immune system

Engineered T cells made from stem cells could provide immunity against multiple cancers

/ Yimy Villa / Leave a comment
Dr. Lily Yang

Within all of our bodies there is a special type of “super” immune cell that holds enormous potential. Unlike regular immune cells that can only attack one cancer at a time, these “super” immune cells have the ability to target many types of cancers at once. These specialized cells are known as invariant natural killer T cells or iNKT cells for short. Unfortunately, there are relatively few of these cells normally present in the body.

However, in a CIRM-funded study, Dr. Lily Yang and her team of researchers at UCLA have found a way to produce iNKT cells from human blood stem cells. They were then able to test these iNKT cells on mice with both human bone marrow and human cancers. These mice either had multiple melanoma, a type of blood cancer, or melanoma, a solid tumor cancer. The researchers then studied what happened to mice’s immune system, cancers, and engineered iNKT cells after they had integrated into the bone marrow.

The results were remarkable. The team found that the blood stem cells now differentiated normally into iNKT cells, producing iNKT cells for the rest of the animal’s life, which was generally about a year. Mice without the engineered stem cell transplants had undetectable levels of iNKT cells while those that received the engineered cells had iNKT cells make up as much as 60% of the total immune system cells. The team also found that the engineered iNKT cells were able to suppress tumor growth in both multiple myeloma and melanoma.

Dr. Yang, in a press release by UCLA health, discussed the significance of the results in this animal model and the enormous potential this could have for cancer patients.

“What’s really exciting is that we can give this treatment just once and it increases the number of iNKT cells to levels that can fight cancer for the lifetime of the animals.” said Yang.

In the same press release, Dr. Yang continued to highlight the study’s importance by saying that,

“One advantage of this approach is that it’s a one-time cell therapy that can provide patients with a lifelong supply of iNKT cells.”

Researchers mentioned that they could control total iNKT cell make up in the immune system depending on how they engineered the blood stem cells. However, more research is needed to determine how these engineered iNKT cells might be useful for treating cancer in humans and evaluating any long-term side effects associated with an increased number of these cells.

The full results of this study were published in the journal Cell Stem Cell.

Stanford study successful in transplant of mismatched stem cells, tissue in mice

/ Yimy Villa / 1 Comment
Dr. Irv Weissman at Stanford University

A transplant can be a lifesaving procedure for many people across the United States. In fact, according to the Health Resources & Services Administration, 36,528 transplants were performed in 2018. However, as of January 2019, the number of men, women, and children on the national transplant waiting list is over 113,000, with 20 people dying each day waiting for a transplant and a new person being added to the list every 10 minutes.

Before considering a transplant, there needs to be an immunological match between the donated tissue and/or blood stem cells and the recipient. To put it simply, a “match” indicates that the donor’s cells will not be marked by the recipient’s immune cells as foreign and begin to attack it, a process known as graft-versus-host disease. Unfortunately, these matches can be challenging to find, particularly for some ethnic minorities. Often times, immunosuppression drugs are also needed in order to prevent the foreign cells from being attacked by the body’s immune system. Additionally, chemotherapy and radiation are often needed as well.

Fortunately, a CIRM-funded study at Stanford has shown some promising results towards addressing the issue of matching donor cells and recipient. Dr. Irv Weissman and his colleagues at Stanford have found a way to prepare mice for a transplant of blood stem cells, even when donor and recipient are an immunological mismatch. Their method involved using a combination of six specific antibodies and does not require ongoing immunosuppression.

The combination of antibodies did this by eliminating several types of immune cells in the animals’ bone marrow, which allowed blood stem cells to engraft and begin producing blood and immune cells without the need for continued immunosuppression. The blood stem cells used were haploidentical, which, to put it simply, is what naturally occurs between parent and child, or between about half of all siblings. 

Additional experiments also showed that the mice treated with the six antibodies could also accept completely mismatched purified blood stem cells, such as those that might be obtained from an embryonic stem cell line. 

The results established in this mouse model could one day lay the foundation necessary to utilize this approach in humans after conducting clinical trials. The idea would be that a patient that needs a transplanted organ could first undergo a safe, gentle transplant with blood stem cells derived in the laboratory from embryonic stem cells. The same embryonic stem cells could also then be used to generate an organ that would be fully accepted by the recipient without requiring the need for long-term treatment with drugs to suppress the immune system. 

In a news release, Dr. Weissman is quoted as saying,

“With support by the California Institute for Regenerative Medicine, we’ve been able to make important advances in human embryonic stem cell research. In the past, these stem cell transplants have required a complete match to avoid rejection and reduce the chance of graft-versus-host disease. But in a family with four siblings the odds of having a sibling who matches the patient this closely are only one in four. Now we’ve shown in mice that a ‘half match,’ which occurs between parents and children or in two of every four siblings, works without the need for radiation, chemotherapy or ongoing immunosuppression. This may open up the possibility of transplant for nearly everyone who needs it. Additionally, the immune tolerance we’re able to induce should in the future allow the co-transplantation of [blood] stem cells and tissues, such as insulin-producing cells or even organs generated from the same embryonic stem cell line.”

