PARENT SESSION
Implantation & Early Development

EXPRESSION OF INTERFERON GAMMA-INDUCIBLE PROTEIN 10 KDa IN THE UTERINE ENDOMETRIUM OF PREGANT EWES.

Nagaoka, Kentaro¹, Sakai, Akiharu¹, Nojima, Hisashi¹, Christenson, Ronald², Imakawa, Kazuhiko¹, Sakai, Senkiti¹, ^{1 2}

ABSTRACT- For the establishment and maintenance of pregnancy, the conceptus needs to escape from the maternal immune system. Distribution of immune cells within the uterus, which is regulated by steroid hormones, cytokines and chemokines, changes during peri-implantation periods. From numerous cDNA subtraction studies between day 14 pregnant and non-pregnant uteri, interferon gamma-inducible protein 10 kDa (IP-10) was identified. This factor belongs to a member of C-X-C chemokines and chemotactic agent for activated T lymphocytes. Although this chemokine is regulated by Type II interferon, IFN-gamma, expression of IP-10 at the endometrium seems to parallel the production of conceptus Type I IFN, IFN-tau. In the present study, therefore, we investigated the relationships between IP-10 and IFN-gamma and IFN-tau. Using Northern blot analysis, we observed that the expression of IP-10 mRNA, detected only in the pregnant uterus, increased as peri-implantation period proceeds. Using RT-PCR, we detected that the expression of endometrial IFN-gamma mRNA also increased during the same period. Immunohistochemical analysis revealed that both IP-10 and IFN-gamma peptides were localized in the epithelial cells and sub-epithelial stroma cells of pregnant uterus whereas IFN-gamma, not IP-10, was also localized in cyclic ewes. In addition, IFN-tau peptide was localized in trophoblast cells and uterine epithelial cells in pregnant ewes. Furthermore, T lymphocytes, CD4+ and CD8+ cells, were found in sub-epithelial stroma of uteri of pregnant ewes. These results suggest that IP-10, regulated by IFN-gamma and/or IFN-tau, may play a role in the recruitment of T lymphocytes to the uterine endometrium during peri-implantation periods.

KEY WORDS: IFN , IFN-gamma, IP-10, implantation