Figure 4

Heterologous protein localisation by immunofluorescence. (A) Intracellular immunofluorescence was detected in all of the cell lines, with differences between the proteins ascribed to MV or EV particles. In cells infected with FP _L1R or FP _A27L the cytoplasmic immunofluorescence was diffuse (panels 1a-c, 2a-c), and in FP _L1R -infected cells, the difference with the negative control was very low. Conversely, specific, granular perinuclear localisation was shown by the cells infected with FP _A33R or FP _B5R (panels 3a-c, 4a-c), which was particularly evident in MRC-5 cells infected with FP _A33R . FPwt-infected cells were negative (panels 5a-c). (B) MRC-5 cells showed membrane immunofluorescence only after infection with the FP _A33R recombinant (panel 1b vs. 1a).