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1.
Front Cell Infect Microbiol ; 14: 1408451, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38828264

RESUMO

Recent studies indicate that human spleen contains over 95% of the total parasite biomass during chronic asymptomatic infections caused by Plasmodium vivax. Previous studies have demonstrated that extracellular vesicles (EVs) secreted from infected reticulocytes facilitate binding to human spleen fibroblasts (hSFs) and identified parasite genes whose expression was dependent on an intact spleen. Here, we characterize the P. vivax spleen-dependent hypothetical gene (PVX_114580). Using CRISPR/Cas9, PVX_114580 was integrated into P. falciparum 3D7 genome and expressed during asexual stages. Immunofluorescence analysis demonstrated that the protein, which we named P. vivax Spleen-Dependent Protein 1 (PvSDP1), was located at the surface of infected red blood cells in the transgenic line and this localization was later confirmed in natural infections. Plasma-derived EVs from P. vivax-infected individuals (PvEVs) significantly increased cytoadherence of 3D7_PvSDP1 transgenic line to hSFs and this binding was inhibited by anti-PvSDP1 antibodies. Single-cell RNAseq of PvEVs-treated hSFs revealed increased expression of adhesion-related genes. These findings demonstrate the importance of parasite spleen-dependent genes and EVs from natural infections in the formation of intrasplenic niches in P. vivax, a major challenge for malaria elimination.


Assuntos
Vesículas Extracelulares , Malária Vivax , Plasmodium vivax , Proteínas de Protozoários , Baço , Vesículas Extracelulares/metabolismo , Plasmodium vivax/genética , Plasmodium vivax/metabolismo , Humanos , Baço/metabolismo , Baço/parasitologia , Malária Vivax/parasitologia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética , Eritrócitos/parasitologia , Eritrócitos/metabolismo , Fibroblastos/parasitologia , Fibroblastos/metabolismo , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Plasmodium falciparum/fisiologia , Adesão Celular , Interações Hospedeiro-Parasita
2.
Int J Mol Sci ; 24(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36982564

RESUMO

Dogs are highly valued companions and work animals that are susceptible to many life-threatening conditions such as canine leishmaniosis (CanL). Plasma-derived extracellular vesicles (EVs), exploited extensively in biomarker discovery, constitute a mostly untapped resource in veterinary sciences. Thus, the definition of proteins associated with plasma EVs recovered from healthy and diseased dogs with a relevant pathogen would be important for biomarker development. For this, we recovered, using size-exclusion chromatography (SEC), EVs from 19 healthy and 20 CanL dogs' plasma and performed proteomic analysis by LC-MS/MS to define their core proteomic composition and search for CanL-associated alterations. EVs-specific markers were identified in all preparations and also non-EVs proteins. Some EVs markers such as CD82 were specific to the healthy animals, while others, such as the Integrin beta 3 were identified in most samples. The EVs-enriched preparations allowed the identification of 529 canine proteins that were identified in both groups, while 465 and 154 were only identified in healthy or CanL samples, respectively. A GO enrichment analysis revealed few CanL-specific terms. Leishmania spp. protein identifications were also found, although with only one unique peptide. Ultimately, CanL-associated proteins of interest were identified and a core proteome was revealed that will be available for intra- and inter-species comparisons.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Cães , Animais , Leishmaniose Visceral/veterinária , Cromatografia Líquida , Proteômica , Espectrometria de Massas em Tandem , Leishmaniose/veterinária , Biomarcadores
3.
J Extracell Biol ; 2(10): e117, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38939734

RESUMO

Parasites are responsible for the most neglected tropical diseases, affecting over a billion people worldwide (WHO, 2015) and accounting for billions of cases a year and responsible for several millions of deaths. Research on extracellular vesicles (EVs) has increased in recent years and demonstrated that EVs shed by pathogenic parasites interact with host cells playing an important role in the parasite's survival, such as facilitation of infection, immunomodulation, parasite adaptation to the host environment and the transfer of drug resistance factors. Thus, EVs released by parasites mediate parasite-parasite and parasite-host intercellular communication. In addition, they are being explored as biomarkers of asymptomatic infections and disease prognosis after drug treatment. However, most current protocols used for the isolation, size determination, quantification and characterization of molecular cargo of EVs lack greater rigor, standardization, and adequate quality controls to certify the enrichment or purity of the ensuing bioproducts. We are now initiating major guidelines based on the evolution of collective knowledge in recent years. The main points covered in this position paper are methods for the isolation and molecular characterization of EVs obtained from parasite-infected cell cultures, experimental animals, and patients. The guideline also includes a discussion of suggested protocols and functional assays in host cells.

