title: Cutting Edge: Innate Lymphoid Cells Suppress Homeostatic T Cell Expansion in Neonatal Mice.
abstract: In adult mice, lymphopenia-induced proliferation (LIP) leads to T cell activation, memory differentiation, tissue destruction, and a loss of TCR diversity. Neonatal mice are lymphopenic within the first week of life. This enables some recent thymic emigrants to undergo LIP and convert into long-lived memory T cells. Surprisingly, however, most neonatal T cells do not undergo LIP. We therefore asked whether neonate-specific mechanisms prevent lymphopenia-driven T cell activation. In this study, we show that IL-7R-dependent innate lymphoid cells (ILCs) block LIP of CD8(+) T cells in neonatal but not adult mice. Importantly, CD8(+) T cell responses against a foreign Ag are not inhibited by neonatal ILCs. This ILC-based inhibition of LIP ensures the generation of a diverse naive T cell pool in lymphopenic neonates that is mandatory for the maintenance of T cell homeostasis and immunological self-tolerance later in life.
authors.affiliation: Institute of Molecular and Clinical Immunology, Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany;
authors.forename: Ute
authors.initials: U
authors.lastname: Bank
authors.affiliation: Institute of Molecular and Clinical Immunology, Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany;
authors.forename: Katrin
authors.initials: K
authors.lastname: Deiser
authors.affiliation: Division of Developmental Immunology, Department of Biomedicine, University of Basel, CH-4058 Basel, Switzerland; and.
authors.forename: Daniela
authors.initials: D
authors.lastname: Finke
authors.affiliation: Department of Molecular Immunology, German Cancer Research Center, 69120 Heidelberg, Germany.
authors.forename: Günter J
authors.initials: GJ
authors.lastname: Hämmerling
authors.affiliation: Department of Molecular Immunology, German Cancer Research Center, 69120 Heidelberg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Arnold
authors.affiliation: Institute of Molecular and Clinical Immunology, Medical Faculty, Otto von Guericke University, 39120 Magdeburg, Germany; thomas.schueler@med.ovgu.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schüler
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000831:Animals, Newborn; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D006706:Homeostasis; D007108:Immune Tolerance; D007113:Immunity, Innate; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D008231:Lymphopenia / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020395:Receptors, Interleukin-7 / Q000276:immunology; D015398:Signal Transduction
chemical_list: D020395:Receptors, Interleukin-7