Evasion of host immunity by viral interleukin-like protein (kw:KW-1125)

Interleukins are secreted regulatory proteins that are members of the family of cytokines (immune system molecules) that regulates immune cell activity. Interleukins are produced by immune system cells such as lymphocytes, macrophages and monocytes, and modulate inflammation and immunity by regulating growth, mobility and differentiation of lymphoid and other cells.

Several viruses encode interleukin-like protein that play a role in immune evasion. They have also been shown to activate cellular signaling cascades that enhance virus replication. EBV, HCMV, EHV and orf virus encode for a homolog of interleukin-10 that is able to downregulate Th1 response. HHV-8 protein K2 shares strong homology with IL6 and was thus also named vIL6. Unlike the human IL6, vIL6 does not require the alpha-subunit receptor IL-R6 for signal transduction. Therefore, vIL6 is able to induce antiapoptotic signaling in cells that do not express IL-6R.