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1.
Mem Inst Oswaldo Cruz ; 114: e180478, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30942278

RESUMO

The population of Brazil is currently characterised by many individuals harbouring low-intensity Schistosoma mansoni infections. The Kato-Katz technique is the diagnostic method recommended by the World Health Organization (WHO) to assess these infections, but this method is not sensitive enough in the context of low egg excretion. In this regard, potential alternatives are being employed to overcome the limits of the Kato-Katz technique. In the present review, we evaluated the performance of parasitological and immunological approaches adopted in Brazilian areas. Currently, the diagnostic choices involve a combination of strategies, including the utilisation of antibody methods to screen individuals and then subsequent confirmation of positive cases by intensive parasitological investigations.


Assuntos
Anticorpos Anti-Helmínticos/análise , Antígenos de Helmintos/análise , Técnicas de Laboratório Clínico/métodos , Fezes/parasitologia , Schistosoma mansoni , Esquistossomose mansoni/diagnóstico , Animais , Brasil/epidemiologia , Doenças Endêmicas , Humanos , Técnicas Imunoenzimáticas , Contagem de Ovos de Parasitas , Schistosoma mansoni/imunologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/epidemiologia , Sensibilidade e Especificidade , Índice de Gravidade de Doença
2.
Front Immunol ; 10: 645, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31001264

RESUMO

Despite significant progress, China faces the challenge of re-emerging schistosomiasis transmission in currently controlled areas due, in part, to the presence of a range of animal reservoirs, notably water buffalo and cattle, which can harbor Schistosoma japonicum infections. Environmental, ecological and social-demographic changes in China, shown to affect the distribution of oncomelanid snails, can also impact future schistosomiasis transmission. In light of their importance in the S. japonicum, lifecycle, vaccination has been proposed as a means to reduce the excretion of egg from cattle and buffalo, thereby interrupting transmission from these reservoir hosts to snails. A DNA-based vaccine (SjCTPI) our team developed showed encouraging efficacy against S. japonicum in Chinese water buffaloes. Here we report the results of a double-blind cluster randomized trial aimed at determining the impact of a combination of the SjCTPI bovine vaccine (given as a prime-boost regimen), human mass chemotherapy and snail control on the transmission of S. japonicum in 12 selected administrative villages around the Dongting Lake in Hunan province. The trial confirmed human praziquantel treatment is an effective intervention at the population level. Further, mollusciciding had an indirect ~50% efficacy in reducing human infection rates. Serology showed that the SjCTPI vaccine produced an effective antibody response in vaccinated bovines, resulting in a negative correlation with bovine egg counts observed at all post-vaccination time points. Despite these encouraging outcomes, the effect of the vaccine in preventing human infection was inconclusive. This was likely due to activities undertaken by the China National Schistosomiasis Control Program, notably the treatment, sacrifice or removal of bovines from trial villages, over which we had no control; as a result, the trial design was compromised, reducing power and contaminating outcome measures. This highlights the difficulties in undertaking field trials of this nature and magnitude, particularly over a long period, and emphasizes the importance of mathematical modeling in predicting the potential impact of control intervention measures. A transmission blocking vaccine targeting bovines for the prevention of S. japonicum with the required protective efficacy would be invaluable in tandem with other preventive intervention measures if the goal of eliminating schistosomiasis from China is to become a reality.


Assuntos
Anti-Helmínticos/uso terapêutico , Doenças dos Bovinos/prevenção & controle , Praziquantel/uso terapêutico , Esquistossomose Japônica/prevenção & controle , Vacinação/veterinária , Vacinas/uso terapêutico , Adolescente , Adulto , Idoso , Animais , Búfalos , Bovinos , Criança , Pré-Escolar , China , Método Duplo-Cego , Humanos , Pessoa de Meia-Idade , Esquistossomose Japônica/transmissão , Esquistossomose Japônica/veterinária , Caramujos , Adulto Jovem
3.
Mem. Inst. Oswaldo Cruz ; 114: e180478, 2019.
Artigo em Inglês | LILACS | ID: biblio-990192

RESUMO

The population of Brazil is currently characterised by many individuals harbouring low-intensity Schistosoma mansoni infections. The Kato-Katz technique is the diagnostic method recommended by the World Health Organization (WHO) to assess these infections, but this method is not sensitive enough in the context of low egg excretion. In this regard, potential alternatives are being employed to overcome the limits of the Kato-Katz technique. In the present review, we evaluated the performance of parasitological and immunological approaches adopted in Brazilian areas. Currently, the diagnostic choices involve a combination of strategies, including the utilisation of antibody methods to screen individuals and then subsequent confirmation of positive cases by intensive parasitological investigations.


