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Bovine herpesvirus-1 (BoHV-1) is associated with the syndrome bovine respiratory disease, which is the major cause of morbidity and mortality within feedlots in Australia and around the world. Currently there are no vaccines that completely prevent BoHV-1 infections and viral shedding. The most efficacious vaccines used are live attenuated which have the potential to revert to wild type and cause disease. DNA vaccines are ideal vaccine candidates as they not only induce humoral and cellular immunity, they are also inexpensive and easy to produce. However, DNA vaccines although efficacious in small animal models have not yielded similar success in large animals. The inconsistent translation of DNA vaccines to large animal models, including cattle, has been associated with poor delivery of the vaccine to the nuclei of cells which is required for antigen transcription. Recently, the human herpesvirus-1 protein VP22 (hVP22) was demonstrated to exhibit the uncommon capacity to spread intercellularly from the cell of expression to the nuclei of neighbouring cells in a golgi and energy independent process. This process was very efficient with hVP22 being identified in all cells of a monolayer after transfection. hVP22 was quickly used to promote the efficiency of DNA vaccines by fusing the hVP22 gene with antigen genes in the vaccine resulting in the increased delivery of the antigenic protein to neighbouring cells. The fusion protein was subsequently degraded and presented as peptides on the cell surface in association with major histocompatibility complex (MHC) class II molecules that lead to an increase in fusion protein specific antibody production. This pathway, although successful augmenting the humoral response, did not increase the amount of antigen presented on MHC class I molecules which is essential for protection against intracellular pathogens. This thesis describes the development of a methodology whereby VP22, fused to a DNA binding protein, was hypothesised to increase the number of cells the DNA vaccine was delivered to and then to facilitate the transport of the DNA vaccine to their nuclei. A homologue of hVP22 has been identified in BoHV-1 and the capacity of the BoHV-1 protein to spread intercellularly and localise in the nuclei of cells was determined in this thesis using a novel and definitive model. Although retaining similar translocation capabilities to hVP22 the BoHV-1 VP22 homologue could not be expressed in bacteria and was subsequently not able to be used to demonstrate the proposed vaccine concept. hVP22 instead was fused to the DNA binding protein, Gal4, for bacterial expression. The purified fusion protein was demonstrated to bind not only oligonucleotides encoding the Gal4 binding sequence but also to a model DNA vaccine encoding Gal4 binding sequences in vitro. However, application of the hVP22 fusion protein:vaccine complex alone or condensed with poly-L-lysine to mammalian cells did not promote the delivery of the DNA vaccine to the nuclei of cells. As part of the DNA vaccine development for BoHV-1 the first nucleotide sequence of the Unique Short region of the Australian BoHV-1 strain V155 (8925 nucleotides) was determined. The sequence information generated permitted insights into epitopes contained within BoHV-1 antigens, particularly glycoprotein D which has been identified as the most appropriate glycoprotein for the purpose of vaccination. Furthermore, comparison of the Unique Short sequence variations between different subtypes of BoHV-1 provided molecular data that may be associated with the observed variation in virulence. Further optimisation of the methodology described in this study is required to facilitate the delivery of the DNA vaccine into cells by the VP22 fusion protein. The future development of strategies that utilise polypeptides to augment delivery of DNA vaccines into cells and then to facilitate the transport of the vaccine to the nuclei of cells, resulting in increased antigen expression, may ultimately lead to the successful application of this vaccine technology in animal models.

