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.
Insulin producing cells avoid immune rejection. The phrase, there is more than one way to skin a cat often applies to the science of trying to develop therapies. A CIRM-funded team at the company Viacyte is working to cure diabetes and has developed a cell line that is a middleman, or precursor cell, part way between a stem cell and a fully mature insulin-producing cell. When transplanted into animal patients it has been shown to mature into the needed cells and correct the faulty sugar levels caused by the disease.
But, the company could not just transplant those cells into patients whose own insulin-producing cells had been destroyed by their immune system without protecting them from that immune attack. In a human trial we are funding that began in September the Viacyte team protects the cells inside a small porous pouch placed under the skin.Now they have reported in Cell Stem Cell work done with researchers at the University of California, San Francisco that shows that a drug-like pretreatment can alter the animal’s immune response and let the new cells survive without the protective pouch. Those cells, called PEC-01, were protected by agents that blocked a very specific part of the immune system that causes immune rejection—a much gentler treatment than the immune suppression used for organ transplants.
“The demonstration that these new immunotherapies block specific pathways and immune cells that are responsible for attacking pancreatic islet cells and prevent the rejection of implanted PEC-01 cells is an exciting finding that could lead to advances in the way we treat diabetes and other diseases.”
Stem cell work a runner up for discovery of the year. Each year the journal Science names a discovery of the year and nine runners up. This year the Mars rover took top honors but a Harvard team scored a runner up slot for its work creating mature insulin producing cells from stem cells in the lab. Many labs had failed to accomplish this feat over the past several years.
I agree this is a big deal, but many researchers in the field believe that the best place to mature stem cells into the desired tissue is in the patient where they can take cues from the body that are much more complex than what we can recreate in the lab. The Viacyte team cited above uses the in-the-body approach and is already testing the therapy in patients.
Toward the end of the original Harvard press release and at the end of the notice in Science, the authors note that before the work can be used in patients they need to overcome the patient’s immune reaction—something the most recent Viacyte discovery might be able to help achieve.
Clue found for how stem cells make decisions. Many a researcher has used the Bizarro cartoon labeled “Stem Cell Parental Advice” with the thought balloon “You are a stem cell you can become anything you want when you grow up.” Researchers have found that ability to be a double-edged sword. Since stem cells can become anything it is often hard to direct them efficiently down a particular desired path.
Now a Danish team from the University of Copenhagen has documented in Cell Reports a way to block all the various maturation paths and keep the stem cells in a stem cell state. This could be a first step to being able to consistently direct them down one preferred path. Science Codex picked up the university’s press release, which quoted a member of the research team, Joshua Brickman on why this could be valuable:
“If you block all the choices they can make, they stay in the stem cell state. If you only allow them one door to exit from the stem cell state, you should be able to make particular cell types more efficiently. So if you only leave one door open then it’s the path of least resistance and when you give them a push they really go.”
Video captures the excitement of stem cell researchers. Stanford’s research blog Scope produced a fun end-of-the-year piece that includes a video of researcher Margaret Fuller describing why she is so excited to work in this field. One example she cites came from a recent report about using stem cells to help repair lost muscle in wounded soldiers returning from Afghanistan. I’ll let you watch the video to see why she said “It gives me chills just thinking about it.”