Assuntos
Humanos , Schistosoma mansoni , Imunoensaio
4.
Int J Infect Dis ; 54: 130-137, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27939558

RESUMO

Mass drug administration utilising a single oral dose of 40mg/kg of praziquantel (PZQ) has been endorsed and advocated by the World Health Organisation (WHO) for the global control and elimination of schistosomiasis. However, this strategy is failing primarily because the drugs are not getting to the people who need them the most. The current global coverage is 20%, the drug compliance rate is less than 50%, and the drug efficacy is approximately 50%. Thus in reality, only about 5% of the reservoir human population is actually receiving intermittent chemotherapy. Despite claims that more of the drug will soon be made available the current strategy is inherently flawed and will not lead to disease elimination. We discuss the many practical issues related to this global strategy, and advocate for an integrated control strategy targeting the life cycle and the most at-risk. Moreover, we discuss how an integrated control package for schistosomiasis should fit within a larger integrated health package for rural and remote villages in the developing world. A holistic health system approach is required to achieve sustainable control and ultimately disease elimination.


Assuntos
Anti-Helmínticos/uso terapêutico , Esquistossomose/prevenção & controle , Saúde Global , Humanos , Controle de Infecções , Grupos Populacionais , Praziquantel/uso terapêutico , População Rural , Esquistossomose/tratamento farmacológico , Esquistossomose/psicologia
5.
Int J Infect Dis ; 54: 145-149, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27743969

RESUMO

OBJECTIVE: This study assessed the impact of annual versus biennial praziquantel treatment regimens on the prevalence, intensity of infection, and liver fibrosis dynamics of Asiatic schistosomiasis (caused by Schistosoma japonicum) among individuals residing in 18 endemic barangays in Northern Samar, Philippines. METHODS: Five hundred and sixty-five subjects who reported symptoms of gastrointestinal illness and/or were believed to have clinical morbidity based on physical examination were selected for cohort follow-up. RESULTS: The mean prevalence of schistosomiasis was 34% and the mean intensity of infection was 123.1 eggs per gram. Moderate to severe hepatic fibrosis (grade II/III) was demonstrated in approximately 25% of the study population. As expected, a greater reduction in both the prevalence and intensity of infection was documented with two treatment rounds versus one. Overall, hepatic fibrosis (grades I-III) regressed in only 24.3% of those who received a single treatment and in only 19.3% of those who received two doses. The prevalence of grade II-III fibrosis at baseline (25.2%) remained unchanged 2 years after treatment. CONCLUSIONS: These findings suggest that in order to reverse moderate to severe liver fibrosis due to schistosomiasis and improve clinical outcomes, a higher clinical dosage of praziquantel (i.e., 60-80mg/kg) may be required over an extended duration.


Assuntos
Cirrose Hepática/mortalidade , Praziquantel/administração & dosagem , Esquistossomose/tratamento farmacológico , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Esquema de Medicação , Feminino , Humanos , Cirrose Hepática/epidemiologia , Cirrose Hepática/etiologia , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Morbidade , Filipinas/epidemiologia , Schistosoma japonicum/efeitos dos fármacos , Esquistossomose/epidemiologia , Esquistossomose/mortalidade , Esquistossomose/parasitologia , Adulto Jovem
6.
Int J Infect Dis ; 54: 138-144, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27816660

RESUMO

BACKGROUND: Subclinical morbidity due to schistosomiasis was evaluated in 565 patients, and the enhanced liver fibrosis (ELF) test was assessed for the first time as a potential screening tool for disease. METHODS: The prevalence and intensity of infection were determined by Kato-Katz thick smear stool examination at baseline and 2 years after curative treatment. The degree of hepatic fibrosis was assessed by ultrasound. Non-invasive serum biomarkers of hepatic fibrosis were also evaluated. RESULTS: The baseline human prevalence and infection intensity were found to be moderately high at 34% and 123 eggs per gram, respectively. However, hepatic parenchymal fibrosis occurred in 50% of subjects, with grade II fibrosis in 19% and grade III in 6%. The ELF score and higher serum levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) and hyaluronic acid (HA) correlated with the grade of liver fibrosis. CONCLUSIONS: The findings of this study demonstrated that praziquantel treatment had a short-term impact on both the prevalence and intensity of infection, but less of an impact on established morbidity. Higher TIMP-1 and HA serum levels, and an ELF cut-off score of 8 were found to be correlated with the grade of liver fibrosis; these values may, therefore, assist physicians in identifying individuals at greater risk of disease.


