CYP2D6 Allele Frequency in Five Malaria Vivax Endemic Areas From Brazilian Amazon Region

Funding Information: We acknowledge the participants in the study, without whom this research could not have been done. For laboratorial support the authors wish to show their appreciation to Gabriel Barbosa de Abreu (in memorian). To Norman Ratcliffe for the English revision of this manuscript. Part of this work is described in a Master?s Dissertation by PS, conducted at the Applied Microbiology and Parasitology Post-graduation Program, Federal Fluminense University. Publisher Copyright: © Copyright © 2021 Salles, Perce-da-Silva, Rossi, Raposo, Ramirez Ramirez, Pereira Bastos, Pratt-Riccio, Cassiano, Baptista, Cardoso, Banic and Machado.Genetic variability was linked with individual responses to treatment and susceptibility to malaria by Plasmodium vivax. Polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatment. The aim of the study was to investigate whether or not CYP2D6 single nucleotide polymorphisms rs1065852, rs38920-97, rs16947 and rs28371725 are unequally distributed in malaria by Plasmodium vivax individuals from the Brazilian Amazon region. The blood samples were collected from 220 unrelated Plasmodium vivax patients from five different endemic areas. Genotyping was performed using SNaPshot® and real-time polymerase chain reaction methods. In all five areas, the rs1065852 (CYP2D6*10, C.100C > T), rs3892097 (CYP2D6*4, 1846C > T) and rs16947 (CYP2D6*2, C.2850G > A), as a homozygous genotype, showed the lowest frequencies. The rs28371725 (CYP2D6*41, 2988G > A) homozygous genotype was not detected, while the allele A was found in a single patient from Macapá region. No deviations from Hardy-Weinberg equilibrium were found, although a borderline p-value was observed (p = 0.048) for the SNP rs3892097 in Goianésia do Pará, Pará state. No significant associations were detected in these frequencies among the five studied areas. For the SNP rs3892097, a higher frequency was observed for the C/T heterozygous genotype in the Plácido de Castro and Macapá, Acre and Amapá states, respectively. The distribution of the CYP2D6 alleles investigated in the different areas of the Brazilian Amazon is not homogeneous. Further investigations are necessary in order to determine which alleles might be informative to assure optimal drug dosing recommendations based on experimental pharmacogenetics.publishersversionpublishe

The influence of intestinal parasites on Plasmodium vivax-specific antibody responses to MSP-119 and AMA-1 in rural populations of the Brazilian Amazon

Abstract\ud \ud Background\ud Polyparasitism is a common condition in humans but its impact on the host immune system and clinical diseases is still poorly understood. There are few studies of the prevalence and the effect of malaria-intestinal parasite co-infections in the immune response to malaria vaccine candidates. The present study determines whether the presence of malaria and intestinal parasites co-infection is associated with impaired IgG responses to Plasmodium vivax AMA-1 and MSP-119 in a rural population of the Brazilian Amazon.\ud \ud \ud Methods\ud A cross-sectional survey was performed in a rural area of Rondonia State and 279 individuals were included in the present study. At recruitment, whole blood was collected and Plasmodium and intestinal parasites were detected by microscopy and molecular tests. Blood cell count and haemoglobin were also tested and antibody response specific to P. vivax AMA-1 and MSP-119 was measured in plasma by ELISA. The participants were grouped according to their infection status: singly infected with Plasmodium (M); co-infected with Plasmodium and intestinal parasites (CI); singly infected with intestinal parasites (IP) and negative (N) for both malaria and intestinal parasites.\ud \ud \ud Results\ud The prevalence of intestinal parasites was significantly higher in individuals with malaria and protozoan infections were more prevalent. IgG antibodies to PvAMA-1 and/or PvMSP-119 were detected in 74 % of the population. The prevalence of specific IgG was similar for both proteins in all four groups and among the groups the lowest prevalence was in IP group. The cytophilic sub-classes IgG1 and IgG3 were predominant in all groups for PvAMA-1 and IgG1, IgG3 and IgG4 for PvMSP-119. In the case of non-cytophilic antibodies to PvAMA-1, IgG2 was significantly higher in IP and N group when compared to M and CI while IgG4 was higher in IP group.\ud \ud \ud Conclusions\ud The presence of intestinal parasites, mainly protozoans, in malaria co-infected individuals does not seem to alter the antibody immune responses to P. vivax AMA-1 and MSP-119. However, IgG response to both AMA1 and MSP1 were lower in individuals with intestinal parasites.The authors are in debt to the individuals who participated in this study, the\ud Secretary of Health and Laboratory Central (LACEN) of Rondonia, the local\ud malaria control team in Joana D´Arc settlement for their logistic support\ud and the Institute Oswaldo Cruz (Fiocruz) for overall support. This work was\ud supported by PRONEX Malaria network funded by the Brazilian Ministry of\ud Science and Technology (MCT), Conselho Nacional de Desenvolvimento\ud Cientifico e Tecnologico (CNPq, Brazil) and Fundação de Amparo à Pesquisa\ud do Estado do Rio de Janeiro (FAPERJ, Brazil). PROEP, Instituto Oswaldo Cruz\ud (FIOCRUZ, Brazil). JOF is recipient of a Research Productivity Fellowship from\ud CNPq, JCSA is recipient of a fellowship from Instituto Oswaldo Cruz and VAR,\ud MM from CNPq

