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1.
Microorganisms ; 12(2)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38399674

RESUMO

Visceral leishmaniasis (VL) is a chronic systemic disease. In Brazil this infection is caused by Leishmania (Leishmania) infantum. Extracellular vesicles (EVs) released by Leishmania species have different functions like the modulation of host immune systems and inflammatory responses, among others. This study evaluated the participation of EVs from L. (L.) infantum (Leish-EVs) in recognition of the humoral and cellular immune response of hosts with VL. Promastigotes were cultivated in 199 medium and, in the log phase of growth, they were centrifuged, washed, resus-pended in RPMI medium, and incubated for 2 to 24 h, at 25 °C or 37 °C to release Leish-EVs. This dynamic was evaluated using transmission (TEM) and scanning (SEM) electron microscopies, as well as nanoparticle tracking analysis (NTA). The results suggested that parasite penetration in mammal macrophages requires more Leish-EVs than those living in insect vectors, since promastigotes incubated at 37 °C released more Leish-EVs than those incubated at 25 °C. Infected THP-1 cells produced high EV concentration (THP-1 cells-EVs) when compared with those from the control group. The same results were obtained when THP-1 cells were treated with Leish-EVs or a crude Leishmania antigen. These data indicated that host-EV concentrations could be used to distinguish infected from uninfected hosts. THP-1 cells treated with Leish-EVs expressed more IL-12 than control THP-1 cells, but were unable to express IFN-γ. These same cells highly expressed IL-10, which inhibited TNF-α and IL-6. Equally, THP-1 cells treated with Leish-EVs up-expressed miR-21-5p and miR-146a-5p. In conclusion, THP-1 cells treated with Leish-EVs highly expressed miR-21-5p and miR-146a-5p and caused the dysregulation of IL-10. Indirectly, these results suggest that high expression of these miRNAs species is caused by Leish-EVs. Consequently, this molecular via can contribute to immunosuppression causing enhanced immunopathology in infected hosts.

2.
Microorganisms ; 12(1)2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38257943

RESUMO

Extracellular vesicles (EVs) are lipid bilayer envelopes that encapsulate cell-specific cargo, rendering them promising biomarkers for diverse diseases. Chagas disease, caused by the parasite Trypanosoma cruzi, poses a significant global health burden, transcending its initial epicenter in Latin America to affect individuals in Europe, Asia, and North America. In this study, we aimed to characterize circulating EVs derived from patients with chronic Chagas disease (CCD) experiencing a reactivation of acute symptoms. Blood samples collected in EDTA were processed to isolate plasma and subsequently subjected to ultracentrifugation for particle isolation and purification. The EVs were characterized using a nanoparticle tracking analysis and enzyme-linked immunosorbent assay (ELISA). Our findings revealed distinctive differences in the size, concentration, and composition of EVs between immunosuppressed patients and those with CCD. Importantly, these EVs play a critical role in the pathophysiology of Chagas disease and demonstrate significant potential as biomarkers in the chronic phase of the disease. Overall, our findings support the potential utility of the CL-ELISA assay as a specific sensitive tool for detecting circulating EVs in chronic Chagasic patients, particularly those with recurrent infection following an immunosuppressive treatment or with concurrent HIV and Chagas disease. Further investigations are warranted to identify and validate the specific antigens or biomarkers responsible for the observed reactivity in these patient groups, which may have implications for diagnosis, the monitoring of treatment, and prognosis.

3.
Parasite Immunol ; 45(9): e13004, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37475490

RESUMO

This retrospective cohort study analysed extracellular vesicles (EVs) and microRNAs (miRNAs) excreted in canine sera from dogs with canine visceral leishmaniasis (CanVL). A total of 56 canine sera were divided into Group I (28, from healthy dogs) and Group II (28, from the same dogs, but already with CanVL). CanVL was determined by clinical and laboratory diagnoses. Canine sera were ultra-centrifuged to recover EVs (Can-EVs). Analyses by transmission electron microscopy, nanoparticle tracking analysis (NTA), sodium dodecyl sulfate-poli-acrylammide gel eletroforesis (SDS-PAGE) and, Immunoblot confirmed the presence of (i) microvesicles/exosomes and (ii) the tetraspanins CD63 and CD9. EVs secreted by Leishmania (Leishmania) infantum-EVs were reactive against sera from dogs with CanVL (performed by ELISA and Immunoblot). NTA analyses exhibited that concentrations of Can-EVs from dogs with CanVL (7.78 × 1010 Can-EVs/mL) were higher (p < .0001) than the non-infected dogs (mean: 1.47 × 1010 Can-EVs/mL). These results suggested that concentrations of Can-EVs were able to distinguish dogs with CanVL from healthy dogs. The relative expressions of 11 miRNAs species (miR-21-5p, miR-146a-5p, miR-125b-5p, miR-144-3p, miR-194-5p, miR-346, miR-29c-3p, miR-155-5p, miR-24-3p, miR-181a-5p, and miR-9-5p) were estimated in purified miRNAs of 30 canine sera. Dogs with CanVL up-expressed miR-21-5p and miR-146a-5p when compared with healthy dogs. The other miRNA species were poorly or not expressed in canine sera. In conclusion, this study suggests that CanVL induces changes in size and concentration of Can-EVs, as well as, the up-expression of miR-21-5p and miR-146a-5p in infected dogs.