The full results to this study were published in Cell Stem Cell.

Stanford scientist uses CRISPR-Cas9 and stem cells to develop potential “bubble baby” therapy

/ Yimy Villa / 1 Comment
Dr. Matthew Porteus, professor of pediatrics at Stanford University.
Photo courtesy of Stanford Medicine.

Our immune system is an important and essential part of everyday life. It is crucial for fighting off colds and, with the help of vaccinations, gives us immunity to potentially lethal diseases. Unfortunately, for some infants, this innate bodily defense mechanism is not present or is severely lacking in function.

This condition is known as severe combined immunodeficiency (SCID), commonly nicknamed “bubble baby” disease because of the sterile plastic bubble these infants used to be placed in to prevent exposure to bacteria, viruses, and fungi that can cause infection. There are several forms of SCID, one of which involves a single genetic mutation on the X chromosome and is known as SCID-X1

Many infants with SCID-X1 develop chronic diarrhea, a fungal infection called thrush, and skin rashes. Additionally, these infants grow slowly in comparison to other children. Without treatment, many infants with SCID-X1 do not live beyond infancy.

SCID-X1 occurs almost predominantly in males since they only carry one X chromosome, with at least 1 in 50,000 baby boys born with this condition. Since females carry two X chromosomes, one inherited from each parent, they are unlikely to inherit two X chromosomes with the mutation present since it would require the father to have SCID-X1.

What if there was a way to address this condition by correcting the single gene mutation? Dr. Matthew Porteus at Stanford University is leading a study that has developed an approach to treat SCID-X1 that utilizes this concept.

By using CRISPR-Cas9 technology, which we have discussed in detail in a previous blog post, it is possible to delete a problematic gene and insert a corrected gene. Dr. Porteus and his team are using CRISPR-Cas9 to edit blood stem cells, which give rise to immune cells, which are the foundation of the body’s defense mechanism. In a study published in Nature, Dr. Porteus and his team have demonstrated proof of concept of this approach in an animal model.

The Stanford team was able to take blood stem cells from six infants with SCID-X1 and corrected them with CRISPR-Cas9. These corrected stem cells were then introduced into mice modeled to have SCID-X1. It was found that these mice were not only able to make immune cells, but many of the edited stem cells maintained their ability to continuously create new blood cells.

In a press release, Dr. Mara Pavel-Dinu, a member of the research team, said:

“To our knowledge, it’s the first time that human SCID-X1 cells edited with CRISPR-Cas9 have been successfully used to make human immune cells in an animal model.”

CIRM has previously awarded Dr. Porteus with a preclinical development award aimed at developing gene correction therapy for blood stem cells for SCID-X1. In addition to this, CIRM has funded two other projects conducted by Dr. Porteus related to CRISPR-Cas9. One of these projects used CRISPR-Cas 9 to develop a treatment for chronic sinusitis due to cystic fibrosis and the second project used the technology to develop an approach for treating sickle cell disease.

CIRM has also funded four clinical trials related to SCID. Two of these trials are related to SCID-X1, one being conducted at St. Jude Children’s Research Hospital and the other at Stanford University. The third trial is related to a different form of SCID known as ADA-SCID and is being conducted at UCLA in partnership with Orchard Therapeutics. Finally, the last of the four trials is related to an additional form of SCID known as ART-SCID and is being conducted at UCSF.

Boosting immune system cells could offer a new approach to treating Lou Gehrig’s disease

/ Kevin McCormack / 4 Comments

ALS

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is one of those conditions that a lot of people know about but don’t know a lot about. If they are fortunate it will stay that way. ALS is a nasty neurodegenerative disease that attacks motor neurons, the cells in the brain and spinal cord that control muscle movement. As the disease progresses the individual loses their ability to walk, talk, eat, move and eventually to breathe. There are no effective treatments and no cure. But now research out of Texas is offering at least a glimmer of hope.

Dr. Stanley Appel, a neurologist at the Houston Methodist Neurological Institute noticed that many of the ALS patients he was treating had low levels of regulatory T cells, also known as Tregs. Tregs play a key role in our immune system, suppressing the action of molecules that cause inflammation and also helping prevent autoimmune disease.

In an article on Health News Digest Appel said:

Stanley Appel

Dr. Stanley Appel: Photo courtesy Australasian MND Symposium

“We found that many of our ALS patients not only had low levels of Tregs, but also that their Tregs were not functioning properly. We believed that improving the number and function of Tregs in these patients would affect how their disease progressed.”

