Neutralization of early pregnancy factor by passive immunization alters normal embryonic development and cytokine balance

Abstract

The aim of this study was to evaluate the effects of passive immunization with polyclonal anti-swine early pregnancy factor (EPF) antibody in pregnant rats during the pre-implantation period, and to analyse the regional distribution of EPF in placenta of rats. The immunodetection of EPF in rat placenta, as well as fertilization, development and immunological parameters, was evaluated. The average number of embryos and the embryo/corpora lutea ratio of rats treated with anti-EPF antibody were significantly lower than control groups. Also, as expected, the embryos showed a delay in their development. Furthermore, while IL-10 and INF- levels increased, serum and placental TGF- decreased significantly in the group treated with anti-EPF. EPF was presentin giant and decidual cells, as well as in blood vessels and trophoblastic lacuna cells, as demonstrated by positive immunostaining. This study provides new results on the function and location of EPF, and has demonstrated the usefulness of polyclonal anti-swine EPF antibody.