RESUMO
Ferritin is a conserved iron-binding protein involved in host defense and cellular iron metabolism in most organisms. We investigated the expression profiles of two ferritin genes (designated HsFer-1 and HsFer-2) in the hemocytes, gonad, and hepatopancreas of Hyriopsis schlegelii, when challenged with bacteria and metal ions. HsFer gene transcription increased 1.8-7.7- and 1.9-6.1-fold in these tissues after stimulation with Staphylococcus aureus and Vibrio anguillarum, respectively. In addition, following exposure to Fe3+, expression of HsFer-1 and HsFer-2 was elevated by 1.5-6.1- and 3.6-10.1-fold, respectively. Levels of HsFer-1 and -2 mRNA also increased significantly after treatment with Cu2+ and Pb2+ at certain concentrations. Moreover, recombinant HsFer-1 and -2 were able to inhibit the growth of two strains of bacteria, and the former efficiently chelated Fe3+. From these results, we conclude that HsFer-1 and -2 may be involved in iron metabolism and immune defense by inhibiting the growth of bacteria.
Assuntos
Bivalves/imunologia , Ferritinas/imunologia , Interações Hospedeiro-Patógeno/imunologia , Ferro/imunologia , Staphylococcus aureus/metabolismo , Vibrio/metabolismo , Animais , Bivalves/efeitos dos fármacos , Bivalves/genética , Bivalves/microbiologia , Cobre/farmacologia , Ferritinas/genética , Água Doce , Regulação da Expressão Gênica , Gônadas/efeitos dos fármacos , Gônadas/imunologia , Gônadas/microbiologia , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Hemócitos/microbiologia , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/imunologia , Hepatopâncreas/microbiologia , Ferro/química , Ferro/farmacologia , Quelantes de Ferro/química , Chumbo/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento , Transcrição Gênica , Vibrio/crescimento & desenvolvimentoRESUMO
BACKGROUND: In non-alcoholic fatty liver disease (NALFD), it has often been assumed that an elevation in serum ferritin is likely related to inflammation rather than iron overload. MATERIAL AND METHODS: Patients referred with NAFLD were entered into a clinical study of phlebotomy therapy. A liver biopsy with liver iron concentration was done at entry and 6 months after phlebotomy (n = 56) until the patient had a low serum ferritin or developed anemia. Serum ferritin was compared to liver iron concentration, ESR, CRP, BMI and grade of inflammation on liver biopsy. RESULTS: Iron removed by phlebotomy in NAFLD correlated with the decrease in serum ferritin (r = 0.57, p = 0.0014) and liver iron concentration (r = 0.57, p = 0.0013). There was no significant correlations between serum ferritin and ESR, CRP or grade of liver inflammation. CONCLUSIONS: Serum ferritin is related to liver iron storage in NAFLD and decreasing body iron stores by phlebotomy is reflected by an appropriate decrease in serum ferritin. Inflammation is not the cause of the elevated serum ferritin in fatty liver disease.
Assuntos
Ferritinas/metabolismo , Inflamação/sangue , Sobrecarga de Ferro/sangue , Ferro/sangue , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Adulto , Sedimentação Sanguínea , Proteína C-Reativa/imunologia , Feminino , Ferritinas/imunologia , Humanos , Inflamação/imunologia , Ferro/imunologia , Ferro/metabolismo , Sobrecarga de Ferro/imunologia , Sobrecarga de Ferro/metabolismo , Fígado/imunologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/imunologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , FlebotomiaRESUMO
Leishmania infantum infection in humans and dogs can evolve with a wide range of clinical presentations, varying from asymptomatic infections to visceral leishmaniasis. We hypothesized that the immune response elicited by L. infantum infection could modulate whether the host will remain asymptomatic or progress to disease. A total of 44 dogs naturally infected with L. infantum were studied. Leishmania burden was estimated in the blood and spleen by qPCR. The expression of IFN-γ, TNF-α, IL-10 and Iron Regulatory Protein 2 (IRP2) were determined in the spleen by quantitative PCR. Sera cytokines were evaluated by ELISA. Dogs were grouped in quartiles according parasite burden. Increased expression of IFN-γ and TNF-α was associated with reduced Leishmania burden, whereas increased IL-10 and IRP2 expressions were associated with higher Leishmania load. Increased plasma albumin and IFN-γ expression explained 22.8% of the decrease in parasite burden in the spleen. These data confirm that lower IFN-γ response and higher IL-10 correlated with increased parasite load and severity of the visceral leishmaniasis in dogs. The balance between the branches of immune response and the intracellular iron availability could determine, in part, the course of Leishmania infection.