And so that’s what he and his team did. They worked with M.D. Anderson Cancer Center’s Stem Cell Transplantation and Cellular Therapy program on a first-in-human clinical trial. They took blood from three people with different stages of ALS, separated the red and white blood cells, and returned the red blood cells to the patient. They then separated the Tregs from the white blood cells, increased their number in the lab, and then reinfused them into the patients, in a series of eight injections over the course of several months.

Their study, which appears in the journal Neurology,® Neuroimmunology & Neuroinflammation, found that the therapy appears to be safe without any serious side effects.

Jason Thonhoff, the lead author of the study, says the therapy also appeared to help slow the progression of the disease a little.

“A person has approximately 150 million Tregs circulating in their blood at any given time. Each dose of Tregs given to the patients in this study resulted in about a 30 to 40 percent increase over normal levels. Slowing of disease progression was observed during each round of four Treg infusions.”

Once the infusions stopped the disease progression resumed so clearly this is not a cure, but it does at least suggest that keeping Tregs at a healthy, high-functioning level may help slow down ALS.

CIRM is funding two clinical trials targeting ALS. One is a Phase 1 clinical trial with Clive Svendsen’s team at Cedars-Sinai Medical Center, the other is a Phase 3 project with Brainstorm Cell Therapeutics.

Progress to a Cure for Bubble Baby Disease

/ Karen Ring / Leave a comment

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of exciting stem cell stories about advances towards stem cell-based cures for serious diseases. Today we’re featuring stories about the progress of CIRM-funded clinical trials for the treatment of a devastating, usually fatal, primary immune disease that strikes newborn babies.

evangelina in a bubble

Evie, a former “bubble baby” enjoying life by playing inside a giant plastic bubble

‘Bubble baby disease’ will one day be a thing of the past. That’s a bold statement, but I say it with confidence because of the recent advancements in stem cell gene therapies that are curing infants of this life-threatening immune disease.

The scientific name for ‘bubble baby disease’ is severe combined immunodeficiency (SCID). It prevents the proper development of important immune cells called B and T cells, leaving newborns without a functioning immune system. Because of this, SCID babies are highly susceptible to deadly infections, and without treatment, most of these babies do not live past their first year. Even a simple cold virus can be fatal.

Scientists are working hard to develop stem cell-based gene therapies that will cure SCID babies in their first months of life before they succumb to infections. The technology involves taking blood stem cells from a patient’s bone marrow and genetically correcting the SCID mutation in the DNA of these cells. The corrected stem cells are then transplanted back into the patient where they can grow and regenerate a healthy immune system. Early-stage clinical trials testing these stem cell gene therapies are showing very encouraging results. We’ll share a few of these stories with you below.

CIRM-funded trials for SCID

CIRM is funding three clinical trials, one from UCLA, one at Stanford and one from UCSF & St. Jude Children’s Research Hospital, that are treating different forms of SCID using stem cell gene therapies.

Adenosine Deaminase-Deficient SCID

The first trial is targeting a form of the disease called adenosine deaminase-deficient SCID or ADA-SCID. Patients with ADA-SCID are unable to make an enzyme that is essential for the function of infection-fighting immune cells called lymphocytes. Without working lymphocytes, infants eventually are diagnosed with SCID at 6 months. ADA-SCID occurs in approximately 1 in 200,000 newborns and makes up 15% of SCID cases.

CIRM is funding a Phase 2 trial for ADA-SCID that is testing a stem cell gene therapy called OTL-101 developed by Dr. Don Kohn and his team at UCLA and a company called Orchard Therapeutics. 10 patients were treated in the trial, and amazingly, nine of these patients were cured of their disease. The 10th patient was a teenager who received the treatment knowing that it might not work as it does in infants. You can read more about this trial in our blog from earlier this year.

In a recent news release, Orchard Therapeutics announced that the US Food and Drug Administration (FDA) has awarded Rare Pediatric Disease Designation to OTL-101, meaning that the company will qualify for priority review for drug approval by the FDA. You can read more about what this designation means in this blog.

X-linked SCID

The second SCID trial CIRM is funding is treating patients with X-linked SCID. These patients have a genetic mutation on a gene located on the X-chromosome that causes the disease. Because of this, the disease usually affects boys who have inherited the mutation from their mothers. X-linked SCID is the most common form of SCID and appears in 1 in 60,000 infants.

UCSF and St. Jude Children’s Research Hospital are conducting a Phase 1/2 trial for X-linked SCID. The trial, led by Dr. Brian Sorrentino, is transplanting a patient’s own genetically modified blood stem cells back into their body to give them a healthy new immune system. Patients do receive chemotherapy to remove their diseased bone marrow, but doctors at UCSF are optimizing low doses of chemotherapy for each patient to minimize any long-term effects. According to a UCSF news release, the trial is planning to treat 15 children over the next five years. Some of these patients have already been treated and we will likely get updates on their progress next year.

