Slides were blocked by avidin and biotin prior to H2O2 quenching

dies, phagocytosis of unopsonized P.aeruginosa by human and murine peritoneal and alveolar macrophages was shown to depend on the presence of glucose in the culture medium [62,63]. However, the glucose dependency did not apply to phagocytosis of P. aeruginosa opsonized with polyclonal rabbit serum, latex particles, unopsonized zymosan, or RBCs opsonized with IgG or IgM and complement. Although we only examined COZ phagocytosis and used only two macrophage cell lines here, our findings suggest that glucose availability may be important for a wider range of actindependent processes and monocyte cell types. One rarely discussed process in this context is macropinocytosis activity, which also requires a dynamic actin cytoskeleton. Macropinocytosis activity of macrophages is AMPK-mediated and induced by low glucose conditions [64]. In turn, macropinocytosis may contribute to nutrient uptake capacity, although glucose import probably occurs mainly through GLUT in LPS-stimulated macrophages [6]. Here we would like to speculate that the differences in membrane ruffling (not shown) and recovery of phagocytic activity upon reintroduction of glucose (75% vs. 45%) that we observed between Maf-DKO and RAW 264.7 cells may have to do with the extend of macropinocytosis activity - and (-)-Blebbistatin site 19653056″ title=View Abstract(s)”>PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19653056 metabolic regulation thereof - in these cell lines. It is of note here that phagocytosis and macropinocytosis are mechanistically related processes, and � especially in the initiation phase � also share many morphological features. Alteration of the actin organization, due to loss of MafB, may also explain the differences between the two types of macrophages studied here [65]. Why is presence of glucose so important for formation of actin rich protrusions a