Nature Cell Biology

Lack of diversity leaves cloud hanging over asthma drug study

/ Kevin McCormack / 2 Comments
Asthma spacer, photo courtesy Wiki Media Creative Commons

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If you want to know if a new drug or therapy is going to work in the people it affects the most you need to test the drug or therapy in the people most affected by the disease. That would seem blindingly obvious, wouldn’t it? Apparently not.

Case in point. A new asthma medication, one that seemingly shows real promise in reducing attacks in children, was tested on an almost entirely white patient population, even though Black and Puerto Rican children are far more likely to suffer from asthma.

The study enrolled more than 400 children, between the ages of 6 and 11, with moderate to serious uncontrolled asthma and treated them with a medication called Dupixent. The results, published in the New England Journal of Medicine, were impressive. Children given Dupixent had an average drop in severe asthma attacks of 65 percent compared to children given a placebo.

The only problem is 90 percent of the children in the study were white. Why is that a problem? Because, according to the Asthma and Allergy Foundation of America, only 9.5 percent of white children have asthma, compared to 24 percent of Puerto Rican children and 18 percent of Black children. So, the groups most likely to suffer from the disease were disproportionately excluded from a study about a treatment for the disease.

Some people might think, “So what! If the medication works for one kid it will work for another, what does race have to do with it?” Quite a lot actually.

A study in the Journal of Allergy and Clinical Immunology concluded that: “Race/ethnicity modified the association between total IgE (an antibody in the blood that is a marker for asthma) and asthma exacerbations. Elevated IgE level was associated with worse asthma outcomes in Puerto Ricans… Our findings suggest that eligibility for asthma biologic therapies differs across pediatric racial/ethnic populations.”

The article concluded by calling for “more studies in diverse populations for equitable treatment of minority patients with asthma.” Something that clearly didn’t happen in the Dupixent study.

While that’s more than disappointing, it’s not surprising. A recent study of vaccine clinical trials in JAMA Network Open found that:

  • Overall, white individuals made up almost 80 percent of people enrolled.
  • Black individuals were represented only 10.6 percent of the time.
  • Latino participants were represented just 11.6 percent of the time. 

Additionally, in pediatric trials, Black participants were represented just over 10 percent of the time and Latino participants were represented 22.5 percent of the time. The study concluded by saying that “diversity enrollment targets are needed for vaccine trials in the US.”

I would expand on that, saying they are needed for all clinical trials. That’s one of the many reasons why we at the California Institute for Regenerative Medicine (CIRM) are making Diversity, Equity and Inclusion an important part of everything we do, such as requiring all applicants to have a written DEI plan if they want funding from us. Dr. Maria Millan, our President and CEO, recently co-authored an article in Nature Cell Biology, driving home the need for greater diversity in basic science and research in general.

DEI has become an important part of the conversation this past year. But the Dupixent trial shows that if we are truly serious about making it part of what we do, we have to stop talking and start acting.

Creating a New Model for Diversity in Scientific and Medical Research

/ Kevin McCormack / Leave a comment

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Nature Cell Biology cover

The global pandemic has highlighted many of the inequities in our health care system, with the virus hitting communities of color the hardest. That has led to calls for greater diversity, equity and inclusion at every level of scientific research and, ultimately, of medical care. A recently released article in the journal Nature Cell Biology, calls for “new models for basic and disease research that reflect diverse ancestral backgrounds and sex and ensure that diverse populations are included among donors and research participants.”

The authors of the article are Dr. Maria T. Millan, CIRM’s President & CEO; Rick Horwitz Senior Advisor and Executive Director, Emeritus, Allen Institute for Cell Science; Dr. Ekemini Riley, President, Coalition for Aligning Science; and Dr. Ruwanthi N. Gunawardane, Executive Director of the Allen Institute for Cell Science.

Dr. Maria Millan, CIRM’s President & CEO, says we need to make these issues a part of everything we do. “At CIRM we have incorporated the principles of promoting diversity, equity and inclusion in our research funding programs, education programs and future programs. We believe this is essential to ensure that the therapies our support helps advance will reach all patients in need and in particular communities that are disproportionately affected and/or under-served.”

The article highlights how, in addition to cultural, environmental, and socioeconomic factors, genetic factors also appear to play a role in the way disease affects different people. For example, 50 percent of people in South Asia have genetic traits that increases their risk for severe COVID-19, in contrast only 16 percent of Europeans have those traits.