4.
J Immunol Res ; 2022: 5230603, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36033396

RESUMO

Chagas disease, caused by the protozoa parasite Trypanosoma cruzi, is a neglected tropical disease and a major public health problem affecting more than 6 million people worldwide. Many challenges remain in the quest to control Chagas disease: the diagnosis presents several limitations and the two available treatments cause several side effects, presenting limited efficacy during the chronic phase of the disease. In addition, there are no preventive vaccines or biomarkers of therapeutic response or disease outcome. Trypomastigote form and T. cruzi-infected cells release extracellular vesicles (EVs), which are involved in cell-to-cell communication and can modulate the host immune response. Importantly, EVs have been described as promising tools for the development of new therapeutic strategies, such as vaccines, and for the discovery of new biomarkers. Here, we review and discuss the role of EVs secreted during T. cruzi infection and their immunomodulatory properties. Finally, we briefly describe their potential for biomarker discovery and future perspectives as vaccine development tools for Chagas Disease.


Assuntos
Doença de Chagas , Vesículas Extracelulares , Trypanosoma cruzi , Biomarcadores , Humanos , Imunidade
5.
Mol Cell Proteomics ; 21(10): 100406, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36030044

RESUMO

Latent liver stages termed hypnozoites cause relapsing Plasmodium vivax malaria infection and represent a major obstacle in the goal of malaria elimination. Hypnozoites are clinically undetectable, and presently, there are no biomarkers of this persistent parasite reservoir in the human liver. Here, we have identified parasite and human proteins associated with extracellular vesicles (EVs) secreted from in vivo infections exclusively containing hypnozoites. We used P. vivax-infected human liver-chimeric (huHEP) FRG KO mice treated with the schizonticidal experimental drug MMV048 as hypnozoite infection model. Immunofluorescence-based quantification of P. vivax liver forms showed that MMV048 removed schizonts from chimeric mice livers. Proteomic analysis of EVs derived from FRG huHEP mice showed that human EV cargo from infected FRG huHEP mice contain inflammation markers associated with active schizont replication and identified 66 P. vivax proteins. To identify hypnozoite-specific proteins associated with EVs, we mined the proteome data from MMV048-treated mice and performed an analysis involving intragroup and intergroup comparisons across all experimental conditions followed by a peptide compatibility analysis with predicted spectra to warrant robust identification. Only one protein fulfilled this stringent top-down selection, a putative filamin domain-containing protein. This study sets the stage to unveil biological features of human liver infections and identify biomarkers of hypnozoite infection associated with EVs.


Assuntos
Vesículas Extracelulares , Malária Vivax , Parasitos , Humanos , Camundongos , Animais , Malária Vivax/tratamento farmacológico , Malária Vivax/parasitologia , Plasmodium vivax , Proteômica , Proteoma , Filaminas , Fígado , Biomarcadores , Espectrometria de Massas
6.
Front Cell Infect Microbiol ; 12: 920204, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35873153

