BioMed
Immunologist Daniel M. Davis traces how cells coordinate the body’s defenses and how discoveries about their receptors led to drugs that unleash attacks on tumors.
The immune system tells self from non-self, detects germs, and responds to danger, all at the same time and messily. No one over-arching principle captures everything it does. Hunting for a single grand theory may even be the wrong goal.
Life's mechanisms are too complex to fit tidy explanations, however satisfying those explanations feel. A good account of such a system has to tolerate several overlapping logics running at once, rather than forcing one clean narrative onto it.
Major immune discoveries often came from scientists their peers first mocked. One antiviral substance in the blood was jokingly dismissed by colleagues before it was accepted. Early ridicule is weak evidence that an idea is wrong.
Radical rethinks of how immunity works came from chains of successes and failures across many collaborators. Failures are at least as valuable as successes, and no scientist makes progress alone.
The body's protection comes from a vast, intricate network of specialist cells, regulatory proteins and dedicated genes working continually together. Its power comes from coordination among many parts, not from any single defender.
A defense system's hardest problem is not attacking but choosing targets. It must strike germs while leaving alone harmless foreign material such as food and a pregnancy's placenta. Getting this choice wrong in either direction causes disease.
The immune system has built-in brakes that hold back its own killer cells. Drugs that remove those brakes let the body's natural defenses attack tumors. This has made some cancers and autoimmune diseases once thought untreatable treatable, and a few curable.
The body's own defenses are more powerful and flexible than any drug invented. The most promising new treatments do not replace that system but harness and redirect it.
How well immunity works depends on stress, sleep, age, diet and state of mind. The timing of a vaccine can matter, and early-life surroundings can shift the risk of autoimmune disease. Ordinary habits like sleep, good food and mindfulness appear to help.