A leptospirose é uma zoonose de importância mundial causada por bactérias do gênero Leptospira. No Brasil, a maioria dos casos é causada por L. interrogans sorovar Copenhageni. O objetivo destre trabalho foi identificar adesinas de leptospira pela técnica de Phage display. Bibliotecas com fragmentos genômicos resultaram na idendificação de ligantes de leptospira com afinidade por tecidos de hamster. Uma varredura dessas bibliotecas contra heparan sulfato proteoglicano (HSPG) identificou como ligantes as proteínas LigA e LigB. Proteínas recombinantes foram produzidas e submetidas à ligação às células de mamíferos e aos componentes de matriz extracelular. LigB recombinante foi capaz de se ligar ao HSPG, à heparina e às células de mamíferos. HSPG e heparina foram capazes de reduzir significativamente a interação dessa proteína com as células. Estes resultados evidenciam o papel de proteínas da leptospira na sua interação com o hospedeiro e ilustram a possibilidade do uso da técnica de phage display para identificar possíveis adesinas. / Leptospirosis is a worldwide important zoonosis caused by bacteria of the genus Leptospira. In Brazil, most cases is caused by L. interrogans serovar Copenhageni. Our goal was to identify leptospiras adhesins by phage display technique. Libraries of genomic fragments resulted in the identification of ligands with affinity for leptospiras hamster tissues. Screening these libraries against heparan sulfate proteoglycan (HSPG) identified the proteins LigA and LigB. Recombinant proteins were produced and subjected to binding to mammalian cells and extracellular matrix components. LigB recombinant was able to bind to HSPG, heparin and mammalian cells. HSPG and heparin were able to significantly reduce the interaction of this protein with cells. These results highlight the role of leptospiras proteins in its interaction with the host and illustrate the possibility of the use of phage display technique to identify potential adhesins.

O HPV (Papilomavírus Humano) causa verrugas anogenitais e alguns tipos de câncer, como o câncer de colo do útero. Seu capsídeo é composto pelas proteínas L1 e L2. A L1 se autoestrutura em VLPs, utilizadas nas atuais vacinas comerciais. Para a geração de vacinas com maior espectro de proteção, a L2 é promissora, pois gera proteção cruzada. Para caracterizar VLPs de L1L2 do HPV16, células HEK293T cotransfectadas tiveram a expressão proteica analisada por citometria de fluxo, Western blotting, microscopia confocal a laser e eletrônica de transmissão. As proteínas L1 (60kDa) e L2 (100kDa) estavam presentes no núcleo e no citoplasma celular, formando VLPs de L1L2 de conformação heterogênea, cuja máxima expressão ocorre 12h após a transfecção. As VLPs extraídas estavam em diferentes estágios de estruturação. Foi possível estabelecer um sistema eficaz de produção heteróloga das proteínas de VLPs de L1L2, que poderão ser utilizadas em testes pré-clínicos, na pesquisa básica e contribuir no desenvolvimento de uma vacina profilática de amplo espectro de ação contra o HPV. / HPV (Human Papillomavirus) is the causative agent of anogenital warts and several types of cancer, as cervical cancer. The HPV capsid is composed of L1 and L2 proteins. L1 can self-assemble into VLPs (virus-like particles), the basis for HPV commercially available vaccines. To generate broad-spectrum vaccines L2 shows the greatest promise, due to cross-protection. To characterize VLPs composed of HPV16 L1 and L2 proteins, cotransfected HEK293T cells were analyzed by flow cytometry, confocal laser scanning microscopy, transmission electron microscopy and Western blotting. Proteins L1 (60kDa) and L2 (100kDa) were present in cell nucleus and cytoplasm, forming heterologous L1L2 VLPs with highest expression at 12h post-transfection. Extracted VLPs were at different maturation stages. It was possible to establish an efficient system of heterologous L1, L2 and L1L2 VLPs production. After some adjustments in protocols, these particles could be used in preclinical tests, HPV basic research and also in the development of an HPV broad-spectrum vaccine.