Four 1H12 E. ruminantium open reading frames cloned into the pCMViUBs mammalian expression vector and used as a recombinant DNA vaccine against heartwater repeatedly provided complete protection in sheep (using a cocktail or the individual ORFs) against a laboratory needle challenge while 1/5 of sheep were protected after a natural tick challenge. The lack of protection under natural field conditions could be attributed to the delivery strategy used and therefore there is a need to investigate other delivery methods. Polymeric microparticles based on PLGA polymers have been used extensively to target the delivery of vaccine to antigen presenting cells, play a role in the induction of cellular immunity and can be used as a single dose vaccine mimicking prime/boost vaccination. In this study, the four 1H12 pCMViUBs_ORFs and their respective recombinant proteins were either encapsulated into or adsorbed onto microparticles using a modified double emulsion solvent evaporation technique. The particles were formulated to release DNA on day zero and day 21 and recombinant proteins on day 42 thus mimicking a two times DNA prime/recombinant protein-boost immunization strategy. Encapsulation did not have any detrimental effects on the stability of the recombinant proteins as determined by gel electrophoresis and western blotting. The in vitro incubation of microparticles in either a Float-A-Lyzer® dialyzer or an eppendorf tube showed the potential of microparticles to be used as a vaccine because of their release profiles that mimics a heterologous prime/boost immunization strategy. Microparticles formulated using polymers with low glycolide ratios released 80% of the encapsulated proteins within the first week of in vitro incubation with most of the proteins released on day 1. Microparticles formulated using polymers with 50:50 monomer ratios released the recombinant proteins during week 1 and 3 of in vitro incubation. These microparticles did not release any protein in week 2 (day 7-14). Microparticles with 0.5% cetyltrimethylammonium bromide (CTAB) on their surfaces adsorbed DNA and released more than 40% of DNA on day 1 with 100% release by day 14. RG502H microparticles formed with PVA as the internal phase viscosity enhancer released intact DNA only from day 12 to day 21. A cocktail of these microparticles could therefore be used as an autobooster vaccine thus reducing the need for repeated immunizations needed to obtain protective immunity. Potential scientific publication Tshikhudo, N.P., Pretorius, A., Putterill, J., and van Kleef, M. 2009, “Biodegradable microparticles as a single dose delivery system for Ehrlichia ruminantium vaccines”, Journal of Controlled Release, (draft manuscript). Publication of results in conference proceedings / abstracts NanoAfrica 2009: Biodegradable microspheres as a single dose delivery system for Ehrlichia ruminantium vaccines: N. Tshikhudo, A. Pretorius, J. Putterill and M. van Kleef. / Dissertation (MSc)--University of Pretoria, 2009. / Veterinary Tropical Diseases / unrestricted

Filarial infections are major causes of morbidity in the tropics and sub-tropics, afflicting over 150 million people in about 80 countries, causing debilitating symptoms such as elephantiasis (lymphatic filariasis), dermatitis and blindness (onchocerciasis or river blindness). Current control of lymphatic filariais relies on mass drug treatment with diethylcarbamazine（DEC) and albendazole while ivermectin is used against onchocerciasis. Repeat treatment is frequently required and this highlights the possibility of development of drug resistance. In addition, risk of adverse reactions following treatment excludes some patients from control programmes. Such circumstances urgently call for the development of complementary control measures such as vaccination. DNA vaccines are novel type of subunit vaccine in which production of the immunizing antigen is induced in host cells after introduction of a plasmid or recombinant viral vector containing the gene that encodes the antigen. DNA vaccines are relatively simple and cheap to produce and their stability makes them particularly suitable for use in remote regions that lack the cold-chain storage facilities required of conventional vaccines. Filarial nematodes are tissue-dwelling parasites that survive for many years in immunocompetent hosts. It is proposed that this longevity is, in part, due to the capacity of the parasites to modulate potentially lethal Th2 responses of their hosts. Consequently, the efficiency of a filarial vaccine may depend on how well it circumvents filarial-driven immunosuppression. To test this hypothesis, a series of DNA vaccines were developed and tested in the Litomosoides sigmodontis-mouse model of filarial infections. The L. sigmodontis Abundant Larval Transcript-1 (Ls-ALT) and Cysteine Protease Inhibitor (Ls-CPI) genes were cloned and genetically engineered to ablate their immunomodulatory properties by deleting the acid domain and by site mutation, respectively. In addition, the L. sigmodontis Venom Allergen Homologue (Ls-VAH) and Thioredoxin Peroxidase (Ls-TPX) were used in their native forms as vaccine targets. To improve immunisation and antigen processing by the host, these parasite genes were fused to a DNA sequence encoding an antibody that specifically binds dendritic cell surface protein (αDEC205 single chain Fv). DNA plasmids carrying mutated forms and/or anti-DEC205 were then co-administered with plasmids encoding the Th2 promoting cytokine IL4, and/or antigen-presenting cell activating MIP1α and Flt3L. Mice immunized with mutated forms (ADDALT and CPImu) of parasite antigens produced more specific antibody post-challenge and showed strongly increased lymphocyte stimulation above controls immunized with the native form. The immune response was further enhanced when plasmids encoding IL4, MIP1α, Flt3L and anti-DEC-205 forms were co-administered, resulting in production of a Th2/IgG1 phenotype. Significant reduction of worm burden (82.3%) was achieved by a cocktail vaccination which combined the ADDALT and CPImu candidates. Mice immunized with Ls-VAH and Ls-TPX DNA carried by αDEC205 elicited Th2-biased responses with up-regulated IgG1 and IgE antibodies as well as enhanced IL5, IL4, and IL13 and diminished IFNγ production compared to controls. The immune responses were further driven towards the Th2/IgG1 phenotype when Ls-VAH and Ls-TPX were injected with plasmids encoding ADDALT and CPImu and with the adjuvants Flt3L, MIP1α and IL4. This resulted in reduction in worm burden of 55.7% (cocktail vaccine containing Ls-VAH) and 41.6% (cocktail vaccine containing Ls-TPX) respectively in vaccinated animals.

