Activation of pDCs following <i>Cpn</i> infection.

Abstract

<p>C57BL/6 mice were intranasally infected with <i>Cpn</i> (3×10⁶ IFUs). Mice were killed at day 9 p.i., and lungs were aseptically collected. To analyse pDCs, lung cells were stained and analysed by flowcytometery as decribed in the <i>Materials and Methods</i>. pDCs were identified as mPDCA+ CD11c ^int/lo cells. <b><i>A,</i></b> pDC expansion after <i>Cpn</i> infection. Shown are representative dot plots with the percentages of pDCs in <i>Cpn</i> infected mice in comparison with uninfected mice (left) and the graphical summary for the absolute numbers of pDCs in the lungs. Total pDC number per mouse lung was calculated as % mPDCA+ CD11c ^int/lo cells x total number of cells per mouse lung/100. <b><i>B,</i></b> Expression of MHC II and costimulatory molecules CD40, CD80 and CD86 on gated pDCs (filled histograms) and isotype control (dotted line) are shown. The mean fluorescence intensity (<i>left</i>) and the percentages of positive cells (<i>right</i>) are indicated. <b><i>C,</i></b> pDCs purified (as described in <i>Materials and Methods</i>) from <i>Cpn</i> infected (PDC-Inf) and uninfected mice (PDC-N) were cultured in the presence or absence of <i>Cpn</i> (SK-EB). IL-12p40, IL-12p70 in the 72 hrs supernatants were measured by ELISA. IFNα production by pDCs was analysed by intracellular staining and the graph shows the percentages of IFNα producing cells. Results are shown as mean ± SD. At least three independent experiments with four mice in each group were performed and one representative experiment is shown. *, p<0.05, and ***, p<0.001, Student’s t test.</p