O presente trabalho propõe o desenvolvimento e a caracterização de uma estratégia vacinal de caráter profilático contra o vírus da dengue (VD), baseada nas proteínas NS1 e domínio III da proteína E (EIII), empregando proteínas recombinantes em ensaios de imunização por via sub-cutânea em modelo murino. Estes antígenos foram obtidos pela clonagem e expressão de suas sequências de DNA codificadoras em sistema procarioto (E. coli). Além disso, formas atóxicas da toxina termo-lábil (LTG33D e LTK63) de E. coli enterotoxigência (ETEC) foram obtidas e incorporadas como adjuvantes às formulações vacinais. As respostas celulares e humorais anti-NS1 e anti-EIII foram monitoradas por ELISA para anticorpos e citocinas, ICS (do inglês intracellular citokine staining) e atividade citotóxica in vivo. Observamos que animais imunizados com a NS1 recombinante adicionada da LTG33D foram capazes de gerar respostas imunológicas com produção de anticorpos específicos e alta afinidade pelo antígeno. Em ensaios de desafio realizados para avaliar a proteção vacinal conferida à infecção por uma linhagem referência do o VD tipo 2 (NGC) observamos que essa formulação conferiu uma proteção de 50% aos animais imunizados. Paralelamente a esses resultados, demonstramos que a EIII não é um bom antígeno vacinal e que pode induzir anticorpos capazes de acentuar a infecção do VD. Descrevemos ainda a obtenção e a caracterização genética e patológica de um isolado clínico de VD tipo 2 naturalmente letal para camundongos Balb/C. A nova cepa viral (JHA1) demonstrou ser capaz de induzir perda de peso corporal, dano tecidual geral, e distúrbios hematológicos similares aos observados em humanos infectados pelo VD, podendo ser aplicada como modelo de infecção na avaliação de candidatos vacinais. Os resultados obtidos neste trabalho representam uma importante contribuição na área de desenvolvimento de estratégias vacinais contra a dengue e representam uma base importante para futuros estudos sobre a patologia da dengue. / The present study proposes the development and characterization of a strategy for prophylactic vaccination against dengue virus (VD) based on the NS1 protein and the domain III of the envelope glycoprotein (EIII), using recombinant proteins in subcutaneous immunization in a murine model. These antigens were obtained by cloning and expression of their DNA coding sequences in prokaryotic system (E. coli). In addition, the s non-toxic forms of the heat-labile toxin from enterotoxigenic E. coli (ETEC) (LTK63 and LTG33D) were obtained and incorporated as adjuvants to vaccine formulations. Anti-NS1 and anti-EIII cellular and humoral immune responses were monitored by antibody and cytokine ELISA, , intracellular citokine staining (ICS) and in vivo cytotoxic activity. We observed that animals immunized with the recombinant NS1 and LTG33D were capable to induce immune responses including specific antibodies with high affinity for the antigen. In challenge assays performed to evaluate the immunization protective efficacy such vaccine conferred protection of 50% against infection with a reference type 2 VD (VD2) strain(NGC). Alongside to these results, we demonstrated that EIII is not a good vaccine antigen and can induce the generation of antibodies that enhance DENV infection. We also described the isolation and the genetic and pathological characterization of a VD2 clinical isolate naturally lethal to immunocompetent Balb/c mice. The new strain was shown to cause weight loss, general tissue damage, and hematological disturbances similar to those observed in VDinfected humans, and therefore, may be applied as infection model to evaluate vaccine candidates. The results obtained in this study represent an important contribution to DENV vaccine development and established an important background for future studies of the dengue pathology.

