MCMV Infection and Viral Challenge Protocols

Il33^−/− mice were bred in-house (38 (link)). C57BL/6 mice were purchased from Charles River Laboratories or Envigo. Sex-matched mice aged 7–9 wk were used in all experiments. Smith-strain MCMV was propagated in vivo and prepared via sorbitol gradient purification (39 (link)). Mice were infected i.p. with 3 × 10⁴ PFU of MCMV. ΔgL-SL8-MCMV was prepared as described previously (24 (link)). Mice were infected i.p. with 4 × 10⁵ PFU of ΔgL-SL8-MCMV. In some experiments, 2 μg of rIL-33 (BioLegend) was administered i.p. at the time of infection. Replication-deficient recombinant adenovirus type 5 (pAdZ5-CV5) expressing immediate-early protein 3 (rAd-IE3) was engineered and purified as described previously (40 (link)). Mice were challenged i.p. with 5 × 10⁸ PFU of rAd-IE3 or 2 × 10⁶ PFU of recombinant vaccinia virus expressing OVA (rVV-OVA) (41 (link)). All mouse experiments were performed at Cardiff University under U.K. Home Office Project License 30/2969 (London, U.K.).