title: Cutting edge: rapid in vivo killing by memory CD8 T cells.
abstract: In this study, we examined the cytotoxic activity of effector and memory CD8 T cells in vivo. At the peak of the CTL response following an acute lymphocytic choriomeningitis virus infection, effector CD8 T cells exhibited extremely rapid killing and started to eliminate adoptively transferred target cells within 15 min by a perforin-dependent mechanism. Although resting memory CD8 T cells are poorly cytolytic by in vitro (51)Cr release assays, there was rapid elimination (within 1-4 h) of target cells after transfer into immune mice, and both CD62L(high) and CD62L(low) memory CD8 T cells were able to kill rapidly in vivo. Strikingly, when directly compared on a per cell basis, memory CD8 T cells were only slightly slower than effector cells in eliminating target cells. These data indicate that virus specific memory CD8 T cells can rapidly acquire cytotoxic function upon re-exposure to Ag and are much more efficient killers in vivo than previously appreciated.
authors.affiliation: Emory Vaccine Center and Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Barber
authors.forename: E John
authors.initials: EJ
authors.lastname: Wherry
authors.forename: Rafi
authors.initials: R
authors.lastname: Ahmed
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D016923:Cell Death / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods; D003602:Cytotoxicity, Immunologic; D007156:Immunologic Memory; D016130:Immunophenotyping; D007700:Kinetics; D018655:Lymphocyte Count; D008216:Lymphocytic Choriomeningitis / Q000276:immunology / Q000473:pathology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism