Medicine: Immunity in Bottles

The credulity of U.S. doctors was sorely strained when Caltech biochemists revealed last spring that for the first time they had created antibodies in laboratory flasks. These artificial antibodies—the substances which form in the blood to fight poisons or diseases—were capable of attacking only a few simple chemical poisons (TIME, March 30). The latest news from Caltech is even more incredible: antibodies against bacterial disease, pneumonia III (one of the several forms of lung infection), have now been made synthetically. This achievement of Biochemists Linus Pauling and Dan Campbell is still in the realm of experimental medicine, and flask-prepared solutions will not yet replace the immunizing serums for clinical use now developed in horses and other living animals.* But the significance of the discovery for the future of medicine is incalculable.

The Caltech biochemists believe that their discovery is further proof that immunization, whose physiological mechanics has long been a major mystery, is a molecular phenomenon. In the blood stream of animals are large protein molecules called serum globulin. If a bacterium, virus, poison molecule or other “antigen” is near the point where these molecules are formed, the adaptable globulin molecules change their shape and assume structures complementary to those of the invading antigens, so that they can combine with them and neutralize them. After the infection or poisoning has been overcome, these changed globulin molecules remain in the blood as antibodies, ready to attack any later enemies. Hence immunity. Pauling and Campbell made their artificial pneumonia antibodies from serum globulin extracted from beef blood. Steps in the process: 1) the globulin molecules were heated to 135° F. for two weeks to make their structures “unfold”; 2) a complex sugar secreted by the pneumonia type III bacteria was added to the flask; 3) the solution was slowly cooled so that the molecules folded up again. But influenced by the bacterial sugar, the folding molecules assumed a modified structure in the flask, just as they would in the blood stream. Thus they became antibodies. Several tests showed that the artificial pneumonia antibodies were strikingly like natural antibodies, but the researchers do not yet claim that they are as potent.

*Or sometimes, as with infantile paralysis and meningitis, extracted from the blood of human beings who have recovered from a disease.