35.7%. In malabar grouper, after injected twice with 50 £gg of VLPs, the antibody titer raised 33.3% than inoculation once in six weeks. After brown-marbled grouper was injected with 450 £gg of VLPs, the high antibody titer reached to 1.57 at five weeks post primary immunization. Specific antibodies still can be detected after seven months. In the in vitro assay with MGNNV of 103.5 TCID50/mL, neutralizing antibody titer of control fish were all lower than 1:50. The neutralizing antibody titer of anti-serum of dragon grouper was detected at 1:200 at one week, and raised to 1:1600 at four weeks and 1:6400 at eleven weeks after primary vaccination. In malabar grouper and brown-marbled grouper, the neutralizing antibody titers were 1:3200 and 1:400, respectively, in one month. The antibody titer can not increased by Freund¡¦s complete adjuvant. The fish produced high antibody titer and high protection by immunization with VLPs.