Toxocara canis extract fractions promote mainly the production of Th1 and regulatory cytokines by human leukocytes in vitro.

Helminths possibly down-modulate immune responses to airborne allergens through the induction of a regulatory network. The identification of helminths bioactive molecules is highly desirable, given their immunomodulatory potential which could be used in immunotherapies for allergy and autoimmune diseases. To investigate the immunoregulatory potential of the adult Toxocara canis crude extract and ten protein fractions of its extract, human peripheral blood mononuclear cells (PBMC) from 10 allergic and 9 non-allergic individuals were cultivated, in vitro, in the presence or absence of these antigens, and their supernatants were evaluated for cytokine production (TGF-β, IL-10, IL-12, TNF-α, IL-6, IL-5, IL13, and IL-17).

Recombinant proteins of helminths with immunoregulatory properties and their possible therapeutic use.

The inverse relationship between helminth infections and the development of immune-mediated diseases is a cornerstone of the hygiene hypothesis and studies were carried out to elucidate the mechanisms by which helminth-derived molecules can suppress immunological disorders. These studies have fostered the idea that parasitic worms may be used as a promising therapeutic alternative for prevention and treatment of immune-mediated diseases. We discuss the current approaches for identification of helminth proteins with potential immunoregulatory properties, including the strategies based on high-throughput technologies.

Candidin and trichophytin stimulate the production of Th1 and regulatory cytokines by peripheral blood mononuclear cells: implication for their use as adjuvants in immunotherapy.

Aim: This study's objective was to investigate whether candidin or trichophytin elicit recall immune responses that could potentially inhibit a Th2 response.

Materials & Methods: Peripheral blood mononuclear cells from nine allergic and seven nonallergic individuals were cultivated in vitro in the presence or absence of these fungal extracts.

Results: Trichophytin or candidin, or both, stimulated the production of regulatory cytokines (TGF-β and/or IL-10), accompanied or not by stimulation of production of cytokines associated with the Th1 response (TNF-α, IL-12 and IFN-γ), but without stimulation of Th2 cytokines (IL-5 and IL-13) and IL-17, by peripheral blood mononuclear cells of most allergic and nonallergic individuals.