Assuntos
Exossomos , Vesículas Extracelulares , Leishmaniose Visceral , MicroRNAs , Cães , Animais , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/metabolismo , Estudos Retrospectivos , MicroRNAs/genética
4.
Braz J Microbiol ; 53(4): 2321-2327, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35906453

RESUMO

Brazilian porcupine poxvirus (BPoPV) is a new poxvirus recently described in porcupines (Coendou prehensilis) from Brazil. Herein, we described a free-ranging adult male Coendou (Sphiggurus) spinosus rescued after being found lethargic on the ground in a rural area. The animal presented crusty, edematous, and suppurative skin lesions on the face, tail, and perineum, and yellowish ocular secretion. The diagnosis was performed by histopathology, transmission electron microscopy (TEM), PCR, and sequencing. Microscopically, proliferative and necrotizing dermatitis, subacute, multifocal with ballooning degeneration, and eosinophilic intracytoplasmic viral inclusion bodies were observed. TEM confirmed large brick-shaped virions inside the keratinocyte cytoplasm, measuring about 200-280 × 120-180 nm. Partial fragment of intracellular mature virion membrane protein gene and putative metalloproteinase gene was successfully amplified and sequenced, and the strain herein denoted IAL/21 V-102 was classified as BPoPV, showing 99.4% of nucleotide identity to the reference strain UFU/USP001. Enrofloxacin 10% (10 mg/kg) was administered every 24 h through intramuscular injection for 10 days, dipyrone/metamizole (25 mg/kg) every 24 h orally (PO) for 3 days, 0.5 ml (mL) of thymomodulin every 24 h PO for 30 days, and each 48 h for another 15 days. The lesions were cleaned and debrided every 15 days. Seventy-five days after the beginning of the treatment, the cutaneous lesions regressed, the animal gained weight, and was clinically stable. After treatment, the skin biopsy showed only mild epidermal acanthosis, intra-cellular edema, and mild lymphoplasmacytic perivascular dermatitis. No viral particles were observed by TEM and no poxviral DNA was amplified by PCR. This study documents the first case of confirmed and treated BPoPV infection in a hairy dwarf porcupine. The implemented therapeutic plan eliminated the infection and improved the general state of the animal.


Assuntos
Dermatite , Porcos-Espinhos , Infecções por Poxviridae , Animais , Masculino , Pele , Microscopia Eletrônica de Transmissão
5.
Parasite Immunol ; 43(9): e12869, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34028833

RESUMO

This study characterized extracellular vesicles (EVs) of sera from mice infected with Toxoplasma gondii or immunized with EVs derived T gondii. EVs were purified of sera from four groups (5 A/Sn mice/group). EV-IM: Mice immunized with T gondii-released EVs; ACT: mice in acute infection; CHR: mice in chronic infection; and NI: normal mice. EVs were purified by ultracentrifugation. Concentration of serum-derived EVs from NI group was smaller than EV-IM, ACT and CHR groups. Most of the EVs from ACT and CHR groups were microvesicles, and they were bigger than the NI group. The same results were shown by Transmission Electron Microscopy. The presence of exosomes was shown in immunoblotting by tetraspanin (CD63 and CD9) evidence. Splenocytes of EV-IM, CHR and NI groups were stimulated with T. gondii derived EVs. EV-IM and CHR groups up-expressed IFN-γ; TNF-α and IL-17, when compared with the NI group. IL-10 was up-expressed only in the EV-IM group. EV-IM, ACT and CHR groups expressed more miR-155-5p, miR-29c-3p and miR-125b-5p than the NI group. Host-T gondii interaction can occur, also, via EVs. miRNAs participate in the modulation of cellular immune response against T gondii. These data give subsidies to propose the differentiation between infect or noninfect hosts by concentration of EVs.


