Merozoite-Protein Loaded Liposomes Protect against Challenge in Two Murine Models of Infection.

Liposomes loaded with GPI-anchored proteins induce a strong and effective response against protozoan pathogens when immunized in mice. On the basis of results using merozoite proteins loaded on liposomes, we tested whether a similar approach would be protective in the XL and NK65 models of lethal murine malaria infections. We also analyzed the enhancing capacity of additional adjuvants.

Nanobiotechnologic approach to a promising vaccine prototype for immunisation against leishmaniasis: a fast and effective method to incorporate GPI-anchored proteins of Leishmania amazonensis into liposomes.

Liposomes are known to be a potent adjuvant for a wide range of antigens, as well as appropriate antigen carriers for antibody generation response in vivo. In addition, liposomes are effective vehicles for peptides and proteins, thus enhancing their immunogenicity. Considering these properties of liposomes and the antigenicity of the Leishmania membrane proteins, we evaluated if liposomes carrying glycosylphosphatidylinositol (GPI)-anchored proteins of Leishmania amazonensis promastigotes could induce protective immunity in BALB/c mice.

Nanopharmaceutical approach of epiisopiloturine alkaloid carried in liposome system: preparation and in vitro schistosomicidal activity.

Schistosomiasis is a neglected tropical disease caused by blood flukes of the genus Schistosoma. This disease control has been widely made by praziquantel-reference drug, but resistance to this drug has already been found. There has been the finding of an imidazole alkaloid in jaborandi leaves-epiisopiloturine, which has known activity against adult, young and egg forms of Schistosoma mansoni.

Dermaseptin 01 as antimicrobial peptide with rich biotechnological potential: study of peptide interaction with membranes containing Leishmania amazonensis lipid-rich extract and membrane models.

This article addresses the interactions of the synthetic antimicrobial peptide dermaseptin 01 (GLWSTIKQKGKEAAIAAA- KAAGQAALGAL-NH(2) , DS 01) with phospholipid (PL) monolayers comprising (i) a lipid-rich extract of Leishmania amazonensis (LRE-La), (ii) zwitterionic PL (dipalmitoylphosphatidylcholine, DPPC), and (iii) negatively charged PL (dipalmitoylphosphatidylglycerol, DPPG). The degree of interaction of DS 01 with the different biomembrane models was quantified from equilibrium and dynamic liquid-air interface parameters. At low peptide concentrations, interactions between DS 01 and zwitterionic PL, as well as with the LRE-La monolayers were very weak, whereas with negatively charged PLs the interactions were stronger.

Using multidimensional projection techniques for reaching a high distinguishing ability in biosensing.

Recent advances in the control of molecular engineering architectures have allowed unprecedented ability of molecular recognition in biosensing, with a promising impact for clinical diagnosis and environment control. The availability of large amounts of data from electrical, optical, or electrochemical measurements requires, however, sophisticated data treatment in order to optimize sensing performance. In this study, we show how an information visualization system based on projections, referred to as Projection Explorer (PEx), can be used to achieve high performance for biosensors made with nanostructured films containing immobilized antigens.

Biosensors for efficient diagnosis of leishmaniasis: innovations in bioanalytics for a neglected disease.

The need for reliable, fast diagnostics is closely linked to the need for safe, effective treatment of the so-called "neglected" diseases. The list of diseases with no field-adapted diagnostic tools includes leishmaniasis, shigella, typhoid, and bacterial meningitis. Leishmaniasis, in particular, is a parasitic disease caused by Leishmania spp.

Lipid microspheres loaded with antigenic membrane proteins of the Leishmania amazonensis as a potential biotechnology application.

Lipid microspheres (LM) are excellent drug delivery or vaccines adjuvant systems and are relatively stable. The aim of this work is to develop and characterize a system that is able to encapsulate and present antigenic membrane proteins from Leishmania amazonensis. Membrane proteins are important for vaccine's formulation because these proteins come in contact with the host cell first, triggering the cell mediated immune response.

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.

Hypoxia modulates expression of the 70-kD heat shock protein and reduces Leishmania infection in macrophages.

Hypoxia, a microenvironmental factor present in diseased tissues, has been recognized as a specific metabolic stimulus or a signal of cellular response. Experimental hypoxia has been reported to induce adaptation in macrophages such as differential migration, elevation of proinflammatory cytokines and glycolytic enzyme activities, and decreased phagocytosis of inert particles. In this study we demonstrate that although exposure to hypoxia (5% O2, 5% CO2, and balanced N2) did not change macrophage viability, or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cleavage and proliferation, it significantly reduced expression of the 70-kD heat shock protein (HSP70), which was restored to prehypoxia levels after reoxygenation.

Effect of hypoxia on macrophage infection by Leishmania amazonensis.

In the present study, we compared the effect of 5% oxygen tension (hypoxia) with a normal tension of 21% oxygen (normoxia) on macrophage infection by the protozoan parasite Leishmania amazonensis. Macrophages from different sources (human cell line U937, murine cell line J774, and murine peritoneal macrophages) exposed to hypoxia showed a reduction of the percentage of infected cells and the number of intracellular parasites per cell. Observations on the kinetics of infection indicated that hypoxia did not depress L.