FIG. 1.

CVA24v requires cell surface sialic acid for efficient binding to and infection of CHO cells. (A) CHO cells in suspension were first pretreated at 37°C for one hour with or without V. cholerae neuraminidase, incubated with 5,000 ³⁵S-labeled CVA24v virions per cell at 4°C for one hour, washed to remove unbound virions, and then analyzed in a scintillation counter for cell-associated radioactivity. CPM, counts per minute. (B) Adherent CHO cells were infected with 20,000 CVA24v virions per cell, fixed in methanol, and stained as described in Materials and Methods. CVA24v antigen-positive cells were then quantified in a fluorescence microscope. The results are presented as means ± standard deviations of duplicate samples from at least three independent experiments (MOCK, CHO-MOCK [mock with respect to CAR]; CAR, CHO-CAR; CD55, CHO-CD55; ICAM1, CHO-ICAM-1; CD46, CHO-CD46; 2241, CHO-2241; Lec2; and Pro-5 [parental cell line to Lec2]).