Influence of different isoforms of recombinant trophoblastic interferons on prostaglandin production in cultured XXXX endometrial cells.

@entity172 @entity398 @entity17440 @entity1421 @entity32589 @entity72647 @entity3774 @entity291
In ruminants, interferon produced by the trophectoderm ( @entity32589 ) is recognized as the embryonic signal responsible for maternal recognition of pregnancy. @entity32589 is believed to act by down-regulating @entity172 receptors, thus preventing appearance of @entity398 receptors responsible for the release of @entity3774 (PGF(2alpha)) by the endometrium. The present study was undertaken to determine in vitro the biological activities of different @entity32589 isoforms and document putative alternate luteotrophic mechanisms. Endometrial cells in primary cultures were treated with five different rIFN-tau isoforms: two ovine isoforms (ro-4 and @entity72647 ) and three @entity291 isoforms (rb-1a, rb-2b and rb-3b). Their effect was quantified by measurement of @entity1421 and PGF(2alpha) production by ELISA and induction of cyclooxygenase ( @entity17440 ) by Western and Northern analysis and correlated with antiviral activity previously reported. The overall pattern of response to the IFNs tested suggests that low concentrations (<1 microg/ml) reduced the production of both PGs and higher concentrations (>1 microg/ml) stimulated preferentially @entity1421 ; however, exceptions were noted. Isoform rb-2b with high antiviral activity inhibited PG production in both cell types at all concentrations tested. IFNs rb-1a and @entity72647 had similar antiviral activities, inhibiting PG at low concentrations and stimulating them at high concentrations. Isoform rb-3b stands out relative to the other IFNs tested because it induced a variable non-dose-dependent effect on PG production and low antiviral activity. An increase in @entity17440 protein expression and messenger was correlated with increased PG production. The results showing two distinct responses to @entity32589 depending on its concentration and/or isoform and the absence of correlation with antiviral activity suggest that complex transduction mechanisms are involved.