RESUMO

Plasmodium vivax is the most widely distributed human malaria parasite representing 36.3% of disease burden in the South-East Asia region and the most predominant species in the region of the Americas. Recent estimates indicate that 3.3 billion of people are under risk of infection with circa 7 million clinical cases reported each year. This burden is certainly underestimated as the vast majority of chronic infections are asymptomatic. For centuries, it has been widely accepted that the only source of cryptic parasites is the liver dormant stages known as hypnozoites. However, recent evidence indicates that niches outside the liver, in particular in the spleen and the bone marrow, can represent a major source of cryptic chronic erythrocytic infections. The origin of such chronic infections is highly controversial as many key knowledge gaps remain unanswered. Yet, as parasites in these niches seem to be sheltered from immune response and antimalarial drugs, research on this area should be reinforced if elimination of malaria is to be achieved. Due to ethical and technical considerations, working with the liver, bone marrow and spleen from natural infections is very difficult. Recent advances in the development of humanized mouse models and organs-on-a-chip models, offer novel technological frontiers to study human diseases, vaccine validation and drug discovery. Here, we review current data of these frontier technologies in malaria, highlighting major challenges ahead to study P. vivax cryptic niches, which perpetuate transmission and burden.


Assuntos
Antimaláricos , Malária Vivax , Malária , Animais , Medula Óssea/parasitologia , Modelos Animais de Doenças , Humanos , Malária/tratamento farmacológico , Malária Vivax/prevenção & controle , Camundongos , Plasmodium vivax
7.
Rev. salud pública ; 24(2)mar.-abr. 2022.
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1536725

RESUMO

Objetivo Evaluar el impacto del embarazo en mujeres con una alta carga de enfermedad, especialmente con enfermedades crónicas no transmisibles (ECNT) en los costos de una aseguradora de salud. Materiales y Métodos Estudio de costos retrospectivos realizado en Famisanar EPS entre 2016 y 2018. Utilizamos múltiples modelos de regresión lineal para evaluar; los costos generales se calcularon para cada paciente. La perspectiva de la aseguradora fue considerada para el análisis. Resultados El universo de estudio estuvo conformado por 458 249 mujeres en edad fértil afiliadas a Famisanar EPS entre los 15 y 49 años, de las cuales 24 030 (5,2%) mujeres tienen alguna relación con el ECNT. De ellas, 2454 (10,2%) fueron al parto y cesárea. Habíamos determinado los costos del embarazo en mujeres sanas en USD 200,41 y el embarazo en mujeres con ECNT USD 519,95 (97,5%) en términos de los costos de las complicaciones en la atención de gestación. Mediante la regresión multinomial, comparamos los embarazos de ECNT con los otros grupos de mujeres. No observamos diferencias significativas en zona e ingresos, observamos diferencias significativas en la edad. Conclusión El ECNT preexistente en mujeres embarazadas puede conducir al uso de recursos adicionales en el sistema de salud. El ECNT en la sociedad representa una carga severa para un sistema de salud debido a los altos costos, especialmente cuando se habla de mujeres que tienen un ECNT y están embarazadas.


Objetive Evaluate the impact of pregnancy on women with a high disease burden, especially with Chronic Non-Communicable Diseases (CNCD) in the costs of a health insurer. Materials and Methods Retrospective costing study conducted at Famisanar EPS between 2016 and 2018. We used multiple linear regression models to evaluate; the overall costs were calculated for each patient. The insurer's perspective was taken into account for the analysis. Results The study universe was made up of 458 249 women of childbearing age affiliated to Famisanar EPS between 15 and 49 years, of which 24 030 (5.2%) women have some relationship with the CNCD, of these, 2 454 (10.2%) went to childbirth and caesarean section. We had determined the costs of pregnancy healthy's women in USD 200.41 and pregnancy CNCD's women USD 519.95 (97.5%) in terms of the costs for the complication's gestation care. Using multinomial regression, we compared the pregnancy with CNCD with the other groups of women. We did not observe any significant differences in ingress and zone. However, we observe signicant differences in the age. Conclusion Pre-existing CNCD in pregnant women can lead to the use of additional resources in the health system. CNCD in society represent a severe burden for a health system due to high costs and especially when talking about women who have an CNCD and are in pregnant. The study also indicates that female infertility treatments are important for cost containment in health systems.

