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Disease Protection (disease + protection)
Selected AbstractsInnate immune responses induced by CpG oligodeoxyribonucleotide stimulation of ovine blood mononuclear cellsIMMUNOLOGY, Issue 2 2003Angelo Mena Summary Examples exist in the literature that demonstrate that treatment with immunostimulatory cytosine,phosphate,guanosine (CpG)-DNA can protect mice against infection by intracellular pathogens. There are, however, few studies reporting that CpG-DNA offers similar disease protection in other species. In this study, we assessed the potential of a class A and class B CpG oligodeoxynucleotide (ODN) to induce innate immune responses in sheep, an outbred species. Using peripheral blood mononuclear cells, we have for the first time demonstrated CpG-ODN-induced innate immune responses, including natural-killer-like activity [non-major histocompatibility complex (MHC)-restricted cytotoxicity], interferon-, secretion and 2,-5,A oligoadenylate synthetase activity, that could contribute to immune protection in sheep. The type and magnitude of these responses were dependent on ODN class and non-MHC-restricted killing was not associated with interferon-, production. The latter observation is in contrast with observations reported for mice and humans. These observations support the conclusion that differences in CpG-ODN-induced responses exist among species and that specific ODN sequences can significantly influence innate immune responses. [source] The Potential Use of a Silicon Source as a Component of an Ecological Management of Coffee PlantsJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2008J. C. Martinati Abstract Coffee is one of the most important agricultural export commodities in the world and it represents the main export from some developing countries. Therefore, the development of new methods of coffee management that improves production without causing any damage to the environment is an attractive alternative for producers. Much effort has been invested towards understanding the mode of action of compounds that can induce resistance against several pathogens without injuring the environment. Many researches have considered silicon efficient in avoiding plant pathogen penetration and development. Our aim was to verify the effect of potassium silicate and calcium/magnesium silicate in the development of coffee seedlings (Coffea arabica cv. Mundo Novo) as well as to evaluate the incidence of coffee leaf rust development under greenhouse conditions. The experiment was a completely randomized design with 12 treatments with 10 plants per treatment. The treatments were 0, 0.25, 1.25, 2.5, 4 and 5 ,m of Si for each source of silicon incorporated into the soil. The seedlings were inoculated with a urediniospores suspension of Hemileia vastatrix (2 mg/ml) at the seventh month after planting (six pair of leaves). Evaluations were performed by counting the number of lesions per leaf. The statistical analysis showed that the number of lesions reduced by up to 66% at the highest silicon dose when compared to the number of lesions in control plants. Infected plants were found to have a linear decrease of lesions with the increase of silicate concentration. The lowest number of lesions per leaf area was observed in plants that received 5 ,m of Si from potassium silicate. This result indicates the use of silicon as an alternative for an ecological management system for coffee disease protection. [source] Domains of group A streptococcal M protein that confer resistance to phagocytosis, opsonization and protection: implications for vaccine developmentMOLECULAR MICROBIOLOGY, Issue 1 2006Jason D. McArthur Summary Streptococcus pyogenes (group A streptococcus) colonizes skin and throat tissues resulting in a range of benign and serious human diseases. Opsonization and phagocytosis are important defence mechanisms employed by the host to destroy group A streptococci. Antisera against the cell-surface M protein, of which over 150 different types have been identified, are opsonic and contribute to disease protection. In this issue of Molecular Microbiology, Sandin and colleagues have comprehensively analysed the regions of M5 protein that contribute to phagocytosis resistance and opsonization. Human plasma proteins bound to M5 protein B- and C-repeats were shown to block opsonization, an observation that needs to be carefully considered for the development of M protein-derived vaccines. While safe and efficacious human group A streptococcal vaccines are not commercially available, candidate M protein-derived vaccines have shown promise in murine vaccine models and a recent phase 1 human clinical trial. [source] Effects of dietary prebiotics on the growth, feed efficiency and non-specific immunity of juvenile red drum Sciaenops ocellatus fed soybean-based dietsAQUACULTURE RESEARCH, Issue 3 2010J Alejandro Buentello Abstract Previous work has demonstrated several benefits of dietary prebiotics for fish. Here, we report the effects of added dietary fructooligosaccharide (FOS), mannanoligosaccharide (MOS), transgalactooligosaccharide (TOS) and GroBiotic® -A (GBA) on the weight gain, feed efficiency and non-specific immunity of juvenile red drum fed soybean meal (SBM)-based diets, in brackish water at 25 ± 1 °C. Test diets incorporated FOS, MOS, TOS or GBA at 10 g kg,1 in place of cellulose in a basal diet with 40% crude protein, half from SBM and half from fishmeal. After a 4-week feeding period, experimental fish were challenged by exposure to Amyloodinium ocellatum, after which growth and survival were monitored for 2 more weeks. Feed efficiency, serum lysozyme and intracellular superoxide anion production were significantly (P<0.05) enhanced by prebiotic supplementation. Likewise, survival after A. ocellatum exposure was significantly higher for fish fed GBA, MOS and TOS (87%, 84% and 78%) versus 58% for fish fed either the FOS or the basal diet. Taken together, these results indicate that inclusion of several prebiotics at 10 g kg,1 of the diet is adequate to improve the feed efficiency of red drum as well as to enhance disease protection. [source] Leishmania donovani infection down-regulates TLR2-stimulated IL-12p40 and activates IL-10 in cells of macrophage/monocytic lineage by modulating MAPK pathways through a contact-dependent mechanismCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2008Dinesh Chandra Summary The failure of Leishmania, an intracellular pathogen, to stimulate a pro-inflammatory response following entry into macrophages has been well reported. This occurs in spite of the fact that ligands for the toll-like receptors (TLR) have been recently shown on the parasite surface and their role in disease protection well documented. The outcome of infection in leishmaniasis is determined by the Th1 versus Th2 nature of the effector response and the generation of IL-12 and IL-10 by the infected macrophages is important for this decision. We evaluated the effect of L. donovani infection of monocytes (cell line THP-1, and monocytes derived from human peripheral blood) on Pam3cys (TLR2 ligand) and lipopolysaccharide (TLR4 ligand) stimulated production of IL-12p40 and IL-10. L. donovani infection caused suppression of TLR2 and TLR4-stimulated IL-12p40, with an increase in IL-10 production. Parasites also modulated the TLR2-stimulated mitogen-activated protein kinase (MAPK) pathway by suppressing MAPK P38 phosphorylation and activating extracellular regulated kinase (ERK)1/2 phosphorylation. These effects could be reversed either by using a MAPK P38 activator, anisomycin, or ERK1/2 inhibitor, U0126. L. donovani caused modulation of TLR2-stimulated MAPK pathways in a contact-dependent mechanism. In addition parasite structural integrity but not viability was required for suppression of TLR2-stimulated IL-12p40 and activation of IL-10. These observations suggest that L. donovani has evolved survival strategies that subvert the pro-inflammatory response generated through TLRs. [source] | |||||||||||||