RESUMO
BACKGROUND: It is well established that infection by Plasmodium vivax is a result of host-parasite interactions. In the present study, association with the IL1/IL2 cytokine profiles, anticircumsporozoite protein antibody levels and parasitic loads was evaluated in individuals naturally infected with P. vivax in an endemic area of the Brazilian Amazon. METHODS: Molecular diagnosis of P. vivax and variants was performed using the PCR-RFLP method and IL1B -511C>T, IL2 -330T>G and IL2+114T>G polymorphisms were identified using PCR-RFLP and allele-specific PCR. IL-1ß and IL-2 cytokine levels were detected by flow cytometry and circumsporozoite protein (CSP) antibodies were measured by ELISA. RESULTS: Three variants of P. vivax CSP were identified and VK247 was found to be the most frequent. However, the prevalence and magnitude of IgG antibodies were higher for the VK210 variant. Furthermore, the antibody response to the CSP variants was not associated with the presence of the variant in the infection. Significant differences were observed between the single nucleotide polymorphism (SNP) -511T>C in the IL1B gene and levels of antibodies to the VK247 and P. vivax-like variants, but there were no associations between SNPs in IL1 and IL2 genes and their plasma products. CONCLUSIONS: Individuals with the rs16944 CC genotype in the IL1ß gene have higher antibody levels to the CSP of P. vivax of VK247 and P. vivax-like variants.
Assuntos
Malária Vivax , Plasmodium vivax , Formação de Anticorpos , Brasil , Humanos , Imunoglobulina G , Interleucina-1beta , Malária Vivax/genética , Plasmodium vivax/genética , Polimorfismo Genético , Proteínas de Protozoários/genéticaRESUMO
El cáncer es una enfermedad que se presenta de diferentes formas y con distintos orígenes, con evidencias de que su incidencia está en aumento. La relación entre cáncer y factores socio-ambientales es muy fuerte, siendo la información sobre esta patología de vital importancia para una comunidad. Aunque existe varias maneras de abordar la problemática, es difícil desarrollar una modalidad que permita de manera rápida y efectiva relacionar en lugar y tiempo la aparición de nuevos pacientes. De lograrlo, en un futuro no muy lejano se podría formular hipótesis de trabajo sobre factores sociales o ambientales relacionados con esta patología. En consecuencia, hemos trabajado en el desarrollo e implantación de un Sistema de Información Geográfico Integral en base a datos aportados por el Servicio de Anatomía Patológica y Oncología de pacientes con cáncer, contando con datos espaciales y temporales de vivienda y trabajo. El objetivo del presente trabajo fue que el sistema aporte datos útiles para realizar registro y detección de asociaciones de cáncer y posibles focos contaminantes.
Assuntos
Humanos , Epidemiologia , Neoplasias , Mapeamento Geográfico , Sistemas de Informação em SaúdeRESUMO
Polymorphisms in cytokine genes can alter the production of these proteins and consequently affect the immune response. The trihybrid heterogeneity of the Brazilian population is characterized as a condition for the use of ancestry informative markers. The objective of this study was to evaluate the frequency of -1031T>C, -308G>A and -238G>A TNFA, +874 A>T IFNG and -819C>T, and -592C>A IL10 gene polymorphisms and their association with malaria vivax and genomic ancestry. Samples from 90 vivax malaria-infected individuals and 51 noninfected individuals from northern Brazil were evaluated. Genotyping was carried out by using ASO-PCR or PCR/RFLP. The genomic ancestry of the individuals was classified using 48 insertion/deletion polymorphism biallelic markers. There were no differences in the proportions of African, European, and Native American ancestry between men and women. No significant association was observed for the allele and genotype frequencies of the 6 SNPs between malaria-infected and noninfected individuals. However, there was a trend toward decreasing the frequency of individuals carrying the TNF-308A allele with the increasing proportion of European ancestry. No ethnic-specific SNPs were identified, and there was no allelic or genotype association with susceptibility or resistance to vivax malaria. Understanding the genomic mechanisms by which ancestry influences this association is critical and requires further study.
