Influence of Echinococcus multilocularis infection on immune response of mice and their offspring

Parasitic infection during pregnancy represents a serious stress factor and affects the course of pregnancy and the foeto-maternal relationship. The infection may not clinically manifest itself, however it can modulate the immune response of the offspring for a long-time. The influence of secondary Echinococcus multilocularis infection on the proportion of CD4+ and CD8+ T cells and the level of anti-Echinococcus antibodies were studied in Balb/c mice. The female mice were infected with homogenised metacestode material containing 2000 E. multilocularis protoscoleces (Group 1, 2). Group 1 was fertilised on day 60 post infection, while Group 2 remained unfertilised. Group 3 was uninfected and fertilised on the same day as Group 1. The numbers of both T cell subpopulations were higher in non-pregnant than in pregnant mice. In late pregnancy, the decline of CD4+, however, the increase of CD8+ T-cell subtypes were observed in both, infected and uninfected mothers, respectively. The strong humoral response with the high production of IgM and IgG2b antibodies in infected mice was detected. In infected mothers, IgG2b level was higher than in infected nonpregnant mice during almost whole monitored period. In Group 1, delivery caused suppression of Th2 immune response, represented by IgG1, under the level observed in uninfected mothers. The findings show the changes in helper regulatory and cytotoxic immunity mechanisms of infected mothers. In offspring of infected mothers all IgG subclasses were detected, however specific IgM were not transmitted neither transplacentary, nor transmammary.