Of Mice and Men, SHEEFs and Chimeras

When scholars study a thing, they strive

To kill it first, if it’s alive;

Then they have the parts and they’ve lost the whole

For the link that’s missing was the living soul.

— Johann Wolfgang von Goethe, Faust: First Part

In his June 5 column titled, “Sympathy for the Devil,” Archbishop Charles Chaput observed that the enduring popularity of the character of Faust over the years tells us something about Western culture.

“Who is Faust? He’s the man of letters who sells his soul to the devil on the promise that the devil will show him the secrets of the universe.”

Faust doesn’t come to God’s creation as a seeker after truth, beauty, and meaning. He comes impatient to know, the better to control and dominate, with a delusion of his own entitlement, as if such knowledge should be his birthright.

The archbishop’s comments are particularly timely when considering the current status of Embryonic Stem Cell Research (ESCR). Recent media reports suggest that scientists engaging in ESCR may be making some Faustian bargains of their own.

In 2009, President Obama issued an executive order allowing federal funding for virtually all types of embryonic stem cell research. This bending of ethical and legal principles was justified by the belief that unfettered ESCR would lead to cures for any number of heretofore untreatable medical conditions. Predictably, though, the scientists’ “impatience to know” pushed experimentation far beyond generating cells and tissues. New technologies are leading to the creation of entirely independent life forms, “born” from artificial manipulation of cells. And the line separating animal from human is becoming very blurred.

Chimeras: Solving the Organ Donation Problem?

According to organdonor.gov, there are over 199,000 men, women, and children on the national transplant waiting list. Sadly, 22 of these people die each day from the lack of a needed organ. Frustrated by the shortage of donors, scientists are actively exploring the possibility of growing human organs in animals.

As reported by Nicholas Wade of the New York Times (1/26/17), the human-organ-growing pigs are called chimeras. They are created by implanting human stem cells into an early pig embryo, resulting in an animal composed of mixed pig and human cells. In addition to their potential use in generating replacement organs, chimeras are used to study neurological diseases and drug treatments for AIDS.

Of course, the creation of chimeras raises serious ethical concerns. The most frightening of these is the potential for some of the human cells to become incorporated into the animal’s brain or reproductive cells, resulting in an animal that possesses human qualities. As Wade phrased it,  “Almost no one wants a talking pig… [or] to see what might result from the union between a pig with human sperm and a sow with human eggs.”

In fact, the potential for such a macabre outcome compelled the National Institutes of Health (NIH) to ban federal funding for human-animal chimera research in 2015. However, pressure from the research community and the existence of privately-funded chimera experiments motivated the NIH to submit a proposal lifting that funding ban in August, 2016.

Chimeras and Church Teaching

Fr. Tad Pacholczyk of the National Catholic Bioethics Center (NCBC), points out that “despite our initial hesitations, certain kinds of human/animal chimeras are likely to be justifiable and reasonable.”

[We] recognize, for example, how thousands of patients who have received replacement heart valves made out of pig or cow tissues are already themselves a type of human/animal chimera.

However, in an interview with Crux (February 6, 2016), Fr. Pacholczyk defined the very specific, immutable circumstances required to make such research morally permissible in light of Catholic teaching:

• The procedures must not involve the creation or destruction of human embryos.

• They must not involve the replication of major pillars of human identity in animals, such as the brain system.

• They must not involve the production of human gametes, meaning the basic building blocks of human reproduction.

In its harshly critical response to the NIH proposal, the United States Conference of Catholic Bishops (USCCB) condemned the NIH for “running roughshod over [a] basic moral principle…to create beings who do not fully belong to either the human race or the host animal species.”

Referencing Fr. Pacholczyk, the USCCB highlighted how the NIH proposal violates all three of the requisite ethical conditions he described.

[This research] relies on the destruction of human embryos; it contemplates producing entities with partly or wholly human brains; and it allows for producing living entities who have human gametes (though researchers will be told to take precautions so these entities do not engage in “breeding”).

Because of the multiple ethical and legal concerns, the USCCB concluded that the “NIH proposal is seriously flawed [and] should be set aside.”

