concanavalin-a and Ascariasis

Adult worm extract from Ascaris suum (Asc) has immunosuppressive activity and elicits Th2/IL-4/IL-10 response. This study evaluated the prophylactic and therapeutic effect of Asc in a murine model of concanavalin A (ConA)-induced autoimmune hepatitis (AIH). BALB/c mice received ConA, iv, (20 mg/kg), and three groups of animals were formed: (1) AIH, received only ConA; (2) AIH + Asc prophylactic, treated with Asc (1 mg/ml), ip, 30 min before of the AIH; and (3) AIH + Asc therapeutic, treated with Asc 2 h after the AIH. Plasma transaminase and immunoglobulins (measured at 8 and 24 h and 7 days after treatment) and cytokine production (IL-4, IL-10, IL-13, and IFN-γ) by splenocytes upon ConA and Asc stimulus were compared. The livers were weighed and examined histologically. In the AIH group, there was an increase in liver weight, transaminase levels, and total immunoglobulins. These parameters were reduced by 8-24 h and 7 days in the prophylactic group, but in the therapeutic group, only on day 7. The survival rate of mice in the AIH group was 38.5%, compared to 67% in the therapeutic Asc group. The survival rate of the animals with AIH that were prophylactically treated with Asc was 100%. A decrease of cellular infiltration and high levels of IL-4, IL-10, and IL-13 were induced by Asc. An increase of liver fibrosis was also observed, but with less intensity with prophylactic treatment. Thus, the Ascaris components have an inhibitory effect on AIH, with an intense Th2 immune response.

Topics: Animals; Antigens, Helminth; Ascariasis; Ascaris suum; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Autoimmune; Immunomodulation; Interleukin-10; Interleukin-13; Interleukin-4; Mice; Mice, Inbred BALB C

The effect of Ascaris suum infection and treatment with fenbendazole on the blastogenic response of peripheral blood lymphocytes to A. suum antigens and to three phytomitogens was assayed by the lymphocyte transformation technique. Repeated infections with A. suum led to the development of sensitized lymphocytes primarily responding to egg hatching fluid antigen. Treatment with fenbendazole decreased the number of specific sensitized lymphocytes, but favorably increased the resistance of pigs to reinfection. Immunity to reinfection did not correlate with the strength of the blastogenic response to A. suum antigens. Repeated infection with A. suum negatively affected the development of the blastogenic response to phytomitogens in the pigs, leading to a partial depression of the responsiveness of lymphocytes and to the partial suppression by serum. Responses to pokeweed mitogen were affected more than the responses to concanavalin A and phytohemagglutinin.

Topics: Animals; Ascariasis; Concanavalin A; Female; Fenbendazole; Lectins; Lymphocyte Activation; Male; Phytohemagglutinins; Pokeweed Mitogens; Swine; Swine Diseases