What are researchers trying to find with studying fetal tissue?

An explosive climate has surrounded US research with fetal tissues since July, when an anti-abortion group called the Center for Medical Progress in Irvine, California, released covertly filmed videos in which senior physicians from the Planned Parenthood Federation of America bluntly and dispassionately discussed their harvesting of fetal organs from abortions for use in research. Planned Parenthood is a non-profit women’s health provider that received US$528 million of government money in 2014, much of it in reimbursements for services ranging from contraception to cancer screenings, which it provides largely to poor women. Abortions, which are performed at about half of Planned Parenthood’s 700 clinics, constitute 3% of its services. A handful of clinics in two states supply fetal tissue for research.

Cell lines derived from aborted fetal tissue have been fairly commonplace in research and medicine since the creation in the 1960s of the WI-38 cell strain, which was derived at the Wistar Institute in Philadelphia, Pennsylvania, and MRC-5, which came from a Medical Research Council laboratory in London (see Nature 498, 422–426; 2013). Viruses multiply readily in these cells, and they are used to manufacture many globally important vaccines, including those against measles, rubella, rabies, chicken pox, shingles and hepatitis A.

Companies have shipped at least 5.8 billion vaccines made with these two cell lines which, with others, have become standard laboratory tools in studies of ageing and drug toxicity. (Research with such lines is not covered by US regulations governing the use of fresh fetal cells and tissue nor captured in the NIH database.) In the past 25 years, fetal cell lines have been used in a roster of medical advances, including the production of a blockbuster arthritis drug and therapeutic proteins that fight cystic fibrosis and haemophilia.

But off-the-shelf fetal cell lines are of limited use for scientists because they do not faithfully mimic native tissue and represent only a subset of cell types: WI-38 and MRC-5, for example, were derived from fetal lungs. The lines can also accumulate mutations after replicating in vitro over time. And creating humanized mice such as Su’s requires whole pieces of fetal organs to provide sufficient numbers of stem cells. For all of these reasons, researchers turn to fresh tissue.

In the United States, this is collected at medical centres and clinics that perform abortions under a patchwork of laws and regulations governing consent, tissue collection and transfer (see ‘Fetal tissue and the law’). US law says that clinics can recover “reasonable payments” to offset the costs of providing the tissue, but it makes it a felony to profit from doing so. Planned Parenthood officials say that its clinics obtain full and informed consent from women choosing to donate fetal remains for research, and the organization announced in October that its clinics will no longer recover costs of $45–60 per specimen for collecting the tissue.