Plasmodium vivax cell traversal protein for Ookinetes and Sporozoites (PvCelTOS) gene sequence and potential epitopes are highly conserved among isolates from different regions of Brazilian Amazon

This work was supported by Brazilian National Research Council–CNPq/PAPES, (Conselho Nacional de Desenvolvimento Científico e Tecnológico/Programa de Apoio e Pesquisa Estratégica em Saúde) Fiocruz. JdCLJ is recipient of a FAPERJ APQ1 (E-26/210.653/2015), Jovem Cientista do Nosso Estado (E26/203.255/2016).Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Immunoparasitology. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Clinical Immunology. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Immunoparasitology. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Computational Modeling Group. Fortaleza, CE, Brazil.University of Campinas. Department of Genetics, Evolution and Bioagents. Laboratory of Tropical Diseases - Prof. Luiz Jacintho da Silva. Campinas, SP, BrazilMinistério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Imunogenética da Malária. Ananindeua, PA, Brasil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Malaria Research. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Clinical Immunology. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Oswaldo Cruz Institute. Laboratory of Immunoparasitology. Rio de Janeiro, RJ, Brazil.The Plasmodium vivax Cell-traversal protein for ookinetes and sporozoites (PvCelTOS) plays an important role in the traversal of host cells. Although essential to PvCelTOS progress as a vaccine candidate, its genetic diversity remains uncharted. Therefore, we investigated the PvCelTOS genetic polymorphism in 119 field isolates from five different regions of Brazilian Amazon (Manaus, Novo Repartimento, Porto Velho, Plácido de Castro and Oiapoque). Moreover, we also evaluated the potential impact of non-synonymous mutations found in the predicted structure and epitopes of PvCelTOS. The field isolates showed high similarity (99.3% of bp) with the reference Sal-1 strain, presenting only four Single-Nucleotide Polymorphisms (SNP) at positions 24A, 28A, 109A and 352C. The frequency of synonymous C109A (82%) was higher than all others (p<0.0001). However, the non-synonymous G28A and G352C were observed in 9.2% and 11.7% isolates. The great majority of the isolates (79.8%) revealed complete amino acid sequence homology with Sal-1, 10.9% presented complete homology with Brazil I and two undescribed PvCelTOS sequences were observed in 9.2% field isolates. Concerning the prediction analysis, the N-terminal substitution (Gly10Ser) was predicted to be within a B-cell epitope (PvCelTOS Accession Nos. AB194053.1) and exposed at the protein surface, while the Val118Leu substitution was not a predicted epitope. Therefore, our data suggest that although G28A SNP might interfere in potential B-cell epitopes at PvCelTOS N-terminal region the gene sequence is highly conserved among the isolates from different geographic regions, which is an important feature to be taken into account when evaluating its potential as a vaccine candidate

Plasmodium vivax Cell Traversal Protein for Ookinetes and Sporozoites (PvCelTOS) gene sequence and potential epitopes are highly conserved among isolates from different regions of Brazilian Amazon

The Plasmodium vivax Cell-traversal protein for ookinetes and sporozoites (PvCelTOS) plays an important role in the traversal of host cells. Although essential to PvCelTOS progress as a vaccine candidate, its genetic diversity remains uncharted. Therefore, we investigated the PvCelTOS genetic polymorphism in 119 field isolates from five different regions of Brazilian Amazon (Manaus, Novo Repartimento, Porto Velho, Pla A cido de Castro and Oiapoque). Moreover, we also evaluated the potential impact of non-synonymous mutations found in the predicted structure and epitopes of PvCelTOS. The field isolates showed high similarity (99.3% of bp) with the reference Sal-1 strain, presenting only four Single-Nucleotide Polymorphisms (SNP) at positions 24A, 28A, 109A and 352C. The frequency of synonymous C109A (82%) was higher than all others (p<0.0001). However, the non-synonymous G28A and G352C were observed in 9.2% and 11.7% isolates. The great majority of the isolates (79.8%) revealed complete amino acid sequence homology with Sal-1, 10.9% presented complete homology with Brazil I and two undescribed PvCelTOS sequences were observed in 9.2% field isolates. Concerning the prediction analysis, the N-terminal substitution (Gly10Ser) was predicted to be within a B-cell epitope (PvCelTOS Accession Nos. AB194053.1) and exposed at the protein surface, while the Val118Leu substitution was not a predicted epitope. Therefore, our data suggest that although G28A SNP might interfere in potential B-cell epitopes at PvCelTOS N-terminal region the gene sequence is highly conserved among the isolates from different geographic regions, which is an important feature to be taken into account when evaluating its potential as a vaccine candidate112CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJsem informaçãoE-26/210.653/201

