by Matt Richtel
In the Festival of Life, neutrophils are first responders.
“If you scrape your hand right now, and get an infection, the first cell there would the neutrophils. The macrophage comes soon thereafter,” said Dr. Anthony Fauci, whom I mentioned earlier, the director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, and one of the most influential contemporary scientists. His story will eventually become closely intertwined with that of Bob Hoff, the man who fought HIV to a draw.
In much smaller concentration in the body are two other defenders, the eosinophil (less than 5 percent of the white blood cell population) and the basophil (less than 2 percent). Combined, they are known as granulocytes. This name reflects their function. These cells contain tiny enzymatic granules that digest and destroy pathogens.
In the 1970s an experiment involved yet another immune cell—the natural killer. The discovery is interesting in and of itself, and also because it was part of the broader reframing of the understanding of the immune infrastructure. The scientific narrative had been about the primacy of the T cell and the B cell. That narrative was falling apart.
The story emerged in 1975 in a paper titled “‘Natural’ Killer Cells in the Mouse,” published in the European Journal of Immunology. It described an experiment that didn’t seem to add up.
The study involved mice raised in antiseptic environments such that they had not faced a challenge to the immune system. As a result, it was not possible that the immune systems of these mice would’ve had a chance to learn and respond to a particular threat.
Cells from the spleens of these pure mice were extracted. They were introduced in a test tube to cancer—specifically, leukemia cells.
The strangest thing happened. There was an immune reaction. The spleen’s immune cells attacked. That alone wasn’t necessarily at odds with previous learning; after all, perhaps the immune cells had antibodies that recognized something foreign. But, quite oddly, the attack didn’t involve any B cells or T cells. The response was less specific than the targeted nature of B cell and T cell attacks. These “new” cells swarmed instantly in a kind of raw, generic manner that seemed more consistent with a knee-jerk attack than the specified, deliberate nature postulated by clonal selection theory.
This was different, and possibly hugely important. But what were these things?
The scientists called them “natural killer cells.” They seemed to belong to the same family as T cells and B cells, but they behaved very differently.
“The natural killer cells did not get much respect when they were discovered,” reflected David Raulet, an expert in the field from the University of California at Berkeley. “A lot of people working on T cells sneered at them and didn’t think of them as relevant.”
The authors of the paper themselves acknowledged an oddity. In a summary, they wrote that “the spontaneous” attack of the mouse spleen cells “is exerted by small lymphocytes of yet undefined nature.”
A natural killer cell. (NIAID/NIH)
One reason scientists had trouble absorbing the new information was that, just as the human body itself struggles with the alien, science can have trouble making peace with ideas that seem foreign. Scientists and thinkers with entrenched theories rejected the challenge to the prominence of T cells and B cells, as if these new discoveries were alien tissue or pathogenic bacteria. Ideas, memes, can elicit a kind of autoimmune response, an overreaction that feels protective initially but can ultimately prove counterproductive and make it harder to find truth. (On the other hand, kudos to immunology for finally giving a name—natural killer cells—that was accessible, described what the cells actually did, and that Madison Avenue would at long last have lovingly embraced.)
How did this litany of new cells fit together? What was the interplay?
“We couldn’t connect the dots,” Dr. Fauci said. How did all these things work together?
A partial answer came from the mid-1970s revelation about fever—a discovery set off by the temperature spikes exhibited by the Caribbean woman who showed up at Yale and that became the obsession of Dr. Charles Dinarello.
16
Fever
“For centuries before the introduction of the thermometer, fever was a well-recognized sign of disease,” Dr. Dinarello wrote in 1978, as he was changing the world of immunology. “Only during the past three decades has the mechanism by which disease causes a rise in body temperature begun to be clarified.”
Dr. Dinarello dates the relevant research to 1943, when a Russian scientist who had relocated to the United States found that he could induce fever in rabbits by injecting them with pus. Pus, it turns out, is the detritus of neutrophils, the cells that rush into action at the first sign of insult. They kill what is around them and die in the process. When you observe pus oozing from your body, you’re seeing these dead cells.