According to the New York Times, the NIH has yet to declare a final decision. Consequently, the 2015 federal funding ban for human-animal chimera experiments remains in effect.

Raising SHEEFS

If the prospect of scientists creating human-animal creatures wasn’t strange enough, Carl Zimmer of the New York Times reported that researchers are also closing in on the ability to assemble stem cells that can organize themselves into synthetic human embryos.

Soon, experts predict, they will learn how to engineer these cells into new kinds of tissues and organs. Eventually, they may take on features of a mature human being ( New York Times, 3/21/17).

Called “synthetic human entities with embryolike features,” or SHEEFs, they are the next step beyond in vitro fertilization. However, unlike embryos created by uniting egg and sperm cells in a petri dish, SHEEFS are produced without the use of gametes.

In a study published in March, Dr. Magdalena Zernicka-Goetz and her colleagues at the University of Cambridge injected two types of mouse stem cells, embryonic and trophoblastic (placenta-forming cells), into a microscopic framework that allowed for the growth of a three dimensional structure.

After five days, the jumble of cells had multiplied and self organized into distinct cell populations. The embryonic stem cells had diverged into two populations. One cluster contained cells that would give rise to the heart, bone, and muscle, while another contained cells that would go on to become the brain, skin, and eyes.

The Cambridge team is now hoping to create similar artificial embryos with human cells. But before they can do so, they must overcome the “14-Day Rule.”

The 14-Day Rule

First defined in 1979, the 14-Day Rule, is a research limiting policy, self-imposed by the scientific community. As described by Dr. John Asch, the rule declares “that experiments with intact human embryos must not allow them to develop beyond the earlier of day 14 or the appearance of the primitive streak (PS).”

“[The primitive streak] is a faint band of cells marking the beginning of an embryo’s head-to-tail axis… The formation of the primitive streak is significant because it represents the earliest point at which an embryo’s biological individuation is assured. [Some] people reason that at this stage a morally significant individual comes into being.” (Nature, May 4, 2016)

In the opinion of Fr. Pacholczyk, the 14-Day Rule was contrived simply “to enable scientists to get beyond the knowledge that they’re experimenting on or destroying fellow humans.” In fact, the rule has “not actually restricted real-world human embryo research,” and has only endured because scientists have lacked the technical ability, until now, to maintain human embryos in the lab for any longer than that amount of time.

Considering the fact that the rule may now actually begin to hamper what some of them are interested in doing, they are pushing, unsurprisingly, to “revisit” and “recalibrate” the rule.

Dr. Asch suggests, however, the rapid advances in SHEEF technology “actually pose a deeper challenge to current ethics-based embryo and stem-cell research guidelines that cannot be met by [simply] …adjusting the 14-day rule.”  To what extent scientists wish to be governed by objective moral standards, or if they’ll continue to devise a relative code of ethics like the 14-Day Rule, remains to be seen.

Fueling the “Throw-Away Culture”

On May 18, meeting with people suffering from Huntington’s disease, a rare and incurable genetic brain disorder, Pope Francis addressed the scientists and medical personnel who accompanied them.

I encourage you to always pursue [a cure] with means that do not contribute to fueling that “throw-away culture” that at times infiltrates even the world of scientific research. Some branches of research, in fact, utilize human embryos, inevitably causing their destruction. But we know that no ends, even noble in themselves, such as a predicted utility for science, for other human beings or for society, can justify the destruction of human embryos.

Pope Francis has always strongly condemned embryonic stem cell research, particularly in his encyclical, Laudato Si. He wrote that there is “a tendency to justify transgressing all boundaries when experimentation is carried out on living human embryos.” (136) Certainly, the creation of chimeras and SHEEFs are examples of science not only transgressing boundaries, but essentially erasing them altogether. It doesn’t stop there, either, as more questionable developments are on the horizon, such as using skin cells to create babies.

The dangerous desire of mankind to free itself from the constraints of male vs female, the necessity of the procreative act to conceive children, as well as any form of imperfection or disability, will, in turn, give scientists greater freedom “to [disregard] the great ethical principles,  and [consider] any practice whatsoever as licit.”  As Pope Francis warns, “a technology severed from ethics will not easily be able to limit its own power.” (136)

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