REGULATION OF PLACENTAL MONOCYTE CHEMOTACTIC AND ACTIVATING FACTOR DURING PREGNANCY AND CHORIOAMNIONITIS

A number of placental cytokines participate in the fete-maternal defen ce mechanism. Monocyte chemotactic and activating factor (MCAF) is one of these chemokines. We investigated the pattern of placental MCAF pr oduction, the localization of MCAF-producing cells in the placenta, an d alterations in its expression in chorioamnionitis. The amounts of MC AF protein produced by the placenta increased during pregnancy irrespe ctive of the presence of uterine contraction. MCAF mRNA was expressed at equivalent levels in the first and second trimester placenta, but a t higher levels in the third trimester placenta. Chorioamnionitis in t he third trimester placenta induced a 10-fold increase in MCAF protein production and a 3-fold increase in MCAF mRNA level. Immunohistochemi cal analysis of the placenta revealed the MCAF-producing cells to be t rophoblasts. Stimulation of placental cells with lipopolysaccharide au gmented MCAF production. These results indicate unique transcriptional and developmental regulation of MCAF mRNA and protein production duri ng pregnancy and chorioamnionitis. Placental MCAF may be involved in t he fete-maternal defence mechanism by activating fete-placental and ma ternal monocytes in chorioamnionitis.