April 4, 2013
Cell Therapy Could Become As Common As Mainstream Medicine
April Flowers for redOrbit.com - Your Universe Online
A new study from the University of California, San Francisco (UCSF) reveals that treating patients with cells may one day become as common as it is now to treat the sick with drugs from engineered proteins, antibodies, or smaller chemicals. The team outlines their vision of cell-based therapy as a "third pillar of medicine" in an online edition of Science Translational Medicine.
"Today, biomedical science sits on the cusp of a revolution: the use of human and microbial cells as therapeutic entities," said Wendell Lim, PhD, a UCSF professor and director of the UCSF Center for Systems and Synthetic Biology.
According to the scientists, cell therapies have the potential to address critical, unmet needs in the treatment of some of the deadliest diseases. These include diabetes, cancer and inflammatory bowel diseases.
Cells can carry out functions that can't be performed by the small-molecule drugs produced by big pharmaceutical companies. Targeted drugs created by biotech firms in the wake of the genetic engineering revolution are not as effective as cells, either. Cells are adaptable, for example, and able to sense their surroundings. This allows them to vary their responses to better suit physiologic conditions, unlike today's drugs.
According to the researchers, continued advances in cellular engineering could provide a framework for the development of cellular therapies that are safe and predictable.
Michael Fischbach, PhD, assistant professor in the UCSF School of Pharmacy and an expert on the human microbiome, and Jeffrey Bluestone, PhD, executive vice chancellor and provost at UCSF and a leading diabetes and transplant rejection researcher collaborated with Lim on the study.
The researchers have organized a symposium on the potential of cell therapy supported by UCSF and Science Translational Medicine, taking place April 12, 2013. It will feature talks and discussions by some of the nation's leading scientists in stem cell therapy, immunotherapy and the human microbiome. The microbiome consists primarily of the many hundreds of interacting species of bacteria that live within and upon us.
Cells were first used successfully in bone marrow and organ transplants over forty years ago. The strategies envisioned today, however, are more complex. They involve manipulating cells based on new knowledge of how genes program their development and inner workings.
Immune system cells are among those that carry out critical functions naturally. Researchers are working on manipulating these cells to create better-targeted and more effective therapies. Immune responses directed against cancer are often weak, for example, so populations of immune cells that target specific molecules found on cancer cells are being engineered and grown by researchers. These new experimental treatments are already credited with remarkable recoveries from deadly leukemia.
Therapeutic promise is also being seen in bacterial cells, which make up over 90 percent of the cells living within and on our bodies. These microbes interact with our own cells and affect our health.
The recent use of fecal transplants to introduce communities of health-promoting bacteria into patients with recurrent Clostridium difficile infections, a serious gastrointestinal condition that can be life threatening, is a dramatic demonstration of the potential of bacteria to treat disease.
According to the researchers, combinations of bacteria that also are engineered to fight inflammation might prove to be even more effective in treating Crohn's disease and other inflammatory bowel diseases.
Other applications for cell therapy could include combinations of bacterial and human engineered cells. Gut bacteria might be deployed to convert certain carbohydrates into non-digestible forms to control weight gain. These bacteria could also signal engineered human cells lining the epithelial walls to trigger a program that sends a message to the brain that appetite has been satisfied.
There are still many engineering and regulatory challenges to cell therapy. Reliable control of many aspects of cells are needed, including their activation, population growth, programmed death, migration to specific sites in the body, interactions and communications with other cells, production of small therapeutic molecules, and decision making.
Many scientists are leery of cell therapies because of the complexity of cells. However, this complexity might make such therapies more predictable than other drugs, according to the researchers, because complicated, naturally occurring feedback circuits tend to restrict cellular activity. Researchers ought to be able develop a systematic understanding of the cell's control modules to tune and reshape how cells behave just as cells already use molecular circuits to act very precisely.
"If small molecules and biologics are tools, then cells are carpenters – and architects and engineers as well," Fischbach said in a statement.