IFITM3 KO DCs are more susceptible to influenza virus infection.

<p>(a) B6 or IFITM3 KO mice were infected via the intranasal route with 10⁴ PFU of influenza virus (Pr8) and 24 or 48 hrs later mice were culled and single cell preparations of lung cells were stained for expression of viral NP. The proportion of lung DCs staining positive for influenza virus NP was then determined by flow cytometry. Representative flow cytometry plots are shown (n = 4–6 mice, data pooled from 3 independent experiments, numbers represent mean + sem) (b) Dendritic cells (CD11c+MHCII+ F4/80-) were sort purified from the lungs of with B6 or IFITM3 KO mice 48 hrs after intranasal infection with 10⁴ PFU of influenza virus (Pr8). The total amount of viral RNA present in the DC population was measured by real time PCR. Data are pooled from 3 independent experiments. Graph represents the fold increase in viral RNA normalized to the amount of viral RNA present in the B6 DCs. (c-d) CD103+ and CD11b+ DC were sort purified from the lungs of B6 or IFITM3 KO mice infected with influenza virus (moi 10) and cells were fixed 24 hr later, stained for influenza virus NP and examined by flow cytometry. (c) Representative flow cytometry profiles are shown. Data is representative of 3 independent experiments. (d) Graph depicts the mean percent infection + sem (data is pooled from 3 independent experiments, Student’s t test, **<i>P</i><0.01, ***<i>P</i><0.001) (e) DCs were sort purified from the spleens of B6 and IFITM3 KO mice and monolayers of cells were infected with influenza virus at the doses indicated. At 12 hr post-infection, cells were fixed and stained for expression of viral NP and the percentage of infected cells was determined in at least 5 random fields (>200 cells). Data show the mean percent infection + sem (data is pooled from 3 independent experiments, Student’s t test, **<i>P</i><0.01, ***<i>P</i><0.001, ****P<0.0001) (f) Bone marrow derived B6 or IFITM3 KO DCs were infected with IAV (moi 1) and 2 and 20 hours later the amount of viral mRNA was measured by qRT-PCR. Graph represents the fold increase in viral RNA in IFITM3 KO DCs relative to the amount present in the B6 DCs (data pooled form 5–9 experiment, symbols represent individual experiments) (g) DCs purified from the spleens of B6 and IFITM3 KO mice were infected with IAV (moi 10) or were left uninfected and 12 hours later the proportion of viable cells was measured by flow cytometry. Graphs depict the percentage of maximum survival (data pooled from 2 independent experiments, Student’s t test, **<i>P</i><0.01).