[The extracellular heat shock protein 70 and its functions].

Various stress factors induce the accumulation of intracellular heat shock proteins, in particular heat shock protein 70 (Hsp70), which is considered as the main component of cellular response to stress. Though initially Hsp70 was thought to be a typical intracellular protein, the strong evidence now exists demonstrating that the Hsp70 exits mammalian cells not only following necrotic cell death but also by a process involving its active release. This review discusses the mechanisms of Hsp70 release and immunomodulatory and signaling functions of extracellular Hsp70.