The immunogenicity and protective efficacy of a DNA vaccine encoding a truncated groEL heat shock gene (pcDNA3/groEL) from Burkholderia pseudomallei was evaluated in vaccinated BALB/c mice infected with B. pseudomallei or B. cenocepacia. After vaccination, the levels of anti-GroEL total IgG and IgG2a were increased in mouse sera. The clonal expansion of the spleen cells increased, and the GroEL protein induced IFN-£^ production by spleen cells. The anti-GroEL antibody-mediated opsonic killing effect was not able to eliminate the growth of B. pseudomallei but was able to eliminate the growth of B. cenocepacia. After intravenous challenge of the vaccinated Balb/c mice with B. pseudomallei, the number of bacteria colonizing the in liver and/or spleen was not reduced. Over 50% of vaccinated mice infected with B. pseudomallei died within 7 days post-infection. By contrast, the bacterial loads in organs were significantly reduced if the vaccinated mice were infected with B. cenocepacia. All of vaccinated mice were alive 7 days post-infection. Liver damage, as assessed by histological observation, and abnormalities in the levels of liver enzymes rapidly resolved in vaccinated mice. We suggest that B. pseudomallei groEL plasmid DNA immunization of Balb/c mice induces a Th1-type immune response and provides cross-protection against B. cenocepacia but not against B. pseudomallei infection.

O presente estudo teve como principal objetivo aprimorar os efeitos antitumorais de uma nova estratégia imunoterapêutica para controle de tumores induzidos pelo vírus do papiloma humano tipo 16 (HPV-16). Para tal finalidade foi utilizado um novo conceito de imunoterapia ativa, baseada em uma vacina de DNA recombinante, desenvolvida no Laboratório de Desenvolvimento de Vacinas da USP (pgDE7h) e diferentes abordagens experimentais delineadas com a finalidade de aumentar a eficácia terapêutica do tratamento. Desta forma, o presente trabalho focou no desenvolvimento de novos sistemas de entrega para a vacina de DNA empregando três nanocarregadores distintos, de natureza lipídica, proteica ou peptídica, e a avaliação da eficácia terapêutica desses frente a tumores pré-estabelecidos. O presente trabalho também avaliou a combinação da imunoterapia, baseada no vetor pgDE7h, com a quimioterapia, empregando o composto cisplatina, de forma a permitir o tratamento de tumores em estágios mais avançados de crescimento. Os resultados demonstram que a associação do plasmídeo vacinal com vesículas peptídicas mostrou-se capaz de ativar células dendríticas murinas in vitro e promover aumento na sobrevivência de animais frente ao modelo de tumores subcutâneos, sem induzir toxicidade. Quando combinada ao tratamento com cisplatina, a vacina, principalmente associada à eletroporação, demonstrou um efeito sinérgico, promovendo regressão total de tumores, aumento expressivo na ativação de linfócitos T CD8 E7-específicos, indução de resposta de memória efetora e memória residente e controle de populações imunossupressoras de forma sistêmica e no microambiente tumoral. Em resumo, a pesquisa ampliou os conhecimentos sobre a ação da imunoterapia ativa contra tumores induzidos por HPV e abriu perspectivas importantes para sua utilização em condições clínicas. / The present study aimed to improve the antitumor effects of a new immunotherapeutic strategy for the control of tumors induced by human papillomavirus type 16 (HPV-16). For this purpose, a new concept of active immunotherapy based on a recombinant DNA vaccine developed at the Laboratory of Vaccine Development at USP (pgDE7h) was used, and different experimental approaches were designed to increase the therapeutic efficacy of the treatment. Thus, the present work focused on the development of new delivery systems for the DNA vaccine using three distinct nanocarregadores, of a lipid, protein or peptidic nature, and the evaluation of the therapeutic efficacy of these in front of pre-established tumors. The present study also evaluated the combination of pgDE7h-based immunotherapy with chemotherapy using the cisplatin compound to allow the treatment of tumors in more advanced stages of growth. The results demonstrate that the association of the peptide-vesicle vaccine plasmid was shown to activate murine dendritic cells in vitro and promote increased survival of animals against the subcutaneous tumor model without inducing toxicity. When combined with cisplatin treatment, the vaccine, mainly associated with electroporation, demonstrated a synergistic effect, promoting total tumor regression, expressive increase in the activation of CD8 E7-specific T lymphocytes, induction of effector and resident memory response and control of immunosuppressive populations in a systemic way and in the tumor microenvironment. In summary, the research expanded knowledge about the action of active immunotherapy against HPV-induced tumors and opened important perspectives for its use under clinical conditions.

