Part:BBa_K4156097
pCadC-Bxb1
pCadC-Bxb1 is constructed with pH-sensitive promoter pCadC and serine integrase Bxb1.
Usage and Biology
pCadC is regulated by the membrane lineage activator protein (CadC) and exhibits higher activity in acidic medium than in neutral pH medium. It is used in response to acidic conditions to allow the strain to rapidly localize to tumor cells and activate downstream gene transcription.Bxb1 is used to control downstream logic gate switching and to provide gene signaling amplification.
Characterization
Lactate (plldR) and pH (pPepT)Induced promoter-controlled effector engineered strain co-incubated with RKO cells
Figure 7 shows the RKO cell activity after incubation of each strain in fresh DMEM medium, normoxic conditions(OD=0.6, 30 μl, 3 hours). It can be seen that the RKO relative viability of the experimental groups with the addition of the effector strains in the fresh culture medium did not change significantly compared to the WT group, except for the plac+HlyE positive control. Figure 8 shows the RKO cell activity of each strain after incubation in 3 day DMEM medium, normoxic conditions. It can be concluded that in the 3 day DMEM medium, due to the accumulation of metabolites such as cellular lactate, the lactate promoter and pH promoter were activated in the engineered strains and started to synthesize therapeutic proteins, resulting in a decrease in the relative viability of RKO compared to the WT group, especially in the pLldR+switch+HlyE and pCadC+switch+HlyE groups with the addition of the amplified gene switch. switch+HlyE group with the addition of the amplifying gene switch significantly reduced the RKO relative viability. In contrast, the decrease in RKO relative viability in the pLldR+φ174E+switch+HlyE group and pCadC+φ174E+switch+HlyE group was not significant, probably due to the decrease in the number of bacteria and the decrease in the number of synthesized therapeutic proteins by the addition of lysis genes.
Coincubation of different doses of effector engineered strains (OD=0.6) with RKO cells
Figure 9 shows the RKO cell activity after incubation with different doses of plldR and pCadC control effector strains in 3 day DMEM medium, normoxic conditions. The RKO cell activity decreased with increasing doses of effector strains.
30 μl effector engineered strains (OD=0.6) were co-incubated with RKO cells for different times
Figure 10 shows the RKO cell activity after incubation of plldR and pCadC control effector strains for different times under 3 day DMEM medium, normoxic conditions. It can be seen that the RKO cell activity decreased with the increase of co-incubation time.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12INCOMPATIBLE WITH RFC[12]Illegal NheI site found at 368
- 21INCOMPATIBLE WITH RFC[21]Illegal BamHI site found at 642
Illegal XhoI site found at 729 - 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000INCOMPATIBLE WITH RFC[1000]Illegal BsaI.rc site found at 1476
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