Assuntos
Exossomos , Vesículas Extracelulares , MicroRNAs , Toxoplasma , Toxoplasmose , Animais , Camundongos
6.
Acta Trop ; 219: 105915, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33861971

RESUMO

This study investigated the participation extracellular vesicles (EVs) in Toxoplasma gondii-host interaction. EVs of three T. gondii strains (RH, ME-49 and VEG) were purified by chromatography and ELISA. Results of "nanoparticle tracking analysis" and scanning electron microscopy showed that RH strain released more EVs than other strains. Images of transmission electron microscopy showed that in beginning of incubation (culture medium), EVs were inside of tachyzoites preparing to be released. After 24 hours, they were largely produced inside tachyzoites and were released through plasma membrane. The parasite burden of mice infected with RH strain plus EVs was increased and with early death of 1-2 days compared of those that received only parasites. EV proteins of ME-49 and VEG strains were poorly reactive to sera of infected patients in imunoblot. However, those from RH strain were reactive against sera of patients with cerebral toxoplasmosis. EVs stimulated murine splenocytes caused similar production of IFN-γ and IL-10 levels. RH strain derived EVs stimulated more TNF-α than those stimulated by other strains. T. gondii and infected hosts can express the same miRNAs (miR-155-5p, miR-125b-5p, miR-423-3p). In conclusion, T. gondii derived EVs promote host-parasite interactions, modulate host immune responses, carry virulent factors and cause an imbalance in cellular immune response.


Assuntos
Vesículas Extracelulares/metabolismo , Toxoplasma/citologia , Animais , Humanos , Imunidade Celular , Interleucina-10/sangue , Camundongos , MicroRNAs/sangue , Toxoplasma/imunologia , Toxoplasmose Animal/imunologia , Fator de Necrose Tumoral alfa/sangue
7.
Int J Parasitol ; 51(7): 559-569, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33713649

RESUMO

The study aim was to analyze whether microvesicles and exosomes, named extracellular vesicles (EVs), purified from Toxoplasma gondii are able to stimulate the protective immunity of experimental mice when administered, as challenge, a highly virulent strain. EVs excreted from T. gondii tachyzoites (RH strain) were purified by chromatography and used for immunization assays in inbred mouse groups (EV-IM). Chronic infected (CHR) and naive (NI) mice were used as control groups, since the immune response is well known. After immunizations, experimental groups were challenged with 100 tachyzoites. Next, parasitemias were determined by real-time PCR (qPCR), and survival levels were evaluated daily. The humoral response was analyzed by detection of IgM, IgG, IgG1 and IgG2a, and opsonization experiments. The cellular response was evaluated in situ by immunohistochemistry on IFN-γ, IL-10, TNF-α and IL-17 expression in cells of five organs (brain, heart, liver, spleen and skeletal muscles). EV immunization reduced parasitemia and increased the survival index in two mouse lineages (A/Sn and BALB/c) infected with a lethal T. gondii strain. EV-IM mice had higher IgG1 levels than IgM or IgG2a. IgGs purified from sera of EV-IM mice were able to opsonize tachyzoites (RH strain), and mice that received these parasites had lower parasitemias, and mortality was delayed 48 h, compared with the same results from those receiving parasites opsonized with IgG purified from NI mice. Brain and spleen cells from EV-IM mice more highly expressed IFN-γ, IL-10 and TNF-α. In conclusion, EV-immunization was capable of inducing immune protection, eliciting high production of IgG1, IFN-γ, IL-10 and TNF-α.


Assuntos
Vesículas Extracelulares , Toxoplasma , Animais , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Vacinação
8.
Braz. j. infect. dis ; 24(2): 150-159, Mar.-Apr. 2020. tab, graf
Artigo em Inglês | LILACS, Coleciona SUS (Brasil) | ID: biblio-1132431

RESUMO

ABSTRACT Background: Latent HIV-1 is a major hurdle in obtaining HIV-1 sustained virological remission (SVR). Here we explored histone deacetylation inhibition property of nicotinamide (NAM; n = 17) for the first time in comparison to a combination of methyltransferase inhibitors (MTIs; Chaetocin and BIX01294; n = 25) to reactivate latent HIV ex vivo in CD8-depleted PBMCs from antiretroviral treated aviremic individuals. Results: NAM reactivated HIV-1 from 13/17 (76.4%) samples compared to 20/25 (80.0%) using MTIs with mean viral load (VLs) of 4.32 and 3.22 log10 RNA copies/mL, respectively (p = 0.004). Mean purging time after NAM and MTIs stimulation was 5.1 and 6.75 days, respectively (p = 0.73). Viral purging in autologous cultures exhibited blunted HIV recovery with fluctuating VLs followed by a complete viral extinction when expanded in allogenic system. Electron microscopy from five supernatants revealed anomalous viral particles, with lack of complete viral genomes when characterized by ultradeep sequencing through metagenomics approach (n = 4). Conclusion: NAM alone was more potent HIV-1 activator than combination of MTIs, with potential of clinical use.


Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Quinazolinas/farmacologia , Azepinas/farmacologia , Ativação Viral/efeitos dos fármacos , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Niacinamida/farmacologia , Metiltransferases/antagonistas & inibidores , Piperazinas/farmacologia , Leucócitos Mononucleares/virologia , Linfócitos T CD4-Positivos , Regulação Viral da Expressão Gênica , Latência Viral , Carga Viral/efeitos dos fármacos , Tropismo Viral/efeitos dos fármacos
9.
PLoS One ; 15(3): e0229602, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32126572

RESUMO

AIM: This study analyzed microvesicles and exosomes, called as extracellular vesicles (EVs) excreted in serum and cerebrospinal fluid (CSF) from patients with cerebral or gestational toxoplasmosis. METHODS: Clinical samples from 83 individuals were divided into four groups. Group I, 20 sera from healthy individuals and pregnant women (seronegative for toxoplasmosis); group II, 21 sera from seropositive patients for toxoplasmosis (cerebral or gestational forms); group III, 26 CSF samples from patients with cerebral toxoplasmosis/HIV co-infection (CT/HIV) (seropositive for toxoplasmosis); and group IV, 16 CSF samples from seronegative patients for toxoplasmosis, but with HIV infection and other opportunistic infections (OI/HIV). Serum and CSF samples were ultracentrifuged to recover EVs. Next, vesicle size and concentration were characterized by Nanoparticle Tracking Analysis (NTA). RESULTS: Concentrations of serum-derived EVs from toxoplasmosis patients (mean: 2.4 x 1010 EVs/mL) were statically higher than of non-infected individuals (mean: 5.9 x 109 EVs/mL). Concentrations of CSF-derived EVs were almost similar in both groups. CT/HIV (mean: 2.9 x 109 EVs/mL) and OI/HIV (mean: 4.8 x 109 EVs/mL). Analyses by NTA confirmed that CSF-derived EVs and serum-derived EVs had size and shape similar to microvesicles and exosomes. The mean size of EVs was similar in serum and CSF. Thus, the concentration, and not size was able distinguish patients with toxoplasmosis than healthy individuals. Presence of exosomes was also confirmed by transmission electron microscopy and evidence of tetraspanins CD63 and CD9 in immunoblotting. Relative expressions of miR-146a-5p, miR-155-5p, miR-21-5p, miR-29c-3p and miR-125b-5p were estimated in exosomal miRNA extracted of EVs. Serum-derived EVs from group II (cerebral and gestational toxoplasmosis) up-expressed miR-125b-5p and miR-146a-5p. CSF-derived EVs from CT/HIV patients) up-expressed miR-155-5p and miR-21-5p and were unable to express miR-29c-3p. CONCLUSION: These data suggest the participation of EVs and exosomal miRNAs in unbalance of immune response as elevation of TNF-α, IL-6; and downregulation of IFN-γ in cerebral and gestational forms of toxoplasmosis.


Assuntos
Complicações Parasitárias na Gravidez/sangue , Complicações Parasitárias na Gravidez/líquido cefalorraquidiano , Toxoplasmose Cerebral/sangue , Toxoplasmose Cerebral/líquido cefalorraquidiano , Toxoplasmose/complicações , Micropartículas Derivadas de Células/genética , Micropartículas Derivadas de Células/patologia , Exossomos/genética , Exossomos/patologia , Vesículas Extracelulares/genética , Vesículas Extracelulares/patologia , Feminino , Expressão Gênica , Infecções por HIV/sangue , Infecções por HIV/líquido cefalorraquidiano , Infecções por HIV/complicações , Voluntários Saudáveis , Humanos , MicroRNAs/sangue , MicroRNAs/líquido cefalorraquidiano , MicroRNAs/genética , Microscopia Eletrônica de Transmissão , Gravidez , Complicações Parasitárias na Gravidez/genética , Toxoplasmose/sangue , Toxoplasmose/líquido cefalorraquidiano , Toxoplasmose Cerebral/genética
10.
Braz J Infect Dis ; 24(2): 150-159, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32105620

