Description:
<jats:p><jats:bold>Problem: </jats:bold> Toll‐like receptors (TLRs) are expressed on placental cells. The aim of this study is to analyze signaling components activated in placenta cells after TLR ligand engagement.</jats:p><jats:p><jats:bold>Methods of study: </jats:bold> In chorioncarcimoma cell lines the regulation of TLRs was determined by real time polymerase chain reaction as well as by fluorescence‐activated cell sorter analysis. Activation of NF‐<jats:italic>κ</jats:italic>B was determined in a reporter assay system and the activation of the mitogen‐activated protein kinase signaling pathways by immunoblot analysis.</jats:p><jats:p><jats:bold>Results: </jats:bold> Both lipopolysaccharide (LPS) and DNA oligonucleotides containing unmethylated CpG motifs (CpG) induced the enhanced expression of TLR2 mRNA as well as a TLR2 surface protein expression. Functionally, incubation of JAR cells with microbial stimuli such as LPS activated NF‐<jats:italic>κ</jats:italic>B, as well as the phosphorylation of ERK1/2 and p38 MAP kinases and secretion of interleukin‐8.</jats:p><jats:p><jats:bold>Conclusion: </jats:bold> The functional expression of TLRs on placental cells may play an important role in the initiation of an immune response in the developing fetus.</jats:p>