Babesia bovis RON2 binds to bovine erythrocytes through a highly conserved epitope.

B. bovis invasion of bovine erythrocytes requires tight junction formation involving AMA-1/RON2 complex interaction. RON2 has been considered a vaccine candidate since antibodies targeting the protein can inhibit parasite invasion of target cells; however, the mechanism controlling B. bovis RON2 interaction with red blood cells is not yet fully understood. This study was thus aimed at identifying B. bovis RON2 protein regions associated with interaction with bovine erythrocytes. Natural selection analysis of the ron2 gene identified predominantly negative selection signals in the C-terminal region. Interestingly, protein-cell and competition assays highlighted the RON2-C region's role in peptide 42918-mediated erythrocyte binding, probably to a sialoglycoprotein receptor. This peptide (1218SFIMVKPPALHCVLKPVETL1237) lies within an intrinsically disordered region of the RON2 secondary structure flanked by two helical residues. The study provides, for the first time, valuable insights into RON2's role in interaction with its target cells. Future studies are required for studying the peptide's potential as an anti-B. bovis vaccine component.

Developing Anti-Babesia bovis Blood Stage Vaccines: A New Perspective Regarding Synthetic Vaccines.

Bovine babesiosis is caused by the Apicomplexa parasites from the genus Babesia. It is one of the most important tick-borne veterinary diseases worldwide; Babesia bovis being the species associated with the most severe clinical signs of the disease and causing the greatest economic losses. Many limitations related to chemoprophylaxis and the acaricides control of transmitting vectors have led to the adoption of live attenuated vaccine immunisation against B. bovis as an alternative control strategy. However, whilst this strategy has been effective, several drawbacks related to its production have prompted research into alternative methodologies for producing vaccines. Classical approaches for developing anti-B. bovis vaccines are thus discussed in this review and are compared to a recent functional approach to highlight the latter's advantages when designing an effective synthetic vaccine targeting this parasite.

Identification of Babesia bovis MSA-1 functionally constraint regions capable of binding to bovine erythrocytes.

Merozoite surface antigen-1 is a glycoprotein expressed by Babesia bovis and is considered a vaccine candidate given that antibodies against it are able to partially block in vitro invasion of bovine erythrocytes. Despite this, no study to date has confirmed the target cell binding properties of the full MSA-1 or its fragments. This research has thus been focused on identifying protein regions playing a role in erythrocyte attachment, based on genetic diversity and natural selection analysis. Two regions under functional constraint (nucleotides 134-428 and 464-629) having a preponderance of negatively-selected signals were identified in silico. Three non-overlapping peptides derived from functionally constraint regions (42422 (39PEGSFYDDMSKFYGAVGSFD58), 42424 (91NALIKNNPMIRPDLFNATIV110) and 42426 (150TDIVEEDREKAVEYFKKHVY169)) were able to specifically bind to a sialoglycoprotein located on the bovine erythrocyte surface as confirmed by sensitive and specific peptide-cell interaction competition assays using both enzymatically treated and untreated red blood cells. Interestingly, it was predicted that peptides 42422 and 42426 have a helical structure and conserved motifs in all strain/isolates. These findings provide evidence, for the first time, related to B. bovis MSA-1 short regions used by the parasite in erythrocyte binding which could be predicted using natural selection analysis. Future work focused on evaluating these peptides' antigenic ability during natural infection, and their ability to induce protection in immunisation assays are needed to confirm their usefulness as synthetic vaccine candidates.

Sistemas de expresión de proteínas recombinantes para el análisis funcional de antígenos de Plasmodium falciparum y Plasmodium vivax: una revisión / Recombinant Protein Expression Systems for Functional Analysis of Plasmodium falciparum and Plasmodium vivax Antigens: A Review / Sistemas de expressão de proteínas recombinantes para o analise funcional de antígenos de Plasmodium falciparum e Plasmodium vivax: uma revisão

