Scientists have found a way to make blood transplantation safer: targeted destruction of stem cells

Imagine that the owner of a hotel wants to drive away some guests and choose to blow up the whole hotel, which is obviously not desirable, and the current stem cell transplantation method is the truth, which will damage other important cells in the body during the treatment process In order to improve the safety of blood transplantation, scientists are trying to selectively destroy human hematopoietic cells, and have made some progress Based on the understanding of proteins produced by different types of blood stem cells, nature elaborates the target stem cell method doi:10.1038/d41586-019-03601-5 The working principle of blood stem cell transplantation: defective hematopoietic cells are replaced by healthy hematopoietic cells (from donors or patients themselves) At present, we mainly kill the existing blood stem cells by means of radiotherapy, chemotherapy and other means to clear the way for the transplanted cells to be re implanted into bone marrow, but this may lead to blood cancer, autoimmune diseases and so on At present, researchers have proposed a new targeting method, that is, eradicating specific stem cells, making room for transplanted cells, and not blindly destroying bone marrow cells Blood stem cells (blue) in the bone marrow (purple) are removed before new stem cells are transplanted Source: Dennis Kunkel microscopy / SPL At the hematology conference, forty seven company mentioned two kinds of antibodies, one is the antibody that can prevent the activity of c-kit molecule, which exists in blood stem cells; the other is the antibody that can inhibit CD47 protein, which exists in some immune cells, and test the research results of these two antibody combinations in monkeys It is found that inhibition of CD47 can make these immune cells clear of stem cells targeted by c-kit antibody, thus improving their effectiveness In the trial, the combination reduced the number of blood stem cells in the bone marrow, but the team has yet to prove whether the treatment can help the transplanted cells reproduce Doctors prepare to collect bone marrow samples from patients: bsip / Uig / Getty Massachusetts, in collaboration with the National Institutes of health, found another antibody that binds to c-kit and then releases a toxin that kills blood stem cells that produce the protein Through the study of mice and a monkey, the data showed that this can kill enough bone marrow stem cells to ensure that the transplanted cells thrive without damaging other cells, such as immune cells A team led by Judith Shizuru, a transplant physician at Stanford University in California, worked with Amgen of thousand oaks in California to develop a third antibody against c-kit They have also used targeted blood stem cell transplants in six infants with genetic diseases that weaken the immune system, and found that stem cells from healthy donors have successfully rooted in the bone marrow of four infants More and more data show that some patients with type 1 diabetes, systemic scleroderma and other immune system diseases, if the mature immune cells in their bone marrow are replaced by their own hematopoietic stem cells, their condition will be relieved Keith Sullivan, a stem cell transplant doctor at Duke University in Durham, North Carolina, said the approach is believed to reset the immune system by eliminating cells that are aggressive against the body's own tissues For the hotel to expel guests, the latest method is that the host let specific guests leave Similarly, targeting to destroy human hematopoietic cells is by targeting some cells in the bone marrow, rather than killing them all.