Drosophila Rab14 mediates phagocytosis in the immune response to Staphylococcus aureus

Authors

  • Aprajita Garg,

    1. Institute for Bioscience and Biotechnology Research, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
    Current affiliation:
    1. Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
    Search for more papers by this author
  • Louisa P. Wu

    Corresponding author
    1. Institute for Bioscience and Biotechnology Research, Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
    • For correspondence. E-mail lwu1@umd.edu; Tel. (+1) 301405 5151; Fax (+1) 301314 9075.

    Search for more papers by this author

Summary

Drosophila haemocytes are essential for the animal to resist Staphylococcus aureus infections. Phagocytosis is a central component of the haemocyte-mediated immune response. It involves regulated interaction between the phagocytic and the endocytic compartments. RabGTPases are pivotal for the membrane trafficking and fusion events, and thus are often targets of intracellular pathogens that subvert phagocytosis. An in vivo screen identified Rab2 and Rab14 as candidates for proteins regulating phagosome maturation. Since Rab14 is often targeted by intracellular pathogens, an understanding of its function during phagocytosis and the overall immune response can give insight into the pathogenesis of intracellular microbes. We generated a Drosophila Rab14 mutant and characterized the resulting immune defects in animals and specifically in haemocytes in response to an S. aureus infection. Haemocyte based immunofluorescence studies indicate that Rab14 is recruited to the phagosome and like Rab7, a well-characterized regulator of the phagocytic pathway, is essential for progression of phagosome maturation. Rab14 mutant haemocytes show impaired recruitment of Rab7 and of a lysosomal marker onto S. aureus phagosomes. The defect in phagocytosis is associated with higher bacterial load and increased susceptibility to S. aureus in the animal.

Ancillary