Interleukin-1 beta, human leukocyte antigen HLA-DR alpha, and transforming growth factor-beta expression in endometrium, placenta, and placental membranes.

Maternal immune recognition of the fetal semiallograft appears to be necessary and beneficial for fetal survival and growth. Interleukin-1 beta and human leukocyte antigen HLA-DR are important for foreign antigen recognition by the immune system, whereas transforming growth factor-beta inhibits many of the immunostimulatory properties of interleukin-1 beta. In this study we found that first-trimester decidua and term placental membranes expressed significantly higher levels of interleukin-1 beta, interleukin-1 beta messenger ribonucleic acid, and human leukocyte antigen HLA-DR alpha messenger ribonucleic acid expression. All tissues found at the maternal-fetal interface, including first-trimester decidua, placenta, and placental membranes, contained transforming growth factor-beta and expressed transforming growth factor-beta 1 messenger ribonucleic acid. On the basis of these findings, we suggest that the increase in decidual interleukin-1 beta and human leukocyte antigen HLA-DR alpha during pregnancy may be involved in maternal recognition of the fetal semiallograft and that transforming growth factor-beta production may regulate the local maternal immune response and prevent rejection of the fetus.