RESUMEN

Endemic in Brazil, visceral leishmaniasis (VL) is a zoonotic infection that is among the most important parasitic diseases transmitted by vectors. Dogs are the main reservoirs of canine leishmaniasis (CanL) and their identification is used in some countries as part of disease prevention and control measures in the canine and human population. In this context, serological tests are necessary, composed of antigens capable of correctly identifying infected dogs, minimizing the number of false-negative cases. This study aimed to identify more immunoreactive peptides derived from two previously described whole proteins (rDyn-1 and rKDDR-plus) and compare their performance to the control antigens rK39 and the crude extract for the detection of dogs infected with L. infantum, especially the asymptomatic ones. The three selected peptides and a mixture of them, along with the rDyn-1, rKDDR-plus, rK39, and crude extract antigens were evaluated using indirect ELISA with sera samples from 186 dogs with CanL, being asymptomatic (n = 50), symptomatic (n = 50), co-infected (n = 19), infected with Babesia sp. (n = 7), Ehrlichia sp. (n = 6), T. cruzi (n = 20) and uninfected (n = 34). The results showed that the rDyn-1 protein and the peptide mixture had the highest sensitivity (100% and 98.32%, respectively) and specificity (97.01 and 98.51, respectively). A high degree of kappa agreement was found for rDyn-1 protein (0.977), mixed peptides (0.965), rKDDR-plus protein (0.953), K-plus peptide 1 (0.930) and Dyn-1 peptide (0.893). The mixture of peptides showed the highest likelihood (65.87). The ELISA using the mixture of peptides and the rDyn-1 protein showed high performance for CanL serodiagnosis. More mix combinations of the peptides and additional extended field tests with a larger sample size are recommended.

Asunto(s)

Enfermedad de Chagas , Enfermedades de los Perros , Leishmania infantum , Leishmaniasis Visceral , Humanos , Perros , Animales , Antígenos de Protozoos , Sensibilidad y Especificidad , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/veterinaria , Leishmaniasis Visceral/epidemiología , Péptidos , Immunoblotting , Oligopéptidos , Ensayo de Inmunoadsorción Enzimática/métodos , Pruebas Serológicas/métodos , Enfermedades de los Perros/epidemiología , Anticuerpos Antiprotozoarios

RESUMEN

Repetitive elements cause assembly fragmentation in complex eukaryotic genomes, limiting the study of their variability. The genome of Trypanosoma cruzi, the parasite that causes Chagas disease, has a high repetitive content, including multigene families. Although many T. cruzi multigene families encode surface proteins that play pivotal roles in host-parasite interactions, their variability is currently underestimated, as their high repetitive content results in collapsed gene variants. To estimate sequence variability and copy number variation of multigene families, we developed a read-based approach that is independent of gene-specific read mapping and de novo assembly. This methodology was used to estimate the copy number and variability of MASP, TcMUC, and Trans-Sialidase (TS), the three largest T. cruzi multigene families, in 36 strains, including members of all six parasite discrete typing units (DTUs). We found that these three families present a specific pattern of variability and copy number among the distinct parasite DTUs. Inter-DTU hybrid strains presented a higher variability of these families, suggesting that maintaining a larger content of their members could be advantageous. In addition, in a chronic murine model and chronic Chagasic human patients, the immune response was focused on TS antigens, suggesting that targeting TS conserved sequences could be a potential avenue to improve diagnosis and vaccine design against Chagas disease. Finally, the proposed approach can be applied to study multicopy genes in any organism, opening new avenues to access sequence variability in complex genomes. IMPORTANCE Sequences that have several copies in a genome, such as multicopy-gene families, mobile elements, and microsatellites, are among the most challenging genomic segments to study. They are frequently underestimated in genome assemblies, hampering the correct assessment of these important players in genome evolution and adaptation. Here, we developed a new methodology to estimate variability and copy numbers of repetitive genomic regions and employed it to characterize the T. cruzi multigene families MASP, TcMUC, and transsialidase (TS), which are important virulence factors in this parasite. We showed that multigene families vary in sequence and content among the parasite's lineages, whereas hybrid strains have a higher sequence variability that could be advantageous to the parasite's survivability. By identifying conserved sequences within multigene families, we showed that the mammalian host immune response toward these multigene families is usually focused on the TS multigene family. These TS conserved and immunogenic peptides can be explored in future works as diagnostic targets or vaccine candidates for Chagas disease. Finally, this methodology can be easily applied to any organism of interest, which will aid in our understanding of complex genomic regions.

