Transient human gene therapy: a novel cytokine regulatory strategy for experimental pancreatitis

The purpose of this study was to evaluate the ability to transfect a murine pancreas with a human cytokine regulatory gene (interleukin-10 [IL-10]) and examine the duration of transgene expression, its effect on the normal pancreas, and its antiinflammatory effect during acute pancreatitis.

Interleukin-1beta and tumor necrosis factor-alpha are known detrimental mediators during the progression of acute pancreatitis, and blockade of either cytokine results in decreased severity of pancreatitis and improved survival. Although gene therapy has been proposed as a method to deliver protein-based therapy during a number of conditions, no means of effectively transfecting the pancreas without inducing injury has been developed.

A plasmid-human IL-10 construct (pMP6-hIL-10) complexed with cationic liposomes was administered by single intraperitoneal injection to healthy mice. Effective transfection (reverse transcriptase-polymerase chain reaction for hIL-10 mRNA), transfected cell type (in situ polymerase chain reaction for hIL-10 DNA), and the effect on the normal pancreas were determined. Additional animals were transfected to determine the effects of this regulatory gene on the severity of pancreatitis.

Nearly 80% of all pancreatic cells expressed human DNA that was subsequently transcribed into mRNA through day 14. The transfection event had no effect on amylase, lipase, or pancreatic histologic appearance. Successful transfection could attenuate subsequently induced pancreatitis (all parameters p < 0.05).

Transient transfection of a human IL-10 gene can be accomplished into all cell types of murine pancreata using a plasmid/ liposome vector. The DNA is effectively transcribed into intact mRNA and does not cause inflammation or acinar cell damage. Transfer of this cytokine regulatory gene decreases the severity of pancreatitis, demonstrating a benefit of gene therapy during this acute inflammatory process.