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Microbial pathogenesis

Role of intracellular free calcium in killing Penicillium marneffei within human macrophages.


PMID 25959526

Abstract

Increases in cytosolic Ca(2+) concentration ([Ca(2+)]c) promote phagocyte antimicrobial responses. Here, we investigated macrophages stimulated by Penicillium marneffei (P.xa0marneffei). [Ca(2+)]c was determined in macrophages loaded with the fluorescent calcium probe Fura 2/AM as they were stimulated by P.xa0marneffei. We found that P.xa0marneffei induced an increase in [Ca(2+)]c in human macrophages. Further, increased [Ca(2+)]c with the ionophore A23187 promoted phagosomal acidification and maturation and reduced intracellular replication of P.xa0marneffei in P.xa0marneffei-infected human macrophages, whereas decreased [Ca(2+)]c with the chelation MAPTAM decreased TNF-α production, inhibited phagosomal acidification and maturation and increased intracellular replication of P.xa0marneffei. These data indicate that Ca(2+) signaling may play an important role in controlling the replication of P.xa0marneffei within macrophages.