169 research outputs found

    Survey on the control methods of Bactrocera oleae (Gmelin) in organic olive groves producing oil and table olives in Sicily

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    In Sicily there are several organic farms producing olive oil and the number of farms has grown in the last years. The control methods of Bactrocera oleae (Gmelin) used by Sicilian organic farms were surveyed in 2004 and 2005. After a bibliographic search on internet and by personal contacts, a sample of 30 organic farms in Sicily was chosen; 23 farms produce bottled extra-virgin oil and 7 produce table olives. Then farms were contacted by phone, some of them visited and olive growers were interviewed. For each farm were put together data about: interventions vs. the olive fruit fly, altitude, surface of the olive grove, olive cultivar, irrigation method, harvesting period, milling procedure, product destination and production results in 2005 and in the previous years. From collected data we can say that obtaining oils of excellent quality and table olives of good quality in organic farming is surely possible; the early harvesting and a quick milling (for the oil) let to obtain good results. The most used interventions are: mass trapping with ammonium carbonate, pheromone and pyrethroids, bottled-traps baited with sardines, yellow sticky traps, sprays with kaolin, Bordeaux mixture or pyrethrum, but there is more than one third of sampled oil producers not using any control method except early harvesting and a quick milling. Unfortunately the organic farms producing table olives in Sicily are very few, perhaps because, differently from olive oil producers, table olive plantings are almost all young and the experience of growers in such organic cultivation is not strong. Also these growers prefer to use mass trapping to control olive fruit fly, but best results were achieved by farmers spraying kaolin, rotenone or copper hydroxide

    Tests on the effectiveness of mass trapping by Eco-trap (Vioryl) in the control of Bactrocera oleae (Gmelin)

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    Tests on the effectiveness of mass trapping by Eco-trap (Vyoril) in the control of Bactrocera oleae (Gmelin) in organic farming were carried out in 2003 and 2004. The tests took place into two organic olive groves located in Agrigento and Trapani (Sicily); in both years the olive cultivar was Cerasuola. In Agrigento, it was considered the effectiveness of Eco-trap vs. bottle traps baited with diammonium phosphate; while in Trapani the effectiveness of Eco-trap added to other products admitted in organic farming (two products containing kaolin and one containing copper) was evaluated. In 2003, year with a low B. oleae population density, no statistically significant difference resulted among Eco-trap, bottle traps with diammonium phosphate and control. In 2004 B. oleae infestations were high; although some statistically significant differences among plots with Eco-traps and plots without them emerged, the additional power of Eco-trap in controlling B. oleae resulted very limited in plots sprayed with kaolin products and more consistent in the plot with copper hydroxide. The economic advantage of the use of Eco-trap, also in comparison with repellent and antiovipositional products, still remains doubtful

    Human CD25+CD4+ T Suppressor Cell Clones Produce Transforming Growth Factor β, but not Interleukin 10, and Are Distinct from Type 1 T Regulatory Cells

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    T regulatory (Tr) cells are essential for the induction of peripheral tolerance. Several types of Tr cells exist, including CD4+ T cells which express CD25 constitutively and suppress immune responses via direct cell-to-cell interactions, and type 1 T regulatory (Tr1) cells, which function via secretion of interleukin (IL)-10 and transforming growth factor (TGF)-β. The relationship between CD25+CD4+ T cells and Tr1 cells remains unclear. Here, we demonstrate at the clonal level that Tr1 and CD25+CD4+ T cells are two distinct subsets of regulatory cells with different cytokine production profiles. Furthermore, CD25−CD4+ T cells can be rendered anergic by IL-10 and differentiated into Tr1 cells in the absence of CD25+CD4+ T cells. Cloned human CD25+CD4+ T cell populations are heterogeneous and only a subset of clones continues to express high levels of CD25 and is suppressive. The intensity of CD25, cytotoxic T lymphocyte antigen (CTLA)-4, and glucocorticoid-induced tumor necrosis factor (TNF) receptor expression correlates with the suppressive capacity of the T cell clones. None of the CD25+CD4+ T cell clones with suppressive function produce IL-10, but all produce TGF-β. Suppression mediated by CD25+CD4+ T cell clones is partially dependent on TGF-β, but not on constitutive high expression of CD25. Together these data indicate that naturally occurring human CD25+CD4+ T cells are distinct from IL-10–producing Tr1 cells

    Co-Graft of Allogeneic Immune Regulatory Neural Stem Cells (NPC) and Pancreatic Islets Mediates Tolerance, while Inducing NPC-Derived Tumors in Mice

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    Data available on the immunomodulatory properties of neural stem/precursor cells (NPC) support their possible use as modulators for immune-mediated process. The aim of this study was to define whether NPC administered in combination with pancreatic islets prevents rejection in a fully mismatched allograft model.Diabetic Balb/c mice were co-transplanted under the kidney capsule with pancreatic islets and GFP(+) NPC from fully mismatched C57BL/6 mice. The following 4 groups of recipients were used: mice receiving islets alone; mice receiving islets alone and treated with standard immunosuppression (IL-2Ralpha chain mAbs + FK506 + Rapamycin); mice receiving a mixed islet/NPC graft under the same kidney capsule (Co-NPC-Tx); mice receiving the islet graft under the left kidney capsule and the NPC graft under the right kidney capsule (NPC-Tx). Our results demonstrate that only the co-transplantation and co-localization of NPC and islets (Co-NPC-Tx) induce stable long-term graft function in the absence of immunosuppression. This condition is associated with an expansion of CD4(+)CD25(+)FoxP3(+) T regulatory cells in the spleen. Unfortunately, stable graft function was accompanied by constant and reproducible development of NPC-derived cancer mainly sustained by insulin secretion.These data demonstrate that the use of NPC in combination with islets prevents graft rejection in a fully mismatched model. However, the development of NPC-derived cancer raises serious doubts about the safety of using adult stem cells in combination with insulin-producing cells outside the original microenvironment

