Eicosanoid pathway on host resistance and inflammation during Mycobacterium tuberculosis infection is comprised by LTB reduction but not PGE increment.

The functions of eicosanoids, a family of potent biologically active lipid mediators, are not restricted to inflammatory responses and they also act as mediators of the pathogenesis process. However, the role of eicosanoids in tuberculosis remains controversial. To investigate the specific role of LTB in Mycobacterium tuberculosis (Mtb) infection, we used 5-lipoxygenase-deficient (5-LO) mice and WT (sv129) mice inoculated intranasally with LTB (encapsulated in PLGA microspheres).

5-lipoxygenase pathway is essential for the control of granuloma extension induced by Schistosoma mansoni eggs in lung.

According to WHO, it is estimated that approximately 2 billion people are infected with intestinal helminths worldwide and the number of people who are cured of these diseases is relatively low, resulting in a large percentage of chronically infected individuals. Schistosomiasis is one of the most important parasitic diseases present in developing countries configuring it as a serious public health problem, directly related to poverty and social disadvantage. Once the parasite infection is established, Schistosoma mansoni eggs fall into the bloodstream and are trapped in the liver microcirculation where a strong granulomatous response and fibrosis formation occurs.

Evaluation of the overall IFN-γ and IL-17 pro-inflammatory responses after DNA therapy of tuberculosis.

Despite the enormous efforts displayed globally in the fight against tuberculosis, the disease incidence has modified slightly, which has led to a renewed interest in immunotherapy. In general, successful immunotherapeutic candidates against tuberculosis are agents that can trigger strong, specific pro-inflammatory responses, especially of the T-helper (Th) 1 pattern. However, how these pro-inflammatory agents effectively kill the bacteria without eliciting immunopathology is not well understood.

Effects of extrusion, lipid concentration and purity on physico-chemical and biological properties of cationic liposomes for gene vaccine applications.

We developed cationic liposomes containing DNA through a conventional process involving steps of (i) preformation of liposomes, (ii) extrusion, (iii) drying and rehydration and (iv) DNA complexation. Owing to its high prophylactic potentiality against tuberculosis, which had already been demonstrated in preclinical assays, we introduced modifications into the conventional process towards getting a simpler and more economical process for further scale-up. Elimination of the extrusion step, increasing the lipid concentration (from 16 to 64 mM) of the preformed liposomes and using good manufacturing practice bulk lipids (96-98% purity) instead of analytical grade purity lipids (99.

Effectiveness, against tuberculosis, of pseudo-ternary complexes: peptide-DNA-cationic liposome.

We report the effects of a synthetic peptide designed to act as a nuclear localization signal on the treatment of tuberculosis. The peptide contains 21 amino acid residues with the following specific domains: nuclear localization signal from SV 40T, cationic shuttle sequence, and cysteamide group at the C-terminus. The peptide was complexed with the plasmid DNAhsp65 and incorporated into cationic liposomes, forming a pseudo-ternary complex.

Serum amyloid P attenuates M2 macrophage activation and protects against fungal spore-induced allergic airway disease.

Background: Aspergillus fumigatus conidia aggravate asthmatic responses. Lung macrophages normally kill fungal conidia, but the presence of type 2 cytokines during asthma contributes to the alternative (or M2) activation of these cells, which secrete proallergic factors and exhibit impaired innate immunity.

Objective: Considering that pentraxins modulate macrophage function, we examined the effect of C-reactive protein (CRP) and serum amyloid P (SAP) in an experimental model of A fumigatus-induced allergic airway disease.

Helminth coinfection does not affect therapeutic effect of a DNA vaccine in mice harboring tuberculosis.

Background: Helminthiasis and tuberculosis (TB) coincide geographically and there is much interest in exploring how concurrent worm infections might alter immune responses against bacilli and might necessitate altered therapeutic approaches. A DNA vaccine that codifies heat shock protein Hsp65 from M. leprae (DNAhsp65) has been used in therapy during experimental tuberculosis.

Serum amyloid P therapeutically attenuates murine bleomycin-induced pulmonary fibrosis via its effects on macrophages.

