Porcine sapovirus binding and infection requires terminal sialic acids.

<p>LLC-PK cells were treated with <i>V. cholerae</i> neuraminidase (NA; removes α2,3-, α2,6- and α2,8-linked sialic acid) or sialidase S (SS; removes α2,3-linked sialic acid) from <i>Streptococcus pneumoniae</i> at the indicated concentrations. (A) NA- or SS-treated cells were incubated with either Alex 594 alone or Alexa 594-labeled PSaV (MOI of 100 pfu/cell), and bound virus was detected by confocal microscopy. (B) ³⁵[S]Methionine/Cysteine-labeled PSaV, FCV or influenza virus (H9N2) (50,000 c.p.m.) were bound to LLC-PK, CRFK or MDCK cells, respectively, pretreated with or without SS indicated, and the binding of radio-labeled PSaV, FCV or influenza virus was quantitated by liquid scintillation counting. (C) PSaV (MOI of 0.1 pfu/cell) was incubated with pretreated LLC-PK cells, and was subsequently analyzed by immunofluorescence assay with rabbit polyclonal antibody against PSaV VPg protein 72 h post infection. (D) PSaV, FCV or influenza virus positive cells (%) were enumerated in three independent microscope fields. All experiments were performed independently three times and figures A and C show a single representative set of results. The scale bars correspond to 20 µm. Error bars denote mean ± SD. *<i>p</i><0.05, **<i>p</i><0.005.