T. brucei is a kinetoplastid parasite that causes sleeping sickness (“nagana”) in cattle. Both the mammalian-host bloodstream (BF) and insect-host procyclic (PF) forms of T. brucei utilize complex fatty acid elongation mechanism. BF T. brucei uses this elongation mechanism to generate multiple long-chained fatty acid species, including myristate (C14:0), which is the primary fatty acid for GPI anchoring of the antigenic molecule variable surface glycoprotein (VSG). This fatty acid elongation mechanism requires a two-carbon donor primer, which is supplied by the carboxylation of acetyl-CoA by Acetyl-CoA Carboxylase (ACC). Our lab generated a knockdown cell line that reduces ACC through RNA interference (RNAi). This cell line has no phenotypic difference in vitro compared to the parental 90-13 strain, suggesting that the ACC RNAi cell line have a mechanism to compensate for the lack of fatty acid elongation. However, ACC RNAi cell line shows reduced virulence in mouse model. To further examine how T. brucei responds to the loss of ACC, we are performing global lipidomics and proteomics analyses. Our preliminary data suggested that there was no change in the free fatty acid level for myristate. However, the data suggested changes in other lipid species. Further investigation in both lipidomics and proteomics will give better understanding the lipid homeostasis in bloodstream T. brucei.
Saliutama, Joshua and Paul, Kimberly, "Lipidomics analysis of acetyl-CoA-depleted Trypanosoma brucei" (2019). Graduate Research and Discovery Symposium (GRADS). 239.