NK cells migrate CCR2-dependent to the BAL during influenza virus infection.

<p>Mixed BM chimeric mice were constructed by injecting a mix of BM from CCR2^−/− (CD45.2) and C57BL/6.SJL (CD45.1) into lethally irradiated CD45.1.2. recipients. After 6–8 weeks, mice were infected with influenza virus or left uninfected. (A) Representative FACS plots showing CD45.1 and CD45.2 staining of NK cells (TCRβ⁻NK1.1⁺) recovered from the indicated organs 5 days p.i. (B-D) Ratio of CD45.2 (CCR2^−/−)/CD45.1 (<i>wt</i>) NK cells calculated by dividing absolute numbers of CD45.2⁺ NK cells by absolute numbers of CD45.1⁺ (<i>wt</i>) NK cells. Ratio of CD45.2/CD45.1 NK cells recovered from the indicated organs shown as average ± S.E.M. at the indicated days (B) and shown as individual mice at day 5 (C), and the ratio in the spleen and BM of individual mice are connected by a line at day 5 (D) after influenza virus infection. Representative results of two independent experiments are shown with 4–6 mice per group. Statistical analysis was performed using a Mann-Whitney U test. *, P<0.05.