Delayed control of lung MCMV infection in neonatal mice.

<p>Neonatal (A–F) or adult (A, C–F) mice were infected as follows: neonates l.p. with 5×10⁴ PFU MCMV-3D, adults intranasal with 10⁶ PFU MCMV-3D. (A–F) Animals were sacrificed at indicated time-points after infection and frozen sections of explanted lungs were performed and analyzed after antibody and DAPI staining. (A) Upper rows show merged images of immune infiltrates associated with MCMV-infected cells (mCherry⁺), lower rows only mCherry signals. (B) Examples and relative distribution of infected cells that are either “contacted” or “not contacted” by neonatal immune cells. (C) Luciferase activity of homogenized lung explants from n = 3–5 animals from 1–2 experiments per time point. (D+E) Number of mCherry+ viable cells or remnants per lung slice, determined by 2 counted slices per animal, normalized to (D) mean of infected cells determined at day 1 p.i or (E) normalized to the maximal value of remnants per group; zero counts were set to <10⁻³ to allow logarithmic illustration, t-test between groups at indicated time-points, n = 2–4 animals per indicated time-point from >3 independent experiments. (F) Number of mCherry⁺ viable cells per lung slice at day 5 p.i., frozen sections of n = 6–7 animals from 2 independent experiments. (B) Median & range, (C–E) each value and a connecting line of medians, (F) mean & SD.