RESUMO
Induction of CD8+ T cell responses against tumor cells and intracellular pathogens is an important goal of modern vaccinology. One approach of translational interest is the use of liposomes encapsulating pore-forming proteins (PFPs), such as Listeriolysin O (LLO), which has shown efficacy at priming strong and sustained CD8+ T cell responses. Recently, we have demonstrated that Sticholysin II (StII), a PFP from the sea anemone Stichodactyla helianthus, co-encapsulated into liposomes with ovalbumin (OVA) was able to stimulate, antigen presenting cells, antigen-specific CD8+ T cells and anti-tumor activity in mice. In the present study, we aimed to compare StII and LLO in terms of their abilities to stimulate dendritic cells and to induce major histocompatibility complex (MHC) class I restricted T cell responses against OVA. Interestingly, StII exhibited similar abilities to LLO in vitro of inducing dendritic cells maturation, as measured by increased expression of CD40, CD80, CD86 and MHC-class II molecules, and of stimulating OVA cross-presentation to a CD8+ T cell line. Remarkably, using an ex vivo Enzyme-Linked ImmunoSpot Assay (ELISPOT) to monitor gamma interferon (INF-γ) producing effector memory CD8+ T cells, liposomal formulations containing either StII or LLO induced comparable frequencies of OVA-specific INF-γ producing CD8+ T cells in mice that were sustained in time. However, StII-containing liposomes stimulated antigen-specific memory CD8+ T cells with a higher potential to secrete IFN-γ than liposomes encapsulating LLO. This StII immunostimulatory property further supports its use for the rational design of T cell vaccines against cancers and intracellular pathogens. In summary, this study indicates that StII has immunostimulatory properties similar to LLO, despite being evolutionarily distant PFPs.
Assuntos
Linfócitos T CD8-Positivos , Linfócitos T Citotóxicos , Animais , Toxinas Bacterianas , Venenos de Cnidários , Células Dendríticas , Proteínas de Choque Térmico , Proteínas Hemolisinas , Camundongos , Camundongos Endogâmicos C57BL , OvalbuminaRESUMO
Se trata de un caso clínico, diagnosticado como quiste hidatídico en forma casual, que ingresa al servicio de medicina interna con el diagnóstico de neumonía. El estudio radiológico informa tres masas circunscritas, uno en el pulmon derecho y dos en el izquierdo, se sospecha de poliquistosis hidatídica pulmonar versus CA metastásico pulmonar, el examen ecográfico indica contenido liquido y la TAC lo confirma
Assuntos
Humanos , Masculino , Feminino , Equinococose , Equinococose Pulmonar , BolíviaRESUMO
Little is known about the mechanism of hepatitis C virion assembly. So the capacity of the entire Hepatitis C virus core protein (HCcAg) produced in Pichia pastoris to form particles either in its native soluble state or after detergent treatment of HCcAg associated to cell debris were studied. Size exclusion chromatography suggested that HCcAg assembled into high molecular weight structures. HCcAg was also specifically recognized by a serum from a chronic HCV carrier patient. This antigen migrated with buoyant density values similar to those obtained for native nucleocapsid particles from infected patients when analyzed using sucrose density gradient centrifugation. The analysis by electron microscopy of purified HCcAg showed aggregates resembling virus-like particles (VLPs) with an average diameter of 30 nm. These results indicated that the HCcAg obtained from P. pastoris assembled into VLPs resembling HCV nucleocapsid particles in a mature stage. Such HCcAg aggregates characterized here could be a valuable tool to elucidate the mechanisms of HCV nucleocapsid assembly.
Assuntos
Hepacivirus/química , Pichia/virologia , Proteínas do Core Viral/química , Vírion/química , Immunoblotting , Peso Molecular , Renaturação Proteica , Proteínas do Core Viral/metabolismoRESUMO
Core protein is one of the most conserved and immunogenic of the hepatitis C virus proteins. Several pieces of experimental evidence suggest its ability for formation of virus like particles alone or in association with other viral proteins in mammalian or yeast cells with great similarity to those detected in patient sera and liver extract. In this work we report an Escherichia coli-derived truncated hepatitis C core protein that is able to aggregate. SDS-PAGE and size exclusion chromatography patterns bring to mind the aggregation of monomers of recombinant protein Co.120. The Co.120 protein migrated with buoyant density of 1.28 g/cm(3) when analyzed using CsCl density gradient centrifugation. Spherical structures with an average diameter of 30 nm were observed using electron microscopy. We report here that VLPs are generated when the first 120 aa of HCV core protein are expressed in E. coli.
Assuntos
Escherichia coli/virologia , Hepacivirus/metabolismo , Proteínas do Core Viral/metabolismo , Western Blotting , Eletroforese em Gel de Poliacrilamida , Hepacivirus/química , Hepacivirus/ultraestrutura , Antígenos da Hepatite C/metabolismo , Antígenos da Hepatite C/ultraestrutura , Microscopia Imunoeletrônica , Proteínas do Core Viral/ultraestruturaRESUMO
Immunological response against envelope protein E1 is very important in natural hepatitis C virus (HCV) infection, although it is insufficient to clear the viraemia. The HCV genomic region encoding the first 149 amino acids of the envelope E1 protein (E1(340), amino acids 192-340) was expressed in Escherichia coli (to a level of 30% of the whole cellular proteins) and purified to 85%. We measured the immune response in rabbits and mice as well as the reactivity against 37 human sera raised against the whole recombinant protein and E1-encoding peptides. From this, 51.1% of human sera were found to react with E1(340). High-level antibodies against E1(340) were obtained in rabbits and mice when immunized. These antibodies had a similar peptide-recognition pattern to that described previously for human sera. The most reactive region was located at the N-terminus of the E1 protein. Cellular immunity in mice was evaluated by delayed-type hypersensitivity assay. It revealed the induction of a CD4+ T-cell-mediated response by this protein. This E1(340) protein and the animal-derived anti-E1 sera are immunological tools that could aid in the monitoring and development of anti-HCV therapies.
