Not your father's immunology - and odd implications thereof

Nor your father's definition of the human.

In the past few weeks we've read of toxic viral payloads in sometimes commensal bacteria, we're read of viral infections that are a critical part of placental formation in at least one mammal, and we've read about T-Reg cells, such as:

• mice without T-Regs developed a fatal inflammatory bowel disease -- not due to autoimmune attacks on bowel cells, but rather due to immune attacks on normally tolerated bowel bacteria
• the best response (mice again) to some parasite infections is to keep a few of the buggers around so the immune system stays tuned. T-Regs help with that.
• T-reg activity may increase in pregnancy in some women to manage tolerance of the foreign fetus
  

This must be starting to at least make its way into medical school infectious disease lectures, and of course there are lots of implications for a range of auto-immune diseases (Is ulcerative colitis an auto-immune attack on GI bacteria, why do parasite infections seem to suppress UC, what's the relationship between cutaneous T-Reg cells, vitamin D, sunlight exposure and multiple sclerosis, etc).

Eventually we'll change the way we treat infections, and probably abandon the idea (still persisting) that patients need to take all their antibiotics to kill all the pathogens. We may eventually move to the long mooted concept that managing infections is about managing the "human" (meaning nuclear DNA, mitochondrial DNA, bacterial DNA, Viral DNA, a few prionic forms and lord knows what else) superorganism and its ecology rather than the traditional view of an attacking "pathogen".

Hmmm. What could this approach imply about managing terrorism?