8.
Cell Biol Int ; 46(6): 883-894, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35253308

RESUMO

Extracellular vesicles (EVs) are lipid bilayer envelopes that encase several types of molecules. Their contents mostly reflect their cell origin and possible targets at other locations in the organism and can be modified in pathological conditions to interfere with intercellular communication, thus promoting disease establishment and development. These characteristics, in addition to their presence in virtually all body fluids, make such vesicles ideal for biomarker discovery in human diseases. Here, we describe the effect of different anticoagulants and the combination of two purification methods for isolation and characterization of circulating EVs from blood of chronic Chagas disease (CCD) patients. We illustrated this procedure by studying a population of patients with Chagas disease at the indeterminate chronic stage, in which the Trypanosoma cruzi is very scarce in circulation. EVs were harvested from blood collected without or with different anticoagulants. Protein and nanoparticle tracking analysis was used to measure EVs size and concentration. The EVs were purified by ultracentrifugation, followed by size-exclusion chromatography and characterized by chemiluminescent enzyme-linked immunosorbent assay and dot blot using antibodies that recognized parasite-derived EVs, such as hyperimmune sera, polyclonal and monoclonal antibodies against trans-sialidase and mucins. In parallel, antibodies against classical human EV markers CD9, CD63, CD81, and CD82, were also analyzed. The results showed that anticoagulants did not interfere with the analyzed parameters and circulating EVs from CCD patients contain T. cruzi antigens and classical human exosomal markers. Overall, our protocol is adequate for the isolation of the total circulating EVs and can serve as an important basis for further studies on biomarker discovery in Chagas' disease.


Assuntos
Doença de Chagas , Vesículas Extracelulares , Trypanosoma cruzi , Anticoagulantes , Biomarcadores/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Trypanosoma cruzi/metabolismo
9.
J Infect Dis ; 225(7): 1274-1283, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32556188

RESUMO

BACKGROUND: The presence of Plasmodium vivax malaria parasites in the human bone marrow (BM) is still controversial. However, recent data from a clinical case and experimental infections in splenectomized nonhuman primates unequivocally demonstrated the presence of parasites in this tissue. METHODS: In the current study, we analyzed BM aspirates of 7 patients during the acute attack and 42 days after drug treatment. RNA extracted from CD71+ cell suspensions was used for sequencing and transcriptomic analysis. RESULTS: We demonstrated the presence of parasites in all patients during acute infections. To provide further insights, we purified CD71+ BM cells and demonstrated dyserythropoiesis and inefficient erythropoiesis in all patients. In addition, RNA sequencing from 3 patients showed that genes related to erythroid maturation were down-regulated during acute infections, whereas immune response genes were up-regulated. CONCLUSIONS: This study thus shows that during P. vivax infections, parasites are always present in the BM and that such infections induced dyserythropoiesis and ineffective erythropoiesis. Moreover, infections induce transcriptional changes associated with such altered erythropoietic response, thus highlighting the importance of this hidden niche during natural infections.


Assuntos
Anemia , Malária Vivax , Animais , Medula Óssea , Eritropoese , Humanos , Malária Vivax/parasitologia , Plasmodium vivax/genética
10.
Parasitol Int ; 87: 102527, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34896615

RESUMO

Human malaria caused by Plasmodium vivax infection (vivax malaria) is a major global health issue. It is the most geographically widespread form of the disease, accounting for 7 million annual clinical cases, the majority of cases in America and Asia and an estimation of over 2.5 billion people living under risk of infection. The general perception towards vivax malaria has shifted recently, following a series of reports, from being viewed as a benign infection to the recognition of its potential for more severe manifestations including fatal cases. However, the underlying pathogenic mechanisms of vivax malaria remain largely unresolved. Asymptomatic carriers of malaria parasites are a major challenge for malaria elimination. In the case of P. vivax, it has been widely accepted that the only source of cryptic parasites is hypnozoite dormant stages. Here, we will review new evidence indicating that cryptic erythrocytic niches outside the liver, in particular in the spleen and bone marrow, can represent a major source of asymptomatic infections. The origin of such parasites is being controversial and many key gaps in the knowledge of such infections remain unanswered. Yet, as parasites in these niches seem to be sheltered from immune response and antimalarial drugs, research on this area should be reinforced if elimination of malaria is to be achieved. Last, we will glimpse into the role of reticulocyte-derived exosomes, extracellular vesicles of endocytic origin, as intercellular communicators likely involved in the formation of such cryptic erythrocytic infections.


