title: CD7(-) T cells are late memory cells generated from CD7(+) T cells.
abstract: CD7(-) T cells constitute a distinct subset within the CD4(+) and CD8(+) T cell populations; their developmental and functional relationship to the majority of CD7(+) T cells, however, remained so far unresolved. We here elucidate that CD7(-) cells represent aging T cells in late memory cell development characterized by a high activation threshold, low effector capacities, and high sensitivity to activation-induced cell death (AICD). In this regard, CD7(-) T cells highly express killer cell lectin-like receptor G1 (KLRG-1), harbor telomeres of shorter lengths, a decreased telomerase expression per cell, and less amounts of T cell receptor rearrangement excision circles (TRECs) compared to CD7(+) cells. CD7(-) T cells are generated in vitro from naive CD7(+) T cells upon repetitive TCR/CD28 engagement, a process that is unidirectional and requires multiple cell divisions. Consequently, clonal expansions of CD7(-) T cells in vivo are less frequent than of CD7(+) T cells, the former can be traced back to those of CD7(+) T cells.
authors.affiliation: Tumorgenetics, Department of Internal Medicine I, University of Cologne, Cologne, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Rappl
authors.forename: David
authors.initials: D
authors.lastname: Schrama
authors.forename: Andreas
authors.initials: A
authors.lastname: Hombach
authors.forename: Eva Katharina
authors.initials: EK
authors.lastname: Meuer
authors.forename: Annette
authors.initials: A
authors.lastname: Schmidt
authors.forename: Jürgen C
authors.initials: JC
authors.lastname: Becker
authors.forename: Hinrich
authors.initials: H
authors.lastname: Abken
mesh_terms: D000328:Adult; D019011:Antigens, CD7 / Q000032:analysis*; D017209:Apoptosis; D018106:CD28 Antigens / Q000502:physiology; D006801:Humans; D007156:Immunologic Memory; D017493:Leukocyte Common Antigens / Q000032:analysis; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D019011:Antigens, CD7; D018106:CD28 Antigens; D011948:Receptors, Antigen, T-Cell; D017493:Leukocyte Common Antigens