Not all CD4+ memory T cells are long lived.
Memory T cells are thought to have several properties that distinguish them from their naïve precursors. They are found in parts of the body that rarely house naïve cells, they respond to antigen with faster proliferation and more rapid progression to effector function, they are less sensitive to the absence of their selecting major histocompatibility complex (MHC), and, above all, they are long lived. Here we show that this last property may not be universal. Some CD4+ T cells that have surface proteins characteristic of memory cells have the same half-life in vivo as naïve cells. The description of these cells as memory cells therefore depends on our definition of the word 'memory'.
Robertson
Jennifer M
JM
Howard Hughes Medical Institute, Integrated Department of Immunology, National Jewish Medical and Research Center and UCDHSC, Denver, CO 80206, USA.
MacLeod
Megan
M
Marsden
Vanessa S
VS
Kappler
John W
JW
Marrack
Philippa
P
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002470:Cell Survival / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*