An Elegant Defense summary

The field of immunology can be traced back to a mystery – or, rather, three mysteries: the mysteries of a chicken, a dog and a starfish. Let’s start with the chicken.

One day in the sixteenth century, while dissecting a chicken, a young Italian anatomist named Fabricius ab Aquapendente discovered a mysterious organ. Located beneath the bird’s tail, and shaped like a pouch, it served no apparent function.

It was the late 1950s, and Dr. Jacques Miller had a lot of dying mice on his hands. Whenever a new mouse died – and that happened regularly – Dr. Miller would cut it open and see the same thing: a little mouse liver covered in lesions. Each mouse had been ravaged by severe infection.

What happened to these poor mice? And who is this scalpel-happy Dr. Miller?

What is self and what is alien to self? What is a part of you and what is other? How does the body know, for instance, which bacteria to attack and which to let alone?

When Dr. Jacques Miller was conducting his research, there weren’t any definitive answers to such questions, but one thing was certain: the immune system could distinguish between self and non-self, though sometimes it would mistake help for harm.

In 1954, the bursa, that pouch-like organ that had so puzzled the young Italian Fabricius ab Aquapendente, finally got its moment in the scientific limelight. A researcher discovered that removing the bursa from chickens severely hindered the animals’ ability to produce antibodies.

In other words, if you removed the bursa, you significantly reduced the number of antibodies. Why was this a big deal?

In the end, after another series of experiments, Dr. Jacques Miller proved Dr. Max Cooper’s hypothesis. 

He discovered that there are indeed two types of lymphocytes – T cells and B cells – and that the B cells originate in bone marrow. These cells make up about 40 percent of human white blood cells – cells that, in addition to explaining the mystery of Gaspare Aselli’s white-blooded dog, are absolutely crucial to survival.

Imagine you’re in a foreign country. While there, you take a swim in a lake. A bit of water gets up your nose, and in that water is a malicious bacterium that neither you nor any of your ancestors has ever been exposed to. The antigen it expresses is utterly foreign to your entire system.

How can your body possibly possess an antibody that corresponds to it?

When your body is invaded by a pathogen, an array of defenses is set in motion. You’re now in a position to understand how these defenses combine.

First, the generic defense. Remember the phagocytic cells observed by Élie Metchnikoff? Well, they come in a variety of different forms. One of these is the neutrophil. These cells constitute about 50 or 60 percent of your white blood cells, and they’re naturally drawn to infection.

By now, you’ve got a pretty firm grasp on how the immune system works. There’s one more component – how cells communicate with one another.

Your body is essentially equipped with an all-natural telecommunications system. It works like this.

It’s time to meet Jason Greenstein. Jason and the author had been friends since childhood – and Jason had always been a vibrant human being, living life his own way.

As a teenager, he was a talented athlete, dominating the basketball court, but he never flaunted his skills or mocked less able players. He always encouraged the author, for instance, who was not nearly as physically adroit as Jason.

Jason had always been a fighter. So he fought. He did chemotherapy – then, when he relapsed, another bout of chemo. When that didn’t work, he had a bone marrow transplant, which wiped out the cancerous B cells (and the healthy ones, too). Still, the cancer came back.

These procedures are devastating in the extreme. Jason’s ability to produce normal blood cells had been severely compromised, and he was neutropenic, meaning he had critically low levels of neutrophils, the white blood cells that act as the body’s first responders. Jason was desolate, his body utterly decimated. Giving up began to sound better than fighting on. Indeed, he was too weak to undergo any further approved treatments.