Passive immunization with monoclonal antibody against a 70-kDa putative adhesin of Sporothrix schenckii induces protection in murine sporotrichosis

Cell-mediated and innate immunity are considered the most important mechanisms of host defense against fungus infections. However, recent studies demonstrated that specific antibodies show different degrees of protection against mycosis. In a previous study, antigens secreted by Sporothrix schenckii induced a specific humoral response in infected animals, mainly against the 70-kDa molecule, indicating a possible participation of antibodies to this antigen in infection control. in the present study, an IgG1 mAb was produced against a 70-kDa glycoprotein of S. schenckii in order to better understand the effect of passive immunization of mice infected with S. schenckii. Results showed a significant reduction in the number of CFU in organs of mice when the mAb was injected before and during S. schenckii infection. Similar results were observed when T-cell-deficient mice were used. Moreover, in a second schedule treatment, the mAb was injected after infection was established, and again we observed a significant reduction in CFU associated with an increase of IFN-gamma production. Also, the 70-kDa antigen is shown to be a putative adhesin present on the surface of this fungus. In conclusion, we report for the first time the protective effect of a specific antibody against S. schenckii.

Plasmodium vivax apical membrane antigen-1: comparative recognition of different domains by antibodies induced during natural human infection

The Apical Membrane Antigen-1 (AMA-1) of Plasmodium sp. has been suggested as a vaccine candidate against malaria. This protein seems to be involved in merozoite invasion and its extra-cellular portion contains three distinct domains: DI, DII, and DIII. Previously, we described that Plasmodium vivax AMA-1 (PvAMA-1) ectodomain is highly immunogenic in natural human infections. Here, we expressed each domain, separately or in combination (DI-II or DII-III), as bacterial recombinant proteins to map immunodominant epitopes within the PvAMA-1 ectodomain. IgG recognition was assessed by ELISA using sera of P. vivax-infected individuals collected from endemic regions of Brazil or antibodies raised in immunized mice. The frequencies of responders to recombinant proteins containing the DII were higher than the others and similar to the ones observed against the PvAMA-1 ectodomain. Moreover, ELISA inhibition assays using the PvAMA-1 ectodomain as substrate revealed the presence of many common epitopes within DI-II that are recognized by human immune antibodies. Finally, immunization of mice with the PvAMA-1 ectodomain induced high levels of antibodies predominantly to DI-II. Together, our results indicate that DII is particularly immunogenic during natural human infections, thus indicating that this region could be used as part of an experimental sub-unit vaccine to prevent vivax malaria. (C) 2008 Elsevier Masson SAS. All rights reserved.

Characterization of interactions between polyphenolic compounds and human serum proteins by capillary electrophoresis

The interaction of ten natural polyphenolic compounds (chlorogenic acid, apigenin, catechin, epicatechin, flavanone, flavone, quercetin, rutin, vicenin-2 and vitexin) with human serum albumin and mixtures of human serum albumin and alpha(1)-acid glycoprotein under near physiological conditions is studied by capillary electrophoresis-frontal analysis. Furthermore, the binding of these polyphenolic compounds to total plasmatic proteins is evaluated using ultrafiltration and capillary electrophoresis. In spite of the relatively small differences in the chemical structures of the compounds studied, large differences were observed in their binding behaviours to plasmatic proteins. The hydrophobicity, the presence/absence of some functional groups, steric hindrance and spatial arrangement seem to be key factors in the affinity of natural polyphenols towards plasmatic proteins.

Characterization of Rubus fruticosus mitochondria and salicylic acid inhibition of reactive oxygen species generation at Complex III/Q cycle: potential implications for hypersensitive response in plants

In addition to adenosine triphosphate (ATP) production, mitochondria have been implicated in the regulation of several physiological responses in plants, such as programmed cell death (PCD) activation. Salicylic acid (SA) and reactive oxygen species (ROS) are essential signaling molecules involved in such physiological responses; however, the mechanisms by which they act remain unknown. In non-photosynthesizing tissues, mitochondria appear to serve as the main source of ROS generation. Evidence suggests that SA and ROS could regulate plant PCD through a synergistic mechanism that involves mitochondria. Herein, we isolate and characterize the mitochondria from non-photosynthesizing cell suspension cultures of Rubus fruticosus. Furthermore, we assess the primary site of ROS generation and the effects of SA on isolated organelles. Mitochondrial Complex III was found to be the major source of ROS generation in this model. In addition, we discovered that SA inhibits the electron transport chain by inactivating the semiquinone radical during the Q cycle. Computational analyses confirmed the experimental data, and a mechanism for this action is proposed.