Asunto(s)

Enfermedad de Chagas , Trypanosoma cruzi , Humanos , Animales , Ratones , Trypanosoma cruzi/genética , Variaciones en el Número de Copia de ADN , Genoma de Protozoos , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/genética , Familia de Multigenes , Enfermedad de Chagas/parasitología , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Mamíferos/genética

RESUMEN

Control of human ascariasis, the most prevalent neglected tropical disease globally affecting 450 million people, mostly relies on mass drug administration of anthelmintics. However, chemotherapy alone is not efficient due to the high re-infection rate for people who live in the endemic area. The development of a vaccine that reduces the intensity of infection and maintains lower morbidity should be the primary target for infection control. Previously, our group demonstrated that immunization with crude Ascaris antigens in mice induced an IgG-mediated protective response with significant worm reduction. Here, we aimed to develop a multipeptide chimera vaccine based on conserved B-cell epitopes predicted from 17 common helminth proteomes using a bioinformatics algorithm. More than 480 B-cell epitopes were identified that are conserved in all 17 helminths. The Ascaris-specific epitopes were selected based on their reactivity to the pooled sera of mice immunized with Ascaris crude antigens or infected three times with A. suum infective eggs. The top 35 peptides with the strongest reactivity to Ascaris immune serum were selected to construct a chimeric antigen connected in sequence based on conformation. This chimera, called ASCVac-1, was produced as a soluble recombinant protein in an Escherichia coli expression system and, formulated with MPLA, was used to immunize mice. Mice immunized with ASCVac-1/MPLA showed around 50% reduced larvae production in the lungs after being challenged with A. suum infective eggs, along with significantly reduced inflammation and lung tissue/function damage. The reduced parasite count and pathology in infected lungs were associated with strong Th2 immune responses characterized by the high titers of antigen-specific IgG and its subclasses (IgG1, IgG2a, and IgG3) in the sera and significantly increased IL-4, IL-5, IL-13 levels in lung tissues. The reduced IL-33 titers and stimulated eosinophils were also observed in lung tissues and may also contribute to the ASCVac-1-induced protection. Taken together, the preclinical trial with ASCVac-1 chimera in a mouse model demonstrated its significant vaccine efficacy associated with strong IgG-based Th2 responses, without IgE induction, thus reducing the risk of an allergic response. All results suggest that the multiepitope-based ASCVac-1 chimera is a promising vaccine candidate against Ascaris sp. infections.

Asunto(s)

Antígenos Helmínticos/administración & dosificación , Ascariasis/prevención & control , Ascaris suum/inmunología , Enfermedades Desatendidas/prevención & control , Vacunas Antiprotozoos/administración & dosificación , Animales , Antígenos Helmínticos/inmunología , Ascariasis/inmunología , Ascariasis/parasitología , Ascariasis/patología , Ascaris suum/aislamiento & purificación , Femenino , Humanos , Pulmón/inmunología , Pulmón/parasitología , Pulmón/patología , Ratones , Enfermedades Desatendidas/inmunología , Enfermedades Desatendidas/parasitología , Enfermedades Desatendidas/patología , Vacunas Antiprotozoos/inmunología , Células Th2/inmunología , Eficacia de las Vacunas , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/inmunología

RESUMEN

Control of human ascariasis, the most prevalent neglected tropical disease globally affecting 450 million people, mostly relies on mass drug administration of anthelmintics. However, chemotherapy alone is not efficient due to the high re-infection rate for people who live in the endemic area. The development of a vaccine that reduces the intensity of infection and maintains lower morbidity should be the primary target for infection control. Previously, our group demonstrated that immunization with crude Ascaris antigens in mice induced an IgG-mediated protective response with significant worm reduction. Here, we aimed to develop a multipeptide chimera vaccine based on conserved B-cell epitopes predicted from 17 common helminth proteomes using a bioinformatics algorithm. More than 480 B-cell epitopes were identified that are conserved in all 17 helminths. The Ascaris-specific epitopes were selected based on their reactivity to the pooled sera of mice immunized with Ascaris crude antigens or infected three times with A. suum infective eggs. The top 35 peptides with the strongest reactivity to Ascaris immune serum were selected to construct a chimeric antigen connected in sequence based on conformation. This chimera, called ASCVac-1, was produced as a soluble recombinant protein in an Escherichia coli expression system and, formulated with MPLA, was used to immunize mice. Mice immunized with ASCVac-1/MPLA showed around 50% reduced larvae production in the lungs after being challenged with A. suum infective eggs, along with significantly reduced inflammation and lung tissue/function damage. The reduced parasite count and pathology in infected lungs were associated with strong Th2 immune responses characterized by the high titers of antigen-specific IgG and its subclasses (IgG1, IgG2a, and IgG3) in the sera and significantly increased IL-4, IL-5, IL-13 levels in lung tissues. The reduced IL-33 titers and stimulated eosinophils were also observed in lung tissues and may also contribute to the ASCVac-1-induced protection. Taken together, the preclinical trial with ASCVac-1 chimera in a mouse model demonstrated its significant vaccine efficacy associated with strong IgG-based Th2 responses, without IgE induction, thus reducing the risk of an allergic response. All results suggest that the multiepitope-based ASCVac-1 chimera is a promising vaccine candidate against Ascaris sp. infections.

