Figure 6.

Microparticles from apoptotic cells mediate macrophage chemoattraction in an ICAM-3-dependent manner. Microparticles were prepared from cultures of apoptotic Mutu BL cells (WT or ICAM-3 deficient) at 16 h post UV. Supernatants were centrifuged to remove cell bodies (7 min; 350 × g) and used neat. (a) Chemotaxis assay: the bottom chamber contained microparticles whereas the top chamber contained dihydroxyvitamin D3-stimulated THP-1 cells. Migration was allowed to proceed for 4 h before staining of migrated cells and quantitation by light microscopy. For each experimental treatment, four replicate wells were used and within each five high-power fields (HPFs) of view counted to quantify the number of migrated cells. Data shown are mean±S.E. of independent experiments (n=7). ^*P<0.05 ANOVA with Tukey's post-hoc test. (b) Chemokinesis control where the chemotactic gradient was disrupted via inclusion of microparticles in both upper and lower chambers. Data shown are mean±S.E. of independent experiments (n=4). ^*P<0.05 ANOVA with Tukey's post-hoc test