Antigen‐presenting Cells in Pregnant and Non‐pregnant Human Myometrium

Citation Ivanisevic M, Segerer S, Rieger L, Kapp M, Dietl J, Kämmerer U, Frambach T. Antigen‐presenting cells in pregnant and non‐pregnant human myometrium. Am J Reprod Immunol 2010; 64: 188–196 Problem Inflammatory cells play a crucial role in human parturition. Different populations of leucocytes invade the reproductive tract. Numerous studies have described the decidual immune cell population in pregnant and non‐pregnant endometrium. However, little is known about the presence of immune cells in human myometrium. Method of study We herein analysed a spectrum of immune cells in human myometrium comparing tissue samples from non‐pregnant (n = 8) and pregnant (n = 10) uteri. Applying immunohistochemistry with a panel of antibodies specific for T cells, monocytes, natural killer cells, B cells and antigen‐presenting cells (CD4, CD8, CD14, CD15, CD16, CD19, CD56, CD68, CD83, HLA‐DR, DC‐Sign, mast cell tryptase), we characterized the immune cell population of human myometrium. Results A significantly higher number of CD14, CD15, CD16, DC‐SIGN as well as CD4‐positive cells were found in myometrium of pregnant compared to non‐pregnant uteri, while mast cells were significantly reduced in pregnant myometrium. Conclusion All markers found increased in pregnant myometrium indicate monocyte/macrophage lineage cells and thus suggest a possible involvement of these cells in healthy pregnancy maintenance. Monocytes/macrophages might produce a microenvironment that permits a controlled invasion of trophoblast cells into the myometrium while preventing a rejection of the semiallogenic conceptus and providing an important barrier against invading pathogenes.