Dr. David Robertshaw, chairman of physiology at Cornell University in Ithaca, N.Y., said CSFs in the adult act on the primitive, undifferentiated "stem" cells in the sternum, ribs and pelvis to produce red and white blood cells in the bloodstream.
"The blood is made up of many types of cells. But the stem cells are the originating type for all of the blood cells. They are genetically coded to become a red cell or certain kind of white cell," he said.
CSFs of both natural or recombinant varieties home in on specific types of stem cells to replenish the kinds of blood cell required by the body in the constant death and replacement cycle of the cells.
"The applications are very wide," insisted Golde. "Consider a situation in which someone is suffering from an overwhelming infection. We can now give them antibiotics to injure the microorganisms, then ameliorate the side effects of that treatment with CSFs."
He said the protein molecules are nothing like the lymphokines interferon and interleukin-2, which bolster maneuvers of circulating lymphocytes in the blood. He said he doubts "that anyone really knows what interferon does."
By contrast, CSF molecules "do one thing and one thing only," said Golde: directly boosting the ranks of the immune system's front-line soldiers in defense against toxins and disease.
"I had a hunch 20 years ago that they would be very important," he said of CSFs. "Things like this really make you stop to think about the new era of medical therapy we're entering."
Said Whitcome: "This represents the first advance in man's ability to regulate the immune response since Jenner and Pasteur. Antibiotics just augment; CSFs give us control."