Egr-1, a Major Link Between Infection and Atherosclerosis?

To the Editor: The study of Bea et al,1 recently published in Circulation Research , investigated the role of Chlamydia pneumoniae infection in mouse macrophages on the induction of tissue factor (TF) via activation of Egr-1. Chlamydial infection of RAW mouse macrophages clearly resulted in enhanced Egr-1 protein expression and a subsequent time-dependent increase in TF mRNA expression and procoagulatory activity. We can confirm the postinfectious Egr-1 induction described by Bea et al. In addition, we can expand their findings and demonstrate a broader regulatory influence of Egr-1 on proatherosclerotic factors in C pneumoniae –infected mononuclear cells that is not limited to prothrombotic molecules and not restricted to mouse macrophages. We performed similar experiments as Bea et al1 but used blood monocytes from healthy blood donors and found that infection with the cardiovascular chlamydial strain CV-6 (isolated from a 68-year-old man with coronary restenosis2) significantly induced …