The 1943 paper posited that the fire was sparked by neutrophils. This was wrong, but it was a start.
Why rabbits? Rabbits make good guinea pigs for science because they can be somewhat trained, and changes to their behavior are relatively easy to observe.
Early on, it was discovered that injecting rabbits with pus could elicit a fever. It was a first step in looking for the exact pyrogenic, or fever-producing, process. Through the 1950s and ’60s, more evidence was added about the process. For instance, the rabbits conserved heat during fever by constricting blood vessels, such that their ears became cold. (Have you ever felt clammy when you have a fever?) “The rabbit becomes quiet and motionless,” Dr. Dinarello wrote in a history. “This observation resulted in the discovery,” he added, that the pyrogen “was a sleep factor.”
Then in 1967, science got closer with a surprising finding. A paper published in The New England Journal of Medicine reported evidence of a pyrogen—a fire starter—in a blood cell different from the neutrophil. Rather than coming from a first-responder killer, the chemical that seemed associated with fever derived from a monocyte, which is a kind of macrophage. Understandably, it had been hard for earlier scientists to tease out these cells. So which was it, neutrophil or monocyte, and what difference did it make anyway?
This was largely the state of affairs when Dr. Dinarello observed a woman at the Yale hospital running a high temperature who shouldn’t have had a fever because she did not have an infection. The case was intriguing, and he was already interested in fever. “I said, ‘Goddammit, I’m going to discover what this molecule is,’” he reflected. He aimed to solve the fever riddle.
Dr. Charles Dinarello—don’t call him Charlie–grew up in a Boston suburb that, as he put it, was filled with Italians, Jews, and Irish. His grandparents were immigrants from mainland Italy and Sicily. His mother never finished high school, and his father was blue collar. Charles wound up, as you now know, at Yale Medical School and finished with a prize for having the most outstanding thesis. It was about fever.
The Vietnam War was raging, and as a medical school student, he’d had the same choice as his med school peers: sign up for government research or risk getting sent to patch up land-mined boys in the helicopter zone. The choice wasn’t quite that simple, but it did feel to many young doctors that government work in Washington would protect them from a combat zone. Dr. Dinarello went for research and wound up working at the National Institutes of Health. Not only that, he earned his way into a remarkable place and time: Building 10 at the NIH, a hall of truly great science, a Willy Wonka factory of experimentation and discovery.
It’s a huge flat-faced brick building, set on a campus that is part of the largest clinical research center in the world. Patients and scientists. Collaboration. It represents an extraordinary commitment to science by the United States and by President Dwight D. Eisenhower. Between 1950 and 1960, the NIH budget grew from $53 million to $400 million. The funding was largely a bipartisan affair, although resistance came from some Republicans wary of expanding government. Nothing like the battles seen today, though. And as
history will bear out, the science done at the NIH would go on to save many lives, including, very arguably, Jason’s. Seeds of salvation for sufferers of cancer, AIDS, autoimmune diseases, flu, and other killers were planted in Building 10. The work done here speaks to the power of a broad field called basic science, defined as science that is aimed at understanding core concepts and isn’t directed at developing, say, a particular medicine to attack a specific disease. Basic science is more diffuse, an act of faith and failure—many projects don’t work out—but the sum of the effort has been the lifeblood of cures for many major diseases.
Dr. Dinarello’s lab was located on Building 10’s impressive eleventh floor, at a time when immunology work there was exploding. The eleventh floor wasn’t impressive for its confines—it was a mess—but rather for the brain power there. Around every corner sat an ambitious, bright, creative thinker.
Dr. Dinarello was easy to pick out. He was the one with rabbit shit under his fingernails. It was from digging around down there with the rabbit rectal thermometer.