Assuntos
Medula Óssea/parasitologia , Eritrócitos/parasitologia , Malária Vivax/sangue , Malária Vivax/prevenção & controle , Baço/parasitologia , Animais , Antimaláricos/uso terapêutico , Exossomos/parasitologia , Humanos , Malária Vivax/tratamento farmacológico , Malária Vivax/epidemiologia , Plasmodium vivax , Reticulócitos/parasitologia , Reticulócitos/ultraestrutura
11.
Sci Rep ; 11(1): 22099, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34764379

RESUMO

The spleen is a hematopoietic organ that participates in cellular and humoral immunity. It also serves as a quality control mechanism for removing senescent and/or poorly deformable red blood cells (RBCs) from circulation. Pitting is a specialized process by which the spleen extracts particles, including malaria parasites, from within circulating RBCs during their passage through the interendothelial slits (IES) in the splenic cords. To study this physiological function in vitro, we have developed two microfluidic devices modeling the IES, according to the hypothesis that at a certain range of mechanical stress on the RBC, regulated through both slit size and blood flow, would force it undergo the pitting process without affecting the cell integrity. To prove its functionality in replicating pitting of malaria parasites, we have performed a characterization of P. falciparum-infected RBCs (P.f.-RBCs) after their passage through the devices, determining hemolysis and the proportion of once-infected RBCs (O-iRBCs), defined by the presence of a parasite antigen and absence of DAPI staining of parasite DNA using a flow cytometry-based approach. The passage of P.f.-RBCs through the devices at the physiological flow rate did not affect cell integrity and resulted in an increase of the frequency of O-iRBCs. Both microfluidic device models were capable to replicate the pitting of P.f.-RBCs ex vivo by means of mechanical constraints without cellular involvement, shedding new insights on the role of the spleen in the pathophysiology of malaria.


Assuntos
Endotélio/parasitologia , Dispositivos Lab-On-A-Chip/parasitologia , Malária Falciparum/parasitologia , Parasitos/fisiologia , Baço/parasitologia , Animais , Biomimética/métodos , Eritrócitos/parasitologia , Hemólise/fisiologia , Humanos , Plasmodium falciparum/fisiologia
12.
Pathogens ; 10(9)2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34578170

RESUMO

Plasmodium malariae has a wide geographic distribution, but mainly at very low parasitemias and in co-infections, leading to an underestimated prevalence of this species. Studies for the detection of antibodies against Plasmodium recombinant proteins are increasingly used to map geographical distributions, seroprevalence and transmission intensities of malaria infection. However, no seroepidemiological survey using recombinant P. malariae proteins has been conducted in Brazil. This work evaluated the antibody response in serum samples of individuals from endemic regions of Brazil (the Amazon region and Atlantic Forest) against five recombinant proteins of P. malariae merozoite surface protein 1 (MSP1), and the MSP1 C-terminal portions of P. vivax and P. falciparum, in a multiplex assay. The positivity was 69.5% of samples recognizing at least one MSP1 recombinant protein. The mean of the Reactivity Index for the C-terminal portion of the P. falciparum was significantly higher compared to the other recombinant proteins, followed by the C-terminal of P. vivax and the N-terminal of P. malariae. Among the recombinant P. malariae proteins, the N-terminal of P. malariae showed the highest Reactivity Index alone. This study validates the use of the multiplex assay to measure naturally acquired IgG antibodies against Plasmodium MSP1 proteins and demonstrate that these proteins are important tools for seroepidemiological surveys and could be used in malaria surveillance.

