transforming-growth-factor-beta and Ascariasis

Helminth infections have the ability to modulate host's immune response through mechanisms that allow the chronic persistence of the worms in the host. Here, we investigated the mechanisms involved on the suppressive effect of Ascaris suum infection using a murine experimental model of LPS-induced inflammation. We found that infection with A. suum markedly inhibited leucocyte influx induced by LPS into air pouches, suppressed secretion of pro-inflammatory cytokines (IL-1β, TNF-α and IL-6) and induced high levels of IL-10 and TGF-β. Augmented frequency of CD4

Topics: Adoptive Transfer; Animals; Ascariasis; Ascaris suum; CD4 Antigens; Cytokines; Female; Forkhead Transcription Factors; Inflammation; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Interleukin-6; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; T-Lymphocytes; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Toxoplasmosis and ascaridiasis evoke polar Th-1 and Th-2 host immune responses, respectively. A study to investigate the specific cytokine profile production by in vitro cultures of peripheral blood mononuclear cells from individuals living under precarious sanitary conditions in a highly endemic area for the parasites Toxoplasma gondii and Ascaris lumbricoides was conducted. High levels of both IFN-gamma (Th-1) and IL-13 (Th-2) were observed in groups of co-infected individuals presenting toxoplasmic ocular lesions. Significantly lower IL-10 and TGF-beta levels were produced by co-infected individuals in comparison with groups of individuals not infected with A. lumbricoides and either positive or negative for T. gondii living under good sanitary conditions (control groups). The possible influence of co-parasitism on the clinical presentation of ocular toxoplasmosis is discussed.

Topics: Adult; Animals; Ascariasis; Ascaris lumbricoides; Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Humans; Interferon-gamma; Interleukin-10; Interleukin-13; Leukocytes, Mononuclear; Male; Toxoplasma; Toxoplasmosis, Ocular; Transforming Growth Factor beta

Ascaris presence in humans has been associated with high levels of blood eosinophils and serum IgE. This study was designed to address the influence of Ascaris infection on allergic and inflammatory parameters of atopic subjects. A cross-sectional design was used, and atopic individuals to be assessed were divided into 3 groups including Ascaris-infected, anti-Ascaris IgG-positive (seropositive), and control subjects. All subjects enrolled had positive skin test reactivity to at least 1 perennial or seasonal allergen; however, levels of C-reactive protein, C3, and C4 were within normal range values. Eosinophil percentage was not significantly different among the groups studied. Total IgE and specific anti-Ascaris IgE levels in the seropositive group were significantly higher than concentrations found in both control and infected groups. Interleukin (IL)-4 release in Ascaris-infected patients was significantly increased versus seropositives, who were able to produce more IL-4 than controls. The levels of IL-10 were lower in the seropositives as well as infected subjects in comparison with controls. CD25(+) lymphocyte populations were significantly increased in the infected group versus the seropositives as well as the controls. Lung function tests of some selected seropositive subjects were significantly impaired. The same parameters of a representative infected patient were not different from controls. Our data on T helper type 2 cells (Th2) and regulatory T cells (Treg) features, as well as CD25(+) lymphocyte increase, suggest an Ascaris-induced mechanism leading to parasite survival. Moreover, the stable control of both T helper type 1 cells (Th1) and Th2 immunity cascades, paralleled by the absence of overwhelming inflammatory systemic reactions and lack of allergic syndromes, may result in a favorable host condition.

Topics: Aged; Analysis of Variance; Animals; Antibodies, Protozoan; Ascariasis; Ascaris lumbricoides; Cross-Sectional Studies; Eosinophils; Feces; Female; Humans; Hypersensitivity, Immediate; Immunoglobulin E; Interferon-gamma; Interleukin-2 Receptor alpha Subunit; Interleukins; Middle Aged; Respiratory Function Tests; Skin Tests; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha