IF EVER there was a telling illustration of the power of the immune system, it came in 2006. Six men in a trial of an experimental drug made by the company TeGenero became critically ill after suffering a catastrophic over-stimulation of the immune system. The T-cells, the "master regulators" of the body's immune system, had turned against it.
Now it seems we may have a "shadow" immune system ruled by B cells, usually portrayed as foot soldiers that do the bidding of T-cells. Tinkering with this aspect of the immune system (page 6) could yield new ways of treating autoimmune diseases and cancer. But, exciting as this is, let's not forget the TeGenero story. We must understand shadow immunity much better before we can even think of tweaking it in people.
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