Genetic immunization, also known as DNA or polynucleotide immunisation, is well documented to induce broad-based immunity in various animal models of infectious and non-infectious diseases. However, the low potency of DNA vaccines has to date precluded the development of commercial vaccines. The aim of this study was to systematically investigate a number of parameters to improve the potency of DNA vaccines for use in chickens, using a low pathogenic avian influenza (LPAI) virus as a proof-of-concept for their ability to produce a humoral immune response. The index virus used in the study was avian influenza virus A/coot/WA/2727/79 (H6N2), isolated from an apparently healthy Eurasian coot in 1979. Prior to any DNA experiments the virus was rigorously characterized. The virus strain was shown to be an H6 subtype by haemaglutination inhibition (HI) testing and as an N2 subtype by gene sequence analysis. The isolate was shown to be able to grow on MDCK cells in the absence of exogenous trypsin. It was further biologically characterized as LPAI with an intravenous pathogenicity index (IVPI) of 0.15 and a motif of 321PQAETRG328 at the cleavage site of the haemagglutinin (HA) protein. It was capable of infecting domestic chickens under experimental conditions with a low level of virus excretion via the cloaca and oropharynx following intravenous or oral and oculonasal inoculation. The full-length HA and nucleoprotein (NP) genes of this H6N2 virus were subsequently cloned into the eukaryotic expression vector VR1012 to generate VR-HA and VR-NP constructs. Six-week-old Hy-Line chickens were intramuscularly injected with either the VR-HA or VR-NP vaccine at different dose rates, with or without lipofectin as adjuvant. Minimal or no detectable antibody was produced, as measured by HI, ELISA and Western blotting-based assay, but high titres of H6-specific HI antibodies appeared 10 days after homologous virus challenge. In contrast to the empty vector controls, there was a significant difference in HI antibody titre between pre- and post-challenge in vaccinated birds, indicating some evidence for the priming effect of the DNA vaccines. Using the frequency of virus shedding as an indicator of protection, lower doses (50 or 100 ¦Ìg per chicken) of either adjuvanted VR-HA or VR-NP vaccine significantly reduced virus shedding in oropharyngeal and cloacal swabs compared to higher doses (300 or 500 ¦Ìg per chicken ) or empty vector control chickens. Although two vaccinations with naked VR-HA alone were not sufficient to induce an effective immune response against a homologous virus challenge, further repeat vaccinations and incorporation of adjuvant did lead to the generation of low to moderate HI antibody titres in some chickens and resulted in no or reduced virus shedding after challenge. Next, to examine the effect of expression vector, three different DNA vectors, pCI, pCI-neo and pVAX1 were used to clone the same HA gene and generate three DNA vaccine constructs. Once again, direct intramuscular injection of the three DNA constructs did not elicit measurable H6-specific HA antibody response in Hy-Line chickens but the 100 µg pCI-HA lipofectin adjuvanted vaccine group showed a significant increase in post-challenge HI titres from the naive control group, indicating that an anamnestic antibody response had been induced by the pCI-HA DNA vaccination. Compared with the controls, the three DNA constructs showed significantly reduced virus shedding in cloacal swabs post virus challenge, suggesting that the three DNA vaccines induced some level of immune response in vaccinated chickens. As with the VR-HA construct, the lower dose groups for each vaccine (50 or 100 g) were more effective at reducing virus shedding from the cloaca than the higher dose group (300 g). To further investigate why the DNA vaccines did not elicit a measurable antibody response, the HA gene incorporating a Kozak enhancer sequence was cloned into an alternative expression vector, pCAGGS, to produce the pCAG-HAk construct. Three-week-old SPF chickens were immunized with this construct either by the intramuscular