Immunoglobulin and cytokine profile in murine secondary hydatidosis

We have investigated specific immune responses in BALB/c mice with experimentally induced secondary hydatidosis. Following intraperitoneal inoculation of brood capsules containing Echinococcus granulosus-protoscoleces, the course of the infection was followed for 513 days. The sera of the mice were screened for the presence of a number of cytokines, and for specific antibodies. During the first 129 days of infection, high levels of cytokines TNF alpha, IL-alpha, IFN gamma, IL-6, and IL-10 and specific IgG1 and IgG3 isotypes were detected, as compared to uninfected controls. The levels of IgM and IgG2a were slightly increased following infection, and remained elevated throughout the period of observation. The levels of IL-1 alpha and specific immunoglobulin of all isotypes except IgM and IgG2a, were significantly decreased 103 days post infection (p.i.), whereas TNF alpha was sharply decreased 129 days p.i. During the period of 129 to 209 days of infection there was an increase in secreted IL-10, and a slow decrease in the levels of IL-6 and IFN gamma. Levels of IgM, IgG, IgG1, and IgG2a plateaued during this period, whereas IgG3 and TNF alpha showed a peak at day 190 p.i. These data suggest the induction of Th2 antibody-mediated immunity with a parallel expansion of Th1-mediated inflammatory responses as important mechanism of host defence against the metacestode.