*2.8. Caspase-3*/*7 Activity*

Cells were cultured in 96-well plate at a density of 5 × 10<sup>3</sup> cells per well. Caspase 3/7 activity in crude cell lysates was measured using the Caspase Glo ® 3/7 Assay Kit (Promega, Madison, USA) according to the manufacturer's protocols. Caspase activity was quantified by luminescence using a FLUOstar Omega Microplate Reader (BMG LABTECH, Orthenberg, Germany).

#### *2.9. Generation of ZIKV Replicon by the ISA Method*

The production of HEK 293T expressing a stable ZIKV RNA replicon with GFP as a reporter protein, named Rep ZIKV-GFP in the study, was based on the sequence of ZIKV strain MR766 Uganda 47-NIID (Genbank access # LC002520) and the ISA (infectious subgenomic amplicons) method as described previously [25]. As a negative control, HEK 293T cells were transfected with pSilencer-puro 2.6 (Ambion, Thermofisher, Les Ulis, France) and pEGFP-C1 (Clontech, Ozyme, Saint-Cyr-l'École, France) plasmids with a ratio of 1 to 10 using lipofectamine 3000 according to supplier's instructions (Thermofisher, Les Ulis, France) and selected for 5 days in puromycin at 1 μg.mL−1.

The production of A549 cells transiently expressing a ZIKV RNA replicon was based on the ISA method and four amplicons overlapping the sequences of BeH819015 isolated in Brazil in 2015 [25] (Figure 7A). Cells were electroporated in the presence of the viral amplicons (Z1 to Z4 fragments) using the Gene pulser II apparatus according to supplier's instructions (Biorad, Marnes-la-Coquette, France) and treated within 2 days with apoptotic inducers. Cell controls in these experiments were A549DUALtransfected with a plasmid encoding GFP (pEGFP-N1) and A549 transfected with the same amplicons as above but lacking the first segmen<sup>t</sup> (the Z1 amplicon) and named REP NEG (Figure 7A).
