(Editor's note: Corrects spelling in last paragraph.)
(CNSNews.com) - American scientists are using tissue from aborted babies in genetically engineered mice to study how certain diseases are spread, and the experiments are being paid for with U.S. tax dollars.
It's not clear how much fetal tissue is used or how it is supplied. Scientists involved in some of the research at the National Institutes of Health refused to speak with Cybercast News Service about their work.
The experiments started 20 years ago, when scientists first began implanting or injecting a mouse without an immune system with human cells or tissue to study diseases, such as HIV/AIDS and certain cancers. While some of the cells and tissue comes from adults, much of it comes from babies aborted at 17-23 weeks' gestation. It is legal, but controversial and not well known outside of research circles.
Over the years, thousands of "SCID-hu" mice (pronounced skid-hew) have been bred for experimentation purposes, making the animal-human hybrid -- or "chimera" -- a hot commodity for researchers.
The SCID-hu mouse originally was created in 1988 by Stanford researcher J. Michael McCune. SCID stands for "severe combined immuno-deficiency." "Hu" stands for human. The mouse itself is not considered to be controversial.
"It has been something of a godsend for modern-day research," said Dr. Joseph Bryant, director of animal research at the University of Maryland's Institute of Human Virology.
"It was discovered several years ago that this mouse, which is kind of like the bubble boy in that it has no real immune system, can't reject tissue, even from a human," Bryant said. "It is used in transplant medicine and cancer research, research on diabetes, for studying HIV, the effects of some drugs, Alzheimer's - you name it.."
Thus far, its use has galvanized AIDS research, according to Dr. Dan Littman, a top SCID-hu researcher at New York University's Medical Center.
"I think in terms of testing for various drugs that may be effective in HIV infection in an animal model, SCID-hu may be as good an animal model as one can get," Littman told Cybercast News Service. "I think it has been successful for that."
The mice are being utilized in so many areas of research that an online search of the scientific literature would generate a vast number of hits. As Bryant put it, "it would take you to the end of the year just to read all of them."
Indeed, though the National Institutes of Health (NIH) would not comment on that research, Cybercast News Service has found records indicating that the federal government is funding hundreds of SCID-hu studies, likely to the tune of millions of dollars.
It's not known exactly how much fetal tissue is being used. Attempts over a period of weeks to obtain details from the NIH have thus far proved unsuccessful. But article after article in prominent scientific journals such as Blood and The Journal of Virology, as well as The Proceedings of the National Academies of Science describe the transplantation of "fetal human tissue" in myriad SCID-hu experiments.
For instance, a 2005 study published in Blood said, "Mice were surgically implanted with human bone chips of fetal femur or tibia from 19- to 23-week gestation human abortuses ...."
Another study, published in 2000 in The Journal of Virology said: "The mice were implanted with 1-mm3 pieces of human fetal thymus and liver when they were 6- to 8-weeks-old. Tissue at 16- to 24-weeks of gestational age was obtained...."
Yet another, from 2001 in The Proceedings of the National Academies of Science said, "Human fetal skin tissue (18 to 23 weeks gestational age) was purchased ... in accordance with all local, state, and federal guidelines."
Humanized rodent models workshop
The use of fetal tissue has become an issue for the scientists who conduct research on the mice -- although their concern is strictly a pragmatic one, it seems.
When top researchers like Littman gathered in September at NIH headquarters in Bethesda, Md., to compare notes on their research, one topic they chose to discuss was the problem of using fetal tissue to recreate -- or "reconstitute" -- a human immune system.
But their issue centered on a technical question -- the ability to get tissue that is "fresh" versus that which is frozen. Tissue from the liver and thymus are transplanted into the mice to create a human immune system in a mouse's body.
To be useful in research, the fetal cells must be alive, even if they come from a dead source, namely, an aborted baby. Using frozen cells that have been purchased from a supplier presents certain problems.
"There is still a lot of disagreement about what kind of reconstitution one gets, depending on the kinds of techniques people use and how robust each of these systems is," Littman said. "There definitely is no general agreement, yet. It's still very much an emerging field."
Frozen or fresh, what seems undisputed is the fact that fetal tissue used in SCID-hu mice is considered commonplace.
