Immunological mechanisms controlling hepatitis C virus infection

Hepatitis C virus (HCV) infection is a significant global health problem, affecting over 150 million\udpeople worldwide. There is increasing evidence that a small percentage of individuals exposed\udto the HCV have the capacity to generate a strong cellular as well as humeral immune response\udagainst the virus and avoid persistent infection, and perhaps do so repeatedly after re-exposure.\udWhile the critical role of the adaptive immune system in HCV infection is well-established, the\udimportance of the innate immune system has been recognized in more recent years. The immune\udsystem has many weapons to combat the HCV infection. These include type I interferons, HCV\udspecific CD4+ cells and CD8+ T cells, cytokine production, natural killer cells, dentritic cells, and\udthe production of anti-HCV neutralizing antibodies. Toll-like receptors form an important element\udof the innate immune response, and there is considerable evidence for their crucial role in HCV\udinfection. In order to limit the availability of the cellular components for viral amplification,\udapoptosis occurs. It involves caspases, the key effectors of apoptotic cell death. This article\udreviews what the immune system does, when HCV attacks the body