GOVERNMENT & POLICY
C&EN TALKS WITH BY BETTE HILEMAN
RICHARD T. JOHNSON Pioneer neuroscientist says major improvements are needed in U.S. prion research programs
A
LTHOUGH TRANSMISSIBLE
spongiform encephalopathies (TSEs), which include mad cow disease, have been under investigation since the 1960s, there are still many important unanswered questions. The incubation periodforvariant Creutzfeldt-Jakob disease (vCJD)— the human form of mad cow disease—is unknown; the minimum dose of misfolded prion proteins needed to cause vCJD is unknown; and the likelihood that new, more easily transmitted prion strains will arise is unknown. Also, researchers still have not been able to determine whether consumption of deer or elk with chronic wasting disease (C WD)—prion disease in cervids—causes illness in humans. Achieving breakthroughs on these questions will probably require increased funding and major structural changes in the U.S. research Î program, says Richard T. § Johnson, professor of neu- £ rology, microbiology, and | neuroscience atJohns Hop- * kins University School of 5 Medicine. Johnson chaired s the Institute of Medicine £ committee that wrote the =
Johnson went to Hopkins in 1969, there were joint meetings involving his lab and Gajdusek's lab in Patuxent, Md. Johnson examined the first chimp that came down with kuru after Gajdusek had inoculated it with braintissuefrom a kuru victim. Because of his long-term interest in TSEs, Johnson has many ideas on how to improve the U.S. research program. Cur rently, the National Institutes of Health spends only about $25 million a year on prion disease research, in contrast to the $250 million that Europe spends. Threequarters of U.S. funds go to just two labs, Nobel Laureate Stanley B. Prusiner's lab at the University of California, San Fran cisco, and Rocky Mountain Laboratories in Hamilton, Mont., which is run by the National Institute ofAllergy & Infectious Diseases. Both facilities do excellent work,
Achieving breakthroughs will probably require increased funding and major structural changes in the U.S. research program.
Johnson says, but many more researchers need to report published in May on ° be involved in the field. research needs for underIn 2002, Congress gave standingTSEs (C&EN, May the Department of De 31,2004, page 21). fense $42 million to study Although Johnson has TSEs in hopes that the done no laboratory work on new money would attract more researchers TSEs, he has been tangentially involved to thefield.But those funds did little to with such research throughout most ofhis stimulate research. "It is very difficult to en career and has written many review articles courage workers to enter the field or to about prion diseases. In the late 1950s, train people in thefieldbecause the facil when he worked at Walter Reed Army In ities required and the type of work it is stitute of Research in Washington, D C , don'tfitwell with the model for research he met D. Carleton Gajdusek, who later funding we have in the U.S.," Johnson won the 1976 Nobel Prize in Physiology or notes. Medicine for his work on kuru, a prion dis To obtain a grant for research on TSEs, ease among the Fore tribespeople of the a scientist needs access to a lab where the New Guinea highlands. "Ifirstgot involved work can be done. Most prion research re in TSEs when I was in Papua New Guinea quires expensive biological safety level II in 1964 and saw kuru," Johnson says. At or level III facilities that can house large that time, scientists believed that kuru was animals, Johnson says. Few universities caused by an unconventional virus. After ο
HTTP://WWW.CEN-ONLINE.ORG
have such facilities. University officials would expect the money for the facilities to come from grants. Another problem is that most prion work on animals requires many years before results can be obtained, he says. Johnson stresses that it is especially im portant to do more research on CWD, which is rapidly spreading among deer and elk populations. "Colleagues in Europe say, Ύαη are potentially sitting on a {CWD} time bomb and doing nothing about it/" he says. He notes several reasons why the disease is worrisome: It is more infectious in the field than any of the other TSEs; deer can contract the disease merely from living in a paddock where a CWD-infected deer lived previously Also, CWD can move across species barriers. When lab monkeys and mice are inoculated with brain tissue from CWD-infected deer, they become infected and die, Johnson says. Furthermore, hunters eat deer and elk, upscale restaurants serve their meat, and cattle sharefieldswith them, he says. Researchers at the Centers for Disease Control & Prevention assume that if
CWD is transmissible to humans, it would cause vCJD. But Johnson says, "Actually, nobody has any idea what symptoms CWD might cause in humans. It might be burning sensations in elderly ladies' feet. The only way we are going tofindout is to increase autopsy rates in this country." Au topsies, which are disappearing, should be done on all people with chronic neurolog ical diseases, he says. It would be really useful to do strain typ ing on the prions from any new cases of mad cow disease that show up in the U.S., Johnson says. Scientists need to know whether the U.S. prion strain is the same virulent strain that arose in England or if it is perhaps a milder form that arose spon taneously in the U.S., he says. It could be a strain that occurs intermittently and caus es no disease in humans, he notes. That would be reassuring and help to restore confidence in American beef. C&EN
/ JULY
26, 200Λ
39