Assuntos
Escherichia coli/genética , Hepatite C/imunologia , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos , Animais , Feminino , Hepatite C/virologia , Humanos , Hipersensibilidade Tardia/imunologia , Soros Imunes , Camundongos , Dados de Sequência Molecular , Coelhos , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/isolamento & purificaçãoRESUMO
BACKGROUND: In this paper, our goal was to determine the optimal isolation conditions, biochemical characterization, and preservation of species of the genus Mobiluncus, associated with bacterial vaginosis in patients attending the family planning clinic. Also, we tried to relate its presence with demographic variables and criteria used in the clinical diagnosis of bacterial diagnosis. METHODS: The specimen from the posterior fornix were collected and transported to the laboratory in a Stuart medium, one at room temperature and the other at 4 degrees C. These samples were inoculated in anaerobic culture media. RESULTS: Of a total of 92 patients studied, 61 (66.3%) were normal, 28 (30.4%) bacterial vaginosis, and 3 (3.3%) had intermediate vaginosis. There was statistically significant relationship only with intrauterine device use (p = 0.00499). The presence of curved rod, using Gram's method, was significantly related with pH (p = 0.00000) positive amines test (p = 0.00000), and the presence of clue cells (p = 0.00000). Mobiluncus was observed in 23 samples (82%), and the majority (15) using RLK agar (cold enrichment technique). With conventional techniques, we identified 12 strains as Mobiluncus curtisii and 3 strains as Mobiluncus mulieris. The strains of Mobiluncus sp. grew better from litmus milk conserved at -30 degrees C. CONCLUSION: Isolating Mobiluncus sp. is fairly easy, if the right media and the techniques are used.
Assuntos
Infecções por Bacteroidaceae , Mobiluncus/isolamento & purificação , Vaginose Bacteriana , Técnicas Bacteriológicas , Infecções por Bacteroidaceae/diagnóstico , Infecções por Bacteroidaceae/epidemiologia , Infecções por Bacteroidaceae/microbiologia , Feminino , Humanos , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/epidemiologia , Vaginose Bacteriana/microbiologiaRESUMO
Protection from the development of experimental autoimmune uveitis (EAU) can be induced by feeding mice interphotoreceptor retinoid binding protein before uveitogenic challenge with the same protein. Two different regimens are equally effective in inducing protective tolerance, although they seem to do so through different mechanisms: one involving regulatory cytokines (IL-4, IL-10, and TGF-beta), and the other with minimal involvement of cytokines. Here we studied the importance of IL-4 and IL-10 for the development of oral tolerance using mice genetically engineered to lack either one or both of these cytokines. In these animals we were able to protect against EAU only through the regimen inducing cytokine-independent tolerance. When these animals were fed a regimen that in the wild-type animal is thought to predominantly induce regulatory cells and is associated with cytokine secretion, they were not protected from EAU. Interestingly, both regimens were associated with reduced IL-2 production and proliferation in response to interphotoreceptor retinoid binding protein. These findings indicate that both IL-4 and IL-10 are required for induction of protective oral tolerance dependent on regulatory cytokines, and that one cytokine cannot substitute for the other in this process. These data also underscore the fact that oral tolerance, manifested as suppression of proliferation and IL-2 production, is not synonymous with protection from disease.
Assuntos
Doenças Autoimunes/imunologia , Proteínas do Olho , Tolerância Imunológica , Interleucina-10/fisiologia , Interleucina-4/fisiologia , Uveíte/imunologia , Animais , Feminino , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Ligação ao Retinol/imunologia , Fator de Crescimento Transformador beta/fisiologiaRESUMO
To determine the prevalence and clinical consequences of hypocalcemia in pediatric intensive care unit patients, we prospectively studied calcium homeostasis in 145 of these patients. The total serum calcium concentration was measured in all patients. The serum ionized calcium concentration was measured in blood samples collected from those 71 (49%) patients who had low total serum calcium values (less than 8.5 mg/dl (2.12 mmol/L). Of the 71 patients, 26 (36.6%) had ionized hypocalcemia. Therefore the prevalence of ionized hypocalcemia was at least 17.9% (26/145). Death occurred in 8 (31%) of 26 patients with ionized hypocalcemia versus 3 (2.5%) of 119 patients with normocalcemia (p less than 0.0001). However, the severity of illness score was higher (p less than 0.05) in the children with ionized hypocalcemia than in normocalcemic children (mean Therapeutic Intervention Scoring System score 33 +/- 17 vs 22 +/- 11, respectively). More of the children with ionized hypocalcemia had sepsis (p = 0.0299) and they required the administration of vasopressor agents more often (p = 0.0002) than their normocalcemic counterparts. Of the 26 patients with ionized hypocalcemia, 17 (65.4%) had biochemical evidence of either absolute or relative hypoparathyroidism, determined by means of an immunoradiometric assay that measures only biologically active parathyroid hormone. We conclude the following: (1) ionized hypocalcemia is common in severely ill children. (2) Patients with ionized hypocalcemia have a higher mortality rate than those with normocalcemia; however, because the former are more severely ill, no causality is apparent or suggested. (3) Functional hypoparathyroidism may occur in critically ill children.