Photochemical cleavage of nitrate ion coordinated to a Cr(III) porphyrin#

Photolysis of the nitrato chromium(III) tetraphenylporphyrinato compound Cr(TPP)(NO(3)) (TPP, tetraphenylporphyrin) in toluene solution clearly leads to the formation of the Cr(IV) oxo complex Cr(TPP)(O) with a quantum yield of 0.011. The other product, NO(2), was detected quantitatively by its reaction with the spin trapping agent 2,2,6,6-tetramethyl-piperidine-1-oxyl.

Distinct conformational properties determined by implicit and explicit representation of protein-solvent interactions. An analytical and computer simulation study

In the protein folding problem, solvent-mediated forces are commonly represented by intra-chain pairwise contact energy. Although this approximation has proven to be useful in several circumstances, it is limited in some other aspects of the problem. Here we show that it is possible to achieve two models to represent the chain-solvent system. one of them with implicit and other with explicit solvent, such that both reproduce the same thermodynamic results. Firstly, lattice models treated by analytical methods, were used to show that the implicit and explicitly representation of solvent effects can be energetically equivalent only if local solvent properties are time and spatially invariant. Following, applying the same reasoning Used for the lattice models, two inter-consistent Monte Carlo off-lattice models for implicit and explicit solvent are constructed, being that now in the latter the solvent properties are allowed to fluctuate. Then, it is shown that the chain configurational evolution as well as the globule equilibrium conformation are significantly distinct for implicit and explicit solvent systems. Actually, strongly contrasting with the implicit solvent version, the explicit solvent model predicts: (i) a malleable globule, in agreement with the estimated large protein-volume fluctuations; (ii) thermal conformational stability, resembling the conformational hear resistance of globular proteins, in which radii of gyration are practically insensitive to thermal effects over a relatively wide range of temperatures; and (iii) smaller radii of gyration at higher temperatures, indicating that the chain conformational entropy in the unfolded state is significantly smaller than that estimated from random coil configurations. Finally, we comment on the meaning of these results with respect to the understanding of the folding process. (C) 2009 Elsevier B.V. All rights reserved.

Sustained release carriers used to delivery bone morphogenetic proteins in the bone healing process

Bone morphogenetic proteins (BMPs) are multi-functional growth factors belonging to the transforming growth factor beta superfamily, especially BMP-2, induce bone formation in vivo, and clinical application in repair of bone fractures and defects is expected. However, appropriate systems to delivery BMPs for practical use need to be developed with the objective to heal cartilage and bone-related diseases in medical, dental and veterinary practice. Thus, the aim of this article was to present an overview of the principals carriers used to delivery BMPs and alternative delivery systems for these proteins.

Partial characterization of proteins from baru (Dipteryx alata Vog) seeds

BACKGROUND: Baru (Dipteryx alata Vog.) is a fruit distributed throughout the Brazilian savanna and contains a seed with a high protein content, whose properties have been rarely explored. The purpose of this study was to characterize this protein, especially by isolation and quantifying its fractions and measuring some of its molecular properties. RESULTS: Baru seeds contain 244 g kg(-1) protein on a dry weight basis. Solubility profiles showed a preponderance of globulins. This fraction dominated the seed composition, with 61.7 wt% of the total soluble proteins. Albumins and glutelins accounted for 14 and 3.3 wt%, respectively. SDS-PAGE resolution of albumin and globulin showed main bands with molecular weights of 84 kDa and 64,66 and 73 kDa, respectively. The total protein of the flour and the globulin showed values of in vitro digestibility of 85.59% and 90.54%, relative to casein. Total globulin produced only one chromatographic peak, both on Sepharose CL-6B gel filtration and on DEAE-cellulose ion-exchange columns, eluted at a concentration of 0.12 mol L(-1) NaCl. CONCLUSION: The baru seed had high protein content with large quantities of storage proteins. The chromatographic and solubility profiles indicate the predominance of a fraction with characteristics of a legumin-type protein. (C) 2011 Society of Chemical Industry

