Fighting deadly diseases … by ignoring them

There’s a famous story about World War II fighter planes. Whenever they’d get caught in a dogfight and return to base full of bullet holes, military personnel would examine the hulls. They’d then order manufacturers to reinforce the armor wherever the planes showed the heaviest damage. Makes perfect sense.

Until one day someone pointed out that the military had things backwards. They didn’t need to reinforce the planes where they saw bullet holes — in fact, this was proof that planes would survive if hit in those spots. Instead, they should reinforce the planes wherever there was no damage, since those areas might still be vulnerable. Anything else was a waste of effort.

The analogy’s not perfect, but this anecdote popped into my head in the past few weeks while researching some radical new treatments for diseases like HIV and cancer. Every instinct we have tells us to fight, fight, fight these ailments, and that the only cure is eradication. But there’s a second way: Living with the disease forever (or at least till something else gives out).

HIV scientists, led Ashley Haase at my alma mater, the University of Minnesota, are developing a therapy that teaches the body to ignore HIV. HIV spreads by highjacking the body’s defense cells, which try to eliminate it. When the virus takes over, the infected cell sends out panic signals that draw more defense cells to it, which allows HIV to colonize them, too, which draws more cells. It’s a cascade. Haase’s theory (and it seems to work in primates), is that stopping the panic response will hinder HIV’s ability to spread.

In the same spirit, doctors such as Robert Gatenby at Moffitt Cancer Center think that the best way to treat cancer might be call a truce with it (subscription req’d). Fighting cancer only seems to make tumors stronger in the long run, since the weakest usually succumb to chemotherapy first.

These are both clever ideas, and they may signal a shift in doctors’ thinking about how to tackle diseases. With microbes especially, biologists now realize that not all of them are bad guys. Bacteria and viruses are utterly integrated into our bodies, and they perform many essential functions, like helping us break down food. We cannot live without these benevolent bugs. And soon we may have the tools to live with even the worst of the microscopic world, too.