Vaccinia Virus-Derived Vectors in Leishmaniases Vaccine Development

Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the diseases has become a high priority. The development of vaccines against the various species of pathogenic Leishmania to humans has been hampered, in part, by the inefficient stimulation of the protective cellular immunity promoted by the administration of purified or recombinant antigens, indicating the need for new approaches. Viral vectors represent an attractive way to deliver and present vaccine antigens that may offer advantages over traditional platforms. Among the most attractive and efficient viral vectors in inducing a cellular immune response, vaccinia virus has been the most used in leishmaniases vaccine trials. The first report of the use of recombinant vaccinia virus (VACV) in the induction of protection against Leishmania infection was made in 1993. Since then, several Leishmania spp. antigenic subunits were cloned into recombinant VACV. Although highly attenuated poxviral vectors are capable of inducing protective immunity against Leishmania spp., their limitation in replicative capacity reduces their potential as compared to replicative vectors. In order to achieve a balance between safety and replication, several VACV strains with intermediate phenotype have been developed

Understanding global changes of the liver proteome during murine schistosomiasis using a label-free shotgun approach.

Schistosomiasis is an endemic disease affecting over 207million people worldwide caused by helminth parasites of the genus Schistosoma. In Brazil the disease is responsible for the loss of up to 800 lives annually, resulting from the desabilitating effects of this chronic condition. In this study, we infected Balb/c mice with Schistosoma mansoni and analysed global changes in the proteomic profile of soluble liver proteins. Our shotgun analyses revealed predominance of up-regulation of proteins at 5weeks of infection, coincidingwith the onset of egg laying, and a remarkable down-regulation of liver constituents at 7 weeks, when severe tissue damage is installed. Representatives of glycolytic enzymes and stress response (in particular at the endoplasmic reticulum)were among the most differentially expressed molecules found in the infected liver. Collectively, our data contribute over 70 molecules not previously reported to be found at altered levels in murine schistosomiasis to further exploration of their potential as biomarkers of the disease.Moreover, understanding their intricate interaction using bioinformatics approach can potentially bring clarity to unknownmechanisms linked to the establishment of this condition in the vertebrate host. Significance: To our knowledge, this study refers to the first shotgun proteomic analysis to provide an inventory of the global changes in the liver soluble proteome caused by Schistosomamansoni in the Balb/cmodel. It also innovates by yielding data on quantification of the identified molecules as a manner to clarify and give insights into the underlying mechanisms for establishment of Schistosomiasis, a neglected tropical disease with historical prevalence in Brazil

The Schistosomiasis SpleenOME: Unveiling the Proteomic Landscape of Splenomegaly Using Label-Free Mass Spectrometry

Schistosomiasis is a neglected parasitic disease that affects millions of people worldwide and is caused by helminth parasites from the genus Schistosoma. When caused by S. mansoni, it is associated with the development of a hepatosplenic disease caused by an intense immune response to the important antigenic contribution of adult worms and to the presence of eggs trapped in liver tissue. Although the importance of the spleen for the establishment of immune pathology is widely accepted, it has received little attention in terms of the molecular mechanisms operating in response to the infection. Here, we interrogated the spleen proteome using a label-free shotgun approach for the potential discovery of molecular mechanisms associated to the peak of the acute phase of inflammation and the development of splenomegaly in the murine model. Over fifteen hundred proteins were identified in both infected and control individuals and 325 of those proteins were differentially expressed. Two hundred and forty-two proteins were found upregulated in infected individuals while 83 were downregulated. Functional enrichment analyses for differentially expressed proteins showed that most of them were categorized within pathways of innate and adaptive immunity, DNA replication, vesicle transport and catabolic metabolism. There was an important contribution of granulocyte proteins and antigen processing and presentation pathways were augmented, with the increased expression of MHC class II molecules but the negative regulation of cysteine and serine proteases. Several proteins related to RNA processing were upregulated, including splicing factors. We also found indications of metabolic reprogramming in spleen cells with downregulation of proteins related to mitochondrial metabolism. Ex-vivo imunophenotyping of spleen cells allowed us to attribute the higher abundance of MHC II detected by mass spectrometry to increased number of macrophages (F4/80+/MHC II+ cells) in the infected condition. We believe these findings add novel insights for the understanding of the immune mechanisms associated with the establishment of schistosomiasis and the processes of immune modulation implied in the host-parasite interactions

Alterações hepatoesplênicas associadas à infecção por Schistosoma mansoni no modelo murino.

