Shyam P. Reddy, Professor and Director of the Cancer Biology Program at Morehouse School of Medicine, shared on LinkedIn:
“The immune system possesses legions of T cells that, if primed, could hunt down and destroy tumors. Now, a UC San Francisco team has invented a way to do this by combining immune cells grown in the lab with samples from a patient’s tumor. Like giving a scent to a hound dog, it shows the immune system how to go after the cancer.
The T cells first need to be taught by dendritic cells, which are rare immune cells that are hard to obtain from cancer patients. The UCSF method gets around this by making dendritic cells from induced pluripotent stem cells (iPSCs), which can be grown in large quantities in the laboratory.
Since typical iPSCs would be rejected by the immune system, the scientists first strip them of identifying information, then prompt them to mature into dendritic cells. Finally, they ‘dress’ the dendritic cells with tiny membrane bubbles made from tumor cells.
These give the dendritic cells many different signs of the cancer to show to T cells.
In laboratory experiments using tumor samples and T cells from patients with leukemia and ovarian cancer, the dressed dendritic cells were able to train the T cells to kill tumors from the same patient. The treatment also slowed tumor growth in a mouse model.
The findings appear in Cell Stem Cell.
‘For cell-based therapies to work, they need to avoid immune rejection by the body, and they need to target the cancer and not healthy tissue,’
said Robert Blelloch, MD, Ph.D., a professor in the Department of Urology at UCSF and senior author of the paper.
‘Our combination of iPSC-derived dendritic cells with patients’ own tumor signature checks both boxes, and we’re very hopeful it could work in the clinic.’
Instead of trying to identify the right cancer targets one by one, the researchers broke apart the membranes of tumor cells and let them form into tiny bubbles. These bubbles merged with the dendritic cells, coating them with tiny pieces of the patient’s tumor.
This both made the dendritic cells look more like the patient’s own cells and carried a wide range of cancer targets. All that information could make it harder for a tumor to escape just by shedding a single target, a problem that can limit other immunotherapies.”
You can also read: Exploring the Next Wave of Combination Therapies in Cancer Immunotherapy – SITC
