Methylenedioxymethamphetamine (Ecstasy) Decreases Neutrophil Activity and Alters Leukocyte Distribution in Bone Marrow, Spleen and Blood

Objective: Looking for possible neuroimmune relationships, we analyzed the effects of methylenedioxymethamphetamine (MDMA) administration on neuroendocrine, neutrophil activity and leukocyte distribution in mice. Methods: Five experiments were performed. In the first, mice were treated with MDMA (10 mg/kg) 30, 60 min and 24 h prior to blood sample collection for neutrophil activity analysis. In the second experiment, the blood of nave mice was collected and incubated with MDMA for neutrophil activity in vitro analysis. In the third and fourth experiments, mice were injected with MDMA (10 mg/kg) and 60 min later, blood and brain were collected to analyze corticosterone serum levels and hypothalamic noradrenaline (NA) levels and turnover. In the last experiment, mice were injected with MDMA 10 mg/kg and 60 min later, blood, bone marrow and spleen were collected for leukocyte distribution analysis. Results: Results showed an increase in hypothalamic NA turnover and corticosterone serum levels 60 min after MDMA (10 mg/kg) administration, a decrease in peripheral blood neutrophil oxidative burst and a decrease in the percentage and intensity of neutrophil phagocytosis. It was further found that MDMA (10 mg/kg) treatment also altered leukocyte distribution in blood, bone marrow and spleen. In addition, no effects were observed for MDMA after in vitro exposure both in neutrophil oxidative burst and phagocytosis. Conclusion: The effects of MDMA administration (10 mg/kg) on neutrophil activity and leukocyte distribution might have been induced indirectly through noradrenergic neurons and/or hypothalamic-pituitary-adrenal axis activations. Copyright (C) 2009 S. Karger AG, Basel

The use of glucan as immunostimulant in the treatment of a severe case of chromoblastomycosis

We report the case of an alternative treatment for a patient with a severe form of chromoblastomycosis that responded poorly to the traditional antifungal therapy. We hereby show, in this study, the improvement of lesions after treatment with itraconazole associated with an intramuscular administration of glucan. We observed that the regression of lesions was associated with an improvement of the cellular immune response. This favourable response that we observed suggests that the therapeutic regimen we used might be an option for the treatment of patients with a severe form of chromoblastomycosis.

Biochemical and biopharmaceutical properties of PEGylated uricase

PEGylation is a successful strategy for improving the biochemical and biopharmaceutical properties of proteins and peptides through the covalent attachment of polyethylene glycol chains. In this work, purified recombinant uricase from Candida sp. (UC-r) was modified by PEGylation with metoxypolyethilenoglycol-p-nitrophenyl-carbonate (mPEG-pNP) and metoxypolyethyleneglycol-4,6-dichloro-s-triazine (mPEG-CN). The UC-r-mPEG-pNP and UC-r-mPEG-CN conjugates retained 87% and 75% enzyme activity respectively. The K(M) values obtained 2.7 x 10(-5) M (mPEG-pNP) or 3.0 x 10(-5) M (mPEG-CN) lot the conjugates as compared to 5.4 x 10(-5) M for the native UC-r, suggesting enhancement in the substrate affinity of the enzyme attached. The effects of pH and temperature on PEGylated UC-r indicated that the conjugates were more active at close physiological pH and were stable up to 70 degrees C. Spectroscopic study performed by circular dichroism at 20 degrees C and 50 degrees C did not show any relevant difference in protein structure between native and PEGylated UC-r. In rabbit and Balb/c mice, the native UC-r elicited an intense immune response being highly immunogenic. On the other hand, the PEGylated UC-r when injected chronically in mice did not induce any detectable antibody response. This indicates sufficient reduction of the immunogenicity this enzyme by mPEG-pNP or mPEG-CN conjugation, making it suitable for a possible therapeutical use. (C) 2009 Elsevier B.V. All rights reserved.

