Infectivity of A549/hSLAM and A549/hSLAM-NS1 cells with HMPV strains.

(A) A549/hSLAM and A549/hSLAM-NS1 cells were infected with VSV at an MOI of 1.0. At 6 hpi, total RNAs were extracted from VSV-infected or mock-infected cells. The levels of mRNA of IFN-β, MX1, and OASL were determined by qPCR, and the values were normalized to levels of the control gene HPRT1. Relative RNA copies are presented as the average and standard errors from triplicated experiments. Statistical significance was calculated using Student’s t test (*P GFP strains was analyzed. The numbers of HMPV-infected cells in VeroE6 cells were set to 100%, and relative infectivity is presented as the average and standard errors from triplicated experiments.