Figure 1. Intramuscular administration of rAAV6:CMV-hPLAP vectors induces skeletal muscle inflammation and damage in a dose and time-dependent manner.

(a) The TA muscles of mice were injected with either 1×10⁸, 1×10⁹ or 1×10¹⁰ genomes of the control vector, or rAA6:CMV-hPLAP and examined 14 days afterwards. TA muscles were dissected and stained with Hematoxylin & Eosin for general morphology, or with NBT/BCIP to determine the expression of human placental alkaline phosphatase (purple). Asterisks identify common features on the serial sections used for morphology and hPLAP activity. (b) A time-course analysis of muscles examined 7, 14, 21 and 28 days after injection of rAAV6 vectors indicates peak times of induction of inflammation in response to rAAV:CMV-hPLAP, as compared to a gene-less vector (rAAV6:CMV-MCS) or rAAV6:Follistatin288.