Figure 4.

Activation of PARP‐1, nuclear translocation of AIF and DNA fragmentation are involved in the death of cells treated with HCMVAIS. Cleavage of PARP‐1 following treatment with HCMVAIS was detected by western blot in (a) Jurkat cells and (b) human PBMCs. STS‐treatment was used as a positive control for caspase cleavage. (c) Nuclear translocation of AIF in Jurkat cells with HCMVAIS treatment by confocal microscopy. Jurkat cells were adhered, fixed, permeabilized, and stained with AIF antibody and Alexa Flour 488‐labeled secondary antibody and the nuclei visualized with ToPro‐3. (d) Inhibition of AIF release with NP (50 mM) decreases the rate of Jurkat cell death. Bars indicate the means ± SEM from three independent experiments. Cell death was measured by TUNEL assay. (e) HCMVAIS induces DNA fragmentation in Jurkat cells; no fragmentation was seen in following treatment with MOCKAIS. STS was used as a positive control for DNA fragmentation; repeated freeze‐thaw cycles and 50% DMSO were used as negative controls. Images are representative of two independent experiments. Statistical significance between experimental means (P value) was determined using Student's t‐test. [Color figure can be viewed at http://wileyonlinelibrary.com]