Fig. 2

Effect of ammonium chloride on the production of progeny virus. CIK cells were treated with ammonium chloride at the indicated concentrations. a CPE of GCRV104 infection viewed under a visible light phase microscope. b Rt-PCR assay of virus yield in the supernatants (infection) and CIK cells (entry). (unpaired t-test, * P < 0.05 and ** P < 0.01). c Western blot analysis to monitor viral replication level in CIK cells. d and e Ultrastructural visualization of the uptake of GCRV into CIK cells by transmission electron microscopy. Cells were pretreated with indicated inhibitors (d: PBS, e: ammonium chloride, 20 mM) for 1 h at 4 °C, then adsorbed with virus (MOI = 50) for 30 min at 4 °C. The cultures were quickly warmed to 28 °C to start infection, and uninternalized virions were removed at 0.5 hpi. After PBS washes, cells were treated with inhibitors again for 48 h at 28 °C. The processed cells were then fixed in electron microscopy grade fixative at 4 °C