RESUMO

BACKGROUND: Latent HIV-1 is a major hurdle in obtaining HIV-1 sustained virological remission (SVR). Here we explored histone deacetylation inhibition property of nicotinamide (NAM; n=17) for the first time in comparison to a combination of methyltransferase inhibitors (MTIs; Chaetocin and BIX01294; n=25) to reactivate latent HIV ex vivo in CD8-depleted PBMCs from antiretroviral treated aviremic individuals. RESULTS: NAM reactivated HIV-1 from 13/17 (76.4%) samples compared to 20/25 (80.0%) using MTIs with mean viral load (VLs) of 4.32 and 3.22 log10 RNA copies/mL, respectively (p=0.004). Mean purging time after NAM and MTIs stimulation was 5.1 and 6.75 days, respectively (p=0.73). Viral purging in autologous cultures exhibited blunted HIV recovery with fluctuating VLs followed by a complete viral extinction when expanded in allogenic system. Electron microscopy from five supernatants revealed anomalous viral particles, with lack of complete viral genomes when characterized by ultradeep sequencing through metagenomics approach (n=4). CONCLUSION: NAM alone was more potent HIV-1 activator than combination of MTIs, with potential of clinical use.


Assuntos
Azepinas/farmacologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Metiltransferases/antagonistas & inibidores , Niacinamida/farmacologia , Quinazolinas/farmacologia , Ativação Viral/efeitos dos fármacos , Adulto , Linfócitos T CD4-Positivos , Feminino , Regulação Viral da Expressão Gênica , Humanos , Leucócitos Mononucleares/virologia , Masculino , Pessoa de Meia-Idade , Piperazinas/farmacologia , Carga Viral/efeitos dos fármacos , Tropismo Viral/efeitos dos fármacos , Latência Viral , Adulto Jovem
11.
Bioorg Chem ; 95: 103510, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31884137

RESUMO

As part of our continuous studies on prospecting metabolites from Brazilian plant species with pharmacologic activity against Trypanosoma cruzi, the n-hexane extract from twigs of Nectandra barbellata (Lauraceae) was subjected to a bioactivity-guided fractionation to afford the sesquiterpene costic acid. As results, costic acid induced a trypanocidal effect with IC50 of 37.8 and 7.9 µM to trypomastigotes and intracellular amastigotes, respectively. When tested in L929 cells, no cytotoxicity was detected in the highest tested concentration (CC50 > 200 µM), resulting in SI values >5 and >25 to trypomastigotes and amastigotes, respectively. Based on these promising results against T. cruzi, a mechanistic study of the parasite death was investigated. The flow cytometry analysis of costic acid-treated parasites showed depolarization of the plasma membrane electric potential. Spectrofluorimetrical analysis and transmission electron microscopy showed no evidence of plasma membrane permeability alteration of trypomastigotes, but strong ultrastructural damage, evidenced by large vacuoles. Although Ca2+ and reactive oxygen species (ROS) levels were unaltered after short time incubation with costic acid, it rapidly affected the mitochondria, leading to a depolarized potential of the membrane, reducing the ATP levels. In silico studies of costic acid showed good predictions for drug-likeness, with adherence to Lipinskís rules of five (RO5), good ADMET properties and no alerts for Pan-Assay Interference Compounds (PAINS). Therefore, costic acid demonstrated promising activity against T. cruzi parasites, with high selectivity to intracellular amastigotes. Considering the lethal action of costic acid in affecting a vital and unique organelle as the mitochondria, it could be considered a new hit compound for future drug design studies for Chagas disease.


Assuntos
Membrana Celular/efeitos dos fármacos , Doença de Chagas/tratamento farmacológico , Sesquiterpenos de Eudesmano/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Membrana Celular/metabolismo , Doença de Chagas/metabolismo , Relação Dose-Resposta a Droga , Humanos , Lauraceae/química , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Conformação Molecular , Caules de Planta/química , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos de Eudesmano/química , Sesquiterpenos de Eudesmano/isolamento & purificação , Relação Estrutura-Atividade , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificação
12.
Iran J Parasitol ; 14(1): 174-179, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31123483

RESUMO

BACKGROUND: Recently, it was proposed the name of Sarcocystis masoni n. sp. for the Sarcocystis that causes microcyst in skeletal muscle of South American camelids. However, there are no ultrastructural reports of microcysts of Sarcocystis in cardiac muscle of alpacas. This study reports ultrastructural features of microcysts of Sarcocystis sp. from cardiac muscle of naturally infected alpacas. METHODS: Thirty alpacas (age range: three to five years) from the province of Junin, Peruvian Central Andes, were included in this study in January 2015. Cardiac muscle samples were evaluated by histology and transmission electron microscopy. RESULTS: Bradyzoites in cysts had typical characteristics of Apicomplexa including organelles, a large nucleus, micronemes, dense bodies, and polysaccharide granules. Moreover, cysts had a thin wall with numerous, short, finger-like shapes with rounded tip protrusions (0.51 × 0.17 µm). CONCLUSION: Sarcocystis sp. from the heart and S. masoni n. sp. from the skeletal muscle have similar ultrastructural characteristics.

