Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.
Cell therapy for Parkinson’s advancing to the clinic. A decade-long moratorium on the transplant of fetal nerve tissue into Parkinson’s patient will end in two months when the first patients in a large global trial will receive the cells. BioScience Technology did a detailed overview on the causes for the moratorium and the optimism about the time being right to try again. The publication also talks about what most people in the field believe will be the long-term solution: moving from scarce fetal tissue to nerve cells grown from readily available embryonic stem cells. The author’s jumping off point was a pair of presentations at the International Society for Stem Cell Research in June, which we wrote about at the time. But the BioScience piece provides more background on the mixed results of earlier studies and references to recent journal publications showing long term—as much as 20 year—benefit for some of those patients.
It goes on to describe multiple reasons why, once the benefit is confirmed with fetal cells, moving to stem cells might be the better way to go. Not only are they more readily available, they can be purified in the lab as they are matured into the desired type of early-stage nerve cell. Researchers believe that some of the side effects seen in the early fetal trials stemmed from the transplants containing a second type of cell that caused jerking movements known as dyskinesias. One stem cell trial is expected to start in 2017, which we discussed in June.
Immunity persists through a special set of stem cells. Our immune system involves so many players and so much cell-to-cell interaction that there are significant gaps in our understanding of how it all works. One of those is how we can have long-term immunity to certain pathogens. The T-cells responsible for destroying invading bugs remember encountering specific ones, but they only live for a few years, generally estimated at five to 15. The blood-forming stem cells that are capable of generating all our immune cells would not have memory of specific invaders so could not be responsible for the long term immunity.
Now, an international team from Germany and from the Hutchison Center in Washington has isolated a subset of so-called “memory T-cells” that have stem cell properties. They can renew themselves and they can generate diverse offspring cells. Researchers have assumed cells like this must exist, but could not confirm it until they had some of the latest gee-wiz technologies that allow us to study single cells over time. ScienceDaily carried a story derived from a press release from the university in Munich and it discusses the long-term potential benefits from this finding, most notably for immune therapies in cancer. The team published their work in the journal Immunity.
Method may reduce the risk of stem cells causing tumors. When teams think about transplanting cells derived from pluripotent stem cells, either embryonic or iPS cells, they have to be concerned about causing tumors. While they will have tried to mature all the cells into a specific desired adult tissue, there may be a few pluripotent stem cells still in the mix that can cause tumors. A team at the Mayo Clinic seems to have developed a way to prevent any remaining stem cells in transplants derived from iPS cells from forming tumors. They treated the cells with a drug that blocks an enzyme needed for the stem cells to proliferate. Bio-Medicine ran a press release from the journal that published the finding, Stem Cells and Development. Unfortunately, that release lacks sufficient detail to know exactly what they did and its full impact. But it is nice to know that someone is developing some options of ways to begin to address this potential roadblock.
Multiple sclerosis just got easier to study. While we often talk about the power of iPS type stem cells to model disease, we probably devote too few electrons to the fact that the process is not easy and often takes a very long time. Taking a skin sample from a patient, reprogramming it to be an iPS cell, and then maturing those into the adult tissue that can mimic the disease in a dish takes months. It varies a bit depending on the type of adult tissue you want, but the nerve tissue that can mimic multiple sclerosis (MS) takes more than six months to create. So a team at the New York Stem Cell Foundation has been working on ways to speed up that process for MS. They now report that they have cut the time in half. This should make it much easier for more teams to jump into the effort of looking for cures for the disease. ScienceCodex ran the foundations press release.