CO-opting the host HO-1 pathway in tuberculosis and malaria.

Infection with Mycobacterium tuberculosis and Plasmodium species results in upregulation of the host heme oxygenase-1 pathway. In tuberculosis infection, this leads to upregulation of the bacterial "dormancy regulon," whereas in malaria, it enhances the efficiency with which sporozoites develop into exoerythrocytic stages. Here we discuss these findings as well as some of the interesting questions they raise.