14.
PLoS Med ; 18(5): e1003632, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34038413

RESUMO

BACKGROUND: A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax. The mechanisms underlying this intense tropism are not clear. We hypothesised that immature reticulocytes, in which P. vivax develops, may display high densities in the spleen, thereby providing a niche for parasite survival. METHODS AND FINDINGS: We examined spleen tissue in 22 mostly untreated individuals naturally exposed to P. vivax and Plasmodium falciparum undergoing splenectomy for any clinical indication in malaria-endemic Papua, Indonesia (2015 to 2017). Infection, parasite and immature reticulocyte density, and splenic distribution were analysed by optical microscopy, flow cytometry, and molecular assays. Nine non-endemic control spleens from individuals undergoing spleno-pancreatectomy in France (2017 to 2020) were also examined for reticulocyte densities. There were no exclusion criteria or sample size considerations in both patient cohorts for this demanding approach. In Indonesia, 95.5% (21/22) of splenectomy patients had asymptomatic splenic Plasmodium infection (7 P. vivax, 13 P. falciparum, and 1 mixed infection). Significant splenic accumulation of immature CD71 intermediate- and high-expressing reticulocytes was seen, with concentrations 11 times greater than in peripheral blood. Accordingly, in France, reticulocyte concentrations in the splenic effluent were higher than in peripheral blood. Greater rigidity of reticulocytes in splenic than in peripheral blood, and their higher densities in splenic cords both suggest a mechanical retention process. Asexual-stage P. vivax-infected erythrocytes of all developmental stages accumulated in the spleen, with non-phagocytosed parasite densities 3,590 times (IQR: 2,600 to 4,130) higher than in circulating blood, and median total splenic parasite loads 81 (IQR: 14 to 205) times greater, accounting for 98.7% (IQR: 95.1% to 98.9%) of the estimated total-body P. vivax biomass. More reticulocytes were in contact with sinus lumen endothelial cells in P. vivax- than in P. falciparum-infected spleens. Histological analyses revealed 96% of P. vivax rings/trophozoites and 46% of schizonts colocalised with 92% of immature reticulocytes in the cords and sinus lumens of the red pulp. Larger splenic cohort studies and similar investigations in untreated symptomatic malaria are warranted. CONCLUSIONS: Immature CD71+ reticulocytes and splenic P. vivax-infected erythrocytes of all asexual stages accumulate in the same splenic compartments, suggesting the existence of a cryptic endosplenic lifecycle in chronic P. vivax infection. Findings provide insight into P. vivax-specific adaptions that have evolved to maximise survival and replication in the spleen.


Assuntos
Plasmodium vivax/fisiologia , Reticulócitos/metabolismo , Baço/metabolismo , Baço/parasitologia , Esplenectomia/estatística & dados numéricos , Adolescente , Adulto , Infecções Assintomáticas , Feminino , Humanos , Indonésia , Malária Vivax/parasitologia , Malária Vivax/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nova Guiné , Estudos Prospectivos , Adulto Jovem
15.
Front Cell Infect Microbiol ; 11: 596104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732657

RESUMO

The spleen is a secondary lymphoid organ with multiple functions including the removal of senescent red blood cells and the coordination of immune responses against blood-borne pathogens, such as malaria parasites. Despite the major role of the spleen, the study of its function in humans is limited by ethical implications to access human tissues. Here, we employed multiparameter flow cytometry combined with cell purification techniques to determine human spleen cell populations from transplantation donors. Spleen immuno-phenotyping showed that CD45+ cells included B (30%), CD4+ T (16%), CD8+ T (10%), NK (6%) and NKT (2%) lymphocytes. Myeloid cells comprised neutrophils (16%), monocytes (2%) and DCs (0.3%). Erythrocytes represented 70%, reticulocytes 0.7% and hematopoietic stem cells 0.02%. Extracellular vesicles (EVs) are membrane-bound nanoparticles involved in intercellular communication and secreted by almost all cell types. EVs play several roles in malaria that range from modulation of immune responses to vascular alterations. To investigate interactions of plasma-derived EVs from Plasmodium vivax infected patients (PvEVs) with human spleen cells, we used size-exclusion chromatography (SEC) to separate EVs from the bulk of soluble plasma proteins and stained isolated EVs with fluorescent lipophilic dyes. The integrated cellular analysis of the human spleen and the methodology employed here allowed in vitro interaction studies of human spleen cells and EVs that showed an increased proportion of T cells (CD4+ 3 fold and CD8+ 4 fold), monocytes (1.51 fold), B cells (2.3 fold) and erythrocytes (3 fold) interacting with PvEVs as compared to plasma-derived EVs from healthy volunteers (hEVs). Future functional studies of these interactions can contribute to unveil pathophysiological processes involving the spleen in vivax malaria.


