title: Regulatory T cells increase the avidity of primary CD8+ T cell responses and promote memory.
abstract: Although regulatory T cells (T(regs)) are known to suppress self-reactive autoimmune responses, their role during T cell responses to nonself antigens is not well understood. We show that T(regs) play a critical role during the priming of immune responses in mice. T(reg) depletion induced the activation and expansion of a population of low-avidity CD8(+) T cells because of overproduction of CCL-3/4/5 chemokines, which stabilized the interactions between antigen-presenting dendritic cells and low-avidity T cells. In the absence of T(regs), the avidity of the primary immune response was impaired, which resulted in reduced memory to Listeria monocytogenes. These results suggest that T(regs) are important regulators of the homeostasis of CD8(+) T cell priming and play a critical role in the induction of high-avidity primary responses and effective memory.
authors.affiliation: INSERM U932, Immunity and Cancer, Institut Curie, F-75248 Paris Cedex 05, France.
authors.forename: Luigia
authors.initials: L
authors.lastname: Pace
authors.forename: Andy
authors.initials: A
authors.lastname: Tempez
authors.forename: Catharina
authors.initials: C
authors.lastname: Arnold-Schrauf
authors.forename: Fabrice
authors.initials: F
authors.lastname: Lemaitre
authors.forename: Philippe
authors.initials: P
authors.lastname: Bousso
authors.forename: Luc
authors.initials: L
authors.lastname: Fetler
authors.forename: Tim
authors.initials: T
authors.lastname: Sparwasser
authors.forename: Sebastian
authors.initials: S
authors.lastname: Amigorena
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D054402:Chemokine CCL1 / Q000378:metabolism; D054407:Chemokine CCL4 / Q000378:metabolism; D018946:Chemokine CCL5 / Q000378:metabolism; D005260:Female; D007111:Immunity, Cellular; D007156:Immunologic Memory; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology; D008212:Lymphocyte Depletion; D051379:Mice; D008810:Mice, Inbred C57BL; D015778:Minor Histocompatibility Antigens; D011506:Proteins / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: C502258:Ccl1 protein, mouse; C503460:Ccl5 protein, mouse; D054402:Chemokine CCL1; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D015778:Minor Histocompatibility Antigens; D011506:Proteins; C102450:Uty protein, mouse