10 septembre 2003
Researchers in Switzerland reversed a genetic developmental defect in mice by injecting their pregnant mothers with a recombinant protein. These smaller-than-normal patients, so-called Tabby mice, lack specialized hairs, teeth, and sweat glands. Both Tabby and its human counterpart of this disease, an X-linked form of ectodermal dysplasia, result from a mutated gene that is highly conserved in mouse and man, ectodysplasin A, or EDA .
Pascal Schneider and colleagues at the University of Lausanne created a friendly Trojan horse of sorts by fusing a correct version of the EDA receptor-binding domain to the C-terminus of immunoglobulin G1's Fc domain. The Fc fusion ensures delivery through placental protein receptors as mother mouse passes immune protection on to her developing pups. The EDA enters the fetal systems to aid development. The treatment resulted in larger mice that had more specialized hair types, better tooth development, and sweat glands (O. Gaide et al., "Permanent correction of an inherited ectodermal dysplasia with recombinant EDA," Nat Med, April 7, 2003).
The EDA ligand is expressed in the skin of normal adult mice, but the effects persisted for treated Tabbys. Says Schneider: "It must have a function, otherwise it would not be expressed ... but we can tell from this experiment that EDA has proven not necessary to maintain the structure which has been creat