CIRM is also funding a third clinical trial out of Stanford University that is hoping to make bone marrow transplants safer for X-linked SCID patients. The team, led by Dr. Judy Shizuru, is developing a therapy that will remove unhealthy blood stem cells from SCID patients to improve the survival and engraftment of healthy bone marrow transplants. You can read more about this trial on our clinical trials page.

SCID Patients Cured by Stem Cells

These clinical trial results are definitely exciting, but what is more exciting are the patient stories that we have to share. We’ve spoken with a few of the families whose children participated in the UCLA and UCSF/St. Jude trials, and we asked them to share their stories so that other families can know that there is hope. They are truly inspiring stories of heartbreak and joyful celebration.

Evie is a now six-year-old girl who was diagnosed with ADA-SCID when she was just a few months old. She is now cured thanks to Don Kohn and the UCLA trial. Her mom gave a very moving presentation about Evie’s journey at the CIRM Bridges Trainee Annual Meeting this past July.  You can watch the 20-minute talk below:

Ronnie’s story

Ronnie SCID kid

Ronnie: Photo courtesy Pawash Priyank

Ronnie, who is still less than a year old, was diagnosed with X-linked SCID just days after he was born. Luckily doctors told his parents about the UCSF/St. Jude trial and Ronnie was given the life-saving stem cell gene therapy before he was six months old. Now Ronnie is building a healthy immune system and is doing well back at home with his family. Ronnie’s dad Pawash shared his families moving story at our September Board meeting and you can watch it here.

Our mission at CIRM is to accelerate stem cell treatments to patients with unmet medical needs. We hope that by funding promising clinical trials like the ones mentioned in this blog, that one day soon there will be approved stem cell therapies for patients with SCID and other life-threatening diseases.

CIRM Board invests in three new stem cell clinical trials targeting arthritis, cancer and deadly infections

/ Kevin McCormack / 8 Comments

knee

Arthritis of the knee

Every day at CIRM we get calls from people looking for a stem cell therapy to help them fight a life-threatening or life-altering disease or condition. One of the most common calls is about osteoarthritis, a painful condition where the cartilage that helps cushion our joints is worn away, leaving bone to rub on bone. People call asking if we have something, anything, that might be able to help them. Now we do.

At yesterday’s CIRM Board meeting the Independent Citizens’ Oversight Committee or ICOC (the formal title of the Board) awarded almost $8.5 million to the California Institute for Biomedical Research (CALIBR) to test a drug that appears to help the body regenerate cartilage. In preclinical tests the drug, KA34, stimulated mesenchymal stem cells to turn into chondrocytes, the kind of cell found in healthy cartilage. It’s hoped these new cells will replace those killed off by osteoarthritis and repair the damage.

This is a Phase 1 clinical trial where the goal is primarily to make sure this approach is safe in patients. If the treatment also shows hints it’s working – and of course we hope it will – that’s a bonus which will need to be confirmed in later stage, and larger, clinical trials.

From a purely selfish perspective, it will be nice for us to be able to tell callers that we do have a clinical trial underway and are hopeful it could lead to an effective treatment. Right now the only alternatives for many patients are powerful opioids and pain killers, surgery, or turning to clinics that offer unproven stem cell therapies.

Targeting immune system cancer

The CIRM Board also awarded Poseida Therapeutics $19.8 million to target multiple myeloma, using the patient’s own genetically re-engineered stem cells. Multiple myeloma is caused when plasma cells, which are a type of white blood cell found in the bone marrow and are a key part of our immune system, turn cancerous and grow out of control.

As Dr. Maria Millan, CIRM’s President & CEO, said in a news release:

“Multiple myeloma disproportionately affects people over the age of 65 and African Americans, and it leads to progressive bone destruction, severe anemia, infectious complications and kidney and heart damage from abnormal proteins produced by the malignant plasma cells.  Less than half of patients with multiple myeloma live beyond 5 years. Poseida’s technology is seeking to destroy these cancerous myeloma cells with an immunotherapy approach that uses the patient’s own engineered immune system T cells to seek and destroy the myeloma cells.”

In a news release from Poseida, CEO Dr. Eric Ostertag, said the therapy – called P-BCMA-101 – holds a lot of promise:

“P-BCMA-101 is elegantly designed with several key characteristics, including an exceptionally high concentration of stem cell memory T cells which has the potential to significantly improve durability of response to treatment.”

Deadly infections

The third clinical trial funded by the Board yesterday also uses T cells. Researchers at Children’s Hospital of Los Angeles were awarded $4.8 million for a Phase 1 clinical trial targeting potentially deadly infections in people who have a weakened immune system.

