Poster Presentation BACPATH 2017

Global proteomic analysis of the early host response to Burkholderia pseudomallei infection (#116)

Deanna Deveson Lucas 1 , Ralf Schittenhelm 2 , Lan Gong 3 , Mark Prescott 3 , Oded Kleifeld 3 , Rod Devenish 3 , John Boyce 1
  1. Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia
  2. Monash Biomedical Proteomics Facility, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
  3. Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia

Meloidosis, caused by the Gram-negative bacillus Burkholderia pseudomallei, is the major cause of fatal pneumonia (40% mortality rate) and sepsis in Northern Australia and South East Asia. B. pseudomallei is intrinsically resistant to most antibiotics, it can cause infection following inhalation of aerosols and there are currently no efficacious vaccines.  Consequently, B. pseudomallei is classified as a Tier 1 Select Agent by the US Centers for Disease Control and Prevention. While it is well known that B. pseudomallei can survive and replicate in phagocytic and non-phagocytic cells, and this intracellular lifecycle is critical for pathogenesis, the host response to Burkholderia infection is poorly understood. We investigated the host response of RAW 264.7 macrophages (RAW cells) to infection with both wild-type B. pseudomallei strain K96243 (WT), and a bipD mutant (ΔBipD), which is unable to escape the phagosome and is less pathogenic than the wild-type parent. Lysates of uninfected, WT-infected and ΔBipD-infected RAW cells were analysed using LC-MS/MS to determine the global proteomic response to infection. Proteins found in higher abundance in RAW cells infected with the wild-type strain included zinc finger transcriptional regulators, transcription factor RelB, multiple ubiquitin associated proteins and proteins involved in osteoclast differentiation. These osteoclast differentiation proteins may play a role in the formation of multi-nucleated giant cells, a cellular phenotype typical of B. pseudomallei infection. Proteins found at higher abundance in the ΔBipD-infected RAW cells included TNF receptor-associated factor 1, syndecan-4, urokinase-type plasminogen activator and interleukin-1 receptor antagonist protein.  There were 22 proteins shared between WT and ΔBipD-infected RAW cells at both 1 and 2 hours. These include C-X-C motif chemokine-2, TNF-a, NFkB inhibitor Z and sequestosome. These results provide insight into the initial host response to B. pseudomallei infection, and may identify how B. pseudomallei exploits the host machinery to successfully replicate in the host.