Scientists at A*STAR’s Singapore Immunology Network (SIgN) have discovered a new class of lipids in the leukemia cells that are detected by a unique group of immune cells. By recognizing the lipids, the immune cells stimulate an immune response to destroy the leukemia cells and suppress their growth. The newly identified mode of cancer cell recognition by the immune system opens up new possibilities for leukemia immunotherapy.
Leukemia is characterized by the accumulation of cancer cells originating from blood cells, in the blood or bone marrow. Current treatments for leukemia largely involve chemotherapy to eradicate all cancer cells, followed by stem cell transplants to restore healthy blood cells in the patients.
In a recent study reported in the Journal of Experimental Medicine (JEM) online, the team co-led by Dr Lucia Mori and Prof Gennaro De Libero identified a new class of lipids, methyl-lysophosphatidic acids (mLPA), which accumulate in leukemia cells. Following which, the team identified a specific group of immune cells, described as mLPA-specific T-cells that are capable of recognising the mLPA in the leukemia cells. The detection triggers an immune response that activates the T cells to kill the leukemia cells and limits cancer progression. The efficacy of the T cells in killing leukemia cells was also demonstrated in a mouse model of human leukemia.
Thus far, only proteins in cancer cells have been known to activate T cells. This study is a pioneer in its discovery of mLPA, and the specific T cells which can identify lipids expressed by cancer cells. Unlike proteins, lipids in cancer cells do not differ between individuals, indicating that the recognition of mLPA by mLPA-specific T-cells happens in all leukemia patients. This new mode of cancer cell recognition suggests that the T-cells can potentially be harnessed for a leukemia immunotherapy that is effective in all patients.
Nick Wilkins was diagnosed with leukemia when he was 4 years old, and when the cancer kept bouncing back, impervious to all the different treatments the doctors tried, his father sat him down for a talk.
John Wilkins explained to Nick, who was by then 14, that doctors had tried chemotherapy, radiation, even a bone marrow transplant from his sister.
“I explained to him that we’re running out of options,” Wilkins remembers telling his son.
There was one possible treatment they could try: an experimental therapy at the University of Pennsylvania.
He asked his son if he understood what it would mean if this treatment didn’t work.