Poliovirus crystals within the endoplasmic reticulum of endothelial and mononuclear cells in the monkey spinal cord

The lumbar motor columns of a cynomolgus monkey that had become tetraplegic after experimental infection with a highly virulent strain of type 3 poliovirus were examined by electron microscopy. Crystalline aggregates of poliovirus occurred within the endoplasmic reticulum of endothelial cells as well as of mononuclear inflammatory cells. This finding suggests that the endoplasmic reticulum might be much more involved in poliovirus multiplication than has been previously supposed.