What Are Cord Blood Mononuclear Cells Used For?
Discover the function of cord blood mononuclear cells, their established role in medical treatments, and their growing importance in regenerative research.
Cord blood, collected from the umbilical cord and placenta after birth, contains a mixture of cells valuable for medicine and scientific research. This blood is a rich source of various stem cells and immune cells, collectively known as cord blood mononuclear cells (CBMNCs). The isolation of these cells provides a non-controversial and readily available supply of cells that can be used to treat diseases and explore new frontiers in medical science.
Composition of Cord Blood Mononuclear Cells
The therapeutic potential of CBMNCs lies in their diverse cellular makeup. The most prominent components are hematopoietic stem cells (HSCs), which are unspecialized cells with the ability to develop into all different types of blood cells. This includes red blood cells that carry oxygen, platelets that help with clotting, and the various white blood cells of the immune system.
Beyond hematopoietic stem cells, the mononuclear cell fraction of cord blood contains other important cell populations. This includes mesenchymal stem cells (MSCs), which can differentiate into bone, cartilage, and fat cells, and also possess the ability to modulate the immune system’s response. The mixture also contains a variety of mature immune cells.
Among these are lymphocytes, a major component of the adaptive immune system. This group is divided into T cells, which identify and kill infected cells, and B cells, which produce antibodies. Natural killer (NK) cells provide a rapid response to virally infected cells and tumor formation, while monocytes can mature into cells that engulf cellular debris and pathogens.
Collection and Processing
The process of obtaining cord blood mononuclear cells begins immediately after a baby’s birth. It is a non-invasive and safe procedure that poses no risk to the mother or child. Blood from the umbilical cord and placenta is collected into a sterile bag containing an anticoagulant. This collected unit is then transported to a laboratory for processing.
At the laboratory, the goal is to isolate the mononuclear cells from other blood components, such as red blood cells and plasma. The most common method is density gradient centrifugation. In this technique, cord blood is layered on a liquid with a specific density and spun at high speed in a centrifuge, which separates the blood into layers based on cellular density.
The less dense mononuclear cells form a distinct white layer known as the “buffy coat,” which is carefully extracted. After isolation, the CBMNCs are counted and prepared for long-term storage. For future use, the cells are cryopreserved, a process involving a protective agent and freezing them in liquid nitrogen. This allows the cells to remain viable for many years in cord blood banks.
Therapeutic Applications
The most established use of CBMNCs is in hematopoietic stem cell transplantation (HSCT). This procedure treats conditions where a patient’s bone marrow is unable to produce healthy blood cells. HSCT is used for a range of diseases, including:
- Cancers like leukemias and lymphomas
- Blood disorders such as sickle cell anemia and thalassemia
- Severe aplastic anemia
- Various inherited immune system deficiencies
During a transplant, the patient first undergoes chemotherapy or radiation to eliminate the diseased bone marrow. The cryopreserved CBMNCs are then thawed and infused into the patient’s bloodstream. These transplanted cells travel to the bone marrow, where the hematopoietic stem cells engraft and begin to produce new, healthy blood and immune cells, rebuilding the patient’s system.
Using cord blood for these transplants offers advantages over traditional bone marrow transplants. The immune cells in cord blood are less mature, which reduces the risk and severity of graft-versus-host disease (GVHD), where the donor’s immune cells attack the recipient’s body. Cord blood also does not require a perfect genetic match, increasing the number of potential donors for patients from diverse ethnic backgrounds.
Role in Regenerative Medicine and Research
While HSCT is the standard, approved use, CBMNCs are a focal point of research in regenerative medicine, a field that aims to repair or replace damaged tissues and organs. The ability of cells within the CBMNC population, particularly mesenchymal stem cells, to reduce inflammation and promote tissue repair is of great interest. Scientists are investigating the potential of these cells to treat conditions that currently have limited therapeutic options.
Clinical trials are underway to evaluate the safety and effectiveness of using CBMNCs for various neurological, autoimmune, and metabolic disorders. For example, research is exploring their use in children with cerebral palsy and autism, where the cells’ capabilities may help improve brain function. Studies are also examining their potential to treat type 1 diabetes and to aid recovery after a stroke.
It is important to note that these applications are still in the experimental stages. Evidence from early-phase trials suggests that CBMNC infusions are generally safe and may offer benefits for some patients. However, more extensive research and larger, controlled clinical trials are necessary to confirm these findings and establish standardized treatment protocols before these therapies can become widely available.