Assuntos
Cirrose Hepática/diagnóstico , Esquistossomose/complicações , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Criança , Pré-Escolar , Feminino , Humanos , Ácido Hialurônico/sangue , Cirrose Hepática/sangue , Cirrose Hepática/etiologia , Cirrose Hepática/mortalidade , Masculino , Pessoa de Meia-Idade , Morbidade , Filipinas , Praziquantel/uso terapêutico , Prevalência , Esquistossomose/tratamento farmacológico , Esquistossomose Japônica/tratamento farmacológico , Inibidor Tecidual de Metaloproteinase-1/sangue , Ultrassonografia , Adulto Jovem
7.
Methods Mol Biol ; 1265: 113-22, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25634271

RESUMO

Stimulating the immune system for potent immune therapy against cancer is potentially a revolutionary method to eradicate cancer. Tumors stimulated with photosensitizers (PSs) not only kill cancer cells but also help to boost the immune system. We recently reported that tumor-associated antigens (TAAs) generated by delivery of a mitochondria-acting PS zinc phthalocyanine (ZnPc) to MCF-7 breast cancer cells followed by laser irradiation can lead to ex vivo stimulation of mouse bone marrow-derived dendritic cells (BMDCs). The antigens generated from the breast cancer cells were also found to cause significant DC maturation and the activated DCs were able to stimulate T cells to cytotoxic CD8(+) T cells. In this protocol, we describe methods to engineer a mitochondria-targeted biodegradable nanoparticle (NP) formulation, T-ZnPc-NPs for delivery of ZnPc to the mitochondria of MCF-7 cells, subsequent photodynamic therapy (PDT) using a long wavelength laser irradiation to produce TAAs, DC stimulation by the TAAs to secrete interferon-gamma (IFN-γ), and matured DC-driven T-cell activation.


Assuntos
Células Dendríticas/metabolismo , Mitocôndrias/metabolismo , Nanoconjugados/química , Linfócitos T/metabolismo , Animais , Antígenos de Neoplasias/química , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer , Linhagem Celular Tumoral , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Camundongos , Mitocôndrias/efeitos da radiação , Fotoquimioterapia , Polietilenoglicóis/química , Poliglactina 910/química , Linfócitos T/imunologia
8.
J Infect Dis ; 211(2): 283-9, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25070942

RESUMO

BACKGROUND: In the Philippines, the current national control strategy for schistosomiasis is annual mass drug administration (MDA) with 40 mg/kg of praziquantel in all schistosomiasis-endemic villages with a prevalence ≥10%. METHODS: A cross-sectional survey of schistosomiasis was conducted in 2012 on 18 221 individuals residing in 22 schistosomiasis-endemic villages in the province of Northern Samar. The prevalence of schistosomiasis, intensity of Schistosoma infection, and morbidity of disease were assessed. RESULTS: Despite an active schistosomiasis-control program in Northern Samar for >30 years, which included a MDA campaign in the last 5 years, the mean prevalence of schistosomiasis among 10 435 evaluated subjects was 27.1% (95% confidence interval [CI], 26.3%-28.0%), and the geometric mean intensity of infection among 2832 evaluated subjects was 17.2 eggs per gram of feces (95% CI, 16.4-18.1). Ultrasonography revealed high levels of schistosomiasis-induced morbidity in the schistosomiasis-endemic communities. Left lobe liver enlargement (≥70 mm) was evident in 89.3% of subjects. Twenty-five percent of the study population had grade II/III liver parenchyma fibrosis, and 13.3% had splenomegaly (≥100 mm). CONCLUSIONS: MDA on its own was insufficient to control the prevalence of schistosomiasis, intensity of Schistosoma infection, or morbidity of the disease. Alternative control measures will be needed to complement the existing national MDA program.


Assuntos
Anti-Helmínticos/administração & dosagem , Praziquantel/administração & dosagem , Esquistossomose/tratamento farmacológico , Esquistossomose/prevenção & controle , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Estudos Transversais , Tratamento Farmacológico/métodos , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Filipinas/epidemiologia , Prevalência , População Rural , Adulto Jovem
9.
Int J Infect Dis ; 28: 193-203, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25250908

RESUMO

Schistosomiasis is a chronic enteropathogenic disease caused by blood flukes of the genus Schistosoma. The disease afflicts approximately 240 million individuals globally, causing approximately 70 million disability-adjusted life years lost. Chronic infections with morbidity and mortality occur as a result of granuloma formation in the intestine, liver, or in the case of Schistosoma haematobium, the bladder. Various methods are utilized to diagnose and evaluate liver fibrosis due to schistosomiasis. Liver biopsy is still considered the gold standard, but it is invasive. Diagnostic imaging has proven to be an invaluable method in assessing hepatic morbidity in the hospital setting, but has practical limitations in the field. The potential of non-invasive biological markers, serum antibodies, cytokines, and circulating host microRNAs to diagnose hepatic fibrosis is presently undergoing evaluation. This review provides an update on the recent advances made with respect to gastrointestinal disease associated with chronic schistosomiasis.


