Researchers at the University of Chicago have developed an engineered strain of Bifidobacterium longum, a probiotic bacterium naturally found in the gut, to carry immune-stimulating treatments directly into pancreatic tumors. In animal models, this therapy slowed the growth of pancreatic tumors by selectively activating T cells that fight cancer and showed even stronger effects when combined with chemotherapy, radiotherapy or immunotherapy. The findings suggest that BifidoSumIL-2 could eventually provide a new way to improve how pancreatic tumors respond to treatment.

The engineered bacteria were designed to release a modified version of interleukin-2 (IL-2) once it reaches a tumor. IL-2 is a potent immune signaling molecule that activates T cells involved in attacking cancer, but conventional IL-2 treatment can produce serious side effects and stimulate immune cells that weaken the antitumor response. The researchers used SumIL-2, a modified form of IL-2 engineered to more precisely activate cancer-fighting T cells while reducing stimulation of regulatory T cells. They then placed SumIL-2 inside Bifidobacterium longum so that the therapeutic molecule could be concentrated within tumors instead of throughout the body.

Developing this treatment required scientists from several disciplines, including microbiology, synthetic biology, oncology, and immunology. The engineered bacteria preferentially grow in anaerobic environments, such as many solid tumors, while healthy tissues contain more oxygen and are therefore less suitable for the bacteria. This preference allows Bifidobacterium to function as microscopic drug factories inside tumors, producing SumIL-2 where it is needed rather than throughout the body. The treatment has shown a favorable safety profile in preclinical models and is already well known as a probiotic organism commonly present in yogurt.

This is a summary. Read the original at sciencedaily.com.