title: Protective capacity of memory CD8+ T cells is dictated by antigen exposure history and nature of the infection.
abstract: Infection or vaccination confers heightened resistance to pathogen rechallenge because of quantitative and qualitative differences between naive and primary memory T cells. Herein, we show that secondary (boosted) memory CD8+ T cells were better than primary memory CD8+ T cells in controlling some, but not all acute infections with diverse pathogens. However, secondary memory CD8+ T cells were less efficient than an equal number of primary memory cells at preventing chronic LCMV infection and are more susceptible to functional exhaustion. Importantly, localization of memory CD8+ T cells within lymph nodes, which is reduced by antigen restimulation, was critical for both viral control in lymph nodes and for the sustained CD8+ T cell response required to prevent chronic LCMV infection. Thus, repeated antigen stimulation shapes memory CD8+ T cell populations to either enhance or decrease per cell protective immunity in a pathogen-specific manner, a concept of importance in vaccine design against specific diseases.
authors.affiliation: Department of Microbiology, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Nolz
authors.forename: John T
authors.initials: JT
authors.lastname: Harty
mesh_terms: D000956:Antigens, Viral / Q000276:immunology*; D001117:Arenaviridae Infections / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000821:virology; D049109:Cell Proliferation; D007156:Immunologic Memory; D019041:L-Selectin / Q000276:immunology; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D010641:Phenotype
chemical_list: D000956:Antigens, Viral; D019041:L-Selectin