Host immune response towards virus infection includes antibody mediated as well as cell mediated immune responses. Moreover macrophages, neutrophils and complement proteins also play an important role in clearing the virus infection from the body. Interestingly sometimes host cells sacrifice their life in order to protect other cells and restrict virus spread by a phenomenon called as APOPTOSIS (programmed cell death). Another very important player of host immune system that fights against viral invasion is INTERFERON .

 

INTERFERON:

Interferons are naturally occurring proteins secreted by cells in response to virus infections. When a cell is infected with a virus, it releases interferon which diffuses to the surrounding cells. After binding to the receptors present on the adjacent or surrounding cells; interferon stimulates the production of antiviral proteins in the cells.

Figure 11.1 Activation of interferon following virus infection: