FIGURE 3.

Flavivirus infection confers resistance to death in renal epithelial cells. In all panels, white (clear) bars represent death in cells exposed to cell death inducer alone, without flavivirus. A, both Dengue-2 and Modoc virus infections kill Swiss Webster primary macrophages with levels of death roughly equal that of 70 μm CPT-treated cells. B, no cell killing is observed after Dengue-2 or Modoc infection in Swiss Webster MEFs. Instead, these cells are significantly protected against CPT-induced death. 293T human kidney cells (C), HeLa human carcinoma cells (D), and Vero monkey kidney cells (E) are also protected against death by CPT. F, Dengue-2- and Modoc-infected MDCK cells demonstrate a significant reduction in cell killing compared with mock when exposed to four biochemically unique death stimuli, including DNA damage (CPT), kinase inhibition (STS), protein synthesis inhibition (CHX), and cytopathic viral infection (influenza A). In this and subsequent figures, * = p < 0.05; ** = p < 0.01, and *** = p < 0.001 for the bracketed comparisons.