Team:HZAU-China/Demonstrate
Our project goal is to induce pyroptosis in tumor cells through translocating a pyroptosis-associated protein GSDMD by Salmonella. Expression of the N-terminal of GSDMD fused with eGFP (eGFP-GSDMD-N275) is under the control of the promoter Ptet in ΔsifA Salmonella. Hela GSDMD KO (knockout) cell line were infected with ΔsifA Salmonella. Inducer anhydrotetracycline (ATc) (16μg/mL) was added 3 h after infection. Microscopy shows that eGFP-GSDMD-N275 located in cytoplasm after 5 min of induction and pyroptosis was triggered after 30 min of induction (Figure 1). By counting the population of ruptured cells, a 1.96 fold-change was demonstrated between the induced group and the control group (Figure 2). So, the pyroptosis of host cell in the induced group was triggered by eGFP-GSDMD-N275 as expected. These results demonstrate that we successfully achieved the goal of our project!!!
Figure 1. Hela GSDMD KO cells were infected by Salmonella ΔsifA SL1344 containing high copy number plasmids which express eGFP-GSDMD-N275 under the control of ATc. Photographs were captured 5 min, 30 min, and 90 min after induction, respectively.
Figure 2. Ruptured cells in a field of view were counted (n=8).
In these experiments, the choice of MOI (multiplicity of infection) and infection time were directed by Modeling.