Introducción: Para diseñar vacunas es necesario comprender la función de los antígenos de Plasmodium spp. in-volucrados en la invasión a células hospederas. Diferentes investigaciones han generado proteínas recombinantes utilizando sistemas de expresión heterólogos y así han obtenido moléculas semejantes a las nativas. Con estos avances se desarrollan estrategias que bloquean la infección de estos patógenos. Objetivo: Describir las características y los aspectos metodológicos más importantes de los sistemas de expresión de las proteínas recombinantes en estudios funcionales de Plasmodium spp. Metodología: Revisión descriptiva de estudios publicados en Pubmed, Science Direct, Embase y Medline, entre 2010 y 2020, que incluyeran sistemas recombinantes en células de Escherichia coli, de mamífero y sistemas libres de células, para estudios funcionales de antígenos de Plasmodium falciparum y Plasmodium vivax. Se revisaron 70 artículos originales y 58 cumplieron con los criterios establecidos. Resultados: Obtener proteínas recombinantes mediante un sistema procariota, de mayor rendimiento y bajo costo, ha permitido estudiar un número importante de antígenos. Los sistemas con células de mamífero y libres de células, que permiten modificaciones postraduccionales y plegamiento adecuado de moléculas, se usan para producir librerías de antígenos con estructura conformacional similar a la nativa. Conclusión: El estudio de los antígenos de Plasmodium spp. implicados en la infección y desarrollo de células diana requiere una adecuada selección del método de producción recombinante. El refinamiento de procesos de expresión en sistemas procariotas, eucariotas e in vitro, mediante ingeniería genética y cultivo celular, permitirá mejores rendimientos y menor costo.

Introduction: Understanding the function of Plasmodium spp. Antigens involved in invasion of host cells is necessary to design vaccines. Different studies have generated recombinant proteins using heterologous expression systems, obtaining molecules similar to native ones. These advances are es-sential to develop strategies that block the infection of these pathogens. Objective: Describe the most important characteristics and methodological aspects of recombinant protein expression systems in functional studies of Plasmodium spp. Methodology: Descriptive review of studies published in Pubmed, Science Direct, Embase and Medline, between 2010 and 2020, that included recombinant systems in Escherichia coli cells, mam-malian and cell-free, for functional studies of Plasmodium falciparum and Plasmodium vivax antigens. 70 original articles were reviewed, 58 met the established criteria. Results: Obtaining recombinant proteins by means of a prokaryotic system, with higher performance and low cost, has allowed functional studies of a significant number of antigens. Mammalian cell and cell free systems, which allow for post-translational modifications and adequate folding of molecules, are used to produce antigen libraries with native-like conformational structure. Conclusion:Plasmodium spp. antigen study involved in infection and development in target cells, re-quires adequate selection of the recombinant production method. The refinement of expression pro-cesses in prokaryotic, eukaryotic and in vitro systems, through genetic engineering and cell culture, will allow better yields and lower cost

Introdução: Para desenvolver vacinas, é necessário entender a função dos antígenos de Plasmodium spp. envolvidos na invasão das células hospedeiras. As pesquisas têm gerado proteínas recombinan-tes utilizando sistemas de expressão heterólogos para obter moléculas similares às nativas. Com estes avanços, estratégias que bloqueiam a infecção destes patógenos estão sendo desenvolvidas. Objetivo: Descrever as características mais importantes e aspectos metodológicos dos sistemas de expressão de proteínas recombinantes em estudos funcionais de Plasmodium spp. Metodologia: Revisão descritiva dos estudos publicados em Pubmed, Science Direct, Embase e Medline, entre 2010 e 2020, que incluíram sistemas recombinantes em células de Escherichia coli, de mamífero e sistemas livres de células, para estudos funcionais dos antígenos de Plasmodium fal-ciparum e Plasmodium vivax. Setenta artigos originais foram revisados e 58 preenchiam os critérios estabelecidos. Resultado: A obtenção de proteínas recombinantes usando um sistema procariótico, com maior rendimento e baixo custo, permitiu o estudo de um número significativo de antígenos. Sistemas de células mamíferas e sem células, que permitem modificações pós-tradução e dobramento adequado das moléculas, são usados para produzir bibliotecas de antígenos com uma estrutura semelhante à nativa. Conclusão: O estudo dos antígenos Plasmodium spp. envolvidos na infecção e no desenvolvimento das células-alvo requer uma seleção adequada do método de produção recombinante. O refinamento dos processos de expressão em sistemas procarióticos, eucarióticos e in vitro, através da engenharia genética e da cultura celular, permitirá melhores rendimentos e menores custos.

Two 20-Residue-Long Peptides Derived from Plasmodium vivax Merozoite Surface Protein 10 EGF-Like Domains Are Involved in Binding to Human Reticulocytes.