Assuntos
Interferon gama/genética , Interleucina-10/genética , Malária Vivax/genética , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genética , Adulto , Alelos , Brasil , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Genótipo , Haplótipos/genética , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: The immune response against Plasmodium vivax immunogenic epitopes is regulated by pro- and anti-inflammatory cytokines that determine antibody levels and class switching. Cytokine gene polymorphisms may be responsible for changes in the humoral immune response against malaria. The aim of this study was to evaluate whether polymorphisms in the TNFA, IFNG and IL10 genes would alter the levels of anti-PvAMA1, PvDBP and -PvMSP-119 IgG antibodies in patients with vivax malaria. METHODS: Samples from 90 vivax malaria-infected and 51 uninfected subjects from an endemic area of the Brazilian Amazon were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to identify polymorphisms of the genes TNFA (-1031T > C, -308G > A, -238G > A), IFNG (+874T > A) and IL10 (-819C > T, -592C > A). The levels of total IgG against PvAMA1, PvDBP and PvMSP-119 were determined using an enzyme-linked immunosorbent assay (ELISA). Associations between the polymorphisms and the antibody response were assessed by means of logistic regression models. RESULTS: No significant differences were found in the levels of IgG antibodies against the PvAMA-1, PvDBP or PvMSP-119 proteins in relation to the studied polymorphisms. CONCLUSIONS: Although no associations were found among the evaluated genotypes and alleles and anti-merozoite IgG class P. vivax antibody levels, this study helps elucidate the immunogenic profile involved in the humoral immune response in malaria.
Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Citocinas/genética , Proteínas de Membrana/imunologia , Plasmodium vivax/imunologia , Polimorfismo Genético , Proteínas de Protozoários/imunologia , Receptores de Superfície Celular/imunologia , Brasil , Ensaio de Imunoadsorção Enzimática , Estudos de Associação Genética , Técnicas de Genotipagem , Humanos , Imunoglobulina G/sangue , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de RestriçãoRESUMO
BACKGROUND: Humoral immune responses against proteins of asexual blood-stage malaria parasites have been associated with clinical immunity. However, variations in the antibody-driven responses may be associated with a genetic component of the human host. The objective of the present study was to evaluate the influence of co-stimulatory molecule gene polymorphisms of the immune system on the magnitude of the humoral immune response against a Plasmodium vivax vaccine candidate antigen. METHODS: Polymorphisms in the CD28, CTLA4, ICOS, CD40, CD86 and BLYS genes of 178 subjects infected with P. vivax in an endemic area of the Brazilian Amazon were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The levels of IgM, total IgG and IgG subclasses specific for ICB2-5, i.e., the N-terminal portion of P. vivax merozoite surface protein 1 (PvMSP-1), were determined by enzyme-linked immuno assay. The associations between the polymorphisms and the antibody response were assessed by means of logistic regression models. RESULTS: After correcting for multiple testing, the IgG1 levels were significantly higher in individuals recessive for the single nucleotide polymorphism rs3116496 in CD28 (p = 0.00004). Furthermore, the interaction between CD28 rs35593994 and BLYS rs9514828 had an influence on the IgM levels (p = 0.0009). CONCLUSIONS: The results of the present study support the hypothesis that polymorphisms in the genes of co-stimulatory components of the immune system can contribute to a natural antibody-driven response against P. vivax antigens.
Assuntos
Antígenos de Protozoários/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Fatores Imunológicos/genética , Proteína 1 de Superfície de Merozoito/imunologia , Plasmodium vivax/imunologia , Polimorfismo Genético , Adolescente , Adulto , Idoso , Anticorpos Antiprotozoários/sangue , Brasil , Estudos Transversais , Feminino , Técnicas de Genotipagem , Humanos , Imunogenética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Adulto JovemRESUMO
The development of an effective immune response can help decrease mortality from malaria and its clinical symptoms. However, this mechanism is complex and has significant inter-individual variation, most likely owing to the genetic contribution of the human host. Therefore, this study aimed to investigate the influence of polymorphisms in genes involved in the costimulation of B-lymphocytes in the naturally acquired humoral immune response against proteins of the asexual stage of Plasmodium vivax. A total of 319 individuals living in an area of malaria transmission in the Brazilian Amazon were genotyped for four SNPs in the genes CD40, CD40L, BLYS and CD86. In addition, IgG antibodies against P. vivax apical membrane antigen 1 (PvAMA-1), Duffy binding protein (PvDBP) and merozoite surface protein 1 (PvMSP-119) were detected by ELISA. The SNP BLYS -871C>T was associated with the frequency of IgG responders to PvAMA-1 and PvMSP-119. The SNP CD40 -1C>T was associated with the IgG response against PvDBP, whereas IgG antibody titers against PvMSP-119 were influenced by the polymorphism CD86 +1057G>A. These data may help to elucidate the immunological aspects of vivax malaria and consequently assist in the design of malaria vaccines.
