Negative Impact of Hypoxia on Tryptophan 2,3-Dioxygenase Function

Figure 4

Loss of TDO-mediated antimicrobial functions in HeLa-hTDO cells under hypoxic conditions. Infection experiments: following 72 h prestimulation with denoted amounts of tetracycline, HeLa-hTDO cells infected with Enterococcus faecalis (a and b) or Neospora caninum (Nc-1 strain) (c and d). After 24 h the bacterial growth or after 48 h the parasite growth was determined by measurement of or by the ³H-uracil incorporation method, respectively. (a and c) Single experiment with three replicates and (b and d) summary of three independent experiments with three replicates each. A significant decrease of microbial growth under hypoxia as compared to the normoxia control is marked with asterisks (; ) and was calculated by a two-tailed, unpaired t-test. The bars indicate the mean value SD (a and c) or ± SEM (b and d).

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