“I’m joking,” he told me. Sort of. “But the reality is that I did have rabbit feces under my fingernails for twenty years.”
It was now 1971, and his first task was a bureaucratic one. He had to convince fellow researchers and his boss (a luminary named Sheldon Wolff) that he should be allowed to hunt for the body’s own fever molecule. Some were dubious. Could Dr. Dinarello be sure, for instance, that he’d filtered out every other molecule, and not only that, could he be absolutely sure that the cause of the fever wasn’t an alien substance, an infection?
Consider for a moment the profundity of that question. There had long been an assumption that fever was linked to infection. In contrast, what Dr. Dinarello was pursuing was the idea that infection need not be present, and that, in a manner similar to the case of the woman with lupus he’d witnessed in medical school, the body was generating the fever with its own molecule, without necessarily being prompted from the outside.
Eventually, he got his wish to pursue the project, and then he ran into a very practical problem. Where was he going to obtain the white blood cells? “Where to get billions and billions of monocytes every day? That’s when the project would get serious. It was an important step,” he told me. He has the knack for spinning a yarn, and I could hear him picking up steam. A quick reminder: Monocytes are roughly synonymous with macrophages. The difference is that monocytes are immature macrophages. When these cells come out of the bone marrow, they are monocytes for a few days until they diffuse into the tissue and then become macrophages. For the sake of simplicity, and without losing any accuracy, I’ll just say that Dr. Dinarello suspected macrophages were involved, but he needed a bunch of them.
That’s when he discovered the trailer.
It was out in the parking lot of the NIH. It had been put there to experiment with a new technology that involved giving blood platelet transfusions to cancer patients being treated with chemotherapy. The provision of all these platelets involved using a lot of blood. The white cells weren’t of interest to the folks in the trailer.
“I’d go there every late afternoon and salvage these cells. Just take them, in a blood bag.”
The rabbits were furry white. “I treated them like they were my kids,” Dr. Dinarello said. He would train each rabbit for two weeks so that it would be calm when it underwent the procedure. “After a couple of weeks, they were ready,” he said.
To prepare the environment and the macrophages for injection, he was meticulous about the surroundings. “I stayed away like the plague from any bacterial product that would cause fever. I couldn’t risk any contamination.” He knew that his experiment would be rejected if his peers suspected that the cause of fever was an antigen or a bacterium.
Dr. Dinarello took the white cell “dreck” from the trailer. He then mixed these immune cells with dead staph infection to stimulate a macrophage reaction. He injected the mixture into rabbits, knowing the experiment would provoke a response in his furry friends.
As he tells the story, he pauses, as if struck by the oddity of his obsession. “It took six years to purify this molecule. If you ask me what drove me—why not give up and take on an easy project?—I’ll tell you: It comes from observing the physiological change in this rabbit—to see a rabbit get still, its ears get ice cold. Within ten minutes, there’s this horrible, dramatic thing. I had to know: What is this molecule doing to the brain?”
Four years into his six-year quest, he was interrupted. He had to fulfill a commitment to be chief pediatric resident at Massachusetts General Hospital.
He returned in 1975. By then things were exploding in immunology around the world, with new technology allowing new techniques. One involved radioactive labeling to help identify, purify, or cull out individual molecules. In Building 10, down just two floors on nine, was a guy who was pretty good at the technique. His name was Christian Anfinsen. He’d already won the Nobel Prize, in 1972. Dr. Dinarello asked if Anfinsen might not help close the deal on the rabbits and their fire starter.
Closer and closer they got, homing in on a purified molecule, isolating it from other contaminants and molecules. And then, one day in 1977, something strange happened. The molecule disappeared.
This was the moment, the revelation. When the molecule disappeared, Dr. Dinarello realized the fever-inducing molecule was so purified it only looked absent. Of equal importance, he’d discovered that the amount of that molecule could be virtually nonexistent and still light the body on fire. The importance of this is hard to sufficiently emphasize. It takes very little of this thing to cause a major reaction in the body.