Viruses such as cytomegalovirus, Epstein-Barr, and adenovirus are commonly found in all of us, but our bodies are usually able to easily fight them off. However, patients with weakened immune systems resulting from chemotherapy, bone marrow or cord blood transplant often lack that ability to combat these viruses and it can prove fatal.

The researchers are taking T cells from healthy donors that have been genetically matched to the patient’s immune system and engineered to fight these viruses. The cells are then transplanted into the patient and will hopefully help boost their immune system’s ability to fight the virus and provide long-term protection.

Whenever you can tell someone who calls you, desperately looking for help, that you have something that might be able to help them, you can hear the relief on the other end of the line. Of course, we explain that these are only early-stage clinical trials and that we don’t know if they’ll work. But for someone who up until that point felt they had no options and, often, no hope, it’s welcome and encouraging news that progress is being made.

 

 

California’s stem cell agency rounds up the year with two more big hits

/ Kevin McCormack / 8 Comments

icoc_dec2016-17

CIRM Board meeting with  Jake Javier, CIRM Chair Jonathan Thomas, Vice Chair Sen. Art Torres (Ret.) and President/CEO Randy Mills

It’s traditional to end the year with a look back at what you hoped to accomplish and an assessment of what you did. By that standard 2016 has been a pretty good year for us at CIRM.

Yesterday our governing Board approved funding for two new clinical trials, one to help kidney transplant patients, the second to help people battling a disease that destroys vision. By itself that is a no small achievement. Anytime you can support potentially transformative research you are helping advance the field. But getting these two clinical trials over the start line means that CIRM has also met one of its big goals for the year; funding ten new clinical trials.

If you had asked us back in the summer, when we had funded only two clinical trials in 2016, we would have said that the chances of us reaching ten trials by the end of the year were about as good as a real estate developer winning the White House. And yet……..

Helping kidney transplant recipients

The Board awarded $6.65 million to researchers at Stanford University who are using a deceptively simple approach to help people who get a kidney transplant. Currently people who get a transplant have to take anti-rejection medications for the rest of their life to prevent their body rejecting the new organ. These powerful immunosuppressive medications are essential but also come with a cost; they increase the risk of cancer, infection and heart disease.

icoc_dec2016-3

CIRM President/CEO Randy Mills addresses the CIRM Board

The Stanford team will see if it can help transplant patients bypass the need for those drugs by injecting blood stem cells and T cells (which play an important role in the immune system) from the kidney donor into the kidney recipient. The hope is by using cells from the donor, you can help the recipient’s body more readily adjust to the new organ and reduce the likelihood the body’s immune system will attack it.

This would be no small feat. Every year around 17,000 kidney transplants take place in the US, and many people who get a donor kidney experience fevers, infections and other side effects as a result of taking the anti-rejection medications. This clinical trial is a potentially transformative approach that could help protect the integrity of the transplanted organ, and improve the quality of life for the kidney recipient.

Fighting blindness

The second trial approved for funding is one we are already very familiar with; Dr. Henry Klassen and jCyte’s work in treating retinitis pigmentosa (RP). This is a devastating disease that typically strikes before age 30 and slowly destroys a person’s vision. We’ve blogged about it here and here.

Dr. Klassen, a researcher at UC Irvine, has developed a method of injecting what are called retinal progenitor cells into the back of the eye. The hope is that these cells will repair and replace the cells damaged by RP. In a CIRM-funded Phase 1 clinical trial the method proved safe with no serious side effects, and some of the patients also reported improvements in their vision. This raised hopes that a Phase 2 clinical trial using a larger number of cells in a larger number of patients could really see if this therapy is as promising as we hope. The Board approved almost $8.3 million to support that work.

Seeing is believing

How promising? Well, I recently talked to Rosie Barrero, who took part in the first phase clinical trial. She told me that she was surprised how quickly she started to notice improvements in her vision:

“There’s more definition, more colors. I am seeing colors I haven’t seen in years. We have different cups in our house but I couldn’t really make out the different colors. One morning I woke up and realized ‘Oh my gosh, one of them is purple and one blue’. I was by myself, in tears, and it felt amazing, unbelievable.”

Amazing was a phrase that came up a lot yesterday when we introduced four people to our Board. Each of the four had taken part in a stem cell clinical trial that changed their lives, even saved their lives. It was a very emotional scene as they got a chance to thank the group that made those trials, those treatments possible.

We’ll have more on that in a future blog.

 

 

 

 

Stem cell stories that caught our eye: turning on T cells; fixing our brains; progress and trends in stem cells; and one young man’s journey to recover from a devastating injury

/ Kevin McCormack / Leave a comment

Healthy_Human_T_Cell

A healthy T cell

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.

Directing the creation of T cells. To paraphrase the GOP Presidential nominee, any sane person LOVES, LOVES LOVES their T cells, in a HUGE way, so HUGE. They scamper around the body getting rid of viruses and the tiny cancers we all have in us all the time. A CIRM-funded team at CalTech has worked out the steps our genetic machinery must take to make more of them, a first step in letting physicians turn up the action of our immune systems.

We have known for some time the identity of the genetic switch that is the last, critical step in turning blood stem cells into T cells, but nothing in our body is as simple as a single on-off event. The Caltech team isolated four genetic factors in the path leading to that main switch and, somewhat unsuspected, they found out those four steps had to be activated sequentially, not all at the same time. They discovered the path by engineering mouse cells so that the main T cell switch, Bcl11b, glows under a microscope when it is turned on.

“We identify the contributions of four regulators of Bcl11b, which are all needed for its activation but carry out surprisingly different functions in enabling the gene to be turned on,” said Ellen Rothenberg, the senior author in a university press release picked up by Innovations Report. “It’s interesting–the gene still needs the full quorum of transcription factors, but we now find that it also needs them to work in the right order.”

Video primer on stem cells in the brain.  In conjunction with an article in its August issue, Scientific American posted a video from the Brain Forum in Switzerland of Elena Cattaneo of the University of Milan explaining the basics of adult versus pluripotent stem cells, and in particular how we are thinking about using them to repair diseases in the brain.

The 20-minute talk gives a brief review of pioneers who “stood alone in unmarked territory.” She asks how can stem cells be so powerful; and answers by saying they have lots of secrets and those secrets are what stem cell scientist like her are working to unravel.  She notes stem cells have never seen a brain, but if you show them a few factors they can become specialized nerves. After discussing collaborations in Europe to grow replacement dopamine neurons for Parkinson’s disease, she went on to describe her own effort to do the same thing in Huntington’s disease, but in this case create the striatal nerves lost in that disease.

The video closes with a discussion of how basic stem cell research can answer evolutionary questions, in particular how genetic changes allowed higher organisms to develop more complex nervous systems.

kelley and kent

CIRM Science Officers Kelly Shepard and Kent Fitzgerald

A stem cell review that hits close to home.  IEEE Pulse, a publication for scientists who mix engineering and medicine and biology, had one of their reporters interview two of our colleagues on CIRM’s science team. They asked senior science officers Kelly Shepard and Kent Fitzgerald to reflect on how the stem cell field has progressed based on their experience working to attract top researchers to apply for our grants and watching our panel of outside reviewers select the top 20 to 30 percent of each set of applicants.

One of the biggest changes has been a move from animal stem cell models to work with human stem cells, and because of CIRM’s dedicated and sustained funding through the voter initiative Proposition 71, California scientists have led the way in this change. Kelly described examples of how mouse and human systems are different and having data on human cells has been critical to moving toward therapies.

Kelly and Kent address several technology trends. They note how quickly stem cell scientists have wrapped their arms around the new trendy gene editing technology CRISPR and discuss ways it is being used in the field. They also discuss the important role of our recently developed ability to perform single cell analysis and other technologies like using vessels called exosomes that carry some of the same factors as stem cells without having to go through all the issues around transplanting whole cells.

“We’re really looking to move things from discovery to the clinic. CIRM has laid the foundation by establishing a good understanding of mechanistic biology and how stem cells work and is now taking the knowledge and applying it for the benefit of patients,” Kent said toward the end of the interview.

jake and family

Jake Javier and his family

Jake’s story: one young man’s journey to and through a stem cell transplant; As a former TV writer and producer I tend to be quite critical about the way TV news typically covers medical stories. But a recent story on KTVU, the Fox News affiliate here in the San Francisco Bay Area, showed how these stories can be done in a way that balances hope, and accuracy.

Reporter Julie Haener followed the story of Jake Javier – we have blogged about Jake before – a young man who broke his spine and was then given a stem cell transplant as part of the Asterias Biotherapeutics clinical trial that CIRM is funding.

It’s a touching story that highlights the difficulty treating these injuries, but also the hope that stem cell therapies holds out for people like Jake, and of course for his family too.

If you want to see how a TV story can be done well, this is a great example.

Stem cell stories that caught our eye: a surprising benefit of fasting, faster way to make iPSCs, unlocking the secret of leukemia cancer cells

/ Kevin McCormack / Leave a comment

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.

Fasting

Is fasting the fountain of youth?

Among the many insults our bodies endure in old age is a weakened immune system which leaves the elderly more susceptible to infection. Chemotherapy patients also face the same predicament due to the immune suppressing effects of their toxic anticancer treatments. While many researchers aim to develop drugs or cell therapies to protect the immune system, a University of Southern California research report this week suggests an effective alternative intervention that’s startlingly straightforward: fasting for 72 hours.

