Paul Ehrlich's Receptor Immunology: The Magnificent Obsession (review)

Paul Ehrlich has had his share of biographers, at least in Germany. First out was a small volume in the series "Meister der Heilkunde" by one of his co-workers, Adolf Lazarus (Paul Ehrlich, 1922), who wanted to understand which spiritual and moral forces had contributed to his master's "genial intuition." Paul Ehrlich als Mensch und Arbeiter, the standard work for more than half a century, was published two years later by his former secretary, Martha Marquardt, who filled her firsthand account with charming anecdotes and reconstructed dialogues; it was later revised and translated into English in 1949. These two personal portraits laid the ground for at least three biographies after the Second World War, by Gerhard Venzmer, 1948; Hans Loewe, 1950; and Walter Greiling 1954—all of whom were probably motivated partly by the wish to rehabilitate Ehrlich after the Nazi erasure of his memory. Thirty years later, Ernst Bäumler, a director of the Hoechst chemical company, who had organized a Friend's Association to save Ehrlich's house for posterity, wrote Paul Ehrlich: Scientist for Life (1984). Interestingly, no English or American biographers have tried their hand at Ehrlich, in spite of the fact that he became a well-known figure in the United States with "Dr. Ehrlich's Magic Bullet" (1940), the movie about the discovery of Salvarsan against syphilis, which gave John Huston his first Academy Award nomination for best screenplay.

Ehrlich's biographers have all been enthusiastic, but (with the possible exception of Bäumler) they have not made much effort to dig into the archives or to understand Ehrlich's ouevre from a more detached point of view. Thus to this date there exists no full, scholarly biography of Ehrlich, and particularly no attempt to understand his work against the background of late nineteenth- and early twentieth-century imperial German science and culture. Arthur Silverstein's thorough analysis of the conceptual foundations of Ehrlich's scientific contributions, which has grown out of a couple of articles in the journal Cellular Immunology, is not that kind of work either (it deals neither with der Mensch nor with the broader context of his life and work), but it is nevertheless an important and necessary prerequisite for the much-needed future full-scale biography—should anybody ever be so courageous as to indulge in such a multifaceted enterprise.

The thrust of Silverstein's story is his hero's "magnificent obsession" with the receptor idea—namely, that "every physiological process depends on the initial interaction of some substance with a preformed receptor" (pp. 137-38). The idea first occurred to Ehrlich when he was a medical student and then guided almost everything else that he did, including his work in experimental oncology. The most celebrated result of this line of thinking was his biological side-chain theory of antibody formation—meaning that specific molecular groups (side-chains) on the cell surface are recognized by the antigen and then released into the bloodstream as antibodies. The theory was launched in Ehrlich's Croonian lecture to the Royal Society of London in 1900 and took the emerging immunological discipline by storm, not least because of its pictorial neatness. In the interwar years it fell into disrespute, but it was relaunched, in a more modern form, by Niels K. Jerne and Macfarlane Burnet in the 1950s. The ensuing clonal selection theory became the central dogma of postwar immunology.

Silverstein acknowledges that the point about the receptor idea as the leading thread in Ehrlich's scientific work is partly borrowed from the German-American biochemist Leonor Michaelis, a younger contemporary of Ehrlich. But this is a starting point only—Silverstein skillfully substantiates the claim with a detailed analysis of the Ehrlich papers in the Rockefeller University Archives and a close reading of the early publications. In...