IL6 and infection: Since studies had reported that NH/P68 induced enhanced cytokine gene expression or production in macrophages compared to a virulent isolate [2,3], cytokine gene (IL-1β, IL-6, IL-10, IL-12p40, IL-18, TNF-α) expression in moMΦ after NH/68 or 22653/14 infection were monitored over-time.