Plasmodium parasites' invasion of their target cells is a complex, multi-step process involving many protein-protein interactions. Little is known about how complex the interaction with target cells is in Plasmodium vivax and few surface molecules related to reticulocytes' adhesion have been described to date. Natural selection, functional and structural analysis were carried out on the previously described vaccine candidate P. vivax merozoite surface protein 10 (PvMSP10) for evaluating its role during initial contact with target cells. It has been shown here that the recombinant carboxyl terminal region (rPvMSP10-C) bound to adult human reticulocytes but not to normocytes, as validated by two different protein-cell interaction assays. Particularly interesting was the fact that two 20-residue-long regions (388DKEECRCRANYMPDDSVDYF407 and 415KDCSKENGNCDVNAECSIDK434) were able to inhibit rPvMSP10-C binding to reticulocytes and rosette formation using enriched target cells. These peptides were derived from PvMSP10 epidermal growth factor (EGF)-like domains (precisely, from a well-defined electrostatic zone) and consisted of regions having the potential of being B- or T-cell epitopes. These findings provide evidence, for the first time, about the fragments governing PvMSP10 binding to its target cells, thus highlighting the importance of studying them for inclusion in a P. vivax antimalarial vaccine.

Babesia Bovis Ligand-Receptor Interaction: AMA-1 Contains Small Regions Governing Bovine Erythrocyte Binding.

Apical membrane antigen 1 is a microneme protein which plays an indispensable role during Apicomplexa parasite invasion. The detailed mechanism of AMA-1 molecular interaction with its receptor on bovine erythrocytes has not been completely defined in Babesia bovis. This study was focused on identifying the minimum B. bovis AMA-1-derived regions governing specific and high-affinity binding to its target cells. Different approaches were used for detecting ama-1 locus genetic variability and natural selection signatures. The binding properties of twelve highly conserved 20-residue-long peptides were evaluated using a sensitive and specific binding assay based on radio-iodination. B. bovis AMA-1 ectodomain structure was modelled and refined using molecular modelling software. NetMHCIIpan software was used for calculating B- and T-cell epitopes. The B. bovis ama-1 gene had regions under functional constraint, having the highest negative selective pressure intensity in the Domain I encoding region. Interestingly, B. bovis AMA-1-DI (100YMQKFDIPRNHGSGIYVDLG119 and 120GYESVGSKSYRMPVGKCPVV139) and DII (302CPMHPVRDAIFGKWSGGSCV321)-derived peptides had high specificity interaction with erythrocytes and bound to a chymotrypsin and neuraminidase-treatment sensitive receptor. DI-derived peptides appear to be exposed on the protein's surface and contain predicted B- and T-cell epitopes. These findings provide data (for the first-time) concerning B. bovis AMA-1 functional subunits which are important for establishing receptor-ligand interactions which could be used in synthetic vaccine development.

Proteínas importantes para la invasión de Babesia bovis a las células huésped / Important Proteins for Babesia bovis Invasion to Host Cells / Proteínas importantes para a invasão das células hospedeiras por Babesia bovis

Introducción: La babesiosis bovina es causada por parásitos Apicomplexa del género Babesia, siendo la Babesia bovis la especie asociada con cuadros clínicos más graves de la enfermedad. La invasión de B. bovis a los eritro-citos bovinos implica la interacción entre moléculas de los merozoítos del parásito con receptores de las células huésped. Por ende, conocer las proteínas involucradas en este proceso supone un importante paso para entender la biología del parásito. Objetivo: Describir las principales moléculas implicadas en el proceso de invasión de B. bovis a eritrocitos bovinos. Metodología: Se realizó una búsqueda en NCBI, Medline, LILACS y SciELO usando los términos: "Babesia bovis AND invasion process", "MSA-1", "RON2", "AMA-1", "moving junction", "B. bovis AND Vaccine candidates". Con corte en mayo de 2020, había 61 publicaciones disponibles en inglés que describen el estudio de las anteriores proteínas y su participación en la invasión.Resultados: Por ser clave el proceso de invasión a eritrocitos bovinos para la patogénesis de la babesiosis bovina, la revisión encontró 3 proteínas de B. bovis que participan en el reconocimiento e invasión a las células diana: MSA-1, AMA-1 y RON2. Sin embargo, los detalles a nivel molecular para las interacciones inter e intramoleculares aún no se han dilucidado por completo. Conclusiones: Conocer las moléculas involucradas en las interacciones parásito-hospedero permitirá entender cómo ocurre el proceso de invasión de B. bovis a los eritrocitos y, así, evaluar su futura utilidad como componente de una estrategia de control efectiva contra esta parasitosis

