The immunosuppressive activity of<i>Ascaris suum</i>is due to high molecular weight components

Faquim-Mauro, Eliana L.; Macedo, Mahasti Sahihi de

doi:10.1046/j.1365-2249.1998.00723.x

Cited by 39 publications

(46 citation statements)

References 31 publications

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“…As shown here, this cytokine, which is induced in large amounts by PI components [12], is a major effector molecule in the down-regulation of MHC and costimulatory molecules in our model, because in the complete absence of IL-10 (IL-10-KO mice) the down-regulation simply did not occur. Furthermore, the Ag-presenting ability of DC was not impaired when these cells were obtained from IL-10-deficient mice immunized with OVA+PI, indicating that, in the absence of this cytokine, DC were functionally preserved from the suppressive effects of PI.…”

Section: Discussionmentioning

confidence: 55%

“…We have previously shown that Asc or PI have the same ability as a live infection to strongly suppress the immune response and to induce a typical Th2 response (with IL-4 and IL-10 secretion) which is responsible for the suppressive effect [10][11][12][13][14]. Concerning the mechanisms involved in this effect, we investigated in this work the hypothesis that PI components could act in the inductive phase of the immune response, modulating the Ag presentation process by APC, and consequently T cell activation and proliferation.…”

Section: Discussionmentioning

confidence: 99%

“…Role of IL-10 in the inhibitory effect of PI Since IL-10 plays a major role in the suppression of immune responses inhibiting the Ag-presenting capacity of APC [23,24], and we had previously observed that PI induces large amounts of this cytokine [12], we investigated whether the observed inhibitory effect of PI was IL-10-mediated. To this end, groups of WT and IL-10 -/-C57BL/6 mice were immunized as described before with OVA or OVA+PI.…”

Section: Kinetics Of Mhc Class II Cd80 Cd86 and Cd40 Expression On mentioning

confidence: 99%

“…We have previously shown that an Ascaris suum extract (Asc) from adult worms, as well as its highmolecular-weight components (PI) obtained by gel filtration, inhibit the Th1-and Th2-related immune responses induced by immunization of mice with an unrelated Ag, OVA, such as delayed-type hypersensitivity reactions, antibody production, in vitro lymphoproliferative responses and cytokine secretion induced by in vitro stimulation with Ag or mitogen [11,12]. More recently, it was demonstrated that Asc also suppresses experimental allergic asthma in mice [13].…”

Section: Introductionmentioning

confidence: 99%

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Immunosuppressive components of Ascaris suum down‐regulate expression of costimulatory molecules and function of antigen‐presenting cells via an IL‐10‐mediated mechanism

et al. 2006

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High-molecular-weight components (PI) of Ascaris suum suppress both cell-mediated and humoral responses against ovalbumin (OVA) via an IL-4/IL-10-dependent mechanism. The aim of this work was to investigate the effect of PI on the ability of APC to activate T cells and the role of IL-10 in this process. Flow cytometry analyses of MHC class II, CD80, CD86 and CD40 molecules on LN cells from mice immunized with OVA or OVA+PI showed that PI inhibits expression of these molecules on unfractionated cells and on purified CD11c + cells. A low proliferative response was obtained when OVA-specific TCR-Tg T cells were incubated with CD11c + cells from OVA+PI-immunized mice pulsed with OVA, when compared to those incubated with cells from OVAimmunized mice. Similar results were obtained using as APC CD11c + cells from OVAimmunized mice pulsed with OVA+PI, which also expressed less of the four markers. The inhibitory effect of PI on both the expression of costimulatory molecules and the induction of T cell proliferation was abolished in IL-10-deficient mice. Our data indicate that the potent immunosuppressive effect of A. suum extract components on the host immune system is primarily related to their property of down-regulating the Agpresenting ability of DC via an IL-10-mediated mechanism.

