Fig. 5
Analysis of the cellular entry and distribution of NP and M1 proteins of inactivated and live 22W_KY. Confocal microscopy images showing the distribution of (a) NP protein and (c) M1 protein in A549 cells following treatment at 37 °C for 4 h with formaldehyde-inactivated (F/A), BEI-inactivated, BPL-inactivated, live 22W_KY (positive control), or media-only (negative control). NP protein was labeled with Alexa Fluor 488 (green), the M1 protein was labeled with Alexa Fluor 647 (red), and the nuclei were stained with DAPI (blue). Scale bars represent 20 μm. The quantification of the mean fluorescence intensity (MFI) for (b) NP and (d) M1 signals per cell was performed by selecting the edges of individual cells to measure the MFI for each protein signal. Measurements were obtained from 10 cells per group, and final values were calculated by subtracting the mean MFI of the negative control group from the MFI values of each treatment group. The data are presented as the mean ± SD, and statistical significance was determined using one-way ANOVA, followed by Tukey’s multiple comparison test (***p < 0.001, ****p < 0.0001, ns: not significant)