route (IM) or electroporation (EP). H6 HI antibodies were present in some chickens by 3 weeks after the first IM vaccination and 75% of the chickens vaccinated with 10, 100 or 300 µg pCAG-HAk were antibody positive by 2 weeks after the second IM vaccination. For EP immunization, 87.5% of vaccinated birds seroconverted after the first vaccination and 100% seroconverted after the second vaccination and the H6 HI antibody titres were significantly higher than for chickens vaccinated by IM inoculation. Another group was given a single dose IM vaccination with 100 µg of the pCAG-HAk construct and showed a maximum sero-conversion rate of 53.3% with a peak H6 HI titre of 27 at 5 weeks post-vaccination. This demonstrated that optimization of the expression vector and insertion of a Kozak sequence could synergistically enhance expression of the H6 HA gene and result in a measurable H6 antibody response in SPF chickens. EP was also compared with IM inoculation with the 100 g pCI-HA construct in SPF chickens, resulting in a 50% sero-conversion rate and mean HI titre of 21.3 at 2 weeks after the second vaccination by EP. By comparison, only 25% chickens had trace HI titres by IM inoculation. This indicated that EP was more efficient than IM delivery for both constructs. A codon-optimized complete HA gene from A/coot/WA/2727/79 (H6N2) was then chemically synthesized and cloned into a pCAGGS vector to generate the pCAG-optiHAk construct. SPF chickens immunized twice with either 10 µg or 100 µg of pCAG-optHA showed 37.5% and 87.5% sero-conversion rates respectively, with a mean H6 HI tire of 21.4 and 22.6 at 3 weeks after the second immunization, but the differences were not statistically significant. There were also no significant differences in either the sero-conversion rate or the H6 HI titre between the pCAG-HAk and pCAG-optiHAk groups, suggesting that a codon-optimized HA DNA vaccine did not achieve significantly better immunogenicity than the pCAG-HAk vaccine. In vitro expression of the developed DNA constructs in chicken-, hamster-, monkey- and human-origin cells, as measured by Western blotting and immunofluorescence testing (IFT), showed the strength of H6 HA expression in the following descending order - pCAG-optiHAk/pCAG-HAk, pCI-HAk, VR-HA, pCI-HA, pCIneo-HA and pVAX-HA. The in vivo chicken vaccinations also showed that the pCI-HA construct was more effective than the pCI-neo-HA, and that the pCAG-optiHA or pCAG-HAk constructs were better than pCI-HAk in term of reduction in virus shedding after H6N2 virus challenge. Thus, in vitro HA gene expression directly correlated with the generation of immune responses in vivo, indicating that in vitro studies can be used for pre-selection of expression plasmids prior to development of avian influenza DNA vaccines. Lipofectin as a chemical adjuvant was shown to enhance the DNA-induced immune response but is prohibitively expensive for routine use in poultry vaccines. Thus, an experimental adjuvant for poultry DNA vaccines (Essai) and a new nanoparticle (Phema) adjuvant used for the first time in poultry were compared with conventional aluminum salts (alum) adjuvant in the present study. No HI antibody was detected in any adjuvant-vaccinated Hy-Line chickens following two immunizations. However, in comparison with the naive control group, the alum- and Phema adjuvanted pCAG-HAk groups significantly reduced the frequency of virus shedding in oropharyngeal swabs, but Essai adjuvant was not effective in augmenting the pCAG-HAk vaccine efficacy. This pilot study also emphasised that the traditional aluminum hydroxide adjuvant, either DNA binding or non-binding, may be useful as an adjuvant for enhancing DNA-induced immune responses in chickens owing to its low price and safety record. Overall, DNA immunization with various HA-expressing constructs was shown to be variably effective in inducing immune responses in chickens. The efficacy of DNA vaccines could be synergistically improved by taking appropriate approaches. With continuing research DNA vaccines have the potential to become an important tool for disease prevention and control.