The study published in Cell Stem Cell showed that cycles of prolonged fasting in older mice led to a decrease in white blood cells which in turn set off a regenerative burst of blood stem cells. This restart of the blood stem cells replenished the immune system with new white blood cells. In a pilot Phase 1 clinical trial, cancer patients who fasted 72 hours before receiving chemotherapy maintained normal levels of white blood cells.

A look at the molecular level of the process pointed to a decrease in the levels of a protein called PKA in stem cells during the fasting period. In a university press release carried by Science Daily, the study leader, Valter Longo, explained the significance of this finding:

“PKA is the key gene that needs to shut down in order for these stem cells to switch into regenerative mode. It gives the ‘okay’ for stem cells to go ahead and begin proliferating and rebuild the entire system. And the good news is that the body got rid of the parts of the system that might be damaged or old, the inefficient parts, during the fasting. Now, if you start with a system heavily damaged by chemotherapy or aging, fasting cycles can generate, literally, a new immune system.”

In additional to necessary follow up studies, the team is looking into whether fasting could benefit other organ systems besides the immune system. If the data holds up, it could be that regular fasting or direct targeting of PKA could put us on the road to a much more graceful and healthier aging process.

4955224186_31f969e6fd_m

Faster, cheaper, safer way to use iPS cells

Science, like traffic in any major city, never moves quite as quickly as you would like, but now Japanese researchers are teaming up to develop a faster, and cheaper way of using iPSC’s , pluripotent stem cells that are reprogrammed from adult cells, for transplants.

Part of the beauty of iPSCs is that because those cells came from the patient themselves, there is less risk of rejection. But there are problems with this method. Taking adult cells and turning them into enough cells to treat someone can take a long time. It’s expensive too.

But now researchers at Kyoto University and three other institutions in Japan have announced they are teaming up to change that. They want to create a stockpile of iPSCs that are resistant to immunological rejection, and are ready to be shipped out to researchers.

Having a stockpile of ready-to-use iPSCs on hand means researchers won’t have to wait months to develop their own, so they can speed up their work.

Shinya Yamanaka, who developed the technique to create iPSCs and won the Nobel prize for his efforts, say there’s another advantage with this collaboration. In a news article on Nikkei’s Asian Review he said these cells will have been screened to make sure they don’t carry any potentially cancer-causing mutations.

“We will take all possible measures to look into the safety in each case, and we’ll give the green light once we’ve determined they are sound scientifically. If there is any concern at all, we will put a stop to it.”

CIRM is already working towards a similar goal with our iPSC Initiative.

Unlocking the secrets of leukemia stem cells

the-walking-dead-season-6-zombies

Zombies: courtesy “The Walking Dead”

Any article that has an opening sentence that says “Cancer stem cells are like zombies” has to be worth reading. And a report in ScienceMag  that explains how pre-leukemia white blood cell precursors become leukemia cancer stem cells is definitely worth reading.

The article is about a study in the journal Cell Stem Cell by researchers at UC San Diego. The senior author is Catriona Jamieson:

“In this study, we showed that cancer stem cells co-opt an RNA editing system to clone themselves. What’s more, we found a method to dial it down.”

An enzyme called ADAR1 is known to spur cancer growth by manipulating small pieces of genetic material known as microRNA. Jamieson and her team wanted to track how that was done. They discovered it is a cascade of events, and that once the first step is taken a series of others quickly followed on.

They found that when white blood cells have a genetic mutation that is linked to leukemia, they are prone to inflammation. That inflammation then activates ADAR1, which in turn slows down a segment of microRNA called let-7 resulting in increased cell growth. The end result is that the white blood cells that began this cascade become leukemia stem cells and spread an aggressive and frequently treatment-resistant form of the blood cancer.

Having uncovered how ADAR1 works Jamieson and her team then tried to find a way to stop it. They discovered that by blocking the white blood cells susceptibility to inflammation, they could prevent the cascade from even starting. They also found that by using a compound called 8-Aza they could impede ADAR1’s ability to stimulate cell growth by around 40 percent.

Jamieson

Catriona Jamieson – definitely not a zombie

Jamieson says the findings open up all sorts of possibilities:

“Based on this research, we believe that detecting ADAR1 activity will be important for predicting cancer progression. In addition, inhibiting this enzyme represents a unique therapeutic vulnerability in cancer stem cells with active inflammatory signaling that may respond to pharmacologic inhibitors of inflammation sensitivity or selective ADAR1 inhibitors that are currently being developed.”

This wasn’t a CIRM-funded study but we have supported other projects by Dr. Jamieson that have led to clinical trials.

 

 

 

 

UCSF study explains how chronic inflammation impairs blood stem cell function

/ Karen Ring / Leave a comment

Human blood (red) and immune cells (green) are made from hematopoietic/blood stem cells. Photo credit: ZEISS Microscopy.