Introduction: Bovine babesiosis is caused by Apicomplexas parasites of the genus Babesia, Babesia bovis being the species associated with the most serious clinical conditions of the disease. B. bovisinvasion into the bovine erythrocytes involves the interaction between the parasites merozoites mo-lecules with host cell receptors. Therefore, knowing the proteins involved in the invasion process will enable understanding the parasite biology. Objective: To describe the important molecules involved in the B. bovis invasion process to bovine erythrocytes.Methodology: A search was made on NCBI, Medline, LILACS and SciELO databases using keywords as "Babesia bovis AND invasion process", "MSA-1", "RON2", "AMA-1", "moving junction", "B. bovis AND Vaccine candidates". 61 studies written in English describing the study for proteins that take place during invasion process which have been published until mayo were completely revised. Results: Given that the bovine erythrocyte invasion process is key for the pathogenesis of bovine babesiosis, a review was made where 3 proteins were found to be associated to the recognition and invasion processes of target cells: MSA-1, AMA-1 and RON2. However, the details at molecular level for the inter an intramolecular interaction have not yet been fully elucidated. Conclusions: Study the molecules involved in host-parasite interactions will allow understanding how the B. bovis invasion process to erythrocytes occurs and evaluating their future utility as a component of an effective control strategy for this parasitosis

Introdução: A babesiose bovina é causada por parasitas Apicomplexa do gênero Babesia, sendo a Babesia bovis a espécie associada com os sinais clínicos mais graves da doença. A invasão de B. bovis em eritrócitos bovinos envolve a interação entre moléculas dos merozoítos parasitas com receptores nas células hospedeiras. Por conseguinte, o conhecimento das proteínas envolvidas neste processo é um passo importante para a compreensão da biologia do parasita. Objetivo: Descrever as principais moléculas envolvidas no processo de invasão de B. bovis em eritró-citos bovinos. Metodologia: Foi realizada uma pesquisa no NCBI, Medline, LILACS e SciELO utilizando os termos: "Babesia bovis AND invasion process", "MSA-1", "RON2", "AMA-1", "moving junction", "B. bovis AND Vaccine candidates". Até maio de 2020 estavam disponíveis 61 publicações em inglês, que descreviam o estudo das proteínas acima referidas e o seu envolvimento na invasão. Resultados: Como o processo de invasão de eritrócitos bovinos é fundamental para á patogênese da babesiose bovina, a revisão encontrou 3 proteínas de B. bovis envolvidas no reconhecimento e invasão de células alvo: MSA-1, AMA-1 e RON2. No entanto, os detalhes a nível molecular para as interações Inter e intramoleculares ainda não foram completamente elucidados. Conclusões: A compreensão das moléculas envolvidas nas interações parasita-hospedeiro permitirá entender como ocorre o processo da invasão de B. bovis em eritrócitos e, assim, avaliar sua utilidade futura como componente de uma estratégia efetiva de controle contra esta parasitose

Variables clínicas del parto en posición vertical y horizontal: revisión exhaustiva de literatura / Clinical Behavior of Vertical and Horizontal Deliveries: Exhaustive Literature Review / Variáveis clínicas do parto em posição vertical e horizontal: revisão abrangente de literatura

Introducción: El trabajo de parto representa el acontecimiento más importante durante la culminación del periodo de gestación y, por lo tanto, la adecuada elección de su posición, ya sea vertical u horizontal, resulta indispensable para minimizar las complicaciones maternas y neonatales. Objetivo: Llevar a cabo una revisión de la literatura sobre el comportamiento clínico del parto vertical y horizontal, describiendo los principales resultados en diferentes países del mundo. Método: Revisión documental mediante la búsqueda de la literatura entre 2009 y 2020 en bases de datos especializadas. Resultados: La posición vertical se asoció con una menor duración del trabajo de parto, dolor referido y necesidad de episiotomía; no obstante, esta posición puede incrementar el riesgo de hemorragia posparto y daño perineal. Conclusión: La variedad de desenlaces obstétricos y neonatales asociados a las posiciones de parto vertical y horizontal hacen complejo definir una posición de parto óptima; por lo tanto, se recomienda la libre elección de acuerdo con las características que presente cada paciente

Introduction: Parturition represents the most important event during the culmination of the gestation period and, therefore, the appropriate choice of its position, whether vertical or horizontal, it is essential to minimize maternal and neonatal complications. Objective: To carry out a review of the literature on the clinical behavior of vertical and horizontal delivery, describing the main results in different countries of the world. Method: Document review by searching the literature between the years 2009 and 2020, available in Specialized Databases. Results: The vertical position was associated with a shorter duration of labor obstetric, referred pain, and episiotomy; however, this position may increase the risk of postpartum hemorrhage and perineal damage. Conclusion: The variety of obstetric and neonatal outcomes associated with vertical and horizontal delivery positions make it difficult to define an optimal delivery position and, therefore, free choice is recommended according to the characteristics of each patient