Cells and mediators of inflammation (C-reactive protein, nitric oxide, platelets and neutrophils) in the acute and convalescent phases of uncomplicated Plasmodium vivax and Plasmodium falciparum infection

The haematological changes and release of soluble mediators, particularly C-reactive protein (CRP) and nitric oxide (NO), during uncomplicated malaria have not been well studied, especially in Brazilian areas in which the disease is endemic. Therefore, the present study examined these factors in acute (day 0) and convalescent phase (day 15) patients infected with Plasmodium falciparum and Plasmodium vivax malaria in the Brazilian Amazon. Haematologic parameters were measured using automated cell counting, CRP levels were measured with ELISA and NO plasma levels were measured by the Griess reaction. Our data indicate that individuals with uncomplicated P. vivax and P. falciparum infection presented similar inflammatory profiles with respect to white blood cells, with high band cell production and a considerable degree of thrombocytopaenia during the acute phase of infection. Higher CRP levels were detected in acute P. vivax infection than in acute P. falciparum infection, while higher NO was detected in patients with acute and convalescent P. falciparum infections. Although changes in these mediators cannot predict malaria infection, the haematological aspects associated with malaria infection, especially the roles of platelets and band cells, need to be investigated further

Genetic polymorphisms in the glutamate-rich protein of Plasmodium falciparum field isolates from a malaria-endemic area of Brazil

The genetic diversity displayed by Plasmodium falciparum, the most deadly Plasmodium species, is a significant obstacle for effective malaria vaccine development. In this study, we identified genetic polymorphisms in P. falciparum glutamate-rich protein (GLURP), which is currently being tested in clinical trials as a malaria vaccine candidate, from isolates found circulating in the Brazilian Amazon at variable transmission levels. The study was performed using samples collected in 1993 and 2008 from rural villages situated near Porto Velho, in the state of Rondônia. DNA was extracted from 126 P. falciparum-positive thick blood smears using the phenol-chloroform method and subjected to a nested polymerase chain reaction protocol with specific primers against two immunodominant regions of GLURP, R0 and R2. Only one R0 fragment and four variants of the R2 fragment were detected. No differences were observed between the two time points with regard to the frequencies of the fragment variants. Mixed infections were uncommon. Our results demonstrate conservation of GLURP-R0 and limited polymorphic variation of GLURP-R2 in P. falciparum isolates from individuals living in Porto Velho. This is an important finding, as genetic polymorphisms in B and T-cell epitopes could have implications for the immunological properties of the antigen

Genetic Diversity of Plasmodium vivax Cysteine-Rich Protective Antigen (PvCyRPA) in Field Isolates from Five Different Areas of the Brazilian Amazon

The Plasmodium vivax Cysteine-Rich Protective Antigen (PvCyRPA) has an important role in erythrocyte invasion and has been considered a target for vivax malaria vaccine development. Nonetheless, its genetic diversity remains uncharted in Brazilian malaria-endemic areas. Therefore, we investigated the pvcyrpa genetic polymorphism in 98 field isolates from the Brazilian Amazon and its impact on the antigenicity of predicted B-cell epitopes. Genetic diversity parameters, population genetic analysis, neutrality test and the median-joining network were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. One synonymous and 26 non-synonymous substitutions defined fifty haplotypes. The nucleotide diversity and Tajima&rsquo;s D values varied across the coding gene. The exon-1 sequence had greater diversity than those of exon-2. Concerning the prediction analysis, seven sequences were predicted as linear B cell epitopes, the majority contained in conformational epitopes. Moreover, important amino acid polymorphism was detected in regions predicted to contain residues participating in B-cell epitopes. Our data suggest that the pvcyrpa gene presents a moderate polymorphism in the studied isolates and such polymorphisms alter amino acid sequences contained in potential B cell epitopes, an important observation considering the antigen potentiality as a vaccine candidate to cover distinct P. vivax endemic areas worldwide

Modeling structure and <i>In silico</i> analysis of PvCelTOS.

<p>(A) Synonymous and non-synonymous mutations were illustrated by blue title and red title, respectively, on 3D structure of PvCelTOS. The red and blue clouds represent the negative and positive surface, respectively. (B) Synonymous and non-synonymous mutations found in our population and other described mutations are illustrated by blue bars and red bars, respectively, on PvCelTOS structure. The blue lines represent predicted linear B-cell epitopes and the red lines represent predicted T_CD8+ epitopes. On both (B and T predicted epitopes) the letter and number of each epitope indicate the C-terminal and N-terminal amino acid. The BepiPred values represent the predicted score of linear B-cell epitope in wild type haplotype (H1) and mutate strain (red number). The IEDB MHC-I indicates the mean binding prediction score of T_CD8+ epitopes and respective HLA binding frequency among 27 evaluated HLA. No differences of prediction T-cell epitopes are observed between wild types or mutate PvCelTOS.</p

Geographical map showing the five study sites and the respective Annual Parasitic Incidence (API) (SIVEP-Malaria).

<p>Geographical map showing the five study sites and the respective Annual Parasitic Incidence (API) (SIVEP-Malaria).</p