RESUMEN

The aim of this systematic review was to investigate the studies that evaluated the sensitivity and specificity of serologic tests using recombinant protein antigens from Mycobacterium leprae for leprosy diagnosis. We included 13 studies that were available in PubMed, Brazilian Virtual Library of Health, Web of Science, ScienceDirect and Scopus. From these studies, we found that the recombinant serine-rich 45-kDa protein of M. leprae (ML0411) demonstrated high performance for multibacillary (MB) also to paucibacillary (PB) patients, although this study was tested only for Indian population. Despite that, studies using the ND-O-LID antigen have been able to more accurately identify new cases of leprosy among people living in endemic or non-endemic areas and household contacts in Brazil, Colombia, and the Philippines, especially when combined with other biomarkers. Finally, low sensitivity values for PB patients' antibodies response remain challenging for tests intended to diagnose clinical forms that comprise this classification in leprosy.

Asunto(s)

Lepra , Mycobacterium leprae , Proteínas Recombinantes , Pruebas Serológicas , Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/metabolismo , Brasil , Colombia , Humanos , Lepra/diagnóstico , Mycobacterium leprae/inmunología , Filipinas , Proteínas Recombinantes/metabolismo , Reproducibilidad de los Resultados , Pruebas Serológicas/normas

RESUMEN

Chronic inflammation contributes to neuronal death in Alzheimer's disease (AD) and frontotemporal dementia (FTD). Here we evaluated inflammatory and pro-resolving mediators in AD and behavioural variant of FTD (bvFTD) patients compared with controls, since neuroinflamamtion is a common feature in both diseases. Ninety-eight subjects were included in this study, divided into AD (n = 32), bvFTD (n = 30), and control (n = 36) groups. The levels of hsCRP, IL-1ß, IL-6, TNF, and TGF-ß1, as well as annexin A1 (AnxA1) and lipoxin A4 (LXA4) were measured in blood and cerebrospinal fluid (CSF). The expression profile of AnxA1 was evaluated in peripheral blood mononuclear cells (PBMCs) as well the distribution of ANXA1 rs2611228 polymorphism. We found reduced peripheral levels of hsCRP and TNF in AD compared with bvFTD patients and controls, and increased levels of TGF-ß1 in AD compared to controls. Moreover, reduced plasma levels of AnxA1 were observed in bvFTD compared to AD and controls. There was a significant cleavage of AnxA1 in PBMCs in both dementia groups. The results suggest differential regulation of inflammatory and pro-resolving mediators in bvFTD and AD, while AnxA1 cleavage may impair pro-resolving mechanisms in both groups.

Asunto(s)

Enfermedad de Alzheimer/metabolismo , Anexina A1/metabolismo , Citocinas/metabolismo , Demencia Frontotemporal/metabolismo , Lipoxinas/metabolismo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/inmunología , Anexina A1/sangre , Anexina A1/líquido cefalorraquídeo , Citocinas/sangre , Citocinas/líquido cefalorraquídeo , Diagnóstico Diferencial , Femenino , Demencia Frontotemporal/inmunología , Genotipo , Voluntarios Sanos , Humanos , Inflamación , Lipoxinas/sangre , Lipoxinas/líquido cefalorraquídeo , Masculino , Persona de Mediana Edad