Assuntos
Vesículas Extracelulares , Malária Vivax , Citometria de Fluxo , Humanos , Plasmodium vivax , Baço
16.
Front Cell Infect Microbiol ; 11: 811390, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35141172

RESUMO

Plasmodium vivax is the most widely distributed human malaria parasite with 7 million annual clinical cases and 2.5 billion people living under risk of infection. There is an urgent need to discover new antigens for vaccination as only two vaccine candidates are currently in clinical trials. Extracellular vesicles (EVs) are small membrane-bound vesicles involved in intercellular communication and initially described in reticulocytes, the host cell of P. vivax, as a selective disposal mechanism of the transferrin receptor (CD71) in the maturation of reticulocytes to erythrocytes. We have recently reported the proteomics identification of P. vivax proteins associated to circulating EVs in P. vivax patients using size exclusion chromatography followed by mass spectrometry (MS). Parasite proteins were detected in only two out of ten patients. To increase the MS signal, we have implemented the direct immuno-affinity capture (DIC) technique to enrich in EVs derived from CD71-expressing cells. Remarkably, we identified parasite proteins in all patients totaling 48 proteins and including several previously identified P. vivax vaccine candidate antigens (MSP1, MSP3, MSP7, MSP9, Serine-repeat antigen 1, and HSP70) as well as membrane, cytosolic and exported proteins. Notably, a member of the Plasmodium helical interspersed sub-telomeric (PHIST-c) family and a member of the Plasmodium exported proteins, were detected in five out of six analyzed patients. Humoral immune response analysis using sera from vivax patients confirmed the antigenicity of the PHIST-c protein. Collectively, we showed that enrichment of EVs by CD71-DIC from plasma of patients, allows a robust identification of P. vivax immunogenic proteins. This study represents a significant advance in identifying new antigens for vaccination against this human malaria parasite.


Assuntos
Vesículas Extracelulares , Malária Vivax , Anticorpos Antiprotozoários , Antígenos de Protozoários , Eritrócitos/parasitologia , Vesículas Extracelulares/metabolismo , Humanos , Malária Vivax/parasitologia , Plasmodium vivax , Proteínas de Protozoários/metabolismo , Reticulócitos/metabolismo , Reticulócitos/parasitologia
17.
Malar J ; 19(1): 440, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33256745

RESUMO

Cryptic Plasmodium niches outside the liver possibly represent a major source of hypnozoite-unrelated recrudescences in malaria. Maurizio Ascoli, an Italian physician and scientist, suggested that infection was maintained as a result of the persistence of endoerythrocytic parasites in the circulatory bed of some internal organs, mainly the spleen. This would explain a proportion of the recurrences in patients, regardless of the Plasmodium species. Ascoli proposed a method that included the co-administration of adrenaline, in order to induce splenic contraction, and quinine to clear expelled forms in major vessels. Driven by controversy regarding safety and effectiveness, along with the introduction of new drugs, the Ascoli method was abandoned and mostly forgotten by the malaria research community. To date, however, the existence of cryptic parasites outside the liver is gaining supportive data. This work is a historical retrospective of cryptic malaria infections and the Ascoli method, highlighting key knowledge gaps regarding these possible parasite reservoirs.


Assuntos
Antimaláricos/administração & dosagem , Infecções Assintomáticas , Epinefrina/administração & dosagem , Malária/prevenção & controle , Quinina/administração & dosagem , Baço/efeitos dos fármacos , Doença Crônica/prevenção & controle , História do Século XX
18.
Rev. salud pública ; 22(6): e209, nov.-dic. 2020. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1357409

