Extracts of Ascaris suum egg and adult worm share similar immunosuppressive properties.
Adult Ascaris suum body extract (Asc) prepared from male and female worms (with stored eggs) down-regulates the specific immune response of DBA/2 mice to ovalbumin (OA) and preferentially stimulates a Th2 response to its own components, which is responsible for the suppression of the OA-specific Th1 response. Here, we investigated the participation of soluble extracts prepared from male or female worms or from eggs (E-Asc) in these immunological events. Extracts from either sex (1 mg/animal) or E-Asc (0.35 or 1 mg protein/animal) suppressed the delayed-type hypersensitivity (DTH) reaction (60-85%), proliferative response (50-70%), IL-2 and IFN-gamma secretion (below detection threshold) and IgG1 antibody production (70-90%) of DBA/2 mice to OA. A dose of 0.1 mg E-Asc/animal did not change DTH or proliferation, but was as effective as 0.35 mg in suppressing IL-2 and IFN-gamma, and OA-specific IgG1 antibodies. Lymph node cells from DBA/2 mice injected with Asc (1 mg/animal) or a high dose of E-Asc (1 mg protein/animal) secreted IL-4 upon in vitro stimulation with concanavalin A. As previously demonstrated for Asc, the cytokine profile obtained with the E-Asc was dose dependent and changed towards Th1 when a low dose (0.1 mg protein/animal) was used. Taken together, these results suggest that adult worms of either sex and eggs induce the same type of T cell response and share similar immunosuppressive properties.
Souza
V M O
VM
Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brasil.
Faquim-Mauro
E L
EL
Macedo
M S
MS
D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology; D000947:Antigens, Helminth / Q000276:immunology; D017165:Ascaris suum / Q000276:immunology*; D005260:Female; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010047:Ovalbumin / Q000276:immunology*; D010063:Ovum / Q000737:chemistry; D014020:Tissue Extracts / Q000276:immunology
D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D014020:Tissue Extracts; D010047:Ovalbumin