But while some studies have shown how African American men are at greater risk for prostate cancer than white men, most of the research in this and other areas has been done on white populations of European ancestry. Efforts are already underway to change these disparities. For example, the National Institutes of Health (NIH) has sponsored the All of Us Research Program, which is inviting one million people across the U.S. to help build one of the most diverse health databases in history.

The article in Nature Cell Biology stresses the need to account for diversity at the individual molecular, cellular and tissue level. The authors make the point that diversity in those taking part in clinical trials is essential, but equally essential is that diverse biology is accounted for in the scientific work that leads to the development of potential therapies in order to increase the likelihood of success.

That’s why the authors of the article say: “If we are to truly understand human biology, address health disparities, and personalize our treatments, we need to go beyond our important, ongoing efforts in addressing diversity and inclusion in the workforce and the delivery of healthcare. We need to improve the data we generate by including diverse populations among donors and research participants. This will require new models and tools for basic and disease research that more closely reflect the diversity of human tissues, across diverse donor backgrounds.”

“Greater diversity in biological studies is not only the right thing to do, it is crucial to helping researchers make new discoveries that benefit everyone,” said Ru Gunawardane, Executive Director of the Allen Institute for Cell Science.

To do this they propose creating “a suite” of research cells, such as human induced pluripotent stem cell (hiPSC) lines from a diverse group of individuals to reflect the racial, ethnic and gender composition of the population. Human iPSCs are cells taken from any tissue (usually skin or blood) from a child or adult that have been genetically modified to behave like an embryonic stem cell. As the name implies, these cells are pluripotent, which means that they can become any type of adult cell.

CIRM has already created one version of what this suite would look like, through its iPSC Repository, a collection of more than 2,600 hiPSCs from individuals of diverse ancestries, including African, Hispanic, Native American, East and South Asian, and European. The Allen Institute for Cell Science also has a collection that could serve as a model for this kind of repository. Its collection of over 50 hiPSC

lines have been thoroughly analyzed on both a genomic and biological level and could also be broken down to include diversity in donor ethnicity and sex.

Currently researchers use cells from different lines and often follow very different procedures in using them, making it hard to compare results from one study to another. Having a diverse and well defined collection of research cells and cell models that are created by standardized procedures, could make it easier to compare results from different studies and share knowledge within the scientific community. By incorporating diversity in the very early stages of scientific research, the scientists and therapy developers gain a more complete picture of the biology disease and potential treatments.  

Human immune cells made using pluripotent stem cells in world first

/ Yimy Villa / Leave a comment
Dr. Andrew Elfanty (left) and Dr. Ed Stanley (right), Murdoch Children’s Research Institute in Melbourne, Australia

Our immune system is the first line of defense our bodies use to fight off infections and disease. One crucial component of this defense mechanism are lymphocytes, which are specialized cells that give rise to various kinds of immune cells, such as a T cell, designed to attack and destroy harmful foreign bodies. Problems in how certain immune cells are formed can lead to diseases such as leukemia and other immune system related disorders.

But how exactly do immune cells form early on in the body?

Dr. Andrew Elfanty and Dr. Ed Stanley at Murdoch Children’s Research Institute in Australia have reproduced and visualized a method in the laboratory used to create human immune cells from pluripotent stem cells, a kind of stem cell that can make virtually any kind of cell in the body. Not only can this unlock a better understanding of leukemia and other immune related diseases, it could potentially lead to a patient’s own skin cells being used to produce new cells for cancer immunotherapy or to test autoimmune disease therapies.

Dr. Elefanty and Dr. Stanley used genetic engineering and a unique way of growing stem cells to make this discovery.

As observed in this video, the team was able to engineer pluripotent stem cells to glow green when they expressed a specific protein found in early immune cells. These cells can be seen migrating along blood vessels outlined in red. These cells go on to populate the thymus, which as we discussed in an earlier blog, is an organ that is crucial in developing functional T cells.

In a press release from Murdoch Children’s Research Institute, Dr. Stanley talks about the important role these early immune cells might play.

“We think these early cells might be important for the correct maturation of the thymus, the organ that acts as a nursery for T-cells”

In addition to this, the team also isolated the green, glowing pluripotent stem cells and showed that they could be used for multiple immune cell types, including those necessary for shaping the development of the immune system as a whole.