Animais hematófagos possuem em sua saliva substâncias que permitem a fluidez do sangue, para o sucesso de sua alimentação. Com isso, têm sido descritos diversos componentes com atividades nos diferentes processos hemostáticos (coagulação, fibrinólise e agregação plaquetária). O complexo salivar da sanguessuga Haementeria depressa vem sendo estudado através de bioquímica clássica e análises transcriptômica e proteômica deste tecido determinaram o perfil dos transcritos e das proteínas produzidas. Dentre os transcritos mais abundantes foram encontrados três clones (H06A09, H06A02 e L02F02) que apresentaram 45%, 87% e 94% de similaridade ao LAPP, um inibidor de agregação plaquetária da sanguessuga Haementeria officinallis, a produção destes componentes pelo tecido foi confirmada pela análise proteômica. O LAPP é um inibidor que age pela via do colágeno e possui cerca de 14 kDa e pI de 4,0 e inibe a ligação da plaqueta ao colágeno tanto pelo epítopo do FvW quanto pelo domínio <font face=\"Symbol\">a2<font face=\"Symbol\">b1. Assim, o objetivo do presente trabalho foi clonar, expressar e caracterizar a proteína recombinante ativa, a partir do clone H06A09 para estudos de atividade desta molécula. Para obter a proteína recombinante de interesse inicialmente a clonagem do transcrito foi realizada com sucesso em vetor pAE, porém, a expressão em sistema procarioto apresentou alguns obstáculos já que a molécula não tinha atividade. Uma nova estratégia foi proposta, sendo realizada clonagem em vetor pPIC9K e expressão em sistema eucariótico (leveduras Pichia pastoris - GS115). Após a utilização de diferentes metodologias para estabelecimento das melhores condições para expressão neste sistema, foi eleito o protocolo onde a proteína recombinante era expressa a 28 °C, sob agitação de 260 rpm, e indução por 0,5% de Metanol a cada 24h, durante 72h de expressão. A molécula recombinante expressa e secretada foi submetida a diferentes metodologias para purificação, assim, determinou-se que a estratégia utilizada que melhor isolou a proteína foi a submissão do sobrenadante da expressão à diálise e concentração em sistema de ultrafiltração (Amicon 5 kDa Millipore) seguida de uma cromatografia de gel filtração em Superdex 75 (GE), sistema FPLC, com coleta fracionada. Ensaios de agregação plaquetária confirmaram a atividade inibitória da proteína recombinante tanto em sangue total como em PRP (plasma rico em plaqueta) e plaqueta lavada, especificamente quando o agonista era o colágeno, apresentando IC50 para PRP e plaqueta lavada de 20 e 712 ng, respectivamente. Ensaios por citometria de fluxo indicaram que a proteína recombinante, diferente do LAPP, age na inibição da agregação plaquetária induzida por colágeno, pela ligação à subunidade Ib<font face=\"Symbol\">a do complexo GPIb-IX-V, complexo este que usa o FvW como ponte entre a plaqueta e o colágeno, firmando assim a interação da plaqueta ao subendotélio e posterior agregação. Desta forma, o presente trabalho caracteriza o primeiro inibidor recombinante de agregação plaquetária pela via do colágeno proveniente de sanguessugas Haementeria depressa, e comprova que apesar de apresentar 45% de similaridade estrutural ao LAPP é um inibidor com características funcionais diferentes, e com grande potencial a ser estudado. / Hematophagous animals have in their saliva substances that maintain the blood fluidity to the success of their feeding. Therefore, components have been described by their activities in the hemostatic processes (coagulation, fibrinolysis and platelet aggregation).The salivary complex of Haementaria depressa leech has been studied by classical biochemical and transcriptomic and proteomic analysis of this tissue determined the profile of transcripts and proteins produced by it. Among the most abundant transcripts were found three clones (H06A09, H06A02 e L02F02) that showed 45%, 87% e 94% of similarity to LAPP, an inhibitor of platelet aggregation from Haementeria officinallis, the components production was confirmed by proteomic analysis. LAPP is a inhibitor that acts by collagen pathway and has around 14 kDa and pI of 4.0, and inhibits the binding of platelet