The Ruthenium Complex cis-(Dichloro)tetraammineruthenium(III) Chloride Presents Selective Cytotoxicity Against Murine B Cell Lymphoma (A-20), Murine Ascitic Sarcoma 180 (S-180), Human Breast Adenocarcinoma (SK-BR-3), and Human T Cell Leukemia (Jurkat) Tumor Cell Lines

The aim of present study was to verify the in vitro antitumor activity of a ruthenium complex, cis-(dichloro)tetraammineruthenium(III) chloride (cis-[RuCl(2)(NH(3))(4)]Cl) toward different tumor cell lines. The antitumor studies showed that ruthenium(III) complex presents a relevant cytotoxic activity against murine B cell lymphoma (A-20), murine ascitic sarcoma 180 (S-180), human breast adenocarcinoma (SK-BR-3), and human T cell leukemia (Jurkat) cell lines and a very low cytotoxicity toward human peripheral blood mononuclear cells. The ruthenium(III) complex decreased the fraction of tumor cells in G0/G1 and/or G2-M phases, indicating that this compound may act on resting/early entering G0/G1 cells and/or precycling G2-M cells. The cytotoxic activity of a high concentration (2 mg mL(-1)) of cis-[RuCl(2)(NH(3))(4)]Cl toward Jurkat cells correlated with an increased number of annexin V-positive cells and also the presence of DNA fragmentation, suggesting that this compound induces apoptosis in tumor cells. The development of new antineoplastic medications demands adequate knowledge in order to avoid inefficient or toxic treatments. Thus, a mechanistic understanding of how metal complexes achieve their activities is crucial to their clinical success and to the rational design of new compounds with improved potency.

The Ruthenium Complex cis-(Dichloro) Tetraammineruthenium(III) Chloride Presents Immune Stimulatory Activity on Human Peripheral Blood Mononuclear Cells

Ruthenium compounds in general are well suited for medicinal applications. They have been investigated as immunosuppressants, nitric oxide scavengers, antimicrobial agents, and antimalarials. The aim of this study is to evaluate the immunomodulatory activity of cis-(dichloro) tetraammineruthenium(III) chloride (cis-[RuCl(2)(NH(3))(4)]Cl) on human peripheral blood mononuclear cells (PBMC). The cytotoxic studies performed here revealed that the ruthenium( III) complex presents a cytotoxic activity towards normal human PBMC, only at very high concentration. Results also showed that cis-[ RuCl(2)(NH(3))(4)] Cl presents a dual role on PBMC stimulating proliferation and interleukin-2 (IL-2) production at low concentration and inducing cytotoxicity, inability to proliferate, and inhibiting IL-2 production at high concentration. The noncytotoxic activity of cis-[RuCl(2)(NH(3))(4)] Cl at low concentration towards PBMC, which correlates with the small number of annexin V positive cells and also the absence of DNA fragmentation, suggest that this compound does not induce apoptosis on PBMC. For the first time, we show that, at low concentration (10-100 mu g L(-1)), the cis-[ RuCl(2)(NH(3))(4)] Cl compound induces peripheral blood lymphocytes proliferation and also stimulates them to IL-2 production. These results open a new potential applicability of ruthenium(III) complexes as a possible immune regulatory compound acting as immune suppressor at high concentration and as immune stimulator at low concentration.

Brazilian Adaptation of the Woodcock-Johnson III Cognitive Tests

An adaptation of the standard battery of Woodcock-Johnson III Tests of Cognitive Abilities (WJ-III) for Brazilian children and youth was investigated. The sample was composed of 1094 students (54 percent girls), ages 7-17, living in Sao Paulo state (91 percent). Items from Brazilian school books as well as from the WJ-III Spanish version (Bateria-R) were added to comprehension-knowledge tests. Brazilian words were adapted to the auditory tests according to syllabic division and stressed syllables. Items were examined through IRT and age differences through analysis of variance. Results indicated the need to remove items from all WJ-III subtests with the exception of the visual learning test. Analysis of Variance indicated significant age differences (p <= 0.001) for all tests. Thus, the importance of a Brazilian adaptation for the WJ-III was confirmed.

