抄録
We report here the intracellular dynamics of protein kinase C (PKC) in rabbit alveolar macrophages during phagocytosis using immunoelectron microscopy. Pulmonary alveolar macrophages were obtained by tracheal lavage from rabbits. The harvested cells were exposed to latex beads (1 pm in diameter) for 20 min at 25°C, and then fixed for 1 hr in 4% formaldehyde and 0.1% glutaraldehyde. Ultrathin frozen sections were processed for immunolabelling with anti-PKC monoclonal antibodies (mAbs) against rabbit Type 1 (γ), 2 (β) and 3 (α) PKC. Specific immunostaining was observed in macrophages incubated with anti-Type 2 or 3 mAb, and no apparent staining was observed with anti-Type 1 mAb. Type 2 and 3 mAbs labelling revealed a diffuse cytosolic distribution of the PKC in resting macrophages (without phagocytic pulse using latex beads). In phagocytosing macrophages, the most striking feature was an immunolabelling on the plasma membrane binding to latex beads and the phagosomal membrane. These results demonstrate that binding of latex beads causes a rapid translocation of cytosolic Type 2 and 3 PKC to the latex bead-attached plasma membrane, and imply that these isozymes have a crucial role in phagocytosis of foreign particles.
