In a recent study, scientists used cells from pig snouts to successfully repair severed spinal cords in rats. The pig cells were engineered so that they would not be rejected by the rat’s immune system, as is usually the case with cross-species transplants. In the future, doctors may be able to use these engineered cells to treat human spinal cord injuries, according to an article published in the Aug. 29 issue of Nature Biotechnology.
Attempts to transplant organs from one species to another are usually unsuccessful because the recipient’s immune system rejects the foreign antigens of the donor organ. This new technique addresses the problem by using pig cells that have been engineered to express a human (or rat, in the case of the study) complement inhibitory protein that suppresses immune rejection responses. The scientists used cells from pig snouts because the snout has a concentration of nerve fiber-ensheathing cells, which are particularly suited for spinal cord repair.
When these pig cells were transplanted into rats who had their spinal cords severed, the cells helped regenerate nerves, form new Myelin (the substance that insulates nerve fibers), and restore the relay of nerve signals up and down the severed spinal cords of seven of the 10 treated rats. Scientists found that the nerve fibers grew at a rate of 1 millimeter (.039 inch) per day. Surprisingly, the regenerated nerves actually conducted impulses faster than normal, healthy nerves.
While the research is still in its early stages, the authors of the study suggest that these pig cells might soon be used to treat humans with spinal cord injuries, without triggering immunological