Assuntos
Esquistossomose/diagnóstico , Esquistossomose/parasitologia , Animais , Biomarcadores/sangue , Doença Crônica , Citocinas/sangue , Humanos , Cirrose Hepática/imunologia , Cirrose Hepática/parasitologia , Cirrose Hepática/patologia , Morbidade , Schistosoma/crescimento & desenvolvimento , Esquistossomose/patologia
10.
Int J Parasitol ; 44(9): 659-68, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24929133

RESUMO

Despite major successes in its control over the past 50years, schistosomiasis japonica continues to be a public health problem in the People's Republic of China (P.R. China). Historically, the major endemic foci occur in the lakes and marshlands along the Yangtze River, areas where transmission interruption has proven difficult. The current endemic situation may alter due to the closure of the Three Gorges Dam. Considerable environmental and ecological changes are anticipated that may result in new habitats for the oncomelanid intermediate snail host of Schistosoma japonicum (Sj), thereby increasing the risk of transmission. The current national control program for P.R. China involves a multi-component integrated strategy but, despite targeting multiple transmission pathways, certain challenges remain. As the Chinese government pushes towards elimination, there is a requirement for additional tools, such as vaccination, for long-term prevention. Whereas the zoonotic nature of schistosomiasis japonica adds to the complexity of control, it provides a unique opportunity to develop a transmission blocking vaccine targeting bovines to assist in the prevention of human infection and disease. Mathematical modelling has shown that control options targeting the various transmission pathways of schistosomiasis japonica and incorporating bovine vaccination, mass human chemotherapy and mollusciciding could lead to its elimination from P.R. China. Here we present the study design and baseline results of a four-year cluster randomised intervention trial we are undertaking around the schistosomiasis-endemic Dongting Lake in Hunan Province aimed at determining the impact on schistosome transmission of the multi-component integrated control strategy, including bovine vaccination using a heterologous "prime-boost" delivery platform based on the previously tested SjCTPI vaccine.


Assuntos
Doenças dos Bovinos/parasitologia , Niclosamida/farmacologia , Praziquantel/uso terapêutico , Esquistossomose Japônica/prevenção & controle , Esquistossomose Japônica/veterinária , Adolescente , Adulto , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , Criança , Pré-Escolar , China/epidemiologia , Esquema de Medicação , Feminino , Humanos , Lactente , Masculino , Moluscocidas/farmacologia , Praziquantel/administração & dosagem , Esquistossomose Japônica/epidemiologia , Esquistossomicidas/administração & dosagem , Esquistossomicidas/uso terapêutico , Fatores de Tempo , Vacinas/imunologia , Adulto Jovem
11.
ACS Chem Biol ; 9(5): 1178-87, 2014 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-24617941

RESUMO

Tumor growth is fueled by the use of glycolysis, which normal cells use only in the scarcity of oxygen. Glycolysis makes tumor cells resistant to normal death processes. Targeting this unique tumor metabolism can provide an alternative strategy to selectively destroy the tumor, leaving normal tissue unharmed. The orphan drug dichloroacetate (DCA) is a mitochondrial kinase inhibitor that has the ability to show such characteristics. However, its molecular form shows poor uptake and bioavailability and limited ability to reach its target mitochondria. Here, we describe a targeted molecular scaffold for construction of a multiple DCA loaded compound, Mito-DCA, with three orders of magnitude enhanced potency and cancer cell specificity compared to DCA. Incorporation of a lipophilic triphenylphosphonium cation through a biodegradable linker in Mito-DCA allowed for mitochondria targeting. Mito-DCA did not show any significant metabolic effects toward normal cells but tumor cells with dysfunctional mitochondria were affected by Mito-DCA, which caused a switch from glycolysis to glucose oxidation and subsequent cell death via apoptosis. Effective delivery of DCA to the mitochondria resulted in significant reduction in lactate levels and played important roles in modulating dendritic cell (DC) phenotype evidenced by secretion of interleukin-12 from DCs upon activation with tumor antigens from Mito-DCA treated cancer cells. Targeting mitochondrial metabolic inhibitors to the mitochondria could lead to induction of an efficient antitumor immune response, thus introducing the concept of combining glycolysis inhibition with immune system to destroy tumor.


Assuntos
Antineoplásicos/administração & dosagem , Ácido Dicloroacético/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Mitocôndrias/metabolismo , Inibidores de Proteínas Quinases/administração & dosagem , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ácido Dicloroacético/farmacologia , Glucose/metabolismo , Humanos , Ácido Láctico/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Compostos Organofosforados/química , Inibidores de Proteínas Quinases/farmacologia
12.
Int J Parasitol ; 44(3-4): 167-71, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24440417

RESUMO

Schistosomiasis japonica, caused by Schistosoma japonicum, is an important zoonotic disease in China, the Philippines and small pockets of Indonesia. In addition to infecting people, S. japonicum can infect over 40 species of wild and domestic animals which have varying impacts on human infection. It is now generally accepted that bovines, particularly water buffaloes, are the major reservoir for human infection in China as they are naturally infected with schistosomes and deposit more eggs into the environment than humans or any other animal host. This complicates control efforts and the economic burden associated with schistosomiasis morbidity and mortality has taken its toll on both human and livestock populations. Over the last 50years, the schistosomiasis control program in China has made great strides in reducing prevalence and morbidity, and the Chinese authorities now aim to eliminate the disease nationwide in the next decade. Current Chinese control strategies place particular importance on interventions targeting bovines including: praziquantel treatment, barrier farming to prevent grazing in transmission areas, their replacement with mechanized tractors and possible bovine vaccination. A number of studies have shown that in the period following S. japonicum infection, the worm burden drops sharply in water buffaloes and some other animal hosts such as pigs. This is due to a self-cure phenomenon whereby there is parasite clearance by both immune and non-immune factors. Here we review studies investigating the self-cure effect, paying particular attention to S. japonicum infection in water buffaloes, and discuss its potential impact on the future schistosomiasis control and elimination efforts in China. Further understanding of the mechanism of self-cure in water buffaloes could be important for future schistosome vaccine design and delivery.


Assuntos
Búfalos/parasitologia , Esquistossomose Japônica/prevenção & controle , Zoonoses/prevenção & controle , Animais , Anti-Helmínticos/uso terapêutico , Búfalos/imunologia , Bovinos , China , Reservatórios de Doenças/parasitologia , Feminino , Humanos , Masculino , Praziquantel/uso terapêutico , Schistosoma japonicum/imunologia , Schistosoma japonicum/patogenicidade , Esquistossomose Japônica/imunologia , Esquistossomose Japônica/parasitologia , Zoonoses/imunologia , Zoonoses/parasitologia
13.
Int J Infect Dis ; 18: 52-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24211228

RESUMO

Schistosomiasis japonica has a long history in the Philippines. In 1975, 24 endemic provinces were identified in the northern, central, and southern islands of the Philippines. More than five million people were at risk, with approximately one million infected. In 2003, new foci of infection were found in two provinces in the north and central areas. For the past 30 years, human mass drug administration (MDA), utilizing the drug praziquantel, has been the mainstay of control in the country. Recent studies have shown that the schistosomiasis prevalence ranges from 1% to 50% within different endemic zones. Severe end-organ morbidity is still present in many endemic areas, particularly in remote villages with poor treatment coverage. Moreover, subtle morbidities such as growth retardation, malnutrition, anemia, and poor cognitive function in infected children persist. There is now strong evidence that large mammals (e.g. water buffaloes, cattle) contribute significantly to disease transmission, complicating control efforts. Given the zoonotic nature of schistosomiasis in the Philippines, it is evident that the incidence, prevalence, and morbidity of the disease will not be controlled by MDA alone. There is a need for innovative cost-effective strategies to control schistosomiasis in the long term.


Assuntos
Controle de Doenças Transmissíveis/tendências , Schistosoma/isolamento & purificação , Esquistossomose Japônica/epidemiologia , Animais , Búfalos , Bovinos , Controle de Doenças Transmissíveis/métodos , Humanos , Incidência , Filipinas/epidemiologia , Praziquantel/uso terapêutico , Prevalência , Schistosoma/efeitos dos fármacos , Esquistossomose Japônica/tratamento farmacológico , Esquistossomose Japônica/prevenção & controle , Esquistossomose Japônica/transmissão
14.
ACS Nano ; 7(8): 7392-402, 2013 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-23899410

RESUMO

One of the limitations for clinical applications of dendritic cell (DC)-based cancer immunotherapy is the low potency in generating tumor antigen specific T cell responses. We examined the immunotherapeutic potential of a mitochondria-targeted nanoparticle (NP) based on a biodegradable polymer and zinc phthalocyanine (ZnPc) photosensitizer (T-ZnPc-NPs). Here, we report that tumor antigens generated from treatment of breast cancer cells with T-ZnPc-NPs upon light stimulation activate DCs to produce high levels of interferon-gamma, an important cytokine considered as a product of T and natural killer cells. The remarkable ex vivo DC stimulation ability of this tumor cell supernatant is a result of an interleukin (IL)-12/IL-18 autocrine effect. These findings contribute to the understanding of how in situ light activation amplifies the host immune responses when NPs deliver the photosensitizer to the mitochondria and open up the possibility of using mitochondria-targeted-NP-treated, light-activated cancer cell supernatants as possible vaccines.