Introdução: O trabalho de parto representa o acontecimento mais importante no final do período gestacional e, portanto, a escolha apropriada da posição, seja vertical ou horizontal, é indispensável para minimizar as complicações maternas e neonatais. Objetivo: Realizar uma revisão bibliográfica sobre o comportamento clínico do parto vertical e hori-zontal, descrevendo os principais resultados em diferentes países do mundo. Método: Revisão documental através de pesquisa da literatura em bases de dados especializadas entre os anos 2009 e 2020. Resultados: A posição vertical foi associada a uma duração mais curta do parto, dor referida e ne-cessidade de episiotomía; contudo, esta posição pode aumentar o risco de hemorragia pós-parto e dano perineal. Conclusão: A variedade de resultados obstétricos e neonatais associados às posições de parto vertical e horizontal torna complexa a escolha de uma posição de parto ótima; por conseguinte, recomen-da-se a livre escolha de acordo com as caraterísticas de cada paciente

Plasmodium falciparum pre-erythrocytic stage vaccine development.

Worldwide strategies between 2010 and 2017 aimed at controlling malarial parasites (mainly Plasmodium falciparum) led to a reduction of just 18% regarding disease incidence rates. Many biologically-derived anti-malarial vaccine candidates have been developed to date; this has involved using many experimental animals, an immense amount of work and the investment of millions of dollars. This review provides an overview of the current state and the main results of clinical trials for sporozoite-targeting vaccines (i.e. the parasite stage infecting the liver) carried out by research groups in areas having variable malaria transmission rates. However, none has led to promising results regarding the effective control of the disease, thereby making it necessary to complement such efforts at finding/introducing new vaccine candidates by adopting a multi-epitope, multi-stage approach, based on minimal subunits of the main sporozoite proteins involved in the invasion of the liver.

Fundamentos y aplicaciones biomédicas de las principales tecnologías de secuenciación: una revisión de literatura / Biomedical Foundations and Applications of Major Sequencing Technologies: A Literature Review / Fundamentos e aplicações biomédicas das principais tecnologias de sequenciamento: uma re-visão da literatura

Introducción: el objetivo de la secuenciación es determinar la composición de los nucleótidos presentes en el ADN o el ARN. Desde la finalización del proyecto genoma humano, surgieron diversas tecnologías de secuenciación rápida como Roche 454, SOLiD, Illumina, Ion Torrent, PacBio y Oxford Nanopore, más precisas y costoeficientes, que permiten desarrollar proyectos a gran escala y estudiar genes y genomas, la composición de microbiomas, enfermedades metabólicas y enfermedades genéticas que afectan a la población. Objetivo: describir los fundamentos de los métodos de secuenciación de ADN y sus aplicaciones en las ciencias biomédicas. Métodos: revisión descriptiva de las principales estrategias de secuenciación de ADN de primera, segunda y tercera generación y su aplicación en el entorno biomédico, a partir de la búsqueda de artículos en bases de datos electró-nicas especializadas en investigación científica. Se encontraron 118 documentos, de los cuales se excluyeron 6, por no cumplir con los criterios de inclusión, y se seleccionaron 112, por cumplir con todos los requisitos. Conclusiones:el surgimiento de los métodos de secuenciación de siguiente generación arroja una gran canti-dad de datos, incluidos genomas secuenciados completamente de varias especies, con un rendimiento extenso, tiempos reducidos y costoeficiencia, que lleva a la completa transformación de las ciencias de la vida y logra un progreso sin precedentes en el análisis de genomas, la evaluación de la ecología microbiana y el diagnóstico de enfermedades.