The small envelope of hepatitis B virus (HBV) can self-assembles into virus-like particles (VLPs) and they are highly immunogenic. The use of hepatitis B surface antigen (HBsAg) as a vector to deliver foreign CTL epitopes has met with little success due to the constraints of HBsAg stability and secretion imposed by the insertion of foreign sequence into critical regions. In this study, the efficacy of the small HBsAg envelope protein to deliver foreign CTL epitopes using a protective CTL epitope of human respiratory syncytial virus (RSV) was investigated. The strategy of deleting a DNA sequence encoding HBsAg-specific CTL epitopes at different sites and replacing with DNA sequence encoding RSV CTL epitope resulted in recombinant HBsAg DNA immunogens which elicited effector and memory CTL responses in vitro, and RSV protective responses in vivo when these recombinant HBsAg DNAs were used to immunised mice. These data demonstrate the efficacy of HBsAg DNA as a vector for the delivery of disease relevant protective CTL responses. They also suggest the applicability of the approach to derive recombinant HBsAg DNA immunogens simultaneously encoding protective CTL epitopes for multiple diseases. The use of HBsAg VLPs has been used globally as administered vaccine for hepatitis B virus infection makes it an attractive vector candidate to deliver immunogens for other diseases. Since the HBsAg DNAs we tested formed recombinant HBsAg VLPs, our results have implications for the development of vaccination strategies using either recombinant HBsAg DNA or VLP vaccines.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-04-04T18:49:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2011-Dissertação-ElydaLima.pdf: 2803583 bytes, checksum: 5b93b96556bc230adb5bb7ca5a4fb423 (MD5) / Made available in DSpace on 2017-04-04T18:49:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2011-Dissertação-ElydaLima.pdf: 2803583 bytes, checksum: 5b93b96556bc230adb5bb7ca5a4fb423 (MD5) Previous issue date: 2011-03-16 / A bovinocultura é um dos principais destaques do agronegócio brasileiro no cenário mundial. No entanto, algumas doenças vêm causando prejuízos consideráveis entre elas está a papilomatose bovina, uma doença infectocontagiosa, de caráter tumoral, com etiologia relacionada a infecção pelo papilomavírus bovino (BPV) que se caracteriza pela formação de tumores em tecidos da pele e mucosa. Hoje se conhecem 11 tipos diferentes de Papilomavírus bovino, sendo os BPvs tipos 1, 2 e 4 oncogênicos. Até o momento não existe vacinas para o controle ou tratamento das papilomaviroses. Diferentes estudos vêm demonstrando que a proteína L2 pode ser uma candidata ao desenvolvimento de estratégias vacinais profiláticas contra o BPV. Neste trabalho, tivemos como objetivo construir um vetor vacinal a partir do plasmídeo pCINeo (Promega®) e do gene L2 de BPV1, avaliando in vitro a expressão do antígeno L2 em células de mamíferos. O gene L2 foi amplificado pela técnica de PCR a partir do genoma completo de BPV1, com uso de oligonucleotídeos específicos contendo um epítopo AU1 no primer forwarde posteriormente clonado em vetor de passagem pGEM-T Easy (Promega®) e subclonado no vetor de expressão pCIneo, gerando a construção pCIL2B1. O plasmídeo foi transfectado in vitroem células 293 para análise funcional da expressão de L2. Os resultados obtidos confirmaram a construção pCIL2B1 por PCR e sequenciamento. A capacidade desta construção expressar o gene L2 e produzir a respectiva proteína em células de mamífero foi confirmada por RT-PCR e western blot (usando anticorpo contra o epítopo AU1). / The cattle industry is one of the main highlights of the Brazilian agribusiness on the international stage. However, some diseases have caused considerable damage including bovine papillomatosis which is an infectious tumorous disease related to bovine papillomavirus (BPV) etiology and characterized by the formation of tumors in tissues of the skin and mucosa. Currently we know 11 different types of bovine papillomavirus, among which the BPv types 1, 2 and 4 are oncogenic. So far there is no vaccine or treatment for the papilomaviroses control. Different studies have reported that the L2 protein may be a candidate for the development of prophylactic vaccine strategies against BPV. The L2 protein has a potential cross-reaction with different BPVs and HPV (HumanPapillomavirus). On this paper, our objective was to construct a vector vaccine from pCINeo plasmid (Promega ®) and the gene of BPV1 L2, evaluating in vitro L2 antigen expression in mammalian cells.The L2 gene was amplifiedby PCR from thecomplete genome ofBPV1, using specifico ligo nucleotidescontainingan AU1epitopein the for wardprimerand subsequently cloned intop GEM-T Easyvector(Promega ®)and subclonedin expression vector pCIneo, pCIL2B1generatingbuilding. The plasmid was transfectedinto 293 cellsin vitrofunctional analysisforthe expression ofL2. ObtainingconstructionpCIL2B1was confirmed by PCRand sequencing.The capacityof this construction to express the geneand produce their L2 protein inmammalian cellswas confirmed by RT-PCR and western blot (usinganti body against the epitopeAU1). The results confirmed the L2 gene expression in mammalian cellsand the consequent production of the protein L2 BPV-1.

