CD7(-) T cells are late memory cells generated from CD7(+) T cells.
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.
Rappl
Gunter
G
Tumorgenetics, Department of Internal Medicine I, University of Cologne, Cologne, Germany.
Schrama
David
D
Hombach
Andreas
A
Meuer
Eva Katharina
EK
Schmidt
Annette
A
Becker
Jürgen C
JC
Abken
Hinrich
H
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*
D019011:Antigens, CD7; D018106:CD28 Antigens; D011948:Receptors, Antigen, T-Cell; D017493:Leukocyte Common Antigens