Figure 2. Increased chemerin levels in broncho-alveolar lavage fluid during PVM infection.

(A) At selected time points after viral inoculation, chemerin levels were determined by ELISA in BAL fluids of ChemR23^−/− and wild-type C57BL/6 mice. (B) Chemerin transcript levels were determined by quantitative RT-PCR. The data were normalized using two housekeeping genes (YWHAZ and CANX) as references, and reported to the chemerin transcript level in uninfected control mice. The displayed data are the mean ± SEM for groups of minimum seven animals. (C) The biological activity of chemerin was measured in BAL fluids obtained at day 9 post-infection from wild-type (WT) and ChemR23^−/− mice after a reverse phase HPLC fractionation (C18 column) using an aequorin-based intracellular Ca²⁺ mobilization assay. The data shown are the activity of fractions (25 to 50% acetonitrile) normalized to the response to ATP upon testing on CHO-K1 cells expressing mouse ChemR23 (CHO-ChemR23+) or not (CHO). The functional response of mouse ChemR23-expressing CHO-K1 cells to recombinant mouse chemerin is shown as inset. Data are representative of three independent experiments. *, p<0.05; **, p<0.01; ***, p<0.001.