Noncytotoxic Lytic Granule-Mediated CD8+ T Cell Inhibition of HSV-1 Reactivation from Neuronal Latency

摘要

Reactivation of herpes simplex virus type 1 from neuronal latency is a common and potentially devastating cause of disease worldwide. CD8⁺ T cells can completely inhibit HSV reactivation in mice, with IFN-γ affording a portion of this protection. Here, we found that CD8⁺ T cell lytic granules are also required for the maintenance of neuronal latency both in vivo and in ex vivo ganglia cultures, and that their directed release to the junction with neurons in latently infected ganglia did not induce neuronal apoptosis. We describe a non-lethal mechanism of viral inactivation in which the lytic granule component, granzyme B, degrades the herpes simplex virus type 1 immediate early protein, ICP4, which is essential for further viral gene expression.