Assuntos
Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Interferon gama/metabolismo , Mitocôndrias/efeitos dos fármacos , Nanopartículas/química , Neoplasias/terapia , Animais , Antígenos de Neoplasias/química , Apoptose , Materiais Biocompatíveis/química , Vacinas Anticâncer/química , Linhagem Celular Tumoral , Células Dendríticas/citologia , Células HeLa , Humanos , Imunoterapia/métodos , Indóis/química , Isoindóis , Células MCF-7 , Camundongos , Camundongos Endogâmicos C57BL , Necrose , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/química , Polímeros/química , Compostos de Zinco
15.
Integr Biol (Camb) ; 5(1): 215-23, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22832596

RESUMO

A therapeutic technology that combines the phototoxic and immune-stimulating ability of photodynamic therapy (PDT) with the widespread effectiveness of the immune system can be very promising to treat metastatic breast cancer. We speculated that the knowledge of molecular mechanisms of existing multi-component therapies could provide clues to aid the discovery of new combinations of an immunostimulant with a photosensitizer (PS) using a nanoparticle (NP) delivery platform. Therapeutic challenges when administering therapeutic combinations include the choice of dosages to reduce side effects, the definitive delivery of the correct drug ratio, and exposure to the targets of interest. These factors are very difficult to achieve when drugs are individually administered. By combining controlled release polymer-based NP drug delivery approaches, we were able to differentially deliver zinc phthalocyanine (ZnPc) based PS to metastatic breast cancer cells along with CpG-ODN, a single-stranded DNA that is a known immunostimulant to manage the distant tumors in a temporally regulated manner. We encapsulated ZnPc which is a long-wavelength absorbing PS within a polymeric NP core made up of poly(d,l-lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG). After coating the outside of the polymeric core with gold NPs (AuNPs), we further modified the AuNP surface with CpG-ODN. In vitro cytotoxicity using 4T1 metastatic mouse breast carcinoma cells shows significant photocytotoxicity of the hybrid NPs containing both ZnPc and CpG-ODN after irradiation with a 660 nm LASER light and this activity was remarkably better than either treatment alone. Treatment of mouse bone marrow derived dendritic cells with the PDT-killed 4T1 cell lysate shows that the combination of PDT with a synergistic immunostimulant in a single NP system results in significant immune response, which can be used for the treatment of metastatic cancer.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Neoplasias da Mama/secundário , Neoplasias da Mama/terapia , Indóis/uso terapêutico , Nanocápsulas/administração & dosagem , Oligodesoxirribonucleotídeos/administração & dosagem , Compostos Organometálicos/uso terapêutico , Fotoquimioterapia/métodos , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Terapia Combinada , Feminino , Isoindóis , Camundongos , Camundongos Endogâmicos BALB C , Nanocápsulas/ultraestrutura , Fármacos Fotossensibilizantes/uso terapêutico , Resultado do Tratamento , Compostos de Zinco
16.
Trop Med Surg ; 1(4)2013 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-25346933

RESUMO

More than one billion people travel internationally each year and approximately 100 million to the tropics. Schistosomiasis is a neglected tropical disease caused by trematode blood flukes of the genus Schistosoma. It currently infects over 250 million people worldwide and results in approximately 25 million disability adjusted life years lost. Clinical manifestations depend on the affected organ. Subtle morbidities have also been documented including: growth retardation, anaemia and poor cognitive function in children. While schistosomiasis has been eradicated from Japan and significantly reduced in parts of China and Egypt, transmission in many other regions remains ongoing due to the wide-spread distribution of the intermediate snail host, poor sanitation, lack of health education and decreasing compliance to mass drug administration. Integrated control has significantly reduced the burden of disease in China but considerable financial capital is needed if similar results are to be duplicated elsewhere. Human vaccination is in various stages of development, and once found, will become an integral part of future control. This comprehensive review examines the epidemiology, pathology, diagnosis, clinical management, prevention and control of the disease.

