Cytokine production in first trimester chorionic villi: detection of mRNAs and protein products in situ.

Growth factor cytokines must play important roles in placental growth and differentiation. We used cDNA-mRNA in situ hybridization to examine whether human first trimester chorionic villi could produce these substances locally. IL-1 beta and IL-4 mRNA was found in both trophoblast layers, whereas CSF-1 and TNF alpha were found mostly in syncytiotrophoblast with much less localization to cytotrophoblast areas. IFN-gamma message was exclusively found in the cytotrophoblast. Immunohistochemical analysis confirmed that cytokines are produced by placental tissue, and the patterns of expression correlated well with the data obtained by in situ hybridization. These data are discussed regarding possible roles of cytokines in regulation of MHC antigen expression by trophoblasts and immunomodulation of decidual lymphocytes.