New Skin Patch More Accurately Monitors Immune Conditions

Researchers at The Jackson Laboratory (JAX) in Maine and the Massachusetts Institute of Technology (MIT) have developed a bandage-like microneedle patch that samples key cells often missed in routine blood samples and biopsies without the need for taking blood or surgical biopsies. The patch, which detects inflammatory signals within minutes and collects specialized immune cells within hours, is already helping doctors and researchers study immune responses in aging and skin autoimmunity, including vitiligo and psoriasis.

The patch was initially developed by Sasan Jalili, PhD, a biomedical engineer and immunologist at JAX, during his postdoctoral training at MIT, and was then further refined, optimized and advanced from mouse models toward clinical application. According to Dr. Jalili, the patch works by harnessing resident memory T cells, immune sentinels that live in skin and other “barrier” tissues and rapidly respond to previously encountered foreign threats, or antigens. When those cells recognize a familiar antigen, such as a fragment of a virus or an allergen, they “sound the alarm,” releasing signals to attract additional immune cells from the bloodstream, including the highly specialized T cells that recognize that same threat. The sampled material revealed the number and state of T cells and other signalling molecules, offering a “dynamic” readout of the immune system’s strength and responsiveness to specific diseases and conditions.

In mouse vaccination models, the patch dramatically boosted the recovery of antigen-specific T cells, recruiting many of the cells from the bloodstream rather than skin. And, in a human test at Chan Medical School, the patch also collected a rich mix of immune cells and signalling proteins, including resident memory T cells.

“This study marks the first demonstration of live human immune cell sampling using a microneedle patch,” said Dr. Jalili. “This opens the door to a new way of monitoring immune responses that’s practical, painless and clinically feasible.”

The research team says, in the future, the patch could make it easier to track how people respond to vaccines, infections and cancer therapies by complementing traditional blood tests and biopsies while being far easier on patients.