Lemongrass and citral effect on cytokines production by murine macrophages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunomodulatory effects of tick saliva

Ticks are bloodsucking ectoparasites that cause great damage to host organisms, so these ectoparasites are of great importance in medicine and veterinary medicine. All the biological success achieved by ticks is due to the action of bioactive components present in their saliva, which are synthesized by the salivary glands. These components have great diversity of functions such as enabling feeding and the permanence of ectoparasites on hosts, since they modulate immune system acting as complement inhibitors, immunosuppressors, cytokine expression modulator and chemokine binders of hosts. In addition, these components are an important source of protective antigens. In this sense, salivary glands/saliva are considered a potential source of multifunctional molecules. In this context, many studies have been conducted aiming at searching to establish a better understanding on the biology and morphophysiology of some organs such as salivary glands, as well as elucidate the complex relationship of these ectoparasites with their hosts. Such studies are conducted with the main objective of developing new immunobiological products aimed at the alternative control of ticks, as well as for the identification and isolation of bioactive molecules with pharmacological properties and with great therapeutic potential in the search for treatments for some diseases.

Isolation and characterization of Wharton's jelly-derived multipotent mesenchymal stromal cells obtained from bovine umbilical cord and maintained in a defined serum-free three-dimensional system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

AVALIACAO DA REACAO DE MITSUDA EM PACIENTES VIRCHOVIANOS INATIVOS ANTES E APOS IMUNOTERAPIA

In this study the immunopotentiator levamisole as well as a mixture of BCG/Mycobacterium leprae were investigated in inactive lepromatous leprosy patients by using the Mitsuda reaction as a parameter. Twenty lepromatous patients ten years ago classified as histologically negative for Mitsuda's test were divided into three groups: five patients that were only retested with Mitsuda antigen; eight patients that received oral levamisol and seven patients that received a mixture of alive BCG plus autoclaved M. leprae. The results indicated that: 1) the levamisole did not alter the reactivity to lepromin in any of the patients studied; 2) neither the changes in the reactivity to lepromin by using the mixture (3 cases) nor those that occurred spontaneously (3 cases) were clear. They properly reflected the natural variation of patients with some degree of resistance to Mycobacterium leprae.

IL-12 and neutralization of endogenous IL-10 revert the in vitro antigen-specific cellular immunosuppression of paracoccidioidomycosis patients

Treatment of patients with paracoccidioidomycosis is still a challenge. Patients present defective lymphoproliferation and IFN-γ responses to the main Paracoccidioides brasiliensis antigen (gp43), which correlates with disease severity. Here, we demonstrated that the patients show also a defective synthesis of interleukin (IL)-12. Therefore, we attempted to revert this immune disfunction by adding IL-12 and neutralizing anti-IL-10 antibody to gp-43-stimulated peripheral blood mononuclear cell cultures. Both treatments increased IFN-γ secretion to levels observed with healthy sensitized individuals, but affected proliferation only modestly. When combined, the treatments further increased IFN-γ synthesis and cell proliferation. The addition of suboptimal concentrations of IL-2 also further increased the IL-12-mediated secretion of IFN-γ. Interestingly, the immune modulation was mostly antigen-specific, since the responses to Candida albicans' antigen were not affected. These results suggest that appropriate immune intervention with cytokines and/or anti-cytokines may help in the treatment of PCM. © 2002 Elsevier Science Ltd. All rights reserved.

Papel das proteínas Yops de Yersinia pseudotuberculosis na ativação dos linfócitos B

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interação das enterotoxinas estafilocócicas com o sistema imune do hospedeiro

Staphylococcal enterotoxins are among the most common etiologic agents that cause food poisoning and, possibly, nonmenstrual toxic shock syndrome. These enterotoxins are also called superantigens because they are potent T cell and macrophages activators. The superantigens bind directly to the major histocompatibility complex class II molecules on antigen-presenting cells and stimulate T cells expressing specific Vβ elements in the cell receptors. Excessive production of cytokines by these cells and macrophages are responsible for the pathogenesis of food poisoning. These cytokine include tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-1, proinflamatory mediators with potent immunoenhancing effects; the nitric oxide (NO). It still has both effects citotoxic and regulatory roles in immune function.

Farming technology, biochemistry characterization, and protective effects of culinary-medicinal mushrooms Agaricus brasiliensis S. Wasser et al. and Lentinus edodes (Berk.) Singer: Five years of research in Brazil