Assuntos
Anticorpos Antiprotozoários/imunologia , Antígenos CD , Imunoglobulina G/imunologia , Malária Vivax , Plasmodium vivax/imunologia , Polimorfismo de Nucleotídeo Único/imunologia , Proteínas de Protozoários/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/genética , Antígenos CD/imunologia , Feminino , Humanos , Malária Vivax/genética , Malária Vivax/imunologia , Masculino , Pessoa de Meia-IdadeRESUMO
Co-stimulatory molecules are essential in the orchestration of immune response and polymorphisms in their genes are associated with various diseases. However, in the case of variable allele frequencies among continental populations, this variation can lead to biases in genetic studies conducted in admixed populations such as those from Brazil. The aim of this study was to evaluate the influence of genomic ancestry on distributions of co-stimulatory genes polymorphisms in an admixed Brazilian population. A total of 273 individuals from the north of Brazil participated in this study. Nine single nucleotide polymorphisms in 7 genes (CD28, CTLA4, ICOS, CD86, CD40, CD40L and BLYS) were determined by polymerase chain reaction-restriction fragment length polymorphism. We also investigated 48 insertion/deletion ancestry markers to characterize individual African, European and Amerindian ancestry proportions in the samples. The analysis showed that the main contribution was European (43.9%) but also a significant contribution of African (31.6%) and Amerindian (24.5%) ancestry. ICOS, CD40L and CD86 polymorphisms were associated with genomic ancestry. However there were no significant differences in the proportions of ancestry for the other SNPs and haplotypes studied. Our findings reinforce the need to apply AIMs in genetic association studies involving these polymorphisms in the Brazilian population.
Assuntos
Receptores Coestimuladores e Inibidores de Linfócitos T/genética , Genética Populacional , Imunidade/genética , Polimorfismo de Nucleotídeo Único , Alelos , Brasil , Mapeamento Cromossômico , Etnicidade/genética , Evolução Molecular , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Mutação INDEL , Desequilíbrio de Ligação , MasculinoRESUMO
BACKGROUND: Several studies have recently demonstrated that the immune responses against malaria is governed by different factors, including the genetic components of the host. The IL-4 gene appears to be a strong candidate factor because of its role in the regulation of the Th2 response. The present study investigated the role of IL-4 polymorphisms in the development of IgG antibodies against PvAMA-1 and the IL-4 levels in individuals infected with Plasmodium vivax in a malaria endemic area in the Brazilian Amazon. METHODS: The study sample included 83 patients who were diagnosed with P. vivax infection using thick smear and confirmed by nested-PCR. The IL-4 -590C>T and IL-4 -33C>T polymorphisms were genotyped by PCR-RFLP, and the intron 3 VNTR was genotyped by PCR. A standardised ELISA protocol was used to measure the total IgG against PvAMA-1. The cytokine/chemokine levels were measured using a Milliplex multiplex assay (Millipore). All of the subjects were genotyped with 48 ancestry informative markers to determine the proportions of African, European and Amerindian ancestry using STRUCTURE software. RESULTS: Of the 83 patients, 60 (73%) produced IgG antibodies against PvAMA-1. A significant decrease in the percentage of respondents was observed among the primo-infected individuals. No significant differences were observed in the frequencies of genotypes and haplotypes among individuals who were positive or negative for IgG antibodies against PvAMA-1. Furthermore, no significant correlation was observed between the IL-4 polymorphisms, antibody levels, IL-4 levels, and parasitemia. CONCLUSIONS: This study indicated that the polymorphisms identified in the IL-4 gene are not likely to play a role in the regulation of the antibody response against PvAMA-1 and IL-4 production in vivax malaria.
