Invisibility cloak allows transplanted brain cells to evade immune system

Cell therapy using stem-cell-derived products is becoming a realistic prospect for treating many diseases. That includes Parkinson’s disease, where preclinical and clinical studies have evaluated the use of nerve, or neural, grafts.

A big problem with introducing grafts into the body is that they’re considered foreign objects, and unless anti-rejection drugs are given, the immune system targets them. Now, research led by The Florey Institute of Neuroscience and Mental Health (The Florey) in Australia has developed an ingenious way of avoiding that problem.

Researchers engineered hPSCs to “overexpress 8 immunomodulatory transgenes.” Overexpression just means making lots of something. "Immunomodulatory' is something that calms or adjusts the immune system. And transgenes are genes scientists have inserted into a cell that weren’t there originally. So, what does this engineering do? It allows the stem-cell-derived neurons that comprise the graft to evade the immune system.

“We’ve engineered neurons which are like those currently in clinical trials for Parkinson’s disease, but we’ve also given them an invisibility cloak,” Clare Parish said. “They can hide in plain sight from the immune system. This could mean an end to the need for anti-rejection drugs.” The engineered grafts were tested in “humanized” mice whose immune systems have been altered to mimic ours.

Image source: The Florey.