Mumps virus alters aggregation of acetylcholine receptors in cultured rat skeletal muscle cells.

Cultured myoblasts, but not myotubes, from rat skeletal muscles were infected with the RW strain of mumps virus. Such myoblasts then fused to form myotubes containing viral antigen. The infected myotubes showed a significant decrease in the number of dorsal, linear acetylcholine receptor (AChR) aggregates as determined by FITC-conjugated alfa-bungarotoxin. Infected myotubes co-cultivated with spinal cord cells showed no increase in the number of dorsal, linear AChR aggregates, compared to normal, uninfected myotubes. In addition, an increased proliferation of the myoblasts, which remained uninfected in the infected cultures, was noted. This may indicate a release of a growth stimulating factor from the virus containing cells. This study shows that mumps virus infection can lead to an altered receptor organization in a morphologically preserved cell.