Immune response of mice to Echinococcus multilocularis infection after therapy with amphotericin B colloidal dispersion

The effect of amphotericin B colloidal dispersion (ABCD) on selected immunological parameters and growth of the larval cysts in mice infected intraperitoneally with Echinococcus multilocularis protoscoleces was observed. ABCD was administered at a dose 10 mg/kg body weight twice a week from week 5 to 10 post infection (p.i.). The Echinococcus infection suppressed the proliferative response of splenic T lymphocytes to nonspecific mitogen concanavalin A throughout almost the whole course of the experiment and ABCD administration did not affect this inhibittion. The increase in the proliferative response of B lymphocytes to lipopolysaccharide was found in infected mice with ABCD treatment from week 6 to 10 p.i. ABCD induced a significant rise of the splenic CD4 T cell subpopulation in infected mice only on week 6 p.i. The CD8 T subpopulation was not influenced by the therapy. The level of serum Th1 cytokine IFN-γ in infected and ABCD treated mice was elevated only at week 8 p.i., while the level of serum Th2 cytokine IL-5 was not influenced by the therapy. The ABCD treatment inhibited the IFN-γ production by splenocytes in vitro from week 6 to 10 p.i. On the contrary, the IL-5 production in vitro was stimulated at weeks 8 and 12 p.i. None antiparasitic effect of ABCD on larval growth was determined.

Results suggest that amphotericin B colloidal dispersion did not affect the inhibited Th1 immune response after parasite infection. On the contrary, ABCD advanced the Th2 immune response development, which allows the progressive growth of the parasite.