13.
Proc Natl Acad Sci U S A ; 116(6): 2300-2305, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30670660

RESUMO

Endothelial heterogeneity has important implications in health and disease. Molecular markers selectively expressed in the vasculature of different organs and tissues are currently being explored in targeted therapies with promising results in preclinical and clinical studies. Noteworthy is the role that combinatorial approaches such as phage display have had in identifying such markers by using phage as nanoparticles and surrogates for billions of different peptides, screening noninvasively the vascular lumen for binding sites. Here, we show that a new peptide motif that emerged from such combinatorial screening of the vasculature binds selectively to blood vessels in the brain in vivo but not to vessels in other organs. Peptides containing a conserved motif in which amino acids Phenylalanine-Arginine-Tryptophan (FRW) predominate could be visualized by transmission electron microscopy bound to the junctions between endothelial cells in all areas of the brain, including the optic nerve, but not in other barrier-containing tissues, such as intestines and testis. Remarkably, peptides containing the motif do not bind to vessels in the retina, implying an important molecular difference between these two vascular barriers. Furthermore, the peptide allows for in vivo imaging, demonstrating that new tools for studying and imaging the brain are likely to emerge from this motif.


Assuntos
Motivos de Aminoácidos , Encéfalo/metabolismo , Circulação Cerebrovascular/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Ligantes , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/metabolismo , Sequência de Aminoácidos , Animais , Encéfalo/irrigação sanguínea , Técnicas de Visualização da Superfície Celular , Endotélio Vascular/ultraestrutura , Feminino , Imunofluorescência , Camundongos , Peptídeos/química , Peptídeos/metabolismo , Ligação Proteica
14.
Parasite Immunol ; 40(9): e12571, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29974519

RESUMO

This study established a protocol to purify Toxoplasma gondii tachyzoite microvesicles and exosomes, called as extracellular vesicles (EVs). In addition, the investigations were conducted to determine the kinetic of EV release by tachyzoites and whether EV proteins are able to modulate the host immune response. The particle size and concentration released by tachyzoites in culture medium at different incubation-period were characterized by nanoparticle tracking analysis. Tachyzoites (1 × 106 ) released around 4.37 ± 0.81 × 108 EVs/mL/h, with size varying between 138.2 and 171.9 nm. EVs released into the medium were purified by gel-exclusion chromatography and screened by ELISA, using a pool of human positive sera for toxoplasmosis. EV-fractions contained high concentration of proteins, and EVs were analyzed by scanning and transmission electron microscopies. Tachyzoites released EVs into the culture medium throughout all membrane surface, and these vesicles contain small RNAs/miRNA. Pooled sera from chronically infected human or mice (infected with 2 different T. gondii strains) recognized distinct EV electrophoretic patterns in immunoblotting. T. gondii EVs significantly induced IL-10, TNF-α and iNOS in murine macrophages. In conclusion, this study shows that T. gondii secrete/excrete EVs (microvesicles and exosomes) contain miRNA and they were immunologically recognized by host immune response.


Assuntos
Vesículas Extracelulares/imunologia , Toxoplasma/imunologia , Toxoplasmose/parasitologia , Animais , Ensaio de Imunoadsorção Enzimática , Exossomos/imunologia , Exossomos/parasitologia , Vesículas Extracelulares/parasitologia , Humanos , Immunoblotting , Interleucina-10/genética , Interleucina-10/imunologia , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Toxoplasma/genética , Toxoplasmose/genética , Toxoplasmose/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-29557985

RESUMO

A great variety of viruses which cause exanthema share other clinical manifestations, making the etiologic identification a very difficult task, relying exclusively on the clinical examination. Rubella virus (RV) infection during the early stages of pregnancy can lead to serious birth defects, known as congenital rubella syndrome (CRS). In the present report, we described the presence of Zika virus (ZIKV) particles in urine samples and also ZIKV isolation in SIRC cells from the urine of a patient in acute phase of suspected rubella disease. The 50-year-old unvaccinated woman living in Sao Paulo, Brazil, was admitted to the emergency room with fever, headache, rash, arthralgia and prostration. Urine samples were collected for virus isolation and RT-qPCR. SIRC and Vero cells were inoculated with urine samples during 7 days. RT-qPCR was performed using measles virus (MV) and RV primers and both were found to be negative. After this result, RT-qPCR was performed for parvovirus B19, herpes virus 6 and ZIKV. The urine sample and the isolate were positive by Real Time PCR for ZIKV and negative for all other viruses tested. The sequences isolated are from the Asiatic lineage.