17.
Nat Med ; 18(11): 1665-72, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23104131

RESUMO

Parasitic worms express host-like glycans to attenuate the immune response of human hosts. The therapeutic potential of this immunomodulatory mechanism in controlling the metabolic dysfunction that is associated with chronic inflammation remains unexplored. We demonstrate here that administration of lacto-N-fucopentaose III (LNFPIII), a Lewis(X)-containing immunomodulatory glycan found in human milk and on parasitic helminths, improves glucose tolerance and insulin sensitivity in diet-induced obese mice. This effect is mediated partly through increased interleukin-10 (Il-10) production by LNFPIII-activated macrophages and dendritic cells, which reduces white adipose tissue inflammation and sensitizes the insulin response of adipocytes. Concurrently, LNFPIII treatment upregulates nuclear receptor subfamily 1, group H, member 4 (Fxr-α, also known as Nr1h4) to suppress lipogenesis in the liver, conferring protection against hepatosteatosis. At the signaling level, the extracellular signal-regulated kinase (Erk)-activator protein 1 (Ap1) pathway seems to mediate the effects of LNFPIII on both inflammatory and metabolic pathways. Our results suggest that LNFPIII may provide new therapeutic approaches to treat metabolic diseases.


Assuntos
Tecido Adiposo , Amino Açúcares , Inflamação , Redes e Vias Metabólicas , Polissacarídeos , Receptores Citoplasmáticos e Nucleares , Tecido Adiposo/crescimento & desenvolvimento , Tecido Adiposo/patologia , Amino Açúcares/administração & dosagem , Amino Açúcares/imunologia , Amino Açúcares/metabolismo , Animais , Células Dendríticas/metabolismo , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Dieta Hiperlipídica , Fígado Gorduroso/imunologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/terapia , Células Hep G2 , Humanos , Inflamação/imunologia , Inflamação/patologia , Inflamação/terapia , Resistência à Insulina/imunologia , Interleucina-10/metabolismo , Fígado/metabolismo , Fígado/patologia , Macrófagos/metabolismo , Redes e Vias Metabólicas/imunologia , Camundongos , Camundongos Obesos/imunologia , Camundongos Obesos/metabolismo , Polissacarídeos/administração & dosagem , Polissacarídeos/imunologia , Polissacarídeos/metabolismo , Receptores Citoplasmáticos e Nucleares/imunologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais
18.
Transplantation ; 90(10): 1071-8, 2010 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-20885339

RESUMO

BACKGROUND: Lacto-N-fucopentaose III (LNFPIII) is a pentasaccharide containing the Lewis(x) trisaccharide that is found on schistosome eggs and in breast milk. LNFPIII conjugates suppress host immune responses and have therapeutic efficacy in mouse models of psoriasis and type 1 diabetes. METHODS: We used nonvascularized neonatal ear-heart transplantation and heterotopic vascularized heart transplantation models to evaluate immunosuppressive effects of LNFPIII and subsequently analyzed the mechanism. RESULTS: We found that administration of LNFPIII conjugates prolonged median graft survival by 80% when 1-day-old DBA/2 hearts were transplanted into ears of B6 mice. A similar graft prolongation was observed in a fully vascularized heterotopic heart transplantation model (DBA/2 into B6), No prolongation was observed with carrier protein (human serum albumin [HSA] or dextran) alone. We found increased programmed death ligand 1 (PD-L1) expression on F4/80 macrophages, CD4+ T cells, and CD11b+ CD11c+ (myeloid) dendritic cells, and increased arginase1 and Ym1 expression, typical of alternatively activated macrophages, in the draining (cervical) lymph node cells. We found accumulation of Foxp3+ regulatory T cells (Tregs) in the lymph nodes draining donor hearts, suggesting a possible role of Treg induction in graft prolongation. Anti-PD-L1 antibody treatment abrogated LNFPIII-mediated the graft survival benefit and Treg accumulation. LNFPIII-treated macrophages had increased PD-L1 expression and significantly prolonged DBA/2 allograft survival when injected intraperitoneally into B6 recipient mice. CONCLUSIONS: LNFPIII prolongs fully allogeneic graft survival in both vascularized and nonvascularized allograft transplantation models. The mechanism of graft prolongation seems to involve both alternatively activated PDL-1 macrophages and recruitment of Foxp3+ Treg cells.