RESUMO

RESUMEN Objetivo Determinar la importancia de la transversalidad desde la prespectiva del sexo-género y edad para reconocer las diferencias y su desigualdad en la actual situación de COVID-19. Materiales y Métodos Enfoque cuantitativo, exploratorio, no experimemental, de corte transversal. Se determinaron regresiones polinomiales que explican mejor las tendencias actuales para sexo-género y edad y se calculó el correspondiente R2. Resultados Las tendencias de casos de contagios confirmados son muy similares entre hombres y mujeres. En fallecimientos, existe una mayor relación entre hombres que en mujeres. En cuanto a la edad, existen diferencias en los casos confirmados concentrados entre 21 y 60 años y en los fallecidos en mayores de 50 años. Conclusiones La pandemia de COVID-19 afecta a ambos sexos. Sin embargo, es más alto el número de hombres fallecidos que de mujeres. En cuanto a la edad, se concentra el contagio entre los 21 y 60 años y la mortalidad en mayores de 50 años. La información suministrada por el Instituto Nacional de Salud de Colombia es limitada, pero cuenta con buenas características en grupos de edad pese a que se pueden realizar mejoras en función del sexo-género en cuanto a raza, el personal de salud, las fuerzas militares y la policía nacional infectados de COVID-19.


ABSTRACT Objective To determine the importance of mainstreaming from the perspective of sex-gender and age to recognize the differences and their inequality in the current situation of COVID-19. Materials and Methods Quantitative, exploratory, non-experimental, cross-sectional approach. Polynomial regressions were determined that better explain the current trends for sex-gender and age, the corresponding R2 was calculated. Results The trends of confirmed contagion cases are very similar between men and women. In deaths there is a greater relationship between men than women. Regarding age, there are differences in confirmed cases concentrated between 21 and 60 years and in those who died in those over 50 years of age. Conclusions The COVID-19 pandemic affects both sexes. However, the number of death men is higher than that of women. Regarding age, contagion is concentrated between 21 and 60 years, mortality in over 50 years. The information provided by the National Institute of Health of Colombia is limited, but it has good characteristics in age groups, although improvements can be made based on sex-gender in terms of race, health personnel, the military, and the policemen infected by COVID-19.

19.
Emerg Infect Dis ; 26(8): 1846-1851, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32687028

RESUMO

Chagas disease is emerging in countries to which it is not endemic. Biomarkers for earlier therapeutic response assessment in patients with chronic Chagas disease are needed. We profiled plasma-derived extracellular vesicles from a heart transplant patient with chronic Chagas disease and showed the potential of this approach for discovering such biomarkers.


Assuntos
Doença de Chagas , Vesículas Extracelulares , Transplante de Coração , Trypanosoma cruzi , Biomarcadores , Doença de Chagas/diagnóstico , Transplante de Coração/efeitos adversos , Humanos
20.
Int J Pharm ; 587: 119627, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32653596

RESUMO

Among several factors behind drug resistance evolution in malaria is the challenge of administering overall doses that are not toxic for the patient but that, locally, are sufficiently high to rapidly kill the parasites. Thus, a crucial antimalarial strategy is the development of drug delivery systems capable of targeting antimalarial compounds to Plasmodium with high specificity. In the present study, extracellular vesicles (EVs) have been evaluated as a drug delivery system for the treatment of malaria. EVs derived from naive red blood cells (RBCs) and from Plasmodium falciparum-infected RBCs (pRBCs) were isolated by ultrafiltration followed by size exclusion chromatography. Lipidomic characterization showed that there were no significant qualitative differences between the lipidomic profiles of pRBC-derived EVs (pRBC-EVs) and RBC-derived EVs (RBC-EVs). Both EVs were taken up by RBCs and pRBCs, although pRBC-EVs were more efficiently internalized than RBC-EVs, which suggested their potential use as drug delivery vehicles for these cells. When loaded into pRBC-EVs, the antimalarial drugs atovaquone and tafenoquine inhibited in vitro P. falciparum growth more efficiently than their free drug counterparts, indicating that pRBC-EVs can potentially increase the efficacy of several small hydrophobic drugs used for the treatment of malaria.


Assuntos
Vesículas Extracelulares , Plasmodium , Sistemas de Liberação de Medicamentos , Eritrócitos , Humanos , Lipossomos , Plasmodium falciparum
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