Assuntos
Rubéola (Sarampo Alemão)/diagnóstico , Infecção por Zika virus/urina , Zika virus/isolamento & purificação , Brasil , Células Cultivadas , Meios de Cultura , Diagnóstico Diferencial , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Infecção por Zika virus/diagnóstico , Infecção por Zika virus/virologia
17.
Geriatr Nurs ; 38(4): 283-290, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27964971

RESUMO

The present study described a group A rotavirus (RVA) outbreak in an age-care facility in Brazil, using epidemiologic and molecular diagnostic methods. A descriptive clinical, epidemiological and environmental investigation was conducted. Stool samples were collected and screened for RVA, Norovirus (NoV), Enteric Adenovirus 40/41 (AdV 40/41) and Astrovirus (AstV) using ELISA, RT-PCR, qRT-PCR, electron microscopy and sequencing methods. Outbreak occurred during 26th-29th October, 2015; 28 individuals affected (22 residents; 6 staff). The attack rate was 25.9% and 8.5% among residents (median-age: 85.5 years) and staff (median-age: 28 years), respectively. Female staff was identified as the index case. RVA G2P[4] genotype was detected in 87.5% (7/8). Genetic analysis demonstrated that the outbreak involved one single strain, suggesting a common-source infection. RVA should be considered during outbreaks investigations in residential facilities, and raise the question if the current licensed RVA vaccines for children could also be helpful for the elderly.


Assuntos
Surtos de Doenças , Gastroenterite , Saúde Pública , Aposentadoria , Infecções por Rotavirus , Rotavirus/classificação , Rotavirus/genética , Adulto , Idoso de 80 Anos ou mais , Brasil , Fezes/virologia , Feminino , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genótipo , Humanos , Masculino , Norovirus/isolamento & purificação , Fatores de Risco , Rotavirus/isolamento & purificação , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia
18.
Antiviral Res ; 134: 172-181, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27623346

RESUMO

Measles is a viral disease highly contagious spread by respiratory transmission. Although infection can be controlled by vaccination, numerous cases of measles have been registered in many areas of the world, highlighting the need for additional interventions. Terrestrial gastropods exude mucus on their body surface when traveling, to protect the body from mechanical injury, desiccation or contact with harmful substances. The mucus of mollusks has been studied as a source of new natural compounds with diverse biological activities. In this study, the antiviral activity of the mucus of the land slug P. boraceiensis was demonstrated in vitro using Vero cells infected with measles virus. The crude sample and four fractions were tested in cultures infected with measles virus and the antiviral activity was assessed by the cytopathic effect in infected cell cultures as well as by immunofluorescence and qPCR. Fractions 39 and 50 of the mucus from P. boraceiensis were analyzed by HPLC-DAD-ESI-MS/MS and infrared spectroscopy. A mixture of polyunsaturated fatty acids was found in the two fractions. A reduction in the growth of the measles virus was observed, measured by qPCR, with a protection index of 80% in Vero cells infected with measles and treated with fraction 39. Fraction 39 exhibited the best antiviral action in vitro and high contents of hydroxy-tritriacontapentaenoic acid and hydroxy-pentatriacontapentaenoic acid were found in this fraction.


Assuntos
Antivirais/farmacologia , Vírus do Sarampo/efeitos dos fármacos , Moluscos/química , Muco/química , Muco/metabolismo , Animais , Antivirais/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Ácidos Carboxílicos/isolamento & purificação , Ácidos Carboxílicos/farmacologia , Chlorocebus aethiops , Descoberta de Drogas , Ácidos Graxos/isolamento & purificação , Ácidos Graxos/farmacologia , Espectrometria de Massas em Tandem , Células Vero , Replicação Viral/efeitos dos fármacos
19.
São Paulo; s.n; 2007. [93] p. ilus, tab.
Tese em Português | LILACS, SES-SP, SESSP-CTDPROD, SES-SP, SESSP-IALPROD, SES-SP, SESSP-TESESESSP, SES-SP | ID: lil-473685

