The effect of Ureaplasma diversum activated mononuclear leukocytes on the development and interferon-tau production by bovine IVF-derived embryos

Ureaplasma diversum is an opportunistic pathogen of the bovine genital trac t causing herd outbreaks of granular vulvitis, abortion and infertility. Ea rly embryonic death probably contributes to reduction of the reproductive p erformance in cows, however, pathogenesis of the disease remains obscure. T he aim of the study was to examine whether activation of mononuclear leukoc ytes by U. diversum may affect embryo development and IFN-tau production. B ovine peripheral blood mononuclear leukocytes were cultured with U.diversum antigen for 24 h. The levels of IL-1, TNF-alpha, NO and GM-CSF in the cell culture supernatants were measured. IVF-derived embryos were cultured in t he presence of supernatants from activated leukocytes. The development of e mbryos until day 6 postinsemination and the rate of morulae/blastocysts wer e determined. IFN-tau production in supernatants of cultured embryos was ex amined by inhibition of a virally-induced cytopathic effect. The results sh owed that U.diversion stimulated mononuclear leukocyte production of IL-1, TNF-alpha and NO. Supernatants from U. diversum-activated cells did not imp air the rates of the embryo development and blastocyst formation. The produ cts of activated leukocytes increased the IFN-tau production by cultured bl astocysts. This suggest that U. diversum infection provides leukocyte-media ted signals for developing embryos for generation of additional production of cytokine an important component of innate immunity. (C) 2001 Elsevier Sc ience Ireland Ltd. All rights reserved.