It turned out that they use the body's own brakes, which normally shut down the immune system after it has done its job killing virus-infected cells.
Functions of NK cells of the group 1 ILC family have been well established, which include killing virus-infected cells through cytolysis mediated by granzymes and perforin, and targeting tumor cells that have lost expression of the class I major histocompatibility complex (MHCI) (Biron et al., 1999; Vivier et al., 2012).
NK cells have been long time considered as cytotoxic lymphocytes competent in killing virus-infected cells and tumors.
Natural Killer (NK) cells, traditionally considered to be major innate effector cells, have been long time relegated to the job of killing virus-infected cells and tumors.
Antigenic stimulation leads to massive clonal expansion of naïve CD8 T cells and to the acquisition of effector functions, including IFN-γ and TNF-α production and cytotoxic activity that render the cells capable of killing virus-infected cells.
T lymphocytes play a pivotal role in the defense of viral infection by directly killing virus-infected cells.
NK cells are an important arm of the innate immune system specialized for killing virus-infected and tumor cells [ 17].
Although granzyme B-induced apoptotic cell death has long been considered the de facto mechanism for killing virus-infected cells, emerging evidence suggest that the enzyme could exert direct antiviral activity through cleavage of the viral proteins [ 15].
There is strong evidence showing that HIV-1-specific CD8+ T cells contribute to the control of HIV-1 replication during acute and chronic stages of infection by killing virus-infected cells and by producing a number of soluble factors with antiviral activities (2).
Although these chemicals are effective in killing viruses in vitro, they can be toxic to the vaginal mucosa in vivo.
This vaccine contains killed virus and is given by injection.
