The descent of memory T cells.
Our T cell repertoire is shaped by antigen encounter. From a naive T cell pool that contains millions of different T cells with unknown specificities, pathogen infection leads to selection of those T cells that can detect pathogen-derived antigens. Following clearance of infection, a population of memory T cells remains and protects the individual from severe reinfection. A central question in the field has been how the generation of long-lived memory T cells, versus short-lived ("terminally differentiated") T cells, is controlled. In this review we discuss the models that have been put forward to explain the generation of memory T cells after infection and the experimental evidence supporting these hypotheses. Based on the available data we propose a new model that stipulates that during immune responses T cells do not acquire different fates that determine their subsequent long-term survival but rather T cells assume different states that simply reflect the likelihood of future survival, states that can still be modulated by external signals.
The Netherlands Cancer Institute, Department of Immunology, Amsterdam, The Netherlands.
Carmen
C
Gerlach
Jeroen W J
JW
van Heijst
Ton N M
TN
Schumacher
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory; D018448:Models, Immunological; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*
D018984:Epitopes, T-Lymphocyte