Mice and RSV infections
Female BALB/c mice were used at 7-9 weeks of age (Animal Resource Centre, Murdoch, Western Australia) and housed in a controlled environment with a 12 hrs light to dark cycle with unrestricted access to food and water. Mice were anaesthetized with 3% isoflurane and infected intranasally with 1x105 pfu/ml live RSV in DMEM, with the total inoculation volume being no greater than 40 μl. Mice were euthanized with pentobarbital (250 mg/kg) following inhaled methoxyflurane anaesthesia.
Mice were weighed daily during the acute period of infection until sacrifice at days 0, 3, 5, 7 and 21 days post-infection. Clinical disease scores were also assessed according to the following criteria as described previously25. Score 0 - Normal appearance, healthy and active; Score 1 - Barely ruffled fur, mildly/intermittent hunched appearance and otherwise healthy; Score 2 – Moderately ruffled fur, elevated respiratory rate, hunched appearance with a crab-like gait, intermittent stillness and reduction of curious behaviour; Score 3 - Ruffled fur, laboured breathing, hunched appearance with a crab-like gait and unresponsive to stimuli.