MELBOURNE, July 7 (Xinhua) -- Researchers in Australia have identified immune cells recruited during pregnancy that may help protect against breast cancer, raising the prospect of new preventive interventions for women who have not had children.
In a study published in Nature Immunology, scientists found that pregnancy triggers an influx of "killer" T cells -- a type of immune cell that helps detect and destroy abnormal cells, including cancer cells -- into breast tissue, according to a statement from Australia's Peter MacCallum Cancer Center (Peter Mac) released on Monday.
The study suggests natural breast cancer protection could someday be induced without pregnancy, helping women who cannot or choose not to conceive.
Higher levels of killer T cells were linked to better outcomes in women, helping to detect and destroy cancerous cells, said the study's co-lead researcher, Associate Professor Kara Britt at Peter Mac.
"We uncovered that the tissue-resident memory T cells are recruited during pregnancy, but survive for a long time and potentially stay in the breast tissue patrolling it for abnormal cells for years," Britt said.
The team examined breast tissue up to a decade after pregnancy and confirmed the long-term presence of these immune cells.
"Our research suggested that the tissue resident T-cells rely on the milk-producing breast cells for survival and growth and were embedded within the milk ducts," said Peter Mac study co-lead, Associate Professor Ajithkumar Vasanthakumar.
Using experimental models, researchers induced similar immune protection against breast cancer with hormone treatments, without the need for pregnancy. ■
