Quantitative measurement of anthrax toxin receptor messenger RNA in primary mononuclear phagocytes.

Two anthrax toxin receptors have been identified, tumor endothelial marker 8 (TEM8) and capillary morphogenesis protein 2 (CMG2). Both receptors have been shown to be capable of facilitating the entry of Bacillus anthracis exotoxins into the cytosol of susceptible cells. The levels of TEM8 and CMG2 RNA transcripts present in human primary macrophages derived from multiple unrelated donors and primary mouse macrophages have not been well described. In this communication, we examined the expression of mRNA transcripts of TEM8 and CMG2 in primary human and mouse macrophages and mouse tissues by standard and quantitative real-time RT-PCR. Our results indicate that CMG2 transcripts are preferentially expressed over TEM8 transcripts in primary human and mouse macrophages as compared to immortalized cell lines.