Immunogenicity of a Whole-Cell Pertussis Vaccine with Low Lipopolysaccharide Content in Infants

The lack of a clear correlation between the levels of antibody to pertussis antigens and protection against disease lends credence to the possibility that cell-mediated immunity provides primary protection against disease. This phase I comparative trial had the aim of comparing the in vitro cellular immune response and anti-pertussis toxin (anti-PT) immunoglobulin G (IgG) titers induced by a cellular pertussis vaccine with low lipopolysaccharide (LPS) content (wP(low) vaccine) with those induced by the conventional whole-cell pertussis (wP) vaccine. A total of 234 infants were vaccinated at 2, 4, and 6 months with the conventional wP vaccine or the wP(low) vaccine. Proliferation of CD3(+) T cells was evaluated by flow cytometry after 6 days of peripheral blood mononuclear cell culture with stimulation with heat-killed Bordetella pertussis or phytohemagglutinin (PHA). CD3(+), CD4(+), CD8(+), and T-cell receptor gamma delta-positive (gamma delta(+)) cells were identified in the gate of blast lymphocytes. Gamma interferon, tumor necrosis factor alpha, interleukin-4 (IL-4), and IL-10 levels in super-natants and serum anti-PT IgG levels were determined using enzyme-linked immunosorbent assay (ELISA). The net percentage of CD3(+) blasts in cultures with B. pertussis in the group vaccinated with wP was higher than that in the group vaccinated with the wP(low) vaccine (medians of 6.2% for the wP vaccine and 3.9% for the wP(low) vaccine; P = 0.029). The frequencies of proliferating CD4(+), CD8(+), and gamma delta(+) cells, cytokine concentrations in supernatants, and the geometric mean titers of anti-PT IgG were similar for the two vaccination groups. There was a significant difference between the T-cell subpopulations for B. pertussis and PHA cultures, with a higher percentage of gamma delta(+) cells in the B. pertussis cultures (P < 0.001). The overall data did suggest that wP vaccination resulted in modestly better specific CD3(+) cell proliferation, and gamma delta(+) cell expansions were similar with the two vaccines.

Human Airway Epithelial Cell Responses to Neisseria lactamica and Purified Porin via Toll-Like Receptor 2-Dependent Signaling

The human airway epithelium is constantly exposed to microbial products from colonizing organisms. Regulation of Toll-like receptor (TLR) expression and specific interactions with bacterial ligands is thought to mitigate exacerbation of inflammatory processes induced by the commensal flora in these cells. The genus Neisseria comprises pathogenic and commensal organisms that colonize the human nasopharynx. Neisseria lactamica is not associated with disease, but N. meningitidis occasionally invades the host, causing meningococcal disease and septicemia. Upon colonization of the airway epithelium, specific host cell receptors interact with numerous Neisseria components, including the PorB porin, at the immediate bacterial-host cell interface. This major outer membrane protein is expressed by all Neisseria strains, regardless of pathogenicity, but its amino acid sequence varies among strains, particularly in the surface-exposed regions. The interaction of Neisseria PorB with TLR2 is essential for driving TLR2/TLR1-dependent cellular responses and is thought to occur via the porin`s surface-exposed loop regions. Our studies show that N. lactamica PorB is a TLR2 ligand but its binding specificity for TLR2 is different from that of meningococcal PorB. Furthermore, N. lactamica PorB is a poor inducer of proinflammatory mediators and of TLR2 expression in human airway epithelial cells. These effects are reproduced by whole N. lactamica organisms. Since the responsiveness of human airway epithelial cells to colonizing bacteria is in part regulated via TLR2 expression and signaling, commensal organisms such as N. lactamica would benefit from expressing a product that induces low TLR2-dependent local inflammation, likely delaying or avoiding clearance by the host.

