FIG. 7.

Effect of NeuAcGM₃ and NeuGcGM₃ as competitive inhibitors of porcine rotavirus infection of MA-104 cells. Aliquots of CsCl-purified rotavirus TLP (1.3 × 10⁴ FFU/ml) were incubated at RT for 15 min with 0 to 43.6 nmol of enterocyte NeuAcGM3, enterocyte NeuGcGM3, or bovine brain GM3 per ml. After cells and reagents were cooled to 4°C, triplicate wells in a 24-well plate were inoculated with 75 μl of the virus-ganglioside preparation as described in Materials and Methods. Following a 15-min incubation period, the virus inocula were aspirated and the monolayers were rinsed. The plates were warmed to 37°C and then incubated at that temperature for 16 to 18 h. Fixation of cell monolayers, immunocytochemical staining, and quantification of the FFU were performed as described in Materials and Methods. Symbols: ○, purified porcine NeuGcGM₃; □, purified porcine NeuAcGM₃. Inset: immunocytochemical detection of rotavirus in MA-104 cell monolayers infected in the presence or absence of NeuGcGM₃. Aliquots of CsCl-purified rotavirus TLP (1.3 × 10⁴ FFU/ml) were incubated at RT for 15 min with 0 (top panel) or 43.6 μM (bottom panel) NeuGcGM₃ before inoculation of cell monolayers. Following incubation at 37°C for 16 to 18 h, monolayers were fixed and stained as described in Materials and Methods.