RESUMEN

The approach to breast cancer has changed in recent decades due to significant advances in screening, early diagnosis, and treatment; however, the risk of cardiovascular injury induced by chemotherapy has remained similar. Anthracyclines are the most common agents used in breast cancer treatment and may lead to cardiotoxicity, which appears to have a direct relationship with accumulated dose and duration of treatment. Therefore, the use of cardiac biomarkers derived from those used in cardiac disease diagnosis has been applied to the early identification, evaluation, and cardiotoxicity monitoring during chemotherapy. Cardiac troponins (cTn) have high specificities and high sensitivity in myocardial injury and are used in the diagnosis and risk stratification of acute coronary syndromes. cTn have been validated by clinical studies in the cardiotoxicity diagnosis and prognosis in patients treated with high doses of anthracyclines alone or in combination, mainly with trastuzumab. Thus, the identification of cardiotoxicity through cTn in the preclinical phase would be crucial for the application of preventive strategies. Here, we analyzed 23 cross-sectional, prospective and retrospective studies using cTn as the biomarker of cardiotoxicity in patients with breast cancer receiving treatment with anthracyclines. Studies showed that the association of cTn with different biomarkers can contribute to the early diagnosis of cardiotoxicity; however the main evidence is that low cTn levels is related to a better outcome with a good negative predictive value (NPV). In conclusion, different studies are still necessary for the adoption of cTn as a routine clinical biomarker in patients with breast cancer receiving anthracycline treatment.

Asunto(s)

Antraciclinas/efectos adversos , Cardiotoxicidad/diagnóstico , Troponina/metabolismo , Antraciclinas/administración & dosificación , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/efectos adversos , Biomarcadores/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Valor Predictivo de las Pruebas

RESUMEN

Fundamento: a Doença de Alzheimer (DA) é o tipo mais comum de demência, sendo histologicamente caracterizada pela deposição de peptídeo ß-amiloide, hiperfosforilação da proteína tau, neuroinflamação e perda neuronal, favorecida por diferentes mecanismos fisiopatológicos. O diabetes mellitus tipo 2 (DM2) ocorre devido à resistência periférica à insulina e à insuficiência insulínica (em fases mais avançadas da doença). Dados epidemiológicos sugerem relação entre DA e DM2, embora os supostos mecanismos fisiopatológicos comuns dessa inter-relação sejam obscuros. Objetivos: revisar os principais mecanismos fisiopatológicos compartilhados pela DA e DM2. Métodos: foram pesquisados artigos de 2000 a 2017 nas bases de dados do Portal CAPES/MEC, utilizando as palavras-chave: doença de Alzheimer, diabetes mellitus tipo 2, lesão vascular, resistência à insulina e estresse oxidativo. Resultados: 127 publicações foram analisadas e 73 incluídas. Lesão endotelial, resistência à insulina e estresse oxidativo foram os aspectos fisiopatológicos mais importantes e comuns à DA e DM2. Conclusão: há indícios de relação entre DA e DM2, embora não esteja clara se a relação é causal. Consequentemente, há a necessidade de estudos mais aprofundados sobre marcadores e mecanismos relacionados, visando o desenvolvimento de programas de prevenção e intervenção nas duas doenças em conjunto. (AU)

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Introduction: Alzheimer's Disease (AD) is the most common type of dementia and is histologically characterized by deposition of ß-amyloid peptide, hyperphosphorylation of tau protein, neuronal loss and neuroinflammation, favored by different pathophysiological mechanisms. The type 2 diabetes mellitus (T2DM) occurs due to peripheral insulin resistance and insulin insufficiency (in later stages of the disease). Epidemiological data suggest a relationship between AD and T2DM, although the supposed common pathophysiological mechanisms of this interrelation are obscure. Objectives: to review the main pathophysiological mechanisms possibly shared by AD and T2DM. Methods: articles were searched from 2000 to 2017 in the databases of Portal CAPES / MEC, using the key words: Alzheimer's disease, type 2 diabetes mellitus, vascular injury, insulin resistance and oxidative stress. Results: we selected 73 from 127 articles. Endothelial injury, insulin resistance and oxidative stress are pathophysiological aspects common to AD and T2DM. Conclusion: there is evidence of a relationship between AD and T2DM, although it is unclear whether the relation is causal. There is a need for more studies about markers and related mechanisms, aiming at the development of prevention and intervention programs in both diseases. (AU)

Asunto(s)

Humanos , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/epidemiología , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/fisiopatología , Enfermedad de Alzheimer/epidemiología , Resistencia a la Insulina , Factores de Riesgo , Péptidos beta-Amiloides/metabolismo , Estrés Oxidativo , Progresión de la Enfermedad