Thesis (MSc (Biochemistry))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The ostrich industry in South Africa is currently threatened by respiratory disease in feedlot ostriches which causes a dramatic loss in production. Ms01, Ms02 and Ms03 were identified as the three ostrichspecific mycoplasmas to be associated with this respiratory disease in ostriches of South Africa. The ostrich-specific mycoplasmas have a major impact on ostrich production and for this reason there is a serious need for treatment for these infections. For this reason, the ostrich industry has undertaken an investigation into the development of vaccines against mycoplasma infections. In this study, an approach to DNA vaccine development will be investigated and applied, specifically for the ostrich mycoplasma Ms02. Firstly, the whole genome of Ms02 was sequenced using GS FLX sequencing technology. The contiguous sequences obtained from the whole-genome sequencing were analysed bioinformatically which included the annotation of the contiguous sequences and the subsequent search for a vaccine candidate gene for the development of a DNA vaccine. The P100 gene of Ms02, which showed a high degree of homology with the P100 gene of the human pathogen M. hominis, was chosen as a vaccine candidate gene for the development of a DNA vaccine. The P100 gene was successfully cloned and subsequently modified by means of site-directed mutagenesis to correct for alternative codon usage, where after the modified P100 gene was subcloned into the mammalian expression vector, pCI-neo for vaccination trials in the near future. / AFRIKAANSE OPSOMMING: Die volstruisbedryf van Suid-Afrika is tans bedreig deur 'n respiratoriese siekte in voerkraal volstruise wat lei tot aansienlike verliese in volstruisproduksie. Ms01, Ms02 en Ms03 is geïdentifiseer as die drie volstruis-spesifieke mikoplasmas wat 'n rol speel in hierdie respiratoriese siektes van volstruise in Suid- Afrika. Die drie volstruis-spesifieke mikoplasmas het 'n groot impak op die produksie van volstruise en om hierdie rede is daar 'n ernstige behoefte aan 'n behandeling van hierdie infeksies. Ten einde mikoplasma infeksies in volstruise te voorkom, het die Suid-Afrikaanse volstruisbedryf 'n ondersoek geloods na moontlike strategieë vir entstof ontwikkeling. In hierdie studie, is 'n benadering van DNA entstof ontwikkeling ondersoek en toegepas, spesifiek teen die volstruis mikoplasma Ms02. Eerstens, is die volledige Ms02 genoomvolgorde bepaal deur gebruik te maak van GS FLX volgordebepalingstegnologie. Die gedeeltelike volgordes verkry vanaf die heelgenoom volgordebepaling is bioinformaties geanaliseer wat die annotering van die gedeeltelike volgordes asook die soektog vir 'n kandidaat entstof geen vir die ontwikkeling van 'n DNA entstof ingesluit het. Die P100 geen van Ms02, wat hoë homologie met die P100 geen van die menslike patogeen M. hominis getoon het, is gekies as die kandidaat entstof geen. Die P100 geen is suksesvol gekloneer en gemodifiseer deur middel van setelgerigte mutagenese om die P100 geen geskik te maak vir die invoeging in die soogdier ekspressie vektor, pCI-neo vir toekomstige entstofproewe.