Assuntos
Antígenos de Protozoários/administração & dosagem , Doenças Endêmicas , Interleucina-4/genética , Vacinas Antimaláricas/administração & dosagem , Malária Vivax/genética , Proteínas de Membrana/administração & dosagem , Plasmodium vivax/imunologia , Polimorfismo Genético , Proteínas de Protozoários/administração & dosagem , Adolescente , Adulto , Idoso , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/imunologia , Brasil/epidemiologia , Feminino , Humanos , Imunoglobulina G/imunologia , Interleucina-4/imunologia , Vacinas Antimaláricas/imunologia , Malária Vivax/epidemiologia , Malária Vivax/imunologia , Malária Vivax/prevenção & controle , Masculino , Proteínas de Membrana/imunologia , Pessoa de Meia-Idade , Proteínas de Protozoários/imunologia , Células Th2/imunologiaRESUMO
BACKGROUND: Plasmodium vivax is the most prevalent malaria species in Brazil. The parasite-host coevolutionary process can be viewed as an 'arms race', in which adaptive genetic changes in one are eventually matched by alterations in the other. METHODS: Following the candidate gene approach we analyzed the CD40, CD40L and BLYS genes that participate in B-cell co-stimulation, for associations with P. vivax malaria. The study sample included 97 patients and 103 controls. We extracted DNA using the extraction and purification commercial kit and identified the following SNPs: -1C > T in the CD40 gene, -726T > C in the CD40L gene and the -871C > T in the BLyS gene using PCR-RFLP. We analyzed the genotype and allele frequencies by direct counting. We also compared the observed with the expected genotype frequencies using the Hardy-Weinberg equilibrium. RESULTS: The allele and genotype frequencies for these SNPs did not differ statistically between patient and control groups. Gene-gene interactions were not observed between the CD40 and BLYS and between the CD40L and BLYS genes. Overall, the genes were in Hardy-Weinberg equilibrium. Significant differences were not observed among the frequencies of antibody responses against P. vivax sporozoite and erythrocytic antigens and the CD40 and BLYS genotypes. CONCLUSIONS: The results of this study show that, although the investigated CD40, CD40L and BLYS alleles differ functionally, this variation does not alter the functionality of the molecules in a way that would interfere in susceptibility to the disease. The variants of these genes may influence the clinical course rather than simply increase or decrease susceptibility.
Assuntos
Fator Ativador de Células B/genética , Antígenos CD40/genética , Ligante de CD40/genética , Malária Vivax/genética , Plasmodium vivax/genética , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Antígenos de Protozoários/genética , Brasil , DNA de Protozoário/análise , Progressão da Doença , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Modelos Logísticos , Malária Vivax/imunologia , Masculino , Adulto JovemRESUMO
Introdução - Extrato bruto da casca de banana nanica (Musa acuminata); melhor fonte de enzima Polifenol oxidase (PFO) [EC.1.14.18.1] foi estudado como material biocatalítico para a oxidação aeróbica de substratos fenólicos. Materiais e Métodos - O extrato bruto de PFO foi obtido como em Perone et al.14 (2000). A atividade da enzima PFO e proteína total foram determinadas nesse extrato. Foi construído um biossensor desse extrato bruto da casca de banana nanica com 75 unidades de PFO, imobilizada com reagente glutaraldeído. Resultados - Esse biossensor, sensível a polifenóis, foi caracterizado e apresentou pH ótimo de imobilização da enzima igual a 6,5 e sensibilidade acentuada para o substrato catecol. Também foi utilizado no estudo da determinação da concentração de taninos em amostras de diversos tipos de chás. Conclusões - Foi verificado que a porcentagem de erro comparando com o método espectrofotométrico apresentou valores menores que 1,0% estando, portanto, de acordo com o procedimento padrão oficial. Comparando os resultados obtidos com esse biossensor e o de extrato bruto da polpa de banana nanica observamos, melhor tempo de armazenamento das membranas com a casca do que com a polpa, e uma diminuição significativa na quantidade de extrato imobilizado. Assim, conclui-se que o extrato de PFO da casca é melhor fonte de enzima do que a polpa e, portanto, será usado na construção dobiossensor. A vantagem do método amperométrico apresentado é possuir baixo custo, rapidez nas determinações e boa sensibilidade comparado com métodos cromatográficos.
Introduction - Crude extract of banana nanica (Musa acuminata); the best source of enzyme Poliphenol oxidase (PPO) [EC.1.14.18.1] was studied as biocatalytic material to the aerobic oxidation of phenolics substrates. Materials and Methods - The crude extract of I was done the same as at Perone et al.14 (2000). The activity from the enzyme PPO and total protein were determined in this extract. It has been built a biosensor of this crude extract from the peel of stunded banana with 75unities of PPO immobilized with glutaraldeyde reagent. Results - This biosensor, sensitive to poliphenol, was characterized and presented immobilizing optimium pH of the enzyme equal to 6.5and acute sensibility to its catechol substrate. It was also used at the study of the determination of tanines concentration in samples of many kinds of tea. Conclusions - It was verified that percentage of error comparing with the spectrophotometric method, has presented lower than 1,0% values according to the standard methods. Comparing the results obtained with this biosensor and the crude extract of the pulp of banana nanica, it was observed the better stock time of the membranes with the peel than with the pulp, and significative diminishing of the amount of immobilized extract. So, we conclude that the extract of PPO from the peel is better source of enzyme than the pulp and it will be used at the construction of the biosensor. The advantage of the amperometrics methods presented is to obtain low cost, fast determination and good sensibility compared to cromatographics methods.