Lectin Switching During Dengue Virus Infection

Dejnirattisai, Wanwisa; Webb, Andrew I.; Chan, Vera; Jumnainsong, Amonrat; Davidson, Andrew; Mongkolsapaya, Juthathip; Screaton, Gavin

The lack of infectivity of DC-produced virus on DCs was also shown using a different mAb, 4G2, which reacts with an epitope on dengue envelope protein ( Figure 1C , lower panel). A time course of infection was performed where DCs or Vero cells were infected with virus produced in C6/36, Vero, or DCs, and infection was monitored by FACS or using a focus-forming assay to measure infectious virus harvested from the supernatants of infected cells ( Figure 1D -E). At 24, 48, and 72 h the DC-produced virus showed a much reduced ability to infect DCs when compared with virus produced in C6/36 or Vero cells. The experiments we have described above used the dengue serotype 2 strain 16681. To see whether these results could be generalized, we checked infection of both DCs and Vero cells with dengue serotype 2 strain New Guinea C, serotype 1 strain Hawaii, serotype 3 strain H87, and serotype 4 strain H241. Infection efficiency was measured by FACS at 24 and 48 hours following infection with virus produced in either C6/36 cells or DCs (Figure 2A-B) . In all cases DC-produced virus was much less infectious for DCs than insect-produced virus, whereas infection of Vero cells was roughly equal.