title: Cutting edge: latecomer CD8 T cells are imprinted with a unique differentiation program.
abstract: Factors that influence T cell responses, such as Ag load, APCs, costimulatory molecules, and cytokines, dramatically change during the course of an immune response. We observed that antiviral CD8 T cells were not recruited from circulation simultaneously, but over a period of 3-4 days. Consequently, locally resident T cells and those that entered secondary lymphoid tissue later were primed in very different environments. The cells recruited later in the response were imprinted with a unique differentiation program, such that their magnitude of proliferation was reduced and their kinetics of expansion was delayed. In addition, we found that the "latecomer" CD8 T cells displayed a unique surface phenotype indicative of reduced stimulation but were not preferentially recruited into the surviving pool of memory cells. This finding demonstrates that the timing of recruitment of individual T cell clones determines the population dynamics of the subsequent immune response.
authors.affiliation: Division of Biological Sciences and Department of Cellular and Molecular Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 02093, USA.
authors.forename: Warren N
authors.initials: WN
authors.lastname: D'Souza
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Hedrick
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000637:transplantation / Q000821:virology; D002454:Cell Differentiation / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D007156:Immunologic Memory; D016130:Immunophenotyping; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology