Cord blood instead of bone marrow
Umbilical cord blood cells cope with cancer better than mature lymphocytes
Ivan Zagorsky, Vesti
It would seem that the immune cells of a newborn child, unlike adults, have not been "hardened" in battles with pathogens and must undergo a long training to strengthen the acquired immunity. However, a new study by scientists from the UK shows that immature immune cells of the fetus recognize and destroy cancer cells in leukemia better than elements of a fully formed immune system do.
Usually, patients with blood cancer undergo chemotherapy. But, unfortunately, this procedure destroys not only the affected, but also healthy blood cells. Therefore, for the treatment of leukemia, a donor bone marrow transplant is often resorted to, which refills the circulatory system with healthy cells. Such transplantation has an additional advantage: once in the blood, new immune cells "clean up" the consequences of cancer.
Recently, instead of stem brain cells, doctors began to use umbilical cord blood, which remains in the placenta and umbilical cord after childbirth and is characterized by a high content of embryonic stem cells. The risk of rejection by the body of immature cells is much lower, but doctors had concerns that such "inexperienced fighters" would cope worse with the remnants of leukemia.
To test this assumption, a team led by Paul Veys from Great Ormond Street Children's Hospital in London injected mature immune cells and cord blood stem cells into mice suffering from a human form of cancer called B-cell lymphoma.
"We thought that fetal cells would be less aggressive and would not fight cancer, but the opposite happened," says Weiss (in the article Umbilical blood cells kill cancer faster than adult cells, published in the journal New Scientist – VM).
It turned out that in mice that received immature cells from the umbilical cord, the disease quickly disappeared, while in the second group of animals, cancer-affected lymphocytes continued to form.
When the scientists examined tumor samples between the introduction of cord blood components and complete cure, they found that the embryonic cells quickly began to produce lymphocytes, known as T-helpers. These white blood cells enhance and coordinate the body's immune response to the appearance of a tumor or the invasion of viruses. In addition, the tumor focus was quickly filled with other lymphocytes – T-killers, which were directly engaged in the destruction of the affected tissues.
"The result was completely unexpected, because compared to the "experienced" cells of an adult organism, the immune cells in the umbilical cord blood have always been considered too naive to recognize and kill pathology," adds Weiss. "But it seems that they can work without prior practice."
The authors of the article published in the publication Blood (Hiwarkar et al., Cord blood T cells mediate enhanced anti-tumor effects compared with adult peripheral blood T cells – VM) suggest that immature cells may have special immunological abilities that provide instant protection for a growing fetus. The results of the study hint that cord blood is the best choice for the treatment of leukemia.