Programa de Pós-Graduação em Ecologia de Biomas Tropicais. Departamento de Biodiversidade, Evolução e Meio Ambiente, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto.A Esquistossomose é uma doença endêmica em vários países, afligindo mais de 207 milhões de pessoas no mundo. É considerada a segunda infecção parasitária mais importante em termos de saúde pública devido ao impacto socio-econômico, podendo ocasionar cerca de 200 mil mortes anualmente. A caracterização do genoma e transcriptoma do Schistosoma mansoni propiciou o emprego de técnicas na área da proteômica as quais vem permitindo maior compreensão da biologia deste parasito em todos os estágios de seu ciclo de vida. Entretanto, até o momento, poucos estudos proteômicos abordaram a relação parasito-hospedeiro. O entendimento desta relação é de fundamental importância para a proposição de novos métodos de diagnóstico, avaliação de prognóstico e tratamento da doença. O presente trabalho teve como foco a análise das alterações no proteoma solúvel de fígado e baço, utilizando o modelo murino de infecção por S. mansoni. A primeira abordagem fundamentou-se na discriminação dos estágios de fase aguda e fase crônica nos animais infectados. Após realização do exame parasitológico de fezes, avaliação das alterações hepatoesplênicas através da relação (% órgão/corpo) e histologia de fígado e baço, foi possível estabelecer que o grupo de animais com 5 semanas de infecção desenvolveu a fase aguda da esquistossomose e animais infectados por 7 semanas apresentaram a fase crônica da doença. A técnica de eletroforese bidimensional comparativa, para proteínas solúveis de fígado e baço de animais controles e infectados, demonstrou alterações nos níveis de expressão de proteínas associadas com processos e vias bioquímicas diversas, como resposta ao estresse celular, tradução, ciclo da uréia e via glicolítica. No fígado, a categoria de proteínas chaperoninas apresentou maior número de representantes com alteração de expressão dentre as quais se destacam GRP-78 (proteína reguladora de glicose 78 kDa), HSP-71 (proteína de choque térmico 71 kDa), Erp-60 (calreticulina) e PDI (proteína dissulfeto isomerase). Por outro lado, proteínas como a CPSase I (carbamoil fosfato sintetase I), albumina, indoletilamina N-metiltransferase, peroxirredoxina-6 e anidrase carbônica III apresentaram expressão diminuída no fígado em decorrência da infecção. O perfil proteômico do fígado do animal infectado correlacionou-se com a análise histológica do órgão na qual se observa uma intensa resposta imune celular. No baço, as proteínas identificadas com alteração de expressão foram calreticulina, fosfoglicerato quinase I, frutose-bifosfato aldolase A, gliceraldeído 3 fosfato desidrogenase, EF-Tu, (fator de elongamento) e aspartato aminotransferase. Em geral, as proteínas diferencialmente presentes no baço de animais infectados apresentaram aumento de expressão, sendo o perfil molecular compatível com a demanda de produção de energia e síntese proteica. Estes dois processos são altamente relevantes para o custeio da intensa proliferação celular observada no órgão. Coletivamente, os resultados obtidos demonstraram que a abordagem proteômica empregada permitiu a identificação de marcadores teciduais induzidos pela infecção por S. mansoni. Abordagens futuras permitirão estabelecer se as alterações teciduais decorrentes da infecção pelo parasito alteram significativamente o proteoma plasmático a ponto de indicar novos biomarcadores da esquistossomose.Schistosomiasis is an endemic disease affecting 207 million people worldwide. It is considered the second most important parasitic disease in terms of public health due to its social and economic impact, leading to an estimated 200 thousand deaths annually. The characterization of the S. mansoni genome and transcriptome has allowed the use of proteomic techniques providing a deeper understanding of the parasite´s biology throughout its life cycle stages. Nevertheless, a few proteomic studies have addressed the host-parasite relationship. Understanding the S. mansoni parasitism is of paramount importance for the proposal of novel diagnostic methods, evaluation of prognosis and treatment of the disease. The present work focused on the spleen and liver soluble proteome-associated alterations in the murine model of experimental schistosomiasis. The first approach involved discrimination between the acute and chronic stages of the disease. After feces examination, measurement of hepatic/spleen mass increase and tissue histology it was established that the 5 week-infected mice developed the acute phase of schistosomiasis whereas animals infected for 7 weeks exhibited the chronic disease. Comparative two dimensional gel electrophoresis, for cytosolic proteins from liver and spleen, demonstrated changes in the expression profile for molecules involved in several cellular processes such as stress response, translation, urea cycle and glycolytic pathway. In the liver, various chaperonins such as GRP-78, HSP-71, Erp-60 and PDI exhibited increased expression profile. In contrast, carbamoyl phosphate synthetase I, albumin, indoethyllamine N-methyltransferase, peroxiredoxin 6 and carbonic anhydrase III were detected at lower levels upon S. mansoni infection. The liver proteomic profile for the infected animal correlated with the histological analysis of the organ in which an intense cellular immune response was observed. In the spleen, the identified proteins displaying altered expression profile were calreticulin, phosphoglycerate kinase I, fructose-biphosphate aldolase A, glyceraldehyde-3-phosphate dehydrogenase, EF-Tu (elongation fator – Tu) and aspartate aminotransferase. Overall, the proteins differentially expressed in the spleen of infected animals displayed up regulation evidencing a molecular profile suitable to provide the demand in energy production and protein synthesis. These two cellular processes are of great relevance to maintain the intense cellular proliferation observed in the organ. Collectively, our results demonstrated that the employed proteomic approach allowed the identification of tissue markers induced by the S. mansoni infection. Future experiments will establish whether the observed tissue alterations promoted by the S. mansoni parasitism significantly alter the plasma proteome to highlight novel biomarkers of schistosomiasis