Assuntos
Doenças do Cão/genética , Interferon gama/imunologia , Interleucina-10/imunologia , Proteína 2 Reguladora do Ferro/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Animais , Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Cães , Feminino , Expressão Gênica , Interações Hospedeiro-Parasita , Interferon gama/genética , Interleucina-10/genética , Ferro/imunologia , Ferro/metabolismo , Proteína 2 Reguladora do Ferro/genética , Leishmania infantum/patogenicidade , Leishmaniose Visceral/genética , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Masculino , Carga Parasitária , Albumina Sérica/imunologia , Albumina Sérica/metabolismo , Índice de Gravidade de Doença , Baço/imunologia , Baço/parasitologia , Baço/patologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Protein-energy malnutrition and micronutrient deficiencies may down-regulate immune response and increase morbidity and mortality due to infection. In this study, a murine model was used to study the effects of protein, iron and zinc deficiencies on the immune response to Leishmania (Leishmania) chagasi infection. Mice were initially fed a standard diet or with a diet containing 3% casein but deficient in zinc and iron. After malnutrition was established, mice were inoculated with L. chagasi and sacrificed four weeks later in order to evaluate liver and spleen parasite loads and serum biochemical parameters. Significant decreases in liver and spleen weight, an increase in the parasite loads in these organs and decreases in serum protein and glucose concentrations in malnourished animals were observed. Furthermore, the production of interferon-gamma by spleen cells from infected malnourished mice stimulated by Leishmania antigen was significantly lower compared with that in control diet mice. These data suggest that malnutrition alters the immune response to L. chagasi infection in the BALB/c model and, in association with the effects on biochemical and anatomical parameters of the host, favored increases in the parasite loads in the spleens and livers of these animals.
Assuntos
Imunidade Adaptativa/imunologia , Deficiências de Ferro , Leishmania infantum , Leishmaniose Visceral/imunologia , Desnutrição Proteico-Calórica/imunologia , Zinco/deficiência , Animais , Citocinas/biossíntese , Modelos Animais de Doenças , Feminino , Ferro/imunologia , Leishmaniose Visceral/sangue , Leishmaniose Visceral/patologia , Fígado/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/biossíntese , Baço/parasitologia , Zinco/imunologiaRESUMO
Protein-energy malnutrition and micronutrient deficiencies may down-regulate immune response and increase morbidity and mortality due to infection. In this study, a murine model was used to study the effects of protein, iron and zinc deficiencies on the immune response to Leishmania (Leishmania) chagasi infection. Mice were initially fed a standard diet or with a diet containing 3 percent casein but deficient in zinc and iron. After malnutrition was established, mice were inoculated with L. chagasiand sacrificed four weeks later in order to evaluate liver and spleen parasite loads and serum biochemical parameters. Significant decreases in liver and spleen weight, an increase in the parasite loads in these organs and decreases in serum protein and glucose concentrations in malnourished animals were observed. Furthermore, the production of interferon-gamma by spleen cells from infected malnourished mice stimulated by Leishmaniaantigen was significantly lower compared with that in control diet mice. These data suggest that malnutrition alters the immune response to L. chagasiinfection in the BALB/c model and, in association with the effects on biochemical and anatomical parameters of the host, favored increases in the parasite loads in the spleens and livers of these animals.