Introduction: The purpose of sequencing is to determine the composition of the nucleotides present in DNA or RNA. Since the completion of the human genome project, several sequencing technologies such as Roche 454, SOLiD, Illumina, Ion Torrent, PacBio and Oxford Nanopore have emerged as tools for rapid sequencing, with greater precision and cost-efficiency, allowing the development of lar-ge-scale projects and the study of genes and genomes, along with the composition of microbiomes and the study of metabolic and genetic diseases that affect the population. Objective: To describe the foundations of the methods of DNA sequencing and their applications in the biomedical sciences. Methods: Descriptive review of the main strategies of first, second and third generation DNA sequencing and their application in the biomedical environment. This review was carried out by searching articles in electronic databases specialized in scientific research. A total of 118 papers were found, of which 6 were excluded as they did not meet the inclusion criteria and 112 were selected as meeting all the requirements. Conclusions: The emergence of next-generation sequencing methods yielding a wealth of data, including fully sequenced genomes of various species, with extensive throughput, reduced time and cost-effec-tiveness that has led to the complete transformation of the life sciences, achieving unprecedented progress in genome analysis, assessment of microbial ecology and disease diagnosis

Introdução: o objetivo do sequenciamento é determinar a composição dos nucleotídeos presentes no DNA ou RNA. Desde a conclusão do projeto do genoma humano, surgiram diversas tecnologias de sequenciamento rápida como Roche 454, SOLiD, Illumina, Ion Torrent, PacBio e Oxford Nanopore, mais precisas e econômicas, que permitem o desenvolvimento de projetos de grande escala e estudo de genes e genomas, composição de microbiomas, doenças metabólicas e genéticas que afetam a popula-ção. Objetivo: descrever os fundamentos dos métodos de sequenciamento de DNA e suas aplicações nas ciências biomédicas. Métodos: revisão descritiva das principais estratégias de sequenciamento de DNA de primeira, segunda e terceira geração e sua aplicação no ambiente biomédico, a partir da busca de artigos em bases de dados eletrônicas especializadas em pesquisa científica. Foram encontrados 118 documen-tos, dos quais 6 foram excluídos por não atenderem aos critérios de inclusão e 112 fo-ram seleciona-dos por atenderem a todos os requerimentos. Conclusões: o surgimento de métodos de sequenciamento de próxima geração rende uma riqueza de dados, incluindo genomas totalmente se-quenciados de várias espécies, com produção extensa, tempos reduzidos e eficiência de custo, levando à transformação completa das ciências da vida e alcançando um progresso sem precedentes no genoma análise, avaliação de ecologia microbiana e diagnóstico de doenças.

Plasmodium falciparum Blood Stage Antimalarial Vaccines: An Analysis of Ongoing Clinical Trials and New Perspectives Related to Synthetic Vaccines.

Plasmodium falciparum malaria is a disease causing high morbidity and mortality rates worldwide, mainly in sub-Saharan Africa. Candidates have been identified for vaccines targeting the parasite's blood stage; this stage is important in the development of symptoms and clinical complications. However, no vaccine that can directly affect morbidity and mortality rates is currently available. This review analyzes the formulation, methodological design, and results of active clinical trials for merozoite-stage vaccines, regarding their safety profile, immunological response (phase Ia/Ib), and protective efficacy levels (phase II). Most vaccine candidates are in phase I trials and have had an acceptable safety profile. GMZ2 has made the greatest progress in clinical trials; its efficacy has been 14% in children aged less than 5 years in a phase IIb trial. Most of the available candidates that have shown strong immunogenicity and that have been tested for their protective efficacy have provided good results when challenged with a homologous parasite strain; however, their efficacy has dropped when they have been exposed to a heterologous strain. In view of these vaccines' unpromising results, an alternative approach for selecting new candidates is needed; such line of work should be focused on how to increase an immune response induced against the highly conserved (i.e., common to all strains), functionally relevant, protein regions that the parasite uses to invade target cells. Despite binding regions tending to be conserved, they are usually poorly antigenic and/or immunogenic, being frequently discarded as vaccine candidates when the conventional immunological approach is followed. The Fundación Instituto de Inmunología de Colombia (FIDIC) has developed a logical and rational methodology based on including conserved high-activity binding peptides (cHABPs) from the main P. falciparum biologically functional proteins involved in red blood cell (RBC) invasion. Once appropriately modified (mHABPs), these minimal, subunit-based, chemically synthesized peptides can be used in a system covering the human immune system's main genetic variables (the human leukocyte antigen HLA-DR isotype) inducing a suitable, immunogenic, and protective immune response in most of the world's populations.

