A hydrophobic ligand-binding protein of the Taenia solium metacestode mediates uptake of the host lipid: implication for the maintenance of parasitic cellular homeostasis

Proteomics. 2007 Nov;7(21):4016-30. doi: 10.1002/pmic.200700332.

Abstract

Parasitic organisms are incapable of de novo fatty acid synthesis due to a down-regulated expression of enzymes involved in the oxygen-dependent pathway. We investigated the uptake of host lipids by a 150-kDa hydrophobic ligand-binding protein (HLBP) of Taenia solium metacestode, an agent causative of neurocysticercosis. The protein was found to be a hetero-oligomeric complex consisting of multiple subunits (M(r) 7, 10, and 15 kDa within pH 8.0-9.7), which may originate from four unique genes of 7- and 10-kDa gene families with 2-3 polymorphic alleles/paralogs. The 15-kDa protein represented glycosylated forms of the 10-kDa. With high binding affinity to lipid analogs, these subunits evidenced high-level sequence identity with other cestode HLBPs and form a novel clade associated with excretory-secretory type HLBP. In vitro experiments with viable worms suggested that the excreted 150-kDa protein might bind to lipids, and participate in the translocation of host lipids across the syncytial membrane. This process was substantially inhibited by the specific anti-150 kDa antibodies. The protein was localized in the parasite syncytium and in the lipid droplets within host granuloma wall, where significant lipase activity was expressed. HLBP-mediated uptake of the host lipid may be critical for the parasite survival and thus could be targeted by chemotherapeutics and/or vaccine.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / immunology
  • Carrier Proteins / metabolism*
  • Genes, Helminth
  • Helminth Proteins / chemistry
  • Helminth Proteins / genetics
  • Helminth Proteins / immunology
  • Helminth Proteins / metabolism*
  • Homeostasis
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Ligands
  • Lipid Metabolism
  • Molecular Sequence Data
  • Molecular Weight
  • Multigene Family
  • Neurocysticercosis / etiology
  • Neurocysticercosis / metabolism
  • Neurocysticercosis / parasitology
  • Neurocysticercosis / prevention & control
  • Phylogeny
  • Sequence Homology, Amino Acid
  • Taenia solium / genetics
  • Taenia solium / immunology
  • Taenia solium / metabolism*
  • Taenia solium / pathogenicity

Substances

  • Carrier Proteins
  • Helminth Proteins
  • Ligands