Assuntos
Amino Açúcares/farmacologia , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Transplante de Coração/imunologia , Imunossupressores/farmacologia , Polissacarídeos/farmacologia , Animais , Animais Recém-Nascidos , Antígeno B7-1/imunologia , Antígeno B7-H1 , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Transplante de Coração/patologia , Ativação de Macrófagos , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Masculino , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Peptídeos/antagonistas & inibidores , Peptídeos/imunologia , Gravidez , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Fatores de Tempo , Transplante Homólogo
19.
Vaccine ; 28(5): 1310-7, 2010 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-19941988

RESUMO

HIV-1 prevalence is highest in developing countries; similarly helminth parasites are often highly endemic in these same areas. Helminths are strong immune modulators, and negatively impact the ability of the infected hosts to mount protective vaccine-specific T cell immune responses for HIV-1 and other pathogens. Indeed, previously we found that Schistosoma mansoni infected mice had significantly impaired HIV-1C vaccine-specific T cell responses. Anthelminthics are available and inexpensive; therefore, in this study, we evaluated whether elimination of schistosome infection prior to vaccination with an HIV-1C DNA vaccine would increase recipients vaccine-specific responses. As expected, splenocytes from S. mansoni infected mice produced significantly elevated amounts of interleukin (IL)-4 and IL-10, and significantly lower amounts of interferon (IFN)-gamma than splenocytes from naïve mice. Following elimination of parasites by praziquantel (PZQ) treatment, splenomegaly was significantly reduced, though splenocytes produced similar or higher levels of IL-10 than splenocytes from infected mice. However, we found that PZQ treatment significantly increased levels of IFN-gamma in response to concanavalin A or SEA compared to splenocytes from untreated mice. Importantly, PZQ treatment resulted in complete restoration of HIV-1C vaccine-specific T cell responses at 8 weeks post-PZQ treatment. Restoration of HIV-1C vaccine-specific T cell responses following elimination of helminth infection was time dependent, but surprisingly independent of the levels of IL-4 and IL-10 induced by parasite antigens. Our study shows that elimination of worms offers an affordable and a simple means to restore immune responsiveness to T cell based vaccines for HIV-1 and other infectious diseases in helminth endemic settings.


Assuntos
Vacinas contra a AIDS/imunologia , Anti-Helmínticos/farmacologia , HIV-1/imunologia , Praziquantel/farmacologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/imunologia , Linfócitos T/imunologia , Animais , Citocinas/imunologia , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Tempo
20.
Immunology ; 129(3): 406-17, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19922421

RESUMO

Prevalence of pro-inflammatory diseases is rising in developed country populations. The increase in these diseases has fuelled the search for new, immune suppressive, anti-inflammatory therapies, which do not impact, or minimally impact, CD4(+) and/or CD8(+) T-cell-mediated immunity. The goal of this study was to determine if antigen-presenting cells (APCs) activated by the anti-inflammatory oligosaccharide, lacto-N-fucopentaose III (LNFPIII), would have an impaired ability to drive CD4(+) T helper (Th) or CD8(+) memory and effector T-cell responses. To investigate this we activated splenic dendritic cells (SDCs) with LNFPIII and examined their ability to drive antigen-specific CD4(+) Th, and CD8(+) memory and cytotoxic T-cell (CTL) responses compared with lipopolysaccharide (LPS) -stimulated SDCs. The LNFPIII-activated SDCs had altered co-stimulatory molecule expression compared with LPS-stimulated SDCs, while the levels of SDC chemokines following activation by either compound were similar. LNFPIII-activated SDCs produced significantly lower levels of interleukin-12 but surprisingly higher levels of interleukin-6 than LPS-activated SDCs. Similar to previous studies using bone-marrow-derived DCs, LNFPIII-activated SDCs induced strong Th2 responses in vivo and ex vivo. LNFPIII activation of APCs was independent of the Toll-interleukin-1 receptor adaptor myeloid differentiating factor 88. Importantly, LNFPIII-matured DCs induced CD8(+) memory and effector CTL responses similar to those driven by LPS-matured DCs, including the frequency of interferon-gamma-producing CD8(+) T cells and induction of CTL effectors. Treatment of APCs by the anti-inflammatory glycan LNFPIII did not impair their ability to drive CD8(+) effector and memory cell-mediated immunity.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Memória Imunológica/imunologia , Linfócitos T Citotóxicos/imunologia , Células Th2/imunologia , Amino Açúcares/farmacologia , Animais , Antígenos CD/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Proliferação de Células , Quimiocina CCL3/metabolismo , Quimiocina CCL5/metabolismo , Citotoxicidade Imunológica/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Feminino , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferon gama/metabolismo , Interleucina-12/metabolismo , Interleucina-2/metabolismo , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fator 88 de Diferenciação Mieloide/genética , Ovalbumina/imunologia , Polissacarídeos/farmacologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Citotóxicos/metabolismo , Células Th1/imunologia , Células Th2/metabolismo
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