“It is perhaps the most important statement of my career,” he said. In technical terms, he’s referring to the discovery that it requires an amount as little as ten nanograms per kilogram of this substance to start fever. In translation: “It was a thousandfold less than anybody ever predicted. It was amazing. This molecule is so potent.”
And it came from a monocyte, one of those immune cells like the macrophage (which devours refuse and pathogen), but one that now appeared to have much broader function. Dr. Dinarello called it a leukocytic pyrogen—a fire starter born of the white blood cells, the leukocytes.
“He realized, ‘Oh my god, it’s not coming from the neutrophil. It’s coming from the monocyte,’” recalled Dr. Fauci, who worked with Dr. Dinarello on the eleventh floor. When Dr. Fauci related the story to me, his own voice rose with elation. His excitement took a moment for me, an outsider, to appreciate, given how thick these conversations are with immunology speak. But the emotion broke through. This was huge.
Dr. Dinarello published his first paper in 1977. His revelation was initially hammered. “The Germans wrote papers against it,” he said. “They said. ‘He’s got contamination.’”
Slowly, though, the reality sank in.
In fact, in Ermatingen in 1979, Switzerland hosted the Second Lymphokine Workshop. The assembled, having accepted the notion, decided to give a new name to these so-called mediators. Henceforth, a leukocytic pyrogen would be known as an interleukin. Inter from a root for “means of communication.” Leuk from the Greek root for white, as in leukocyte (white blood cell).
Broadly, the leukocytic pyrogen was a kind of mediator, communicator.
Interleukin-1, the first interleukin, was born. Dr. Dinarello might fairly be called its midwife. Armed with this knowledge alone, you’re on your way to earning a bachelor’s degree in immunology.
The story doesn’t quite end there. Maybe the most important part was yet to come, and it would make Dr. Dinarello quite a controversial figure.
One Saturday morning in the mid-1970s, there on the eleventh floor of Building 10, Dr. Dinarello was working with another scientist, playing around with his purified molecule. They wanted to see if interleukin-1 had any impact on the larger immune system. Did it do something besides stimulate fever?
In rough terms, the experiment involved giving a deadened human virus to a rab
bit, stimulating interleukin, injecting that product into a mouse, and looking for a T cell reaction. To measure the reaction, they then went into the “counting room,” where the machine that measured the radioactive labeling would click, like a Geiger counter, when measuring a particular molecule or cell.
“We’re watching every two counts to see if the T cells are activated. All of a sudden, the counter went berserk. Ba-bid-a-ba-bid-a. It was like a science fiction movie,” Dr. Dinarello related. Another scientist in the room was the one who had been working with the mice and T cell stimulation. As they watched the clicker go wild, indicating a massive increase in T cells, “Lanny says to me: ‘What the hell did you give me?’” Dr. Dinarello said. “‘This is a millionfold more active than I’ve ever seen.’”
What did this mean?
At the most basic level, it meant that the interleukin-1 was inducing not just fever but also a T cell response.
So what?
Recall that much of immunology was still focused on the prominence of the T cell and B cell, but particularly the T cell as the commander in chief in the alliance. Now, though, it looked like the macrophage was prompting the T cell, not the other way around.
“From 1976 to 1979, I was scared shitless to publish it,” Dr. Dinarello said. “How can a molecule produced by a human monocyte that causes fever in rabbits also cause a lymphocyte reaction in mice? It was heresy for immunologists.” Dr. Dinarello’s idea, which ultimately would be proven correct, goes to the heart of how we now understand the immune system, and also how we’ve come to try to manage and even manipulate it—in cases like those involving Jason, Merredith, Linda, and Bob.
This era, which is still ongoing, involves the discovery of dozens of powerful molecules that show the extraordinary complexity of our elegant defense, the multiple actors with overlapping duties, wonders of science as strange as any fiction. Enter Flash Gordon.