The biotechnology, biochemical characterization, and protective effects of the himematsutake and shiitake mushrooms were studied for the Thematic Project, from 1998 to 2003. A new species, Agaricus Brasiliens is Wasser et al. (= A. blazei Murrill ss. Heinem.), was proposed for the cultivated lineages in Brazil. Interactions among lineages, substrates, casing layers, and fructification inductions (temperature alternations) significantly increased the productivity of A. brasiliensis in Brazil (from 40 g to 200 g of fresh mushroom kg -1 moist compost). However, pests and diseases (mainly Sciaridae flies and false truffle), drastically reduced the productivity of A. brasiliensis (below 50 g kg -1). Biochemically for each mushroom species, the polar extracts, no polars, and medium polarity presented the same organic substances; however, their concentrations differed as a result of the lineages, maturation of the fruit bodies, and cultivation conditions. In this aspect, concentration of linoleic acid in A. brasiliensis (added to animal food) was related directly to the chemical protection against carcinogenic drugs in mice. Aqueous extracts of Lentinus edodes (= Lentinula edodes (Berk.) Pegler) and A. brasiliensis may be preventive chemical protectors against mutagenic and carcinogenic drugs, depending on the lineage and extraction method (tea or juice). However, immunomodulator effects and tumor reduction were only observed with concentrated fractions (hexanic, methanolic, and ATF extracts). Aqueous extracts of A. brasiliensis and L. edodes have antibiotic-like substances and substances able to act as elicitors of resistance responses in some plants (local and systemic) and show a potential to be used in the alternative control of plant pathogens. © 2005 by Begell House, Inc.

Immunomodulatory activities associated with β-glucan derived from Saccharomyces cerevisiae

In this study we investigated the effect of β-glucan derived from Saccharomyces cerevisiae on fungicidal activity, cytokine production and natural killer activity. Spleen and peritoneal cells from female C57BL/6 mice, previously injected (24 or 48 h) with 20 or 100 μg of glucan by i.p. route, were assayed. In vivo β-glucan administration primed spleen cells for a higher production of IL-12 and TNF-α when S. aureus was used as a stimulus. In addition, β-glucan increased NK spleen cells activity against YAC target cells. Some immunomodulatory activities not yet described for β-glucan were observed in this work. © 2005 Institute of Physiology, Academy of Sciences of the Czech Republic.

Genetic vaccine for tuberculosis (pVAXhsp65) primes neonate mice for a strong immune response at the adult stage

Background: Vaccination of neonates is generally difficult due to the immaturity of the immune system and consequent higher susceptibility to tolerance induction. Genetic immunization has been described as an alternative to trigger a stronger immune response in neonates, including significant Th1 polarization. In this investigation we analysed the potential use of a genetic vaccine containing the heat shock protein (hsp65) from Mycobacterium leprae (pVAXhsp65) against tuberculosis (TB) in neonate mice. Aspects as antigen production, genomic integration and immunogenicity were evaluated. Methods: Hsp65 message and genomic integration were evaluated by RT-PCR and Southern blot, respectively. Immunogenicity of pVAXhsp65 alone or combined with BCG was analysed by specific induction of antibodies and cytokines, both quantified by ELISA. Results: This DNA vaccine was transcribed by muscular cells of neonate mice without integration into the cellular genome. Even though this vaccine was not strongly immunogenic when entirely administered (three doses) during early animal's life, it was not tolerogenic. In addition, pVAXhsp65 and BCG were equally able to prime newborn mice for a strong and mixed immune response (Th1 + Th2) to pVAXhsp65 boosters administered later, at the adult life. Conclusion: These results suggest that pVAXhsp65 can be safely used as a priming stimulus in neonate animals in prime-boost similar strategies to control TB. However, priming with BCG or pVAXhsp65, directed the ensuing immune response triggered by an heterologous or homologous booster, to a mixed Th1/Th2 pattern of response. Measures as introduction of IL-12 or GM-CSF genes in the vaccine construct or even IL-4 neutralization, are probably required to increase the priming towards Th1 polarization to ensure control of tuberculosis infection. © 2007 Pelizon et al; licensee BioMed Central Ltd.

DNA vaccine containing the mycobacterial hsp65 gene prevented insulitis in MLD-STZ diabetes

Background: Our group previously demonstrated that a DNA plasmid encoding the mycobacterial 65-kDa heat shock protein (DNA-HSP65) displayed prophylactic and therapeutic effect in a mice model for tuberculosis. This protection was attributed to induction of a strong cellular immunity against HSP65. As specific immunity to HSP60 family has been detected in arthritis, multiple sclerosis and diabetes, the vaccination procedure with DNA-HSP65 could induce a cross-reactive immune response that could trigger or worsen these autoimmune diseases. Methods: In this investigation was evaluated the effect of a previous vaccination with DNA-HSP65 on diabetes development induced by Streptozotocin (STZ). C57BL/6 mice received three vaccine doses or the corresponding empty vector and were then injected with multiple low doses of STZ. Results: DNA-HSP65 vaccination protected mice from STZ induced insulitis and this was associated with higher production of IL-10 in spleen and also in the islets. This protective effect was also concomitant with the appearance of a regulatory cell population in the spleen and a decreased infiltration of the islets by T CD8+ lymphocytes. The vector (DNAv) also determined immunomodulation but its protective effect against insulitis was very discrete. Conclusion: The data presented in this study encourages a further investigation in the regulatory potential of the DNA-HSP65 construct. Our findings have important implications for the development of new immune therapy strategies to combat autoimmune diseases. © 2009 Santos et al; licensee BioMed Central Ltd.

