Project description:A tagged ectopic version of the ELAV-like protein Tb927.8.6650 of T. brucei was expressed in stable cell lines and pulled down. Co-purifying transcripts were analyzed by sequencing to identify RNAs associated with Tb927.8.6650. Overall design: Stable procyclic form cell lines expressing tetracycline-inducible TAP-tagged Tb927.8.6650 were created. Cells were harvested 48h after tet-induction, followed by tandem affinity purification of Tb927.8.6650, extraction of co-purified RNA, and sequencing.
Project description:The first 4 samples belong to the RNA-IP using in situ TAP tagged ZC3H30 in procyclic (insect) form of the parasite T. brucei Lister 427, 2 samples are Elu or eluate, and 2 are FL or flowthrough (unbound) sample. The other 8 samples are also from procyclic cells. 4 samples belong to DKO(ZC3H30 gene double knockout), 2 are non-stressed and 2 are heat shocked samples; the rest 4 samples are DKO-ectopic (ZC3H30 double knockouts, expressing, ectopic copy of ZC3H30) 2 are non-stressed and 2 are heat shocked samples. Heat Shock experiment was done at 39 degree Celsius.
Project description:The host range of African trypanosomes is influenced by innate protective molecules in the blood of primates. A subfraction of human high-density lipoprotein (HDL) containing apolipoprotein A-I, apolipoprotein L-I, and haptoglobin-related protein is toxic to Trypanosoma brucei brucei but not the human sleeping sickness parasite Trypanosoma brucei rhodesiense. It is thought that T. b. rhodesiense evolved from a T. b. brucei-like ancestor and expresses a defense protein that ablates the antitrypanosomal activity of human HDL. To directly investigate this possibility, we developed an in vitro selection to generate human HDL-resistant T. b. brucei. Here we show that conversion of T. b. brucei from human HDL sensitive to resistant correlates with changes in the expression of the variant surface glycoprotein (VSG) and abolished uptake of the cytotoxic human HDLs. Complete transcriptome analysis of the HDL-susceptible and -resistant trypanosomes confirmed that VSG switching had occurred but failed to reveal the expression of other genes specifically associated with human HDL resistance, including the serum resistance-associated gene (SRA) of T. b. rhodesiense. In addition, we found that while the original active expression site was still utilized, expression of three expression site-associated genes (ESAG) was altered in the HDL-resistant trypanosomes. These findings demonstrate that resistance to human HDLs can be acquired by T. b. brucei. Keywords: Trypanosoma, VSG, antigenic switching, HDL-resistance Overall design: Bloodstream stages of the Lister strain 427 T. b. brucei (MiTat 1.2), expressing VSG221, were used in these studies. Cells were cultured in HMI-9 medium with the addition of heat inactivated fetal bovine serum (FBS) (10%) and Serum Plus (10%). T. b. brucei 427-221 is an antigenically stable line and contains a single copy of the vsg221 gene within the 221 expression site (221ES). At a cell density of approximately 1,000,000 cells/ml, T. b. brucei 427-221 were exposed to various amounts of human HDLs for 24 h in a 6 well plate. Surviving trypanosomes were counted using a hemocytometer then diluted into fresh HMI-9 medium and allowed to recover for 5-14 days. Once the cells had grown to a density of approximately 1,000,000 cells/ml, they were once again incubated with human HDLs. Each round of selection was performed with increasing concentrations of human HDLs and freezer stocks were prepared for each surviving population. Over nine months we conducted eight rounds of human HDL selection, resulting in a population of T. b. brucei that survived incubation with 800 µl of human HDLs (160 lytic U).
Project description:A tagged ectopic version of the ELAV-like protein Tb927.8.6650 of T. brucei was expressed in stable cell lines and pulled down. Co-purifying transcripts were analyzed by sequencing to identify RNAs associated with Tb927.8.6650. Stable procyclic form cell lines expressing tetracycline-inducible TAP-tagged Tb927.8.6650 were created. Cells were harvested 48h after tet-induction, followed by tandem affinity purification of Tb927.8.6650, extraction of co-purified RNA, and sequencing.