Babesia bovis: Actualidad del desarrollo de una vacuna / Babesia bovis: An Update on vaccine development / Babesia bovis: Atualidade do desenvolvimento de uma vacina

Introducción. Babesia bovis es el principal agente causal de la babesiosis bovina, una importante enfermedad veterinaria transmitida por garrapatas a nivel mundial. Las estrategias convencionales para controlar esta parasitosis han presentado múltiples limitaciones por lo que el desarrollo de una vacuna basada en antígenos representa una estrategia apropiada para la prevención y el tratamiento. Objetivo. Describir los aspectos relevantes del ciclo de vida del parásito B. bovis, la epidemiología, diagnóstico y la aplicación de diferentes estrategias usadas para controlar esta parasitosis. Además, se discuten potenciales puntos de intervención para desarrollar una vacuna contra este parásito. Metodología. Se realizó una búsqueda en las bases de datos usando los términos: "Babesia bovis AND lyfe cycle", "B. bovis vaccine and Vaccine candidates", entre otras. Los estudios con mayor pertinencia publicados hasta la actualidad se revisaron completamente. Resultados. Los detalles de la biología de parásito B. bovis y el proceso molecular usado para ocasionar la enfermedad en el hospedador son poco conocidos, lo que explica que el desarrollado de estrategias para el control de esta parasitosis no hayan sido del todo eficientes. Por lo tanto, se requiere diseñar nuevas medidas, por ejemplo, desarrollar vacunas de nueva generación basadas en un enfoque funcional que permitan mejorar las condiciones de sanidad animal. Conclusiones. Comprender el complejo ciclo de vida de B. bovis permitirá estudiar las interacciones huésped-parásito-garrapata e identificar moléculas implicadas en la adhesión/invasión celular para evaluar su utilidad como componente de una vacuna que controle esta parasitosis.

Introduction. Babesia bovis is the main causal agent of babesiosis bovine, one important veterinary diseases transmitted by ticks worldwide. Conventional strategies to control this parasitosis have shown several limitations and therefore the development of a vaccine will be an appropriate strategy for prevention and treatment. Objective. To describe relevant aspects of B. bovis parasite's life cycle, the epidemiology, diagnosis, the application of different strategies used to control this parasitosis. In addition, potential points of intervention to develop a vaccine against this parasite has been discussed. Methodology. A search was made using keywords as "Babesia bovis AND lyfe cycle", "B. bovis vaccine and Vaccine candidates" and others. The most relevant studies published to date were completely revised. Results. The details of the B.bovis parasite biology and the molecular process used to cause disease in the host had not been describe in deep; explaining that the development of strategies for the control of this parasitosis have not been entirely efficient. Therefore, it is necessary to design new procedures, for example, to develop new generation vaccines based on a functional approach which improve the animal health conditions. Conclusions. Understand the B. bovise's life cycle complex will allow the host-parasite-tick interactions study and the identification of molecules involved in cell adhesion / invasion to evaluate its usefulness as a vaccine component that controls this parasitosis.

Introdução. Babesia bovis é o principal agente causador da babesiose bovina, uma importante doença veterinária transmitida por carrapatos a nível mundial. As estratégias convencionais para o controle das parasitoses têm presentado múltiplas limitações pelo que o desenvolvimento de uma vacina baseada em antígenos representa uma estratégia apropriada para a prevenção e o tratamento. Objetivo. Descrever os aspectos relevantes do ciclo de vida do parasita B. bovis, a epidemiologia, diagnostico e aplicação de diferentes estratégias usadas para o controle desta parasitose. Além disso, são discutidos possíveis pontos de intervenção para o desenvolvimento de uma vacina contra o parasita. Metodologia. Uma pesquisa foi realizada nas bases de dados usando os termos: "Babesia bovis AND lyfe cycle", "B. bovis vaccine and Vaccine candidates", entre outras. Os estudos mais relevantes publicados até o momento foram completamente revisados. Resultados. Os detalhes da biologia do parasita B. bovis e o processo molecular usado para causar doenças no hospedeiro é pouco conhecido, o que explica que o desenvolvimento de estratégias para o controle desta parasitose não foram completamente eficientes. Portanto, é necessário projetar novas medidas, por exemplo, desenvolver vacinas de nova geração com base em uma abordagem funcional que permita melhorar as condições de saúde animal. Conclusões. Compreender o complexo ciclo de vida de B. bovis permitirá estudar as interações hospede­parasita­carrapatos e identificar moléculas envolvidas na adesão/invasão celular para avaliar sua utilidade como componente de uma vacina que controla essa parasitose.