RESUMEN

In patients with Alzheimer's disease (AD), a persistent and unresolved neuroinflammatory process can contribute to neuronal loss and a decline in their cognitive and functional abilities. Recent studies have demonstrated that the ability to resolve inflammation is impaired in the brains of patients with AD. Preclinical evidence demonstrates the potential of therapeutic interventions on the resolution phase of inflammation in AD. Supplementation of omega-3 fatty acids (n-3 FAs), precursors for specialized pro-resolving mediators, emerged as a possibility for prevention and management of AD. Here, we provide a narrative review of resolving inflammation in AD and the role of n-3 FA supplementation in AD.

Asunto(s)

Enfermedad de Alzheimer/complicaciones , Suplementos Dietéticos , Encefalitis/dietoterapia , Encefalitis/etiología , Ácidos Grasos Omega-3/metabolismo , Enfermedad de Alzheimer/prevención & control , Animales , Humanos

RESUMEN

METHODS: The individuals were categorized in two groups according to the presence or absence of cognitive decline. Cognitive data were related to genetic information. RESULTS: The XbaI -351 AA genotype was more common among cognitive decliners, while -351G allele carriers showed cognitive stability or improvement. CONCLUSION: These results suggest that ESR-1 could be associated with one-year cognitive decline in healthy oldest-old individuals, since the estrogen pathway may be involved with neuroprotection, even in healthy brain aging.

Asunto(s)

Trastornos del Conocimiento/genética , Cognición , Receptor alfa de Estrógeno/genética , Predisposición Genética a la Enfermedad , Polimorfismo Genético , Anciano , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Polimorfismo de Nucleótido Simple , Estudios Prospectivos

RESUMEN

ABSTRACT This prospective study aimed to evaluate the influence of the -351A/G XbaI polymorphism in the estrogen receptor-alpha (ESR-1) gene on global cognitive scores of a community sample of healthy oldest-old individuals within one year of follow up. Methods The individuals were categorized in two groups according to the presence or absence of cognitive decline. Cognitive data were related to genetic information. Results The XbaI -351 AA genotype was more common among cognitive decliners, while -351G allele carriers showed cognitive stability or improvement. Conclusion These results suggest that ESR-1 could be associated with one-year cognitive decline in healthy oldest-old individuals, since the estrogen pathway may be involved with neuroprotection, even in healthy brain aging.

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RESUMO Neste estudo prospectivo foi avaliada a influência do polimorfismo -351A/G XbaI do gene do receptor de estrogênio alfa (ESR-1) sobre o desempenho cognitivo global em idosos muito idosos (≥ 75 anos) saudáveis durante um ano. Métodos Os indivíduos foram divididos em dois grupos de acordo com a presença ou ausência de declínio cognitivo. Dados cognitivos foram relacionados à informação genética. Resultados O genótipo XbaI -351 AA foi mais comum entre indivíduos que apresentaram declínio cognitivo, enquanto carreadores do alelo -351G demonstraram estabilidade ou melhora cognitiva. Conclusão Estes resultados sugerem que ESR-1 poderia estar associado ao declínio cognitivo em curto prazo em idosos saudáveis, possivelmente por meio de propriedades neuroprotetoras do estrogênio, mesmo em cérebros idosos saudáveis.

Asunto(s)

Humanos , Masculino , Femenino , Anciano , Polimorfismo Genético , Cognición , Trastornos del Conocimiento/genética , Predisposición Genética a la Enfermedad , Receptor alfa de Estrógeno/genética , Estudios Prospectivos , Polimorfismo de Nucleótido Simple , Frecuencia de los Genes , Genotipo

RESUMEN

The current childhood obesity epidemic represents a particular challenge for public health. Understanding of the etiological mechanisms of obesity remains integral in treating this complex disorder. In recent years, studies have elucidated the influence of hormones secreted by adipose tissue named adipokines. Adiponectin is a adipokine that exhibits important anti-inflammatory, insulin-sensitizing and anti-atherogenic properties and it is strongly associated to obesity development. It is well known that adiponectin levels decrease with obesity. Furthermore, studies show that some single nucleotide polymorphisms in the gene encoding adiponectin, ADIPOQ, may influence the expression of this protein. The objective of this paper is to provide an up-to-date review of ADIPOQ polymorphisms in the context of childhood obesity.