Fighting cytosolic bacteria and DNA viruses

The first biochemical and genetic evidence that the DNA sensor, AIM2, is critical for immunity against certain bacterial infections and DNA viruses is reported in two papers online this week in Nature Immunology.

The AIM2 inflammasome is a multi-protein complex that induces the release of certain substances which are known to be critical for host defense against microbial invasion. Two groups ― one led by Kate Fitzgerald and the other by Emad Alnemri ― generated mice lacking AIM2 in order to test the effects of its loss on immune responses. They found that AIM2 is critical for immunity against Francisella tularensis, the causative agent of the infectious disease, tularemia. In addition, Fitzgerald's group found AIM2 inflammasome activation is critical for a type of poxvirus and mouse cytomegalovirus infection. It is also partially involved in Listeria monocytogenes infection which gives rise to the bacterial infection listeriosis.

Future studies may go on to clarify what other intracellular microbial bacteria and viruses depend on AIM2.