to collagen by both the epitope domain of vWF as the <font face=\"Symbol\">a2<font face=\"Symbol\">b1. Thereby, the aim of this study was to clone, express and characterize the active recombinant protein from the clone H06A09 for studies of activity of this molecule. To obtain the recombinant protein initially cloning of transcript was successfully performed in pAE vector, however, the protein expressed in prokaryotic system presented some obstacles not presenting activity. A new strategy was proposed, being held in pPIC9K vector and expression in eukaryotic system - yeast Pichia pastoris (GS115). After using different methodologies to establish the best conditions for expression in this system, was elected the protocol where the recombinant protein was expressed in 28 °C, under agitation of 260 rpm, and 0.5% methanol induction every 24 hours during 72 hours of expression. The recombinant molecule was expressed in soluble portion and was subjected to differents methods for purification, so it was determined that the best strategy to isolation of the protein was the concentration and dialysis of the expression supernatant by ultrafiltration system (Amicon 5 kDa Millipore) followed by gel filtration chromatography on Superdex 75 (GE), FPLC system. Tests confirmed the platelet aggregation inhibitory activity of the recombinant protein in whole blood, PRP (platelet rich plasma) and in washed platelets, specifically when the agonist was collagen, with IC50 to PRP and washed platelet of 20 and 712 ng, respectively. Assays by flow cytometry indicated that the recombinant protein, different from LAPP, acts to inhibit platelet aggregation induced by collagen, by the binding to the Ib<font face=\"Symbol\">a subunit of the GPIb-IX-V complex, this complex uses the vWF as a bridge between the platelet and collagen, thus firming the interaction of the subendothelium and subsequent platelet aggregation. Thus, this study characterized the first recombinant inhibitor of platelet aggregation through collagen pathway from Haementeria depressa leeches, and proves that despite having 45% structural similarity to the LAPP is an inhibitor with different functional characteristics, and with great potential to be studied.

O Lopap é um ativador de protrombina da lagarta L. obliqua, pertence à família das lipocalinas e apresenta atividade antiapoptótica. O Lopap foi obtido na forma recombinante (rLopap), na levedura P. pastoris, por metodologia escalonável, e sua atividade foi avaliada in vitro e in vivo. O tratamento com rLopap reduziu o tempo de sangramento em animais anticoagulados com enoxaparina. Por outro lado, um peptídeo derivado do Lopap, designado antiapoptotic peptide (AP), foi capaz de induzir a síntese de colágeno em cultura de fibroblastos e na derme de animais. A região correspondente a AP apresentou propriedades físicas e estruturais semelhantes a seqüências relacionadas em outras lipocalinas com atividade antiapoptótica. Estes resultados abrem perspectivas para aplicações do Lopap, como uma molécula procoagulante, e de AP, através de sua ação na modulação celular, como um componente cosmético, no reparo e remodelamento tecidual e em disfunções que envolvem morte celular e perda de colágeno. / Lopap is a prothrombin activator from the L. obliqua caterpillar, belongs to the lipocalin family, and displays antiapoptotic activity. Lopap was obtained in the recombinant form (rLopap) in the P. pastoris yeast, by a scaled up methodology, and its activity was evaluated in vitro and in vivo. Treatment with rLopap reduced the bleeding time in animals anticoagulated with enoxaparin. On the other hand, a Lopap-derived peptide, designated antiapoptotic peptide (AP), was able to induce collagen synthesis in fibroblast culture and in the animal dermis. The region corresponding to AP had similar physical and structural properties when compared with other antiapoptotic lipocalins. These results open perspectives for the use of Lopap, as a procoagulante molecule, and the use of AP, based on its cell modulation effects, as a cosmetic component, aiding tissue repair and in dysfunctions involving cell death and loss of collagen.

