Antibodies — THE BUSINESS OF BIOTECHNOLOGY

EXCERPT

Chapter Two: The Molecules

Monoclonal Antibodies

Biotechnology will stand as one of the greatest technological advances of the twentieth century, and its potential to leave an enduring imprint on our lives will continue well into the twenty-first century and beyond. Scores of medicines based on the science of biotechnology are now available to patients in the United States and many other countries, and they accounted for over $240 billion in sales in 2018. Monoclonal antibodies (mAbs) comprise the vast majority of approved biologics to date, with sales of $157.3 billion in 2018.

“Antibodies are typically pre-programmed to bind to a specific kind of disease, and when they have done so, killer cells are alerted to destroy the antibody-coated germs.”

Antibody technology allows scientists to create, in the laboratory, proteins that are virtually identical to the normal antibodies that serve as the eyes and ears of our immune systems. Our bodies are populated with billions of these tiny Y-shaped proteins, which circulate through the bloodstream and tissues on the lookout for viruses, bacteria, and other disease-causing agents. Antibodies are typically pre-programmed to bind to a specific kind of disease, and when they have done so, killer cells are alerted to destroy the antibody-coated germs. Antibodies are thus like the lasers that “paint” a military target, which is then destroyed by a computer-driven smart bomb programmed to explode upon contact with the laser-painted target.

The scientists who first discovered the role of antibodies in bringing about the destruction of pathogens by killer cells employed somewhat different, but equally vivid imagery. They called the killer cells “phagocytes,” from the classical Greek words for “eating” and “cell,” because they would engulf and enzymatically chew up a virus or bacterium. An especially large and effective phagocytic cell then was labeled a macrophage, or “big eater.” A virus coated with many antibodies, and thus marked for elimination by macrophages, is said to be “opsonized,” a scientific term derived from the Latin word for relish, like mustard or ketchup, something to make the germ more tasty for the big eaters. Early immunologists clearly had both a sense of humor and a good classical education. Whether we imagine antibodies to be smart bomb components or sandwich toppings, it is clear that antibodies play a crucial role in mobilizing our immune defenses.

Thanks to all of these naturally occurring antibodies, our bodies fend off many diseases every day. Unfortunately, our immune system does not always make antibodies when it should, especially when the disease is caused by one of our own cells, like a cancer cell. Antibodies circulating through the bloodstream conduct surveillance for germs and other foreign invaders, but the immune system distinguishes “self” from “non-self,” with antibodies designed to ward off whatever is non-self and to ignore the body’s own cells. Sometimes however, self-cells become the cause of disease, as in cancer, thus frequently evading the antibodies’ disease-stopping activities.

This is an article that has been published by Oxford University Press in the book From Breakthrough to Blockbuster: The Business of Biotechnology by Donald Drakeman, Lisa Drakeman, and Nektarios Oraiopoulos, published February 14, 2022.