Human blood (red) and immune cells (green) are made from hematopoietic/blood stem cells. Photo credit: ZEISS Microscopy.

Inflammation is the immune system’s natural protective response to infection and injury. It involves the activation and mobilization of immune cells that can kill off foreign invaders and help repair damaged tissue. At the heart of the inflammatory response are hematopoietic stem cells (HSCs). These are blood stem cells found in the bone marrow that give rise to all blood cell types.

Under normal conditions, HSCs lie in a dormant state. But in response to inflammation they are triggered to rapidly divide and to differentiate into the immune cells needed. This initial response is beneficial in fighting off infection, however if left on for too long, HSCs lose their ability to self-renew (or make more of themselves) and regenerate a healthy blood system.

IL-1: Good Cop or Bad Cop?

A key player in the immune response to inflammation is a cytokine protein called Interleukin-1 or IL-1. It plays a beneficial role during an initial or acute inflammatory response: IL-1 along with other pro-inflammatory cytokines signals to HSCs that inflammation or infection is occurring and recruits certain immune cells from the blood into the tissue where they are needed.

However, IL-1 can also have negative effects on the immune system and high levels of this cytokine are found in patients with chronic inflammatory diseases such as obesity, diabetes and atherosclerosis. When HSCs are exposed IL-1 for long periods of time, they lose their regenerative abilities and  overproduce specific types of aggressive immune cells called myeloid cells that are needed to fight infection and repair injury but can also cause chronic inflammation and tissue damage. This can create an imbalance of blood cell types that impairs the function of the immune system.

So is IL-1 the good cop or the bad cop when it comes to inflammation and disease? A new CIRM-funded study from the University of California San Francisco (UCSF), published yesterday in Nature Cell Biology, might have the answer.

A double-edged sword

The study was led by first author Dr. Eric Pietras, who is now an Assistant Professor of Hematology at the University of Colorado Anschutz Medical Campus. He along with senior author and UCSF Professor Dr. Emmanuelle Passegue, were interested in understanding whether IL-1 was a bystander or an active player in causing this transformation in HSCs that leads to chronic inflammatory disease.

To answer this question, Pietras and Passegue exposed mouse HSCs to IL-1, both in a cell culture dish and in mice. They found that IL-1 drove HSCs to rapidly differentiate into myeloid cells by activating a molecular circuit directed by the PU.1 gene, which is important for regulating HSC blood production. However, when mice were exposed to IL-1 for an extended period of 70 days – to mimic chronic inflammation – their HSCs were no longer able to do their normal job of regenerating all the cells of the blood and immune system.

I reached out to Dr. Pietras and asked him to explain what new insights his study has produced about the role of IL-1 during inflammation.

Eric Pietras

Eric Pietras

“IL-1 really is a double-edged sword; it’s great for turning on HSCs when you need them to make new first-responder myeloid cells quickly due to an injury or infection, and on the other hand, failure to turn the signal back off severely disrupts the ability of HSCs to make a balanced, healthy blood system, particularly in a regenerative context. I think this provides us with a clearer picture of why the blood system often functions poorly in chronic inflammatory disease patients.”

 

Negative effects of IL-1 are reversible

There’s good news though. Pietras and his team were able to reverse the negative effects of chronic IL-1 exposure on HSCs by simply removing IL-1. They proved this by transplanting HSCs from mice that were chronically treated with IL-1 and then taken off the treatment for a few weeks into irradiated mice that had no bone marrow and therefore no immune system. The transplanted HSCs were able to repopulate the entire immune system of the irradiated mice and did not show any regenerative dysfunction due to previous IL-1 treatment.

Dr. Pietras commented on the importance of their study:

“An important dimension of our study is to show in principle that HSCs can recover their functionality and return to making a healthy and balanced blood system if you can give them a break from the constant presence of inflammatory signals. This tells us that the negative effects of chronic inflammation on HSCs can be largely reversed if you can provide them with a break from the constant ‘emergency’ state IL-1 makes them think they’re in. This could impact how we treat chronic inflammatory disease.

 

Blocking IL-1 to treat chronic inflammation

So will drugs that inhibit IL-1 be a future therapy for patients suffering from chronic inflammatory disease? Anti-IL-1 drugs have been around for a while – one example is Kineret, which is an FDA-approved treatment for rheumatoid arthritis. But there are many other diseases caused by chronic inflammation that may or may not benefit from such treatment.

Dr. Passegue, in a UCSF press release, explained that their study’s findings are important for determining how anti-IL-1 therapy could be beneficial for patients.

“Understanding this mechanism helps us understand why these drugs are such promising treatments for patients with chronic inflammation.”

She also hinted that IL-1 could be a double-edged sword in stem cell populations of other tissues and that “reducing chronic IL-1 exposure may be an important approach for improving stem cell health and tissue function in the context of both inflammatory disease and normal aging.”

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