A leptospirose é uma zoonose de importância global causada por espiroquetas patogênicas do gênero Leptospira. Foi avaliado o potencial adjuvante da flagelina FliCi de Salmonella enterica sorovar Thyphimurium na indução de resposta imunoprotetora em uma formulação vacinal acelular composta pela proteína LigAc e por seis prováveis lipoproteínas de membrana externa recombinantes de Leptospira interrogans sorovar Copenhageni como alternativa profilática. Grupos de hamsters imunizados com LigAc co-administrada com o pool das proteínas acrescidas de FliCi ou Al(OH)3 apresentaram altos títulos de anticorpos contra as proteínas recombinantes e foram protegidos do desafio letal (86-100%). Grupos imunizados com vacina comercial, bacterina ou pool+LigAc+FliCi apresentaram redução na colonização renal (0-28%). Dados sugerem aumento da expressão dos genes das citocinas de resposta Th1/Th2. Os resultados demonstram que novas formulações vacinais, compostas por proteínas recombinantes e flagelina FliCi como adjuvante, é um caminho promissor. / Leptospirosis is a global zoonotic disease caused by pathogenic spirochetes of the genus Leptospira. In the present study, we evaluated the adjuvant activity of Salmonella enterica FliCi flagellin in the protective immunity induced by the LigAc and also by six other novel recombinant leptospiral outer membrane lipoproteins (OMP) of Leptospira interrogans serovar Copenhageni. Immunization of hamsters with LigAc or LigAc coadministered with OMPs cocktail, both with FliCi or Al(OH)3, induced robust antibody responses against recombinant proteins, and conferred protection after challenge (86-100%). Moreover, only groups inoculated with the commercial vaccine, bacterin or LigAc coadministered with OMPs cocktail and FliCi as adjuvant showed reduced bacterial load in kidneys (0-28%) with significant enhancement of gene expression of both Th1 and Th2 cytokines. Taken together, our data pave the way for the development of novel vaccine formulations against leptospirosis, using recombinant proteins and FliCi as adjuvant.

A proteína de matriz do Virus Respiratório Sincicial humano foi o foco deste trabalho. Verificamos que o gene de matriz possui sítios internos de poliadenilação, sinais de instabilidade de RNA, baixo índice de adaptação de codons (CAI) e conteúdo GC, que podem impedir a expressão gênica vitro. Quando clonado sob controle do promotor de CMVie, o gene selvagem não apresenta expressão detectável, enquanto um gene sintético com a sequência do gene de matriz otimizada apresenta altos níveis de expressão em células transfectadas. Esse alto nível de expressão permitiu a confirmação da presença da proteína M no núcleo no início de sua expressão, por análise em microscopio confocal de varredura a laser, além de sua associação a membranas em regiões conhecidas como lipid rafts. Também foi observado que a proteína M é capaz de associar à proteína tropomiosina. Ainda foram analisados os possíveis domínios funcionais através de expressão de variantes da proteína M com deleções de trechos da proteína. Finalmente foi analisada a capacidade de indução de resposta imune. / The Human Respiratory Syncytial Vírus was the focus of this work. We found that matrix gene has internal polyadenilation sites, RNA instability motifs, low codon adaptation index (CAI) and GC content, that may impair its expression in vitro. When cloned under control of the ieCMV promoter, the wild-type M gene expression was not detectable, whereas a synthetic optimized matrix gene was highly expressed in transfected cells. This high level of expression made possible to follow M nuclear localization in the beginning of its expression by confocal laser scanning microscopy, and its association with membranes in regions known as lipid rafts. It has also been found that the matrix protein associates with tropomyosin. It was further analyzed the possible functional through expression of deviations of the M protein that lack portions of the protein. Finally it was analyzed its capacity to induce an immune response.

No description available.

