There is a growing chorus from within the pro-life movement against PepsiCo for their use of a cell line (derived from a baby aborted in the 1970′s) for testing response to new flavors in the lab. 
This is biologically straightforward, and ethically problematic. From a consumerist and moral perspective, it’s even murkier. Pepsi is just the tip of the iceberg. Let’s build the argument from the biological level, upward.
BIOLOGY
Taste testing is as simple as stimulus and response. We eat/drink something new, and our taste buds either love us, or hate us for the experience. If we zoom in closer on the taste buds of the tongue, we would see that they are made up of many cells. If we zoom in even further on the cells, we come to the apparatus at the surface of the cell responsible for interacting with molecules in food, and creating a response within the cell that will be transmitted to the brain.
This apparatus is pictured above, and is at the core of the ethical debate. The two solid green, parallel lines represent the membrane of the cell. The purple ‘signaling agonist’ at top left is our food molecule. It binds to a receptor molecule that only binds molecules of a very specific shape and size. That receptor then slides to the right and interacts with G-Proteins, which activate other molecules such as Inositol Triphosphate, which in turn triggers what amounts to the old “Mousetrap” game–a cascade of responses within the cell.
It’s more complicated than that, but that’s the fundamental mechanism in question here.
HEK 293 Cells
PepsiCo employs the biotech company, Senomyx, to do their taste testing. Senomyx uses a line of cells that are derived from the kidney of an aborted baby in the 1970′s. The cell line is designated HEK (Human Embryonic Kidney) 293 (isolated and cultured successfully in the researcher’s 293rd experiment. These cells were isolated from the aborted baby’s kidneys and then grown and replicated in the laboratory in a liquid nutrient broth called cell culture medium. As long as one changes the broth periodically, the cells will continue to grow and divide.
In research, certain cell lines become the standard for use in a given field. Typically, the cells that become the standard, such as HEK 293 are remarkably stable, easy to work with, and provide reliable and repeatable results. These characteristics enable researchers to pursue tangential and parallel lines of research with great confidence in the relatedness of different labs’ results when the same cell line is employed. It assures us that we are all speaking the same cellular language, and not different dialects.
Hence the very thing that is a strength can also be a liability if cell lines have base and illegitimate origins. HEK cells are the standard in many fields of research. They are especially good at being used as “living test tubes” for creating proteins, such as the G Protein used in taste sensation.
Senomyx has been able to produce the G proteins within these cells and then isolate these proteins. They have then used these proteins in a proprietary construct to get a test tube response system to different molecules used in flavoring. Therein lies the tastelessness of the research method. The question is whether or not other cell lines exist, from which the same results may be gleaned, and how reliable these alternatives may be.
ETHICS
Let’s look for a moment at the problem of vaccines manufactured in aborted fetal cell lines. It has been suggested in some Catholic circles that the distance between today and the abortion from decades ago that established the cell line, and the proportional good to be gained and evil to be averted through use of the cell line vaccines can be sufficient to merit the use of the vaccines and attenuate complicity and culpability in the abortion. Some might agree, and some might disagree. I’ve heard Catholic bioethicists and clergy on both sides of this issue. But the issue begs a deeper question.
The more that HEK 293 is used (and it is used rather ubiquitously now), how many products are we morally obliged to refrain from using? How many medical treatments, with no ethically sound alternative, must we forgo? HEK 293 is used to manufacture proteins in thousands of labs, and is omnipresent. What do we do with a field already saturated by the use of aborted cell lines?
Obviously, we need ethically sound alternatives that produce the same quality output as the aborted cell lines, so that we may have the scientific basis for a smooth and orderly transfer. Then we need to change the culture of science, which will be no easy feat.
The next issue is what to do about all of the food products that have already been developed using these questionable methods. Even if Pepsi breaks ties with Senomyx, and cleans up their act, do we boycott all foods developed before the conversion?
For now the issue is pretty simple. Pepsi is committed to Senomyx, and I’m more than a few pounds overweight and just starting to shed those pounds. I won’t be purchasing PepsiCo products in the near future, or even the distant future, and even though this research leaves a bad taste in my mouth, the core question remains:
As these cell lines grow in use, where do we draw the line?
