Induction of Inflammation by West Nile virus Capsid through the Caspase-9 Apoptotic Pathway
Figure 3. In vivo West Nile virus capsid (Cp) expression induces apoptosis and inflammation in mice. TUNEL assay was performed on muscle cryosections harvested from mice injected with pcWNV-Cp-DJY (a) or pcDNA3.1 (b). Hematoxylin/eosin staining was performed on mouse tibialis muscle cryosections harvested from mice injected with pcWNV-Cp-DJY (c) or pcDNA3.1 (d) at 48 h postinjection (magnification: 200X [a, b] and 40X [c,d]). Immunohistochemical analysis was performed for detection of WNVCp-DJY protein expression in mouse brain injected with pcDNA3.1 or pcWNV-Cp-DJY as detected with horseradish peroxidase (HRP) (e,f, respectively). TUNEL assay on mouse brain cryosections harvested from pcWNV-Cp-DJY injected mouse was detected with HRP (g) (magnification: 300X [e–g]). Immunohistochemical studies were performed for detection of WNV-Cp-DJY protein expression in mouse brain injected with pcWNV-Cp-DJY or pcDNA3.1 as detected by fluorescein isothiocynate stain (h, i, and j, k, respectively). TUNEL assay on mouse brain cryosections harvested from pcWNV-Cp-DJY–injected mice (l,m) or pcDNA3.1-injected mice as detected with fluorescein isothiocyanate (n,o). WNV-Cp-DJY protein expressing His-positive cells or TUNEL-positive cells were visualized under ultraviolete microscope (h or l, respectively). Nuclear staining for WNV-Cp-DJY– or pcNDA3.1-transfected cells was visualized with appropriate filters (i, m or k, o, respectively) (magnification: 630X [h through o]).