RESUMO

A expressão do oncogene E7 do HPV de alto risco é um dos responsáveis pela carcinogênese cervical, através da sua interferência sobre a via Cdk-Rb-E2F resultando na progressão do ciclo celular anormal e superexpressão das proteínas p16 e Ki-67. O objetivo deste estudo descritivo foi avaliar, em estudo de corte transversal, a positividade das expressões imunocitoquímicas das proteínas p16 e Ki-67 e sua distribuição celular, nas 199 amostras citológicas de base líquida (CBL) de casos com diagnóstico negativo e ASC-US com testesde HPV de alto risco positivo determinados em pelo menos um dos métodos de PCR e/ou HC2. Através da técnica imunocitoquímica, a expressão positiva da proteína p16 foi observada no citoplasma e núcleo enquanto que a proteína Ki- 67 foi apenas nuclear, quando comparada aos seus respectivos controles positivos. A proteína p16 foi positiva em 71/101 amostras de citologia negativa e em 12/16 amostras ASC-US, ambas associadas aos testes de HC2 e/ou PCR positivos para HPV de alto risco. A proteína Ki-67 foi positiva em 76/101 amostras de citologia negativa e em 12/16 amostras ASC-US, ambas também associadas aos testes de HC2 e/ou PCR positivos para HPV de alto risco. A proporção de positividade de Ki-67 aumentou em paralelo com o aumento do grau da positividade de p16 (p 0,001). A expressão da proteína p16 e proteína Ki-67 em amostras citológicas cérvico-vaginais colhidas em meio líquido, com HC2 e/ou PCR positivos para HPV de alto risco em casos com diagnóstico citológico negativo ou ASCUS detectou precocemente a presença de DNA-HPV através da imuno-expressão destas proteínas. Concluímos que estes resultados poderão ser utilizados em estratégias de programas de prevenção, e monitorar com eficiência e efetividade pacientes que poderão desenvolver lesões mais graves, através da detecção precoce das alterações do mecanismo de controle do ciclo celular.


Assuntos
Imuno-Histoquímica , Esfregaço Vaginal , Técnicas Citológicas
20.
São Paulo; s.n; 2007. [93] p. ilus, tab.
Tese em Português | LILACS, Coleciona SUS (Brasil), SES-SP, SESSP-CTDPROD, SES-SP, SESSP-ACVSES, SESSP-IALPROD, SES-SP, SESSP-IALACERVO, SESSP-TESESESSP, SES-SP | ID: biblio-933233

RESUMO

A expressão do oncogene E7 do HPV de alto risco é um dos responsáveis pela carcinogênese cervical, através da sua interferência sobre a via Cdk-Rb-E2F resultando na progressão do ciclo celular anormal e superexpressão das proteínas p16 e Ki-67. O objetivo deste estudo descritivo foi avaliar, em estudo de corte transversal, a positividade das expressões imunocitoquímicas das proteínas p16 e Ki-67 e sua distribuição celular, nas 199 amostras citológicas de base líquida (CBL) de casos com diagnóstico negativo e ASC-US com testesde HPV de alto risco positivo determinados em pelo menos um dos métodos de PCR e/ou HC2. Através da técnica imunocitoquímica, a expressão positiva da proteína p16 foi observada no citoplasma e núcleo enquanto que a proteína Ki- 67 foi apenas nuclear, quando comparada aos seus respectivos controles positivos. A proteína p16 foi positiva em 71/101 amostras de citologia negativa e em 12/16 amostras ASC-US, ambas associadas aos testes de HC2 e/ou PCR positivos para HPV de alto risco. A proteína Ki-67 foi positiva em 76/101 amostras de citologia negativa e em 12/16 amostras ASC-US, ambas também associadas aos testes de HC2 e/ou PCR positivos para HPV de alto risco. A proporção de positividade de Ki-67 aumentou em paralelo com o aumento do grau da positividade de p16 (p 0,001). A expressão da proteína p16 e proteína Ki-67 em amostras citológicas cérvico-vaginais colhidas em meio líquido, com HC2 e/ou PCR positivos para HPV de alto risco em casos com diagnóstico citológico negativo ou ASCUS detectou precocemente a presença de DNA-HPV através da imuno-expressão destas proteínas. Concluímos que estes resultados poderão ser utilizados em estratégias de programas de prevenção, e monitorar com eficiência e efetividade pacientes que poderão desenvolver lesões mais graves, através da detecção precoce das alterações do mecanismo de controle do ciclo celular.


Assuntos
Técnicas Citológicas , Esfregaço Vaginal
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