Immunostimulatory effects of the phenolic compounds from lichens on nitric oxide and hydrogen peroxide production

The effects of isolated compounds from Brazilian lichens and their derivatives on H 2O 2 and NO production were studied using murine macrophages as a part of an attempt to understand their possible immunomodulatory properties. The compound cytotoxicity was studied using MTT assay. Macrophage stimulation was evaluated by the determination of NO (Griess assay) and H 2O 2 (horseradish peroxidase/phenol red) in supernatants of peritoneal macrophage cultures of Swiss mice. This research demonstrated stimulatory activities of some phenolic compounds isolated from lichens and their derivatives on H 2O 2 and NO production. Structure-activity relationships suggest several synthetic directions for further improvement of immunological activity.

Female sex hormones mediate the allergic lung reaction by regulating the release of inflammatory mediators and the expression of lung E-selectin in rats

Background: Fluctuations of estradiol and progesterone levels caused by the menstrual cycle worsen asthma symptoms. Conflicting data are reported in literature regarding pro and anti-inflammatory properties of estradiol and progesterone.Methods: Female Wistar rats were ovalbumin (OVA) sensitized 1 day after resection of the ovaries (OVx). Control group consisted of sensitized-rats with intact ovaries (Sham-OVx). Allergic challenge was performed by aerosol (OVA 1%, 15 min) two weeks later. Twenty four hours after challenge, BAL, bone marrow and total blood cells were counted. Lung tissues were used as explants, for expontaneous cytokine secretion in vitro or for immunostaining of E-selectin.Results: We observed an exacerbated cell recruitment into the lungs of OVx rats, reduced blood leukocytes counting and increased the number of bone marrow cells. Estradiol-treated OVx allergic rats reduced, and those treated with progesterone increased, respectively, the number of cells in the BAL and bone marrow. Lungs of OVx allergic rats significantly increased the E-selectin expression, an effect prevented by estradiol but not by progesterone treatment. Systemically, estradiol treatment increased the number of peripheral blood leukocytes in OVx allergic rats when compared to non treated-OVx allergic rats. Cultured-BAL cells of OVx allergic rats released elevated amounts of LTB4 and nitrites while bone marrow cells increased the release of TNF-α and nitrites. Estradiol treatment of OVx allergic rats was associated with a decreased release of TNF-α, IL-10, LTB4 and nitrites by bone marrow cells incubates. In contrast, estradiol caused an increase in IL-10 and NO release by cultured-BAL cells. Progesterone significantly increased TNF- α by cultured BAL cells and bone marrow cells.Conclusions: Data presented here suggest that upon hormonal oscillations the immune sensitization might trigger an allergic lung inflammation whose phenotype is under control of estradiol. Our data could contribute to the understanding of the protective role of estradiol in some cases of asthma symptoms in fertile ans post-menopausal women clinically observed. © 2010 de Oliveira et al; licensee BioMed Central Ltd.

Evaluation of Agaricus blazei in vivo for antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities

The development of various types of cancer results from the interaction among endogenous, environmental and hormonal factors, where the most notable of these factors is diet. The aim of the present study was to determine the antigenotoxic, anticarcinogenic, phagocytic and immunomodulatory activities of Agaricus blazei. The test antigenotoxicity (Comet Assay) and anticarcinogenic (Test of Aberrant Crypt Foci) assess changes in DNA and/or intestinal mucosa that correlate to cancer development. Tests of phagocytosis in the spleen and differential count in blood cells allow the inference of modulation of the immune system as well as to propose a way of eliminating cells with DNA damage. Supplementation with the mushroom was carried out under pre-treatment, simultaneous treatment, post-treatment and pre-treatment. +. continuous conditions. Statistical analysis demonstrated that the mushroom did not have genotoxic activity but showed antigenotoxic activity. Supplementation caused an increase in the number of monocytes and in phagocytic activity, suggesting that supplementation increases a proliferation of monocytes, consequently increasing phagocytic capacity especially in the groups pre-treatment, simultaneous and pre-treatment. +. continuous. The data suggest that A. blazei could act as a functional food capable of promoting immunomodulation which can account for the destruction of cells with DNA alterations that correlate with the development of cancer, since this mushroom was demonstrated to have a preventive effect against pre-neoplastic colorectal lesions evaluated by the aberrant crypt foci assay. According to these results and the literature, it is believed that supplementation with A. blazei can be an efficient method for the prevention of cancer as well as possibly being an important coadjuvant treatment in chemotherapy. © 2011 Elsevier Inc.

Antitumor properties of Ganoderma lucidum polysaccharides and terpenoids

Ganoderma lucidum is an edible medicinal mushroom with immunomodulatory and antitumor properties, which are mainly attributed to polysaccharides and triterpenes that can be isolated from mycelia, fruiting bodies and spores. G. lucidum has been us d in a powdered form, as a medicinal beverage and a nutraceutical food (usually dried). In the present review we report some historical facts and the experimental evidence that polysaccharides and triterpenes obtained from this mushroom present potential antitumor activity. Direct effects on tumor cells include induction of apoptosis and interference in the cell cycle, whereas indirect effects are based on the modulation of immune response, usually impaired by cancer cells. Data indicate that G. lucidum can be used as a complementary tool for treatment of cancer patients. © by São Paulo State University.