Revisión de estudios pre-clínicos de candidatos a vacuna contra la malaria causada por Plasmodium falciparum / Review of preclinical studies of candidates for malaria vaccine caused by Plasmodium falciparum / Revisão de estudos pré-clínicos de candidatos á vacina contra a malária causados por Plasmodium falciparum

Introducción. La malaria es una enfermedad que causa aproximadamente 400.000 muertes al año, especialmente en niños menores de 5 años; la búsqueda de una vacuna eficaz y segura sigue siendo un reto para los investigadores, sin embargo, antes de iniciar los estudios de fase clínica, los ensayos preclínicos en modelo animal deben brindar resultados de seguridad e inmunogenicidad que lleven a respuestas eficaces de protección. Objetivo. Revisar las principales características de la respuesta inmunológica y eficacia en estudios pre-clínicos de candidatos a vacuna contra la malaria por Plasmodium falciparum. Métodos. Revisión descriptiva de los principales estudios preclínicos de candidatos a vacuna contra la malaria, basados en subunidades, parásitos atenuados y vacunas multi-estadio, multi-epitope, que se han realizado para evaluar inmunogenicidad y eficacia en modelo animal. Esta revisión se llevó a cabo a partir de la búsqueda de literatura en bases de datos electrónicas especializadas en investigación científica. Se encontraron 118 documentos, de los cuales se seleccionaron 91 y se excluyeron 17 por no cumplir con los criterios de inclusión, para un total de 74 referencias analizadas. Resultados. Muchos candidatos a vacuna contra la malaria causada por Plasmodium falciparum han reportado resultados prometedores contra cepas homologas, sin embargo, ante el reto con cepas heterólogas la eficacia disminuye, por otra parte, la respuesta inmune y protectiva duradera continúa siendo un objetivo clave, convirtiéndose en una prioridad. Conclusiones. Los estudios preclínicos en modelo animal son necesarios antes de avanzar a fases clínicas, la evaluación de inmunogenicidad y eficacia es un aspecto esencial para la evaluación de candidatos a vacuna.

Introduction. Malaria disease causes approximately 400,000 deaths by year, especially in children under 5 years, the search for an effective and safe vaccine, remains to be a challenge for researchers, however before starting the clinical phase studies, preclinical trials in animal models should provide safety and immunogenicity results that lead to effective protective responses. Objective. To review the main characteristics of the immune response and efficacy in pre-clinical studies of candidates for vaccine against malaria by Plasmodium falciparum. Methods. A descriptive review of the main preclinical studies of malaria vaccine candidates, based on subunits, attenuated parasites and multi-stage, multi-epitope vaccines, which have been carried out to evaluate immunogenicity and efficacy, is presented. This review was carried out based on the search of literature in electronic databases specialized in scientific research. 118 documents were found, of which 91 were selected and 17 were excluded because they did not meet the inclusion criteria, for a total of 74 references analyzed. Results. Many candidates for malaria vaccine caused by Plasmodium falciparum have reported promising results against homologous strains, however, given the challenge with heterologous strains, efficacy decreases, on the other hand, the lasting immune and protective response continues to be a key objective, becoming a priority. Conclusions. Preclinical studies in animal models are necessary before advancing to clinical phases, the evaluation of immunogenicity and efficacy is an essential aspect for the evaluation of vaccine candidates.

Introdução: A malária é uma doença que causa aproximadamente 400.000 óbitos por ano, principalmente em crianças menores de 5 anos, a procura por uma vacina eficaz e segura, continua sendo um desafio para os pesquisadores, porém, antes de iniciar os estudos de fase clínica, os testes pré-clínicos no modelo animal devem fornecer resultados de segurança e imunogenicidade que levam a respostas efetivas de proteção. Objetivo: Verificar as principais características da resposta imune e eficácia em estudos pré-clínicos de candidatos à vacina contra a malária por Plasmodium falciparum. Métodos: Revisão descritiva dos principais estudos pré-clínicos de candidatos à vacina contra a malária, com base em subunidades, parasitas atenuados e vacinas de vários estágios e multiepítopo, que foram realizadas para avaliar a imunogenicidade e eficácia em modelos animais. Esta revisão foi realizada com base na pesquisa de literatura em bases de dados eletrônicas especializadas em pesquisa científica. Foram encontrados 118 documentos, dos quais 91 foram selecionados e 17 foram excluídos por não atenderem aos critérios de inclusão, para um total de 74 referências analisadas. Resultados: Muitos candidatos à vacina contra a malária causada por Plasmodium falciparum relataram resultados promissores contra cepas homólogas, no entanto, diante do desafio com cepas heterólogas a eficácia diminui, por outro lado, a resposta imune e protetora duradoura continua sendo um objetivo fundamental, tornando-se uma prioridade. Conclusões: Estudos pré-clínicos em modelo animal são necessários antes de passar para as fases clínicas, a avaliação da imunogenicidade e eficácia é um aspecto essencial para a avaliação dos candidatos a vacina.