Group V secretory phospholipase A2 modulates phagosome maturation and regulates the innate immune response against Candida albicans

J Immunol. 2009 Apr 15;182(8):4891-8. doi: 10.4049/jimmunol.0803776.

Abstract

Phospholipase A(2) (PLA(2)) hydrolyzes the sn-2 position of cell membrane phospholipids to release fatty acids and lysophospholipids. We have previously reported that group V secretory PLA(2) (sPLA(2)) translocates from the Golgi and recycling endosomes of mouse peritoneal macrophages to newly formed phagosomes and regulates the phagocytosis of zymosan, suggesting a role in innate immunity. Here we report that in macrophages lacking group V sPLA(2), phagosome maturation was reduced 50-60% at early time points while the binding of zymosan was unimpaired. The ability of group V sPLA(2) to regulate phagocytosis extended to phagocytosis of IgG- and complement-opsonized sheep RBC. Moreover, macrophages lacking group V sPLA(2) had delays in phagocytosis, phagosome maturation, and killing of Candida albicans. Cytokine production and eicosanoid generation were not impaired by the lack of group V sPLA(2). Furthermore, in a model of systemic candidiasis, mice lacking group V sPLA(2) had an increased fungal burden in the kidney, liver, and spleen at day 7 postinfection and increased mortality. Thus, group V sPLA(2) regulates phagocytosis through major phagocytic receptors and contributes to the innate immune response against C. albicans by regulating phagocytosis and killing through a mechanism that is likely dependent on phagolysosome fusion.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Candida albicans / immunology*
  • Candidiasis / genetics
  • Candidiasis / immunology
  • Candidiasis / metabolism
  • Candidiasis / pathology
  • Group V Phospholipases A2 / deficiency
  • Group V Phospholipases A2 / genetics
  • Group V Phospholipases A2 / metabolism*
  • Immunity, Innate / immunology*
  • Lectins, C-Type
  • Macrophages / enzymology
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Nerve Tissue Proteins / metabolism
  • Phagocytosis
  • Phagosomes / enzymology*
  • Phagosomes / immunology*
  • Survival Rate
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Zymosan / metabolism

Substances

  • Lectins, C-Type
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Tumor Necrosis Factor-alpha
  • dectin 1
  • Zymosan
  • Group V Phospholipases A2
  • Pla2g5 protein, mouse