Results: We noticed that our data (morphology, immunohistochemistry,profile of pro-angiogenic expression)tend to be different between our two groups. Conclusion:These results may help establish- ing new criteria to define optimum uterine receptivity. 8 Identifying the receptor-binding part of PIBF Melinda Halasz 1 , Beata Polgar 1 , NoemiKozma 1 , Gergely Berta 2 , Gabor Toth 3 , Julia Szekeres- Bartho 1 1 Dept. of Medical Microbiology and Immunology, University of Pecs, Hungary; 2 Dept.of Biology, University of Pecs, Hungary; 3 Dept. of MedicalChemistry, University of Szeged, Hungary Problem: The PIBF1-gene contains 18 exons and encodes a protein of 757 aminoacid residues with an 89-kDa molecularmass.We aimed to identify the receptor-binding region of the molecule,by its abil- ity to activate signaltransduction via JAK1/STAT6- pathway in peripheral lymphocytes. Materials and Methods: Recombinant PIBF con- structs and small syntheticPIBF analogues repre- senting different regions of the molecule were designed.EMSA was performed to detectnuclear translocation of STAT6-dimers while intracellular STAT6-phosphorylationwas tested by Western blotting. PIBF-receptor binding ability of the selected analogue was confirmed by confocal microscopy. Results: Nuclear translocation of STAT6-dimers was induced by PN1(exons 2-3-4), PN3(exons 8-9), PN5(exons 3-14-15-16) constructs. Peptide-5 (in PN1) and 8 (in PN3-4) were capableto activate STAT6-phosphorylation. BodipyFL- labelled peptide- 8 bound to the PIBF-receptor and was internalized in a time-dependent manner. Conclusions:These data suggest that the receptor- binding region of PIBF might be a conformational structure that includes remote sequences. 9 Phenotype characterization of the anti-inflammatory behavior of decidual endothelial cells C Agostinis 1 , E Masat 1 , F Bossi 1 , L Lombardelli 2 , C Tripodo 3 , O Radillo 4 , F De Seta 4 , MP Piccinni 2 , R Bulla 1 , F Tedesco 1 1 Dept of Physiology and Pathology, University of Trieste, via Fleming 22, 34127 Trieste, Italy; 2 Dept of Internal Medicine-Immunoallergology Unit, University of Florence, Florence, Italy; 3 Dept of Human Pathology, Uni- versity of Palermo, Palermo, Italy; 4 IRCCS Burlo Garofolo, Trieste, Italy Problem: During pregnancy, an adequate inflamma- tory control is essential for normal intrauterine foetus development. Vascular endothelium is known to play a critical role in regulation of inflammatory processes. We hypothesize a different ability of decidualendo- thelial cells (DEC) compared to endothelium from other districts to respond to inflammatory stimuli. Material and Methods: DEC were isolated and acti- vated with inflammatory stimuli and their response in term of adhesion molecules expression, vascular leak- age and cytokines production was evaluated. These data were compared to the data obtained with HUVEC and microvascularendothelial cells isolated from human skin (ADMEC) and from human endome- trium (UtMEC). Results: Our observations indicate that DEC: 1. expresslow levels of adhesion moleculesafter inflammatory stimulation2. are unable to respond to classic permeabilizing stimuli 3. present a differ- ent cytokine profile. Conclusions:Our results indicate that decidual endothelium hasa differentresting phenotype and showsan anti-inflammatory behaviorcompared to other microvascular endothelium. 10 Low doses of trilostane fail to induce abortion during early gestation in mice and ewes ME Solano 1 , V Parker 3 , S Camous 2 , O Sandra 2 , AJ Douglas 3 , PC Arck 1 1 Charite ´, University Medicine Berlin, Germany; 2 UMR INRA/ENVA FRE CNRS ‘‘Biology of Development and Reproduction’’, Jouy en Josas, France; 3 Centre for Integrative Physiology, University of Edinburgh, UK Problem: Progesterone playsa central role during the maintenance ofpregnancy.Our study aims to ABSTRACTS American Journal of Reproductive Immunology 60 (2008) 85–89 ª 2008 The Authors 88 Journalcompilation ª 2008 Blackwell Munksgaard