Many diseases display a multitude of relevant factors that contribute to the persistence of the disease and difficulty treating it. The multifactorial characteristics of some diseases lead to the requirement of combination of treatments in order to restore health. The latter may necessitate the mixing of treatments, medications, and therapeutics to first halt the disease, then assist the human body in returning itself to a state of normality. For example, chronic wounds exhibit this multifactor characteristic in which there exist many factors that lead to the body’s inability to properly heal in a timely manner. This presents a further threat to the body, such as exposure to infection and long-term pain. In this example, it is important to look at the ultimate cause of a chronic wound, which may be due to presence of other diseases impairing the body’s ability to properly heal. This may include diabetes, initial antibiotic-resistant infection, autoimmune disorders, and poor vasculature. Furthermore, the mentioned causes for chronic wounds may have associations with one another in a single case of a chronic wound. Treating each interrelated cause with drug combinations may run the risk of adverse side effects or further complications due to mixing drugs in a systemic method. The goal of this study is to develop a point-specific, protein-based therapy that incorporates a single-protein molecule with multifunctional characteristics based on what we know about chronic wounds and infections, as a proof of concept of multifunctional proteins. Multifunctionality of a single therapeutic molecule is desirable because it may eliminate the unknowns of how differing individual chemical or protein therapies may interact when simply mixed. In addition, examples of peptides, such as antimicrobial peptides, are known to have synergy, and creating a single protein platform that consists of two synergistic peptides could be of value in the making of a protein with greater activity by guaranteeing that the synergistic peptides are local to one another. Furthermore, broad spectrum activity can be obtained by combining two differing peptides. This proof of concept was accomplished by targeting two proteinases that are upregulated in chronic wounds: Matrix Metalloproteinase-2 (MMP-2) and Neutrophil Elastase. Recombinant DNA techniques were used to create a fusion protein that incorporates an inhibitor of MMP-2, which is a β-Amyloid Precursor Protein-derived Inhibitory Peptide (APP-IP), and PMP-D2, an inhibitor of Neutrophil Elastase. PMP-D2 was joined to the N-terminus of an Elastin-like peptide, while the APP-IP was joined to the C-terminus of the same Elastin-like peptide. Elastin-like peptides (ELPs) are commonly used as a backbone for recombinant protein production as their distinct thermoresponsive characteristics provide adequate protein purification using an inverse transition cycling [3]. In addition, ELPs can serve as point-specific drug delivery platforms with a transition temperature (Tt) near that of normal body temperature causing low diffusivity [3]. Therefore, when ELPs are applied to a site at their Tt, they will aggregate, which provides diffusional limitations of the protein in the application site, and may decrease the reapplication rate needed for a therapeutic, as well as eliminate adverse side effects by retaining the protein to the specific application site. From this dual fusion, the final resulting protein is PMP-D2٠ELP٠APP-IP. This protein was tested for its inhibitory activity of both MMP-2 and Neutrophil Elastase. It was hypothesized that the fusion protein, PMP-D2٠ELP٠APP-IP, would inhibit MMP-2 just as effectively as APP-IP·ELP unaccompanied by PMP-D2, as well as effectively inhibit Neutrophil Elastase to the same degree as PMP-D2·ELP unaccompanied by APP-IP. Furthermore, an additional dually fused ELP fusion protein was currently made with two synergistic antimicrobial peptides fused to each end of the ELP. The two antimicrobial peptides used were human-derived LL37 and insect-derived Cecropin A. This novel fusion peptide contains synergistic increase in antibacterial activity in which preliminary data suggests.

Study of receptor-ligand pair NKR-P1F and Clrg Mouse NKR-P1F:Clr-g receptor:ligand pair is important component of the receptor "zipper" that occurs at the contact between natural killer cell and its target cell, and represents a recently discovered example of lectin-lectin interactions important for recognition among immune cell subsets. In order to study structure of these proteins and interactions between them, we have prepared pET-30a(+) bacterial expression vectors coding parts of extracellular domains of the two receptors. After induction of protein production with IPTG, the proteins precipitated into inclusion bodies, from which they could be refolded in vitro. Refolded proteins were purified using combination of ion exchange and size exclusion chromatography. NKR-P1F construct yielded only small amounts of soluble protein using standard refolding protocols. Furthermore we have experienced difficulties with reproducibility of the refolding results. In the case of Clrg the standard protocols for protein refolding were not sufficient. In order for the Clrg to fold properly, the odd cysteine which does not fit into the pattern usual for this family of receptors was substituted for serine and resulting C148S construct was shown to be more useful. Further, using (benzyldimethylammonio)propanesulfonate in...