TRADE-OFF BETWEEN IMMUNE STIMULATION AND EXPRESSION OF STORAGE PROTEIN GENES

Proteins stored in insect hemolymph may serve (is a source of amino acids and energy for metabolism, and development. The expression of the main storage proteins was assessed in bacterial-challenged honey bees using real-time (RT)-PCH and Western blot.. After ensuring that. the immune system had, been activated by measuring the ensuing expression (, the innate immune response genes, defensin-1 (def-1) and prophenoloxidase (pro PO), we verified the expression of four genes encoding storage proteins. The levels of vitellogenin (vg) mRNA and of the respective protein. were significantly lowered in bees injected with bacteria or water only (injury). An equivalent response was observed in orally-infected bees. The levels of apolipophorin II/I (apoLP-II/I) and hexamerin (hex 70a) mRNAs did not significantly change, but levels of Hex 70a protein subunit showed a substantial decay after bacterial challenge or injury. Infection also caused a strong reduction in the levels of apoLP-III transcripts. Our findings are consistent with a down-regulation, of the express and accumulation of storage proteins as a consequence of activation of the immune system, suggesting that this phenomenon. represents a strategy to redirect resources to combat injury or infection. (C) 2009 Wiley Periodicals, Inc.

Incorporation of antigenic GPI-proteins from Leishmania amazonensis to membrane mimetic systems: Influence of DPPC/cholesterol ratio

The reconstitution of membrane proteins into liposomes is a useful tool to prepare antigenic components that induce immunity. We have investigated the influence of the dipalmitoylphosphatidylcholine (DPPC)/cholesterol molar ratio on the incorporation of a GPI-protein from Leishmania amazonensis on liposomes and Langmuir monolayers. The latter system is a well behaved and practical model, for understanding the effect of variables such as surface composition and lipid packing on protein incorporation. We have found that the DPPC/cholesterol molar ratio significantly alters the incorporation of the GPI-protein. In the absence of cholesterol, reconstitution is more difficult and proteoliposomes cannot be prepared, which we correlated with disruption of the DPPC layer. Our results provide important information that Could be employed in the development of a vaccine system for this disease or be used to produce other GPI-systems for biotechnological application. (c) 2009 Elsevier Inc. All rights reserved.

Synthesis and spectral investigation of Al(III) catechin/beta-cyclodextrin and Al(III) quercetin/beta-cyclodextrin inclusion compounds

Al-catechin/beta-cyclodextrin and Al-quercetin/beta-cyclodextrin (beta-CD) inclusion compounds were synthesized and characterized by IR, UV-vis, H-1 and C-13 NMR and TG and DTA analyses. Because quercetin is sparingly soluble in water, the stability constants of the Al-quercetin/beta-CD and Al-catechin/beta-CD compounds were determined by phase solubility studies. The A(L)-type diagrams indicated the formation of 1:1 inclusion compounds and allowed calculation of the stability constants. The thermodynamic parameters were obtained from the dependence of the stability constants on temperature and results indicated that the formation of the inclusion compounds is an enthalpically driven process. The thermal decomposition of the solid Al-quercetin/beta-CD and Al-catcchin/beta-CD inclusion compounds took place at different stages, compared with the respective precursors, proving that an inclusion complexation process really occurred. (C) 2007 Published by Elsevier B.V.

Study of spectroscopic properties of Europium (III) Tris(beta-diketonate) complex and alpha-Cyclodextrin in aqueous medium

The solubilization of an europium (III) beta-diketonate chelate in aqueous medium and the changes in its photophysical properties upon its inclusion into an alpha-cyclodextrin hydrophobic cavity are described. The complex [Eu(tta)(3)center dot(H(2)O)(2)] (tta = 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione) was synthesized, characterized, and incorporated into the hydrophobic cavity by stirring in an alpha-cyclodextrin aqueous solution. The inclusion was confirmed by (1)H NMR, and the stoichiometry of association was obtained by the Job method. The maximum in the excitation spectrum of the alpha-CD inclusion compound in aqueous solution was shifted 28 nm compared with the maximum of non alpha-CD complex. The emission spectrum of the association is similar to that of the free solid complex and displays the characteristic (5)D(0) -> (7)F(0-4) Eu(3+) transitions.