A presentation made by one conference participant, Dr. Ramesh Akkina of Colorado State University, underscores that fact. The researcher showed his colleagues photographs of a genetically engineered mouse that had received human fetal thymus, liver, lymph nodes and bone-marrow tissue.
Akkina's lab is a "core" facility, meaning it has a federal grant to produce the mice for a network of other researchers through the Colorado Center for AIDS Research. His team used fetal tissue from 18- to 20-weeks of age that was obtained from an undisclosed biomedical "supplier" -- an organization that gets aborted fetuses from abortion clinics and makes the tissue available.
Why use fetal tissue -- and, more specifically, why from fetuses at 18 to 20 weeks -- essentially from late-term abortions?
"That's what was available," the Fort Collins, Colo.-based researcher told Cybercast News Service. "Things are done on the basis of what's available. The discarded tissue is available on a random basis, and if you can get those tissues, you can use them for research purposes. We use whatever's available at the time."
Dr. David Prentice, an analyst with the Family Research Council and adviser to several members of Congress on bioscience issues, said it's no surprise that researchers like Akkina would use fetal tissue on a pragmatic basis. The fact of the matter is that tissue from aborted fetuses is legal, plentiful -- and available.
"It's not that, scientifically, it's such a good source," Prentice said. "It's that it's readily available and inexpensive. Let's be honest, scientists are trying to save dollars -- there's only so much money in your grant, and if you can get a lot of tissue cheaply, you're probably going to go to use what's most available."
"You don't know the quality of tissue you are getting each time," he added. "There will be variations in terms of age, the genetics of the tissue that they get -- it makes for poor science to continue following that route."
No matter how you feel about abortion, the use of tissue ultimately obtained from an abortion clinic is highly problematic, according to Arthur Caplan, director of the Center for Bioethics at the University of Pennsylvania.
"When you get material from an abortion clinic, you really don't know how old that fetus was, you really don't know what you've got -- you don't know if the fetus was healthy or was aborted because of some disease," Caplan said. "You don't actually have the best tool for science."
Legal, but ethical?
Some ethicists, meanwhile, are concerned. Dr. C. Ben Mitchell, executive director of the Center for Bioethics and Human Dignity, said the mixing of human and animal cells that occurs in SCID-hu research is not particularly problematic, but he is concerned about the use of tissue taken from aborted fetuses.
"Many of us would have a problem with that source of cells, simply because it makes one feel complicit with the decision to abort the fetus, or to destroy an embryo for those sources," he told Cybercast News Service .
Legally, however, there is nothing to stop the use of fetal tissue in scientific research.
Transplanting fetal tissue with the goal of helping to cure humans has been legal since 1993. On Jan. 22 of that year, President Clinton ordered Secretary of Health and Human Services Donna Shalala to remove the ban President Reagan had ordered in 1988 on federal funding of any "therapeutic transplantation research" that used human fetal tissue derived from induced abortions.
Congress later passed a law, Public Law 103-43, which states, "no official of the executive branch may impose a policy that the Department of Health and Human Services is prohibited from conducting or supporting any research on the transplantation of human fetal tissue for therapeutic purposes . . ."
But the use of fetal tissue in animal models such as the SCID-hu mouse has never been subject to regulation. In fact, the law does not specifically address the issue of research using fetal transplants in animals -- especially in chimeras or bioengineered animals such as SCID-hu mice.
Moreover, there are few regulations of any kind covering the medical use of human tissue. According to Caplan, whether it comes from an aborted fetus or an adult's amputated limb, it is all treated as biological "material."
"Outside of checking for infectious diseases, there aren't any federal laws that say you can't do this or you can't do that - or, 'You can put it here,' or 'You can't put it there,'" Caplan told Cybercast News Service.
"There are some states that have said, 'We don't want you doing research with fetal tissue' -- Louisiana would be one -- though that law doesn't distinguish between putting it into a rat brain and putting it into a human brain. It just says, 'Don't do research with it.'"
It's a concern that only Congress can address.
The NIH, meanwhile, has refused multiple requests by Cybercast News Service to conduct interviews with the program director for SCID-hu mouse research or others knowledgeable about the program.
NIH spokesman Don Ralbovsky advised Cybercast News Service to file a Freedom of Information Act request, and that even if a FOIA goes through, it will take "some" time to gather the information in question.
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