Phagosome-lysosome (P-L) fusion is one of the central immune-effector responses of host. It is known that phagosome maturation process is associated with numerous signaling cascades and among these, important role of calcium (Ca2+) signaling has been realized recently. Ca2+ plays key roles in actin rearrangement, activation of NADPH oxidase and protein kinase C (PKC). Involvement of Ca2+ in these cellular processes directs phagosomal maturation process. Some of the intracellular pathogens have acquired the strategies to modulate Ca2+ associated pathways to block P-L fusion process. In this review we have described the mechanism of Ca2+ signals that influence P-L fusion by controlling ROS, actin and PKC signaling cascades. We have also discussed the strategies implemented by the intracellular pathogens to manipulate Ca2+ signaling to consequently subvert P-L fusion. A detail study of factors associated in manipulating Ca2+ signaling may provide new insights for the development of therapeutic tools for more effective treatment options against infectious diseases.
Keywords: Calcium signaling; actin kinetics and PKC signaling; intracellular pathogens; phogosomal maturation; reactive oxygen species.