Cross-species transplant in rhesus macaques is step toward diabetes cure ...( St. Louis Oct. 18 2007 With an eye ...),Health

St. Louis, Oct. 18, 2007 With an eye on curing diabetes, scientists at Washington University School of Medicine in St. Louis have successfully transplanted embryonic pig pancreatic cells destined to produce insulin into diabetic macaque monkeys all without the need for risky immune suppression drugs that prevent rejection.

The transplanted cells, known as primordia, are in the earliest stages of developing into pancreatic tissues. Within several weeks of the transplants, the cells became engrafted, or established, within the three rhesus macaque monkeys that received them. The cells also released pig insulin in response to rising blood glucose levels, as would be expected in healthy animals and humans.

"The approach reduced the animals' need for insulin injections and has promise for curing diabetes in humans," says senior investigator Marc Hammerman, M.D., the Chromalloy Professor of Renal Diseases in Medicine. "The transplants worked without a need for immune suppression and that is a major obstacle we have overcome."

The researchers' results appear online and will be published in the journal Xenotransplantation in November.

Although the transplants fell short of producing sufficient insulin to cure the macaques' diabetes, Hammerman predicts that with additional research, including the transplantation of additional embryonic pig cells into the animals, he will be able to reduce their need for insulin injections entirely.

The new research follows on the heels of reports by Hammerman and his colleagues demonstrating that transplanted pig pancreatic primordia can cure both type 1 and type 2 diabetes in rats, without using immune suppression drugs. Other scientists have tried different types of pancreatic cell transplants in animals and humans as a stepping stone to curing diabetes, but they all require anti-rejection drugs. These drugs must be taken daily to stave off rejection and have adverse effects of their own that limit the su
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