Macrophages promote tissue remodeling but few mechanisms exist to modulate their activity during tissue fibrosis. Serum amyloid P (SAP), a member of the pentraxin family of proteins, signals through Fcgamma receptors which are known to affect macrophage activation. We determined that IPF/UIP patients have increased protein levels of several alternatively activated pro-fibrotic (M2) macrophage-associated proteins in the lung and monocytes from these patients show skewing towards an M2 macrophage phenotype.

Experimental tuberculosis: designing a better model to test vaccines against tuberculosis.

Experimental models of infection are good tools for establishing immunological parameters that have an effect on the host-pathogen relationship and also for designing new vaccines and immune therapies. In this work, we evaluated the evolution of experimental tuberculosis in mice infected with increasing bacterial doses or via distinct routes. We showed that mice infected with low bacterial doses by the intratracheal route were able to develop a progressive infection that was proportional to the inoculum size.

Therapeutic efficacy of Cintredekin Besudotox (IL13-PE38QQR) in murine lung fibrosis is unaffected by immunity to Pseudomonas aeruginosa exotoxin A.

Background: We have previously explored a therapeutic strategy for specifically targeting the profibrotic activity of IL-13 during experimental pulmonary fibrosis using a fusion protein comprised of human IL-13 and a mutated form of Pseudomonas aeruginosa exotoxin A (IL13-PE) and observed that the intranasal delivery of IL13-PE reduced bleomycin-induced pulmonary fibrosis through its elimination of IL-13-responsive cells in the lung. The aim of the present study was to determine whether the presence of an immune response to P. aeruginosa and/or its exotoxin A (PE) would diminish the anti-fibrotic properties of IL13-PE.

The synergy between structural stability and DNA-binding controls the antibody production in EPC/DOTAP/DOPE liposomes and DOTAP/DOPE lipoplexes.

We present a comparative study of the physico-chemical properties, in vitro cytotoxicity and in vivo antibody production of surface-complexed DNA in EPC/DOTAP/DOPE (50/25/25% molar) liposomes and DOTAP/DOPE (50/50% molar) lipoplexes. The study aims to correlate the biological behavior and structural properties of the lipid carriers. We used DNA-hsp65, whose naked action as a gene vaccine against tuberculosis has already been demonstrated.

Protective efficacy of different strategies employing Mycobacterium leprae heat-shock protein 65 against tuberculosis.

Background: Tuberculosis is a major threat to human health. The high disease burden remains unaffected and the appearance of extremely drug-resistant strains in different parts of the world argues in favor of the urgent need for a new effective vaccine. One of the promising candidates is heat-shock protein 65 when used as a genetic vaccine (DNAhsp65).

Protection against tuberculosis by a single intranasal administration of DNA-hsp65 vaccine complexed with cationic liposomes.

Background: The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally.

The immune response to toxocariasis does not modify susceptibility to Mycobacterium tuberculosis infection in BALB/c mice.

Mycobacterium tuberculosis and helminth infections coincide geographically and are classically described as TH1 and TH2 pathologies. There is much interest in exploring how concurrent worm infections might alter immune responses to mycobacterial infection. To explore this issue, mice were infected with Toxocara canis and co-infected with M.

Tissue distribution of DNA-Hsp65/TDM-loaded PLGA microspheres and uptake by phagocytic cells.

This study aimed to demonstrate that microspheres, used as delivery vehicle of DNA-Hsp65/TDM [plasmid DNA encoding heat shock protein 65 (Hsp65) coencapsulated with trehalose dimycolate (TDM) into PLGA microspheres], are widely spread among several organs after intramuscular administration in BALB/c mice. In general, we showed that these particles were phagocytosed by antigen presenting cells, such as macrophages and dendritic cells. Besides, it was demonstrated herein that draining lymph node cells presented a significant increase in the number of cells expressing costimulatory molecules (CD80 and CD86) and MHC class II, and also that the administration of the DNA-Hsp65/TDM and vector/TDM formulations resulted in the up-regulation of CD80, CD86 and MHC class II expression when compared to control formulations (vector/TDM and empty).