The Paracoccidioides brasiliensis gp70 antigen is encoded by a putative member of the flavoproteins monooxygenase family

Glycoprotein gp70 is an important intracellular antigen from Paracoccidioides brasillensis that elicits both humoral and cellular immune responses. Herein, the PbGP70 gene cloning from isolate Pb18 using internal peptide sequence information is reported. The deduced protein sequence bears two N-glycosylation sites, antigenic sites and two mouse T-cell epitopes. Anti-recombinant gp70 (rPbgp70) polyclonal antibodies reacted with a 70-kDa component in total cell extract of A brasiliensis, while MAbC5F11 and paracoccidioiclomycosis patients` sera recognized rPbgp70. Confocal microscopy with anti-rPbgp70 and MAbC5F11 showed intense staining and cytoplasmatic co-localization. The protein sequence belongs to the flavoprotein monooxygenase family which groups important anti-oxidative bioactive compounds. We found increased PbGP70 transcript accumulation under oxidative stress induced by H(2)O(2), during fungal growth and in macrophage phagocyted/bound yeasts. Therefore, gp70 might play a dual role in P. brasiliensis by both eliciting immune cellular and humoral responses in the host and protecting the fungus from oxidative stress generated by phagocytic cells. (c) 2009 Elsevier Inc. All rights reserved.

DNAhsp65 vaccination induces protection in mice against Paracoccidioides brasiliensis infection

Heat-shock proteins are Molecules with extensive data showing their potential as immunomodulators of different types of diseases, The gene of HSP65 from Mycobacterium leprae has shown prophylactic and immunotherapeutic effects against a broad arrays of experimental models including tuberculosis, leishmaniasis, arthritis and diabetes. With this in mind, we tested the DNAhsp65 vaccine using an experimental model of Paraccocidiodomycosis, an important endemic mycosis in Latin America. The intramuscular immunization with DNAhsp65 induced, in BALB/c mice, an increase of Th1-levels cytokines and a reduction of fungal burdens resulted in a marked reduction of collagen and lung remodeling. DNAhsp65 may be an attractive candidate for prevention, therapy and as an adjuvant for mycosis treatment. (C) 2008 Elsevier Ltd. All rights reserved.

Leukotrienes Are Potent Adjuvant during Fungal Infection: Effects on Memory T Cells

Leukotrienes (LTs) are potent lipid mediators involved in the control of host defense. LTB(4) induces leukocyte accumulation, enhances phagocytosis and bacterial clearance, and increases NO synthesis. LTB(4) is also important in early effector T cell recruitment that is mediated by LTB(4) receptor 1, the high-affinity receptor for LTB(4). The aims of this study were to evaluate whether LTs are involved in the secondary immune response to vaccination in a murine model of Histoplasma capsulatum infection. Our results demonstrate that protection of wild-type mice immunized with cell-free Ags from H. capsulatum against histoplasmosis was associated with increased LTB(4) and IFN-gamma production as well as recruitment of memory T cells into the lungs. In contrast, cell-free Ag-immunized mice lacking 5-lipoxygenase(-/-), a critical enzyme involved in LT synthesis, displayed a marked decrease on recruitment of memory T cells to the lungs associated with increased synthesis of TGF-beta as well as IL-10. Strikingly, these effects were associated with increased mortality to 5-lipoxygenase(-/-)-infected mice. These data establish an important immunomodulatory role of LTs, in both the primary and secondary immune responses to histoplasmosis. The Journal of Immunology, 2008,181: 8544-8551.

Trypanosoma cruzi: Orchiectomy and dehydroepiandrosterone therapy in infected rats

The ability of gonadal hormones to influence and induce diverse immunological functions during the course of a number of parasitic infections has been extensively studied in the latest decades. Dehydroepiandrosterone and its sulfate are the most abundant steroid hormones secreted by the human adrenal cortex and are considered potent immune-activators. The effects of orchiectomy on the course of Trypanosoma cruzi infection in rats, treated and untreated with DHEA were examined, by comparing blood and cardiac parasitism, macrophage numbers, nitric oxide and IFN-gamma levels. Orchiectomy enhanced resistance against infection with elevated numbers of macrophages, enhanced concentrations of NO and IFN-gamma and reduced amastigote burdens in heart when compared to control animals. DHEA replacement exerted a synergistic effect, up-modulating the immune response. Male sex steroids appear to play fundamental role in determining the outcome of disease, through the regulation and modulation of the activity of the immune response. (C) 2008 Elsevier Inc. All rights reserved.