Brain-resident memory T cells represent an autonomous cytotoxic barrier to viral infection

• DOI: 10.1084/jem.20151916
• Publication Date: 2016-07-04T14:12:22Z
• Authors: Karin Steinbach; Ilena Vincenti; Mario Kreutzfeldt; Nicolas Page; Andreas Muschaweckh; Ingrid Wagner; Ingo Drexler; Daniel Pinschewer; Thomas Korn; Doron Merkler
• Keywords: Bystander effect

Tissue-resident memory T cells (TRM) persist at sites of prior infection and have been shown to enhance pathogen clearance by recruiting circulating immune providing bystander activation. Here, we characterize the functioning brain-resident (bTRM) in an animal model viral infection. bTRM were subject spontaneous homeostatic proliferation largely refractory systemic cell depletion. After reinfection mice, rapidly acquired cytotoxic effector function prevented fatal brain infection, even absence CD8+ cells. Presentation cognate antigen on MHC-I was essential for bTRM-mediated protective immunity, which involved perforin- IFN-γ–dependent mechanisms. These findings identify as organ-autonomous defense system serving a paradigm TRM self-sufficient first line adaptive immunity.