Regulation and Signal Transduction of Toll-Like Receptors in Human Chorioncarcinoma Cell Lines


Address reprint requests to Markus Schnare, Institut für Klinische Mikrobiologie, Immunologie und Hygiene, Universität Erlangen-Nürnberg, Wasserturmstraße 3–5, 91054 Erlangen, Germany.


Problem:  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.

Methods of study:  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-κB was determined in a reporter assay system and the activation of the mitogen-activated protein kinase signaling pathways by immunoblot analysis.

Results:  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-κB, as well as the phosphorylation of ERK1/2 and p38 MAP kinases and secretion of interleukin-8.

Conclusion:  The functional expression of TLRs on placental cells may play an important role in the initiation of an immune response in the developing fetus.