blood cells

New treatment uses altered blood cells to attack leukaemia

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Scientists have figured out how to reprogram the blood of cancer patients to attack their leukaemia, and 19 of the 30 patients who received the treatment remain in complete remission.

blood-transfusion

A team of researchers led by immunotherapist Carl June from the University of Pennsylvania in the US has announced the results of a new treatment for leukaemia patients that turns their own blood cells against their disease.

The researchers chose to work with patients who were dealing with particularly aggressive cases of leukaemia. All of the participants in the study had cancers that had returned at least four times before.

According to Elizabeth Lopatto at the Verge, the treatment works by first having a patient’s T cells – a type of white blood cell that plays a crucial role in the body’s immune response – harvested through a blood transfusion process. These T cells are then engineered to seek out a particular protein called a B cell receptor, found on the surface of the patient’s B cells. B cells are another type of white blood cell that’s specifically targeted by leukaemia.

The patient’s altered T cells will then be transplanted back into their blood stream so they can start hunting B cell receptor proteins, and kill the leukaemia and the B cells they’re attached to.

Of course, this means that the patient’s entire supply of B cells will be wiped out by this treatment. Because the main role of B cells is to produce antibodies to fight anything that might threaten our bodies, including viruses and bacteria, the patients will be left extremely vulnerable until they can generate more. This is something that hospitals will need to be aware of if the treatment ends up being used more widely, but the benefit of this treatment is that it only has to be administered once for it to work.

According to the study, which was published in the New England Journal of Medicine, of the 30 children and adults that received the treatment, complete remission was achieved in 27 patients (90 percent). Remission was sustained past the six-month point in 19 of the 30 patients. One of the early success stories is a nine-year-old girl called Emily Whitehead, who started the treatment when she was six. She’s been cancer-free now for two years.

“This is unlike almost all cell and gene therapies in that it’s actually ahead of the schedule we set for ourselves when we first started treating patients,” June told Lopatto at the Verge. “We pinch ourselves because, you know, until recently we didn’t know if we got lucky or if it would last. Our initial patients are still in remission, so we know it’s durable and reproducible. That’s something that makes us excited every day.”

The team is now working on easing the side effects of the treatment, which include fever, nausea, muscle pain and difficulty breathing.

Cell discovery brings blood disorder cure closer

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A cure for a range of blood disorders and immune diseases is in sight, according to scientists who have unraveled the mystery of stem cell generation. Found in the bone marrow and in umbilical cord blood, HSCs are critically important because they can replenish the body’s supply of blood cells. Leukemia patients have been successfully treated using HSC transplants, but medical experts believe blood stem cells have the potential to be used more widely.
Blood cells (stock illustration). “HSCs are one of the best therapeutic tools at our disposal because they can make any blood cell in the body. Potentially we could use these cells in many more ways than current transplantation strategies to treat serious blood disorders and diseases, but only if we can figure out how they are generated in the first place. Our study brings this possibility a step closer,” oneresearcher said.
A cure for a range of blood disorders and immune diseases is in sight, according to scientists who have unravelled the mystery of stem cell generation.

The Australian study, led by researchers at the Australian Regenerative Medicine Institute (ARMI) at Monash University and the Garvan Institute ofMedical Research, is published today in Nature. It identifies for the first time mechanisms in the body that trigger hematopoietic stem cell (HSC) production.

Found in the bone marrow and in umbilical cord blood, HSCs are critically important because they can replenish the body’s supply of blood cells. Leukemia patients have been successfully treated using HSC transplants, but medical experts believe blood stem cells have the potential to be used more widely.

Lead researcher Professor Peter Currie, from ARMI explained that understanding how HSCs self-renew to replenish blood cells is a “Holy Grail” of stem cell biology.

“HSCs are one of the best therapeutic tools at our disposal because they can make any blood cell in the body. Potentially we could use these cells in many more ways than current transplantation strategies to treat serious blood disorders and diseases, but only if we can figure out how they are generated in the first place. Our study brings this possibility a step closer,” he said.

A key stumbling block to using HSCs more widely has been an inability to produce them in the laboratory setting. The reason for this, suggested from previous research, is that a molecular ‘switch’ may also be necessary for HSC formation, though the mechanism responsible has remained a mystery, until now.

In this latest study, ARMI researchers observed cells in the developing zebra fish — a tropical freshwater fish known for its regenerative abilities and optically clear embryos — to gather new information on the signalling process responsible for HSC generation.

Using high-resolution microscopy researchers made a film of how these stem cells form inside the embryo, which captured the process of their formation in dramatic detail.

Professor Currie said when playing back these films they noticed that HSCs require a “buddy” cell type to help them form. These “buddies,” known as endotome cells, have stem cell inducing properties,

“Endotome cells act like a comfy sofa for pre HSCs to snuggle into, helping them progress to become fully fledged stem cells. Not only did we identify some of the cells and signals required for HSC formation, we also pinpointed the genes required for endotome formation in the first place,” Professor Currie said.

“The really exciting thing about these results is that if we can find the signals present in the endotome cells responsible for embryonic HSC formation then we can use them in vitro to make different blood cells on demand for all sorts of blood related disorder.”

“Potentially it’s imaginable that you could even correct genetic defects in cells and then transplant them back into the body,” Professor Currie said.

Dr Georgina Hollway, from the Garvan Institute of Medical Research said the work highlights how molecular processes in the body play a key role in HSC formation.

“We now know that these migratory cells are essential in the formation of hematopoietic stem cells, and we have described some of the molecular processes involved. This information is not the whole solution to creating them in the lab, but it will certainly help.” said Dr Hollway.

The next phase of the research will see Professor Currie’s team identify more of the molecular cues that trigger HSC production.