    WASP regulates suppressor activity of human and murine CD4+CD25+FOXP3+ natural regulatory T cells

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    A large proportion of Wiskott-Aldrich syndrome (WAS) patients develop autoimmunity and allergy. CD4+CD25+FOXP3+ natural regulatory T (nTreg) cells play a key role in peripheral tolerance to prevent immune responses to self-antigens and allergens. Therefore, we investigated the effect of WAS protein (WASP) deficiency on the distribution and suppressor function of nTreg cells. In WAS−/− mice, the steady-state distribution and phenotype of nTreg cells in the thymus and spleen were normal. However, WAS−/− nTreg cells engrafted poorly in immunized mice, indicating perturbed homeostasis. Moreover, WAS−/− nTreg cells failed to proliferate and to produce transforming growth factor β upon T cell receptor (TCR)/CD28 triggering. WASP-dependent F-actin polarization to the site of TCR triggering might not be involved in WAS−/− nTreg cell defects because this process was also inefficient in wild-type (WT) nTreg cells. Compared with WT nTreg cells, WAS−/− nTreg cells showed reduced in vitro suppressor activity on both WT and WAS−/− effector T cells. Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4+ effector T cells in vitro. Thus, WASP appears to play an important role in the activation and suppressor function of nTreg cells, and a dysfunction or incorrect localization of nTreg cells may contribute to the development of autoimmunity in WAS patients

    Rapamycin Combined with Anti-CD45RB mAb and IL-10 or with G-CSF Induces Tolerance in a Stringent Mouse Model of Islet Transplantation

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    Background: A large pool of preexisting alloreactive effector T cells can cause allogeneic graft rejection following transplantation. However, it is possible to induce transplant tolerance by altering the balance between effector and regulatory T (Treg) cells. Among the various Treg-cell types, Foxp3 +Treg and IL-10-producing T regulatory type 1 (Tr1) cells have frequently been associated with tolerance following transplantation in both mice and humans. Previously, we demonstrated that rapamycin+IL-10 promotes Tr1-cell-associated tolerance in Balb/c mice transplanted with C57BL/6 pancreatic islets. However, this same treatment was unsuccessful in C57BL/6 mice transplanted with Balb/c islets (classified as a stringent transplant model). We accordingly designed a protocol that would be effective in the latter transplant model by simultaneously depleting effector T cells and fostering production of Treg cells. We additionally developed and tested a clinically translatable protocol that used no depleting agent. Methodology/Principal Findings: Diabetic C57BL/6 mice were transplanted with Balb/c pancreatic islets. Recipient mice transiently treated with anti-CD45RB mAb+rapamycin+IL-10 developed antigen-specific tolerance. During treatment, Foxp3 +Treg cells were momentarily enriched in the blood, followed by accumulation in the graft and draining lymph node, whereas CD4 +IL-10 +IL-4 - T (i.e., Tr1) cells localized in the spleen. In long-term tolerant mice, only CD4 +IL-10 +IL-4 - T cells remained enriched in the spleen and IL-10 was key in the maintenance of tolerance. Alternatively, recipient mice were treated with two compounds routinely used in the clinic (namely, rapamycin and G-CSF); this drug combination promoted tolerance associated with CD4 +IL-10 +IL-4 - T cells. Conclusions/Significance: The anti-CD45RB mAb+rapamycin+IL-10 combined protocol promotes a state of tolerance that is IL-10 dependent. Moreover, the combination of rapamycin+G-CSF induces tolerance and such treatment could be readily translatable into the clinic. © 2011 Gagliani et al

    IL-10 Receptor Signaling Is Essential for T R 1 Cell Function In Vivo

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    Interleukin-10 (IL-10) is essential to maintain intestinal homeostasis. CD4+ T regulatory type 1 (TR1) cells produce large amounts of this cytokine and being therefore currently examined in clinical trials as T-cell therapy in patients with inflammatory bowel disease (IBD). However, factors and molecular signals sustaining TR1 cell regulatory activity still need to be identified in order to optimize the efficiency and to ensure the safety of these trials. We investigated the role of IL-10 signaling in mature TR1 cells in vivo

    Cytotoxic and regulatory roles of mucosal-associated invariant T cells in type 1 diabetes

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    Type 1 diabetes (T1D) is an autoimmune disease that results from the destruction of pancreatic β-cells by the immune system that involves innate and adaptive immune cells. Mucosal-associated invariant T cells (MAIT cells) are innate-like T-cells that recognize derivatives of precursors of bacterial riboflavin presented by the major histocompatibility complex (MHC) class I–related molecule MR1. Since T1D is associated with modification of the gut microbiota, we investigated MAIT cells in this pathology. In patients with T1D and mice of the non-obese diabetic (NOD) strain, we detected alterations in MAIT cells, including increased production of granzyme B, which occurred before the onset of diabetes. Analysis of NOD mice that were deficient in MR1, and therefore lacked MAIT cells, revealed a loss of gut integrity and increased anti-islet responses associated with exacerbated diabetes. Together our data highlight the role of MAIT cells in the maintenance of gut integrity and the control of anti-islet autoimmune responses. Monitoring of MAIT cells might represent a new biomarker of T1D, while manipulation of these cells might open new therapeutic strategies
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