Establishment of immortalized Schwann cells from Sandhoff mice and corrective effect of recombinant human beta-hexosaminidase A on the accumulated GM2 ganglioside.

We have established spontaneously immortalized Schwann cell lines from dorsal root ganglia and peripheral nerves of Sandhoff mice. One of the cell lines exhibited genetically and biochemically distinct features of Sandhoff Schwann cells. The enzyme activities toward 4-methylumbelliferyl N-acetyl-beta-D-glucosamine (beta-hexosaminidases A, B, and S) and 4-methylumbelliferyl N-acetyl-beta-D-glucosamine-6-sulfate (beta-hexosaminidases A and S) were decreased, and GM2 ganglioside accumulated in lysosomes of the cells. Incorporation of recombinant human beta-hexosaminidase isozymes expressed in Chinese hamster ovary cells into the cultured Sandhoff Schwann cells via cation-independent mannose 6-phosphate receptors was found, and the incorporated beta-hexosaminidase A degraded the accumulated GM2 ganglioside. The established Sandhoff Schwann cell line is useful for investigation and development of therapies for Sandhoff disease.