And lymph nodes near the liver are close enough to receive chemical distress signals sent by the dying tissue of a diseased liver, Lagasse says. These signals are intended to encourage the regeneration of the remaining healthy liver tissue, but this does not work in cases of severe disease. However, the signals appear to help the growth of liver tissue in neighboring lymph nodes.
“It’s amazing,” says Gouon-Evans. “Having this little incubator in your body [that can grow organs] It’s incredible.”
LIGENESI
About five years ago, Lagasse, along with entrepreneur and drug developer Michael Hufford and transplant surgeon Paulo Fontes, founded LyGenesis to take the technology further. The team is exploring the use of lymph nodes to grow new thymus, kidneys and pancreas.
But the company’s priority is livers. Over the past 10 years, team members have collected promising evidence suggesting they can use their approach to grow new minilivers in mice, pigs and dogs. Mini livers don’t grow indefinitely – the body has an internal regulator that stops liver growth at a certain point, so healthy livers don’t overgrow when they regenerate.
The team’s research in mice with a genetic liver disorder has shown that most cells injected into a lymph node will stay there, but some will migrate to the liver, as long as enough healthy liver tissue remains. These migrating cells can help regenerate and heal the remaining liver tissue. When this happens, the new mini-liver in the lymph node will shrink, keeping the total amount of liver tissue in balance, Lagasse says.
Other studies have focused on pigs and dogs that have the blood supply to the liver diverted, causing the organ to die. Injecting liver cells into the animals’ lymph nodes will eventually rescue their liver function.
In the pig study, for example, the team surgically diverted the blood supply away from the liver in six animals. After the pigs recovered from surgery, the team injected healthy liver cells into their lymph nodes. Doses ranged from 360 million cells injected into three lymph nodes to 1.8 billion cells into 18 lymph nodes.
Within a couple of months, all the animals appeared to have recovered from the liver damage. Tests suggested that his liver function had improved. And when the team later performed autopsies on the animals, the new organs in the lymph nodes looked a lot like miniature healthy livers, each about 2% the size of a typical adult liver. Other studies suggest that treatment takes about three months to have significant benefits.