Cell Therapy is the transfer of whole cells into a patient to replace or repair damaged tissue or cells. Cell therapy transfers healthy cells into a patient’s body to grow, replace, or repair damaged tissue for the treatment of a disease or trauma. The cells used in cell therapies may originate from the patient (autologous cells) or a donor (allogeneic cells). There are autologous therapies that have been approved for use. Kymriah, Provenge, and Yescarta for cancers.
The most common type of allogeneic cell therapy is blood transfusion, in which red blood cells, white blood cells, and pieces of cells called platelets are transferred from a donor to a patient.
If you collected your own blood and gave it back to yourself, that would be an autologous cell therapy. Sometimes before major surgery the patient is asked to ‘donate’ blood that would be used if she needed blood during the surgery.
A bone marrow transplant is a stem cell therapy. Blood forming stem cells from bone marrow are transfused from one person to another. The new blood forming stem cells divide and create all the cells in the blood – white blood cells, red blood cells, and many other types.
One goal of allogeneic cell therapy is so-called “off-the-shelf” cell therapy. The cells would be derived from a donor or donors, and prepared or manufactured in large quantities, ideally to create a treatment that could serve many patients. Allogeneic cell therapies, once demonstrated to be effective, would be manufactured and readily available to a patient.
Different types of cells can be used to create cell therapy using complex tools:
- Embryonic stem cells, pluripotent stem cells derived from embryos not needed after In Vitro Fertilization (IVF)
- Induced pluripotent stem cells (iPSC), derived from skin or blood cells that have been reprogrammed so they become stem cells. The cells can be guided to develop into specific human cells needed for therapeutic purposes.
- Hematopoietic stem cells (HSCs), stem cells responsible for refreshing our supply of healthy blood cells; they can produce billions of new blood cells each day.
- Cord blood cells. Cord blood is the blood left over in the umbilical cord and placenta after a baby is born. It can be collected and stored for future use. The primary source of stem cells in cord blood are hematopoietic stem cells (HSCs). These cells are the building blocks of our blood and immune system. They can be used in the treatment of blood cancers such as leukemias and lymphomas, and disorders such as sickle cell disease and Wiskott-Aldrich syndrome. Additional uses for umbilical cord blood and tissue are currently under investigation. The therapeutic use of cord blood in the United States is regulated by the FDA. Cord blood is not a cure-all. You can learn more here.
- Mesenchymal stromal cells – sometimes called mesenchymal ‘stem cells,’ or MSCs, these are cells that differentiate into the body’s connective tissues, blood, lymphatic system, bone, and cartilage.
- Immunotherapy cells
- Natural Killer (NK) cells
- Dendritic cells
- CAR-T cells, Autologous cells (cells from the patient) that are specially treated and reinfused to eradicate a patient’s cancer. Two approved CAR-T therapies are available in the US Yescarta and Kymriah.
- Lymphocytes are white blood cells that launch the body’s initial immune response. They are found in the circulation system, lymph nodes, tonsils, and spleen.
- Dendritic cells: Cells responsible for the initiation of adaptive immune responses that allow the body’s immune system to fight against damage.
- Other types of cells
- Epithelial stem cells: Cells that form the surfaces and linings of the body
- Retinal Progenitor Epithelial cells are stem cells for the retina. Transplant of RPE is being tested as a cure for blinding retinal disease.
- Neural progenitor cells are the cells that give rise to the various cells of the central nervous system, comprised of the brain and the spinal cord They are being tested for repair of trauma to the spinal cord or peripheral nerves.
- Pancreatic islet cells are clusters of cells inside the pancreas that produce insulin, the hormone required to move glucose (sugar) into cells for energy. Islet cells in a well-functioning pancreas contain cells that produce the hormones necessary for metabolic regulation. Transplant of islets is a proven therapy for Diabetes Type 1, unfortunately, their effect when transplanted is not forever, and the supply of islets is limited.
- Skeletal muscle stem cells. Muscle stem cells are adult stem cells in skeletal muscle tissue which can self-renew and are create new skeletal muscle cells. In healthy bodies, these stem cells are activated in response to muscle injury to regenerate damaged muscle tissue.
How to Learn More
WHAT ARE STEM CELLS, A TED-EX TALK BY CRAIG A. KOHN (2013) – This is a video that gives a reasonable overview of stem cells, despite the many scientific discoveries since 2013. The video says, “using stem cells to replace bodily tissue is called Regenerative Medicine” (1:45). Regenerative Medicine encompasses other scientific tools in addition to stem cells.