Expression analysis of the Toll-like receptors in human peripheral blood mononuclear cells.

Toll-like receptors (TLRs) are key regulators of the innate and adaptive immune response to bacterial, viral, and fungal pathogens. To date, 10 human TLRs and 13 mouse TLRs have been identified and they exhibit tissue-specific mRNA/protein expression patterns. Thus, it is essential that the TLR expression profile of model cell lines be delineated prior to experimentation in order to establish whether the requisite TLRs are expressed in the cell line/type of interest. This may be quickly achieved by employing a reverse transcription-polymerase chain reaction (RT-PCR) approach whereby total RNA isolated from the cell type of interest is used as a template for RT-PCR analysis of TLR expression using TLR1-TLR10 specific oligonucleotides. Herein, total RNA was isolated from human peripheral blood mononuclear cells (PBMCs) and its integrity was confirmed by formaldehyde-formamide RNA gel electrophoresis. Thereafter, total RNA was used as a template for RT-PCR analysis using oligonucleotides specific for the amplification of TLR1-10. We have shown that PBMCs express mRNA encoding TLR1-10. These findings suggest that PBMCs may represent a useful TLR-responsive model cell line for examining TLR1-10 signalling events.