Shotgun proteomics to unravel the complexity of the leishmania infantum exoproteome and the relative abundance of its constituents.

The exoproteome of some Leishmania species has revealed important insights into host–parasite inter-action, paving the way for the proposal of novel disease-oriented interventions. The focus of the presentinvestigation constituted the molecular profile of the L. infantum exoproteome revealed by a shotgunproteomic approach. Promastigotes under logarithmic phase of growth were obtained and harvestedby centrifugation at different time points. Cell integrity was evaluated through the counting of viableparasites using propidium iodide labeling, followed by flow cytometry analysis. The 6 h culture super-natant, operationally defined here as exoproteome, was then conditioned to in solution digestion andthe resulting peptides submitted to mass spectrometry. A total of 102 proteins were identified and cat-egorized according to their cellular function. Their relative abundance index (emPAI) allowed inferencethat the L. infantum exoproteome is a complex mixture dominated by molecules particularly involved innucleotide metabolism and antioxidant activity. Bioinformatic analyses support that approximately 60%of the identified proteins are secreted, of which, 85% possibly reach the extracellular milieu by means ofnon-classic pathways. At last, sera from naturally infected animals, carriers of differing clinical forms ofCanine Visceral Leishmaniasis (CVL), were used to test the immunogenicity associated to the L. infantumexoproteome. Western blotting experiments revealed that this sub-proteome was useful at discrimi-nating symptomatic animals from those exhibiting other clinical forms of the disease. Collectively, themolecular characterization of the L. infantum exoproteome and the preliminary immunoproteomic assaysopened up new research avenues related to treatment, prognosis and diagnosis of CVL