Morphology of LDs in uninfected and <i>C</i>. <i>trachomatis</i>-infected HeLa cells.

<p>(A) A fresh suspension of LDs isolated from HeLa cells was stained with BODIPY 493/503 for 15 min and imaged by fluorescence microscopy (left panel) or processed for TEM (right panel). LDs appear as intact spherical structures. Since no morphological differences between LDs from uninfected and infected cells were observed, a representative image of LDs isolated from uninfected cells is shown (B) Representative confocal images of HeLa cells, uninfected (UI) or infected with <i>C</i>. <i>trachomatis</i> LGV-L2 for 20 h (20 hpi) or 40 h (40 hpi). Cells were stained with BODIPY 493/503 to visualize LDs (green) and Hoechst was utilized to visualize host and bacterial DNA (blue). Bacterial replicative vacuoles (inclusions) are indicated with white arrows. (C) TEM images of uninfected (left panel) and <i>C</i>. <i>trachomatis</i> infected (20 hpi, right panel) HeLa cells. LDs (asterisk) and <i>C</i>. <i>trachomatis</i> (black arrows) are indicated. Note the close apposition of LDs with mitochondria and ER-like membranes (dashed square, left panel) and with the inclusion (right panel). In all cases (A-C) HeLa cells were stimulated with oleic acid 100 μM for 14 h prior to fixation and/or staining to enhance LD production.