Scientists at the University of British Columbia (UBC) have solved a long-standing problem in cancer immunotherapy, successfully growing helper T cells from stem cells in a controlled lab setting for the first time.
The research, published in the journal Cell Stem Cell, removes a significant barrier to producing affordable, ready-made immune cell therapies for cancer, infectious diseases, and autoimmune disorders.
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Cancer cell therapies work best when two types of immune cells operate together. Killer T cells directly attack cancer cells, while helper T cells act as the immune system's coordinators — detecting threats, activating other immune cells, and sustaining immune responses over time.
Scientists had already made progress generating killer T cells from stem cells in the lab, but consistently producing helper T cells had proved elusive — until now.
"Helper T cells are essential for a strong and lasting immune response," said co-senior author Dr Megan Levings, professor of surgery and biomedical engineering at UBC. "It's critical that we have both to maximise the efficacy and flexibility of off-the-shelf therapies."
Engineered cell treatments such as CAR-T therapies have produced remarkable results for patients with previously untreatable cancers. However, they remain expensive, complex to manufacture, and out of reach for many patients globally.
A key reason is that most existing treatments rely on a patient's own immune cells, which must be individually collected and prepared over several weeks.
"The long-term goal is to have off-the-shelf cell therapies that are manufactured ahead of time and on a larger scale from a renewable source like stem cells," said Dr Levings. "This would make treatments much more cost-effective and ready when patients need them."
The UBC team solved the problem by carefully adjusting biological signals that guide how stem cells develop, allowing them to control whether stem cells became helper T cells or killer T cells.
The key was a developmental signal called Notch. The researchers found that while Notch is necessary early in cell development, if the signal stays active too long it blocks the formation of helper T cells.
"By precisely tuning when and how much this signal is reduced, we were able to direct stem cells to become either helper or killer T cells," said co-first author Dr Ross Jones, adding that the process works under conditions directly applicable to real-world biomanufacturing.
Critically, the lab-grown helper T cells did not just resemble genuine immune cells in appearance — they also behaved like them. The cells showed full maturity, carried a wide variety of immune receptors, and were able to develop into specialised subtypes.
"These cells look and act like genuine human helper T cells," said co-first author Kevin Salim, a UBC PhD student. "That's critical for future therapeutic potential."
The researchers say the ability to reliably generate and balance both helper and killer T cells from stem cells could significantly improve the effectiveness of next-generation immune therapies.
"This is a major step forward in our ability to develop scalable and affordable immune cell therapies," said co-senior author Dr Peter Zandstra, professor and director of the UBC School of Biomedical Engineering.
He added that the technology now forms the foundation for testing helper T cells in cancer treatment and for generating new cell types — such as regulatory T cells — for broader clinical applications.