In a proof-of-principle study in mice, scientists at Johns Hopkins Medicine report the creation of a specialized gel that acts like a lymph node to successfully activate and multiply cancer-fighting immune system T-cells. The work puts scientists a step closer, they say, to injecting such artificial lymph nodes into people and sparking T-cells to fight disease.

In the past few years, a wave of discoveries has advanced new techniques to use T-cells – a type of white blood cell – in cancer treatment. To be successful, the cells must be primed, or taught, to spot and react to molecular flags that dot the surfaces of cancer cells. The job of educating T-cells this way typically happens in lymph nodes, small, bean-shaped glands found all over the body that house T-cells. But in patients with cancer and immune system disorders, that learning process is faulty, or doesn’t happen.

To address such defects, current T-cell booster therapy requires physicians to remove T-cells from the blood of a patient with cancer and inject the cells back into the patient after either genetically engineering or activating the cells in a laboratory so they recognize cancer-linked molecular flags.