In the same press release, Dr. Elefanty discusses the future direction that their research could lead to.

“Although a clinical application is likely still years away, we can use this new knowledge to test ideas about how diseases like childhood leukemia and type 1 diabetes develop. Understanding more about the steps these cells go through, and how we can more efficiently nudge them down a desired pathway, is going to be crucial to that process.”

The full results to this study were published in Nature Cell Biology.

How a see-through fish could one day lead to substitutes for bone marrow transplants

/ Kevin McCormack / Leave a comment
Human blood stem cells

For years researchers have struggled to create human blood stem cells in the lab. They have done it several times with animal models, but the human kind? Well, that’s proved a bit trickier. Now a CIRM-funded team at UC San Diego (UCSD) think they have cracked the code. And that would be great news for anyone who may ever need a bone marrow transplant.

Why are blood stem cells important? Well, they help create our red and white blood cells and platelets, critical elements in carrying oxygen to all our organs and fighting infections. They have also become one of the most important weapons we have to combat deadly diseases like leukemia and lymphoma. Unfortunately, today we depend on finding a perfect or near-perfect match to make bone marrow transplants as safe and effective as possible and without a perfect match many patients miss out. That’s why this news is so exciting.

Researchers at UCSD found that the process of creating new blood stem cells depends on the action of three molecules, not two as was previously thought.

Zebrafish

Here’s where it gets a bit complicated but stick with me. The team worked with zebrafish, which use the same method to create blood stem cells as people do but also have the advantage of being translucent, so you can watch what’s going on inside them as it happens.  They noticed that a molecule called Wnt9a touches down on a receptor called Fzd9b and brings along with it something called the epidermal growth factor receptor (EGFR). It’s the interaction of these three together that turns a stem cell into a blood cell.

In a news release, Stephanie Grainger, the first author of the study published in Nature Cell Biology, said this discovery could help lead to new ways to grow the cells in the lab.

“Previous attempts to develop blood stem cells in a laboratory dish have failed, and that may be in part because they didn’t take the interaction between EGFR and Wnt into account.”

If this new approach helps the team generate blood stem cells in the lab these could be used to create off-the-shelf blood stem cells, instead of bone marrow transplants, to treat people battling leukemia and/or lymphoma.

CIRM is also funding a number of other projects, several in clinical trials, that involve the use of blood stem cells. Those include treatments for: Beta Thalassemia; blood cancer; HIV/AIDS; and Severe Combined Immunodeficiency among others.

Meet the proteins that tell stem cells where to move and how

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Protein word art

Word cloud art work which shows all the proteins identified by the researchers

The environment you grow up in can have a huge influence on how you turn out. That applies to people, and to stem cells too. Now a new study has identified 60 proteins that can have a big impact on how cells react to the world around them, and how they communicate with each other.

Just as it is easier for us to move across firm ground than it is to slosh our way through a soggy, muddy field, it’s easier for stem cells to move smoothly and quickly over a solid surface than over a soft, giving surface. This is particularly true for tumor cells, which move much faster on a hard surface than any other kind.

It’s not just speed that is affected by the kind of surface you place stem cells on. For example certain stem cells placed on a hard surface will specialize and turn into bone, whereas if you place those same cells on a very soft surface they will turn into nerve cells.

The problem is we didn’t know much about why that was the case, we didn’t understand the mechanism at play that caused those cells to behave that way.

Now we do.

A team at the University of Manchester in England tackled this problem by researching integrins; these are receptors that are responsible for cell-to-cell communication, cell growth and function. Integrins are typically found at the surfaces and edges of cells and provide proteins with a convenient place to hang out when they interact with the world around them.

The researchers looked at 2400 examples of these integrin-protein clusters and, using mass spectrometry, narrowed their search down to 60 proteins that they identified as being essential in linking information from the integrins to the rest of the cellular world.

The work was published in Nature Cell Biology. In an accompanying news release Dr. Jon Humphries, one of the lead researchers, talked about the significance of the work:

“Understanding how cells sense their environment is an important step in understanding how, for example, cancer cells move or how stem cells take on different jobs.”

His colleague, Professor Martin Humphries, says understanding how cells sense where they are and how to behave gives us new insights into how we can use that knowledge to better control their movement:

“Our findings on how cells sense their environment have unlocked an important key to understanding how we can persuade cells to form different tissues and how we might stop cell movement in diseases such as cancer.”