Assuntos
Animais , Feminino , Camundongos , Imunidade Adaptativa/imunologia , Ferro , Leishmania infantum , Leishmaniose Visceral/imunologia , Desnutrição Proteico-Calórica/imunologia , Zinco , Citocinas/biossíntese , Modelos Animais de Doenças , Ferro/imunologia , Leishmaniose Visceral/sangue , Leishmaniose Visceral/patologia , Fígado , Camundongos Endogâmicos BALB C , Óxido Nítrico/biossíntese , Baço , Zinco/imunologiaRESUMO
Microminerals including copper and iron are essential to immunity and health in human beings. The development of powerful tools in analytical cell biology and molecular genetics has facilitated efforts to identify specific cellular and molecular functions of trace elements in the maturation, activation and functions of host defence mechanisms. Selected recent reports about the role of copper and iron nutrition on immune functions are critically analysed here. Effects of trace element supplementation on infectious morbidity are also reviewed. While micromineral deficiencies, in general, may have widespread effects on nearly all components of immune response, these effects can be reversed by supplementation. However, the conflicting effects of iron deficiency and iron supplementation in vitro on the defensive systems reveals the urgent need for further additional information on the in vivo situation. In the elderly, vaccination against respiratory infections is likely to protect only 30-70% of the population. However, it may be possible to modulate immune function and ultimately reduce the severity of infections through micronutrient supplementation. Thus, microminerals contribute to the maintenance of the balance between immunity and health in humans.
Assuntos
Cobre/fisiologia , Imunocompetência/fisiologia , Ferro/fisiologia , Animais , Doenças Transmissíveis/imunologia , Doenças Transmissíveis/terapia , Cobre/imunologia , Suplementos Nutricionais , Humanos , Imunidade Celular/fisiologia , Ferro/imunologia , CamundongosRESUMO
The data on the relationship between iron deficiency and infection are conflicting. Some researchers conclude that mild iron deficiency is beneficial for immunity, whereas others contend that any deficit is not good for immunity. Additionally, infection or inflammation generate anemia and profound changes in iron metabolism mediated by cytokines. These changes are important confounders to consider in assessments of iron status.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/imunologia , Infecções/metabolismo , Ferro/imunologia , Anemia Ferropriva/etiologia , Citocinas/biossíntese , Eritropoetina/fisiologia , Humanos , Ferro/metabolismo , Ferro/uso terapêuticoRESUMO
Se realizó una revisión de los trabajos realizados con respecto a las posibles asociaciones entre algunas deficiencias nutricionales y el desarrollo de alteraciones en el sistema inmune. Se ha demostrado que la desnutrición energético-proteica ocaciona aumento en la incidencia de infecciones gastrointestinales y respiratorias con disminución importante de la inmunidad celular. Con respecto a nutrimentos específicos, las deficiencias de zinc, hierro y vitamina A entre otros, ejercen influencias negativas sobre la respuesta inmune tanto celular como humoral incluyendo los mecanismos inespecíficos de defensa
Assuntos
Humanos , Animais , Vitaminas na Dieta/metabolismo , Gastroenteropatias/imunologia , Ferro/deficiência , Ferro/imunologia , Desnutrição Proteico-Calórica/imunologia , Desnutrição Proteico-Calórica/fisiopatologia , Infecções Respiratórias/imunologia , Vitamina A/imunologiaRESUMO
Con el objetivo de establecer si existe asociación entre la capacidad de respuesta inmune (evaluada a través de la respuesta fagocitaria) y el estado de nutrición en hierro en gestantes aparentemente sanas, se realizó una investigación de carácter transversal con tres grupos de estudio, uno por cada trimestre de la gestación con un total de 81 embarazadas. Se determinó la fagocitosis y la concentración de hemoglobina y ferritina. En los tres grupos estudiados los indicadores del estado de nutrición en hierro permitieron explicar entre el 14 y el 34 por ciento de la variabilidad de la fagocitosis
Assuntos
Humanos , Feminino , Gravidez , Hemoglobinometria/estatística & dados numéricos , /metabolismo , Ferro/administração & dosagem , Ferro/imunologia , Ciências da Nutrição , Fagocitose/imunologia , Gravidez/imunologiaRESUMO
A autora fez uma revisao da literatura a respeito das relacoes entre ferro e infeccoes, com o objetivo de conhecer os aspectos mais atuais sobre o tema. Tanto a carencia de ferro como as infeccoes sao problemas no nosso meio, sendo necessario que os pediatras conhecam um pouco mais sobre este assunto tao polemico.