E-244: A major determinant of viral infectivity in mouse and human neuronal cells <i>in vitro</i>.

<p>(<b>A</b>-<b>C</b>) Viral growth. NSC-34 (<b>A</b>), SH-SY5Y (<b>B</b>), or BHK-21 (<b>C</b>) cells were infected at an MOI of 0.1 with the parent or one of the following four E-244 mutant viruses: G²⁴⁴E, G²⁴⁴D, G²⁴⁴R, and G²⁴⁴K. At the indicated time points, culture supernatants were harvested for virus titration on BHK-21 cells. (<b>D</b>-<b>F</b>) Viral particle infectivity. NSC-34 (<b>D</b>), SH-SY5Y (<b>E</b>), or BHK-21 (<b>F</b>) cells were infected at an MOI of 1 with each of the five viruses, as indicated. At 12–15 hpi, the number of infected cells was measured by flow cytometry using mouse α-JEV antiserum. The results are the average of two independent experiments, presented as -fold changes in infectivity relative to the parent (infectivity value of 1). (<b>G</b>-<b>I</b>) Viral RNA infectivity/replicability. NSC-34 (<b>G</b>), SH-SY5Y (<b>H</b>), or BHK-21 (<b>I</b>) cells were transfected with RNAs transcribed from the parent or each mutant cDNA, as indicated. At 4 dpt, RNA infectivity was quantified by infectious center assay, coupled with staining of cell monolayers using an α-JEV antiserum. (<b>J</b>-<b>L</b>) Virus yield. At 20 h after RNA transfection, culture supernatants from RNA-transfected NSC-34 (<b>J</b>), SH-SY5Y (<b>K</b>), or BHK-21 (<b>L</b>) cells were harvested for virus titration on BHK-21 cells.