Phorbol myristate acetate treatment of J774 cell line - (May/11/2013 )

Hi all,
I'm doing phagocytosis experiments with J774 (a murine macrophage cell line). The paper which I used as a reference used Phorbol Myristate Acetate (PMA) to "activate" J774 before the phagocytosis assay. I went through a number of papers on the use of PMA in cell culture and it seemed that PMA helps increase reactive oxygen species (ROS) metabolism and also activate the protein kinase C pathways. However I didnt see any differences in the number of yeast uptake (I'm doing experiments with Cryptococcus neoformans, a yeast) between PMA-treated or untreated J774 cells in my experiment. My boss said that PMA may not affect yeast uptake or cell morphology, but eventually increased ROS would kill or slow down yeast growth. I wonder if this is true or not, and I'd appreciate if anyone can somehow show me how PMA affects J774.
I'm a total newbie in cell culture so any helps would be very appreciated!

Many thanks!

Thanh

Any help please? I thought people use this PMA a lot for their macrophage celture