MAPK8 and infection: We next examined the role of IgA protease in inducing apoptosis of epithelial cells upon infection of cells with the parental WT LNP19995 or with the isogenic strains 19995Δiga and 19995Δiga/iga19995. The activation of JNK and apoptotic levels were analysed over time using immunoblotting and flow cytometry, respectively.