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Section: Discussionmentioning

confidence: 55%

Section: Discussionmentioning

confidence: 99%

Section: Kinetics Of Mhc Class II Cd80 Cd86 and Cd40 Expression On mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Immunosuppressive components of Ascaris suum down‐regulate expression of costimulatory molecules and function of antigen‐presenting cells via an IL‐10‐mediated mechanism

et al. 2006

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“…With regard to the nematode Ascaris suum, the regulatory mechanisms induced by its immunosuppressive components have been the focus of our studies for some time. These components correspond to the high molecular weight fraction, eluted in the first peak (PI), after gel filtration chromatography of the adult Ascaris suum body extract 5 . In mice, when PI was combined with ovalbumin (OVA) and adjuvant, both OVA-specific Th1 and Th2 immune responses were found to be impaired (lymphoproliferation, delayed-type hypersensitivity (DTH) reactions, IgG2a/IgG1/IgE and IL-2/ IFN-γ/IL-4/IL-10 production) 5 .…”

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confidence: 99%

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice

Souza

Macedo

2009

Rev. Soc. Bras. Med. Trop.

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High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbuminspecific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils. Key-words:Ascaris suum. Delayed-type hypersensitivity. Immunosuppression. IFN-γ-deficient mice. Neutrophil. RESUMOComponentes de alto peso molecular do extrato de Ascaris suum suprimem a imunidade específica à ovalbumina em camundongos. Em camundongos geneticamente deficientes de IFN-γ a reação de hipersensibilidade tardia específica para ovalbumina foi mais fortemente prejudicada por estes componentes supressivos. Aqui, a celularidade da reação de hipersensibilidade tardia em camundongos deficientes de IFN-γe o incremento na supressão induzida por componentes do Ascaris suum foram analisados. Influxo neutrofílico, dependente de IL-12p40, foi predominante. Dose subótima da fração supressiva do nematódeo inibiu completamente a reação de hipersensibilidade, indicando uma intensificação da imunossupressão em condições de recrutamento intenso de neutrófilos independente de IFN-γ.  Palavras-chaves: Ascaris suum. Hipersensibilidade tardia. Imunossupressão. Camundongos deficientes em IFN-γ. Neutrófilos.

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Gastrointestinal nematodes, trace elements, and immunity

Koski

Scott

2003

J Trace Elements Exper Med

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The exploration of the scientific literature on the interrelationship among trace elements, gastrointestinal nematodes, and their requisite Th2 immunity demonstrates extensive literature but regrettably, research remains inadequate and sparse, with far fewer studies having investigated the interrelationship among trace elements and host immunity in infected hosts. Gastrointestinal nematodes, such as hookworms, Ascaris lumbricoides, and Trichuris trichiura, require activation of the Th2 arm of the immune cascade and the expression of the Th2 cytokines (interleukin‐4, interleukin‐5, and interleukin‐10) and their effectors for worm expulsion. However, parasites have evolved a series of strategies to invade the host and to evade host defense mechanisms. Many of these mechanisms involve metalloproteinases for tissue invasion and enzymes, such as catalase and superoxide dismutase, to minimize free radical damage to the parasitic tissues from the host's immune system. Deficiencies of iron, molybdenum, copper, and zinc, have been associated with higher worm burdens, as have excessive intakes of molybdenum, iron, and copper. The possibility is emerging that there may be an optimum trace element level in the diet above which and below which the parasite is advantaged. Moreover, there is some data to suggest that specific trace elements may be directly toxic to the parasite. J. Trace Elem. Exp. Med. 16: 237–251, 2003. © 2003 Wiley‐Liss, Inc.

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The immunosuppressive activity ofAscaris suumis due to high molecular weight components

Cited by 39 publications

References 31 publications

Immunosuppressive components of Ascaris suum down‐regulate expression of costimulatory molecules and function of antigen‐presenting cells via an IL‐10‐mediated mechanism

Immunosuppressive components of Ascaris suum down‐regulate expression of costimulatory molecules and function of antigen‐presenting cells via an IL‐10‐mediated mechanism

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice

Gastrointestinal nematodes, trace elements, and immunity

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