IFNλ can restrict mCMV replication <i>in vitro</i>.

<p>(A) <i>Ifnλr1</i> expression by 3T3 and BNLCL2 cells was determined by qPCR. (B) 3T3 (top) and BNLCL2 (bottom) cells were incubated with/without 50U/ml IFNα and/or IFNβ, or 50ng/ml IFNλ2 (IL-28A) for 24hrs and infected with mCMV at multiplicities of infection (MOI), as stated in the figure. After 4 days, infectious virions in supernatant were quantified by plaque assay. Statistical significance of PFU in IFNλ2-treated versus control cells is shown. Virus load in spleen (C), liver (D) and salivary glands (E) of WT and <i>Ifnλr1</i>^<i>-/-</i> mice was assessed 4 (D&E) and 33 (E) days p.i. (F) IFNλ2/3 protein in spleen (left), liver (middle) and salivary glands (right) was measured at day 0 and 2 days p.i (spleen and liver) or 0 and 26 days p.i (salivary glands). Results are shown as mean + SEM of 3–7 mice/group. (G) WT and <i>Ifnλr1</i>^<i>-/-</i> mice were infected (i.n) with mCMV in a volume of 25μl or 50μl and after 4 days, lung infectious viral load was quantified by plaque assay. Statistical significance was assessed using 1-way ANOVA (B) or Mann Whitney-U (C-E, G) or students T-Test (F) and is depicted where appropriate. Panel G represents merged data from two experiments whereas all other data represent at least two biological replicates performed separately.