The role of cytokines in the immune response to influenza A virus infection.

Influenza A virus is one of the most important causes of respiratory tract diseases. It replicates in epithelial cells and leukocytes resulting in the production of immune mediators--cytokines, substances with various biological effects. Cytokines, as a part of innate immunity, favor the development of antiviral and TH 1-type immune responses. Cytokines also affect the adaptive immune response and disease manifestation. In the organism, the virus infection results in the production of chemotactic [a regulated upon activation, normal T cell-expressed and -secreted cytokine (RANTES), monocyte chemoattractant proteins (MCP) MCP-1, MCP-3, macrophage inflammatory protein 1 alpha (MIP- 1 alpha), interferon gamma-induced protein 10 (IP-10), and interleukin 8 (IL-8)], pro-inflammatory [IL- 1beta, IL-6, IL-18, and tumor necrosis factor alpha(TNF-alpha)] and antiviral [interferon (IFN) alpha/beta] cytokines. Whilst knowledge of the mechanisms underlying host and tissue specificity has advanced significantly, we still know relatively little about the function of cytokines released from different cells following influenza infection. In this review we deal with the role and mode of possible impact of cytokines on the disease pathogenesis and host immune response.