TNF and viral infectious disease: Along with morphological reactivity, proliferation, phagocytosis of infected cells and different receptor expressions, microglial response to viral infections of the CNS includes release of chemokines and cytokines such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, IFN-γ, promoting further innate and adaptive immune responses (Furr and Marriott, 2012).