title: Turnover of naive- and memory-phenotype T cells.
abstract: On the basis of their surface markers, T lymphocytes are divided into subsets of "naive" and "memory cells". We have defined the interrelationship and relative life spans of naive and memory T cells by examining the surface markers on murine T cells incorporating bromodeoxyuridine, a DNA precursor, given in the drinking water. Three findings are reported. First, using a new method we show that the release of newly formed naive T cells from the unmanipulated thymus is very low (confirming the findings of others with surgical approaches). Second, in thymectomized mice, T cells with a naive phenotype remain in interphase for prolonged periods; however, some of these cells divide and retain (or regain) their "naive" markers. Third, most T cells with a memory phenotype divide rapidly, but others remain in interphase for many weeks. Collectively, the data indicate that long-lived T cells have multiple phenotypes and contain a mixture of memory cells, naive (virgin) cells, and memory cells masquerading as naive cells.
authors.affiliation: Department of Immunology, Scripps Research Institute, La Jolla, California 92037.
authors.forename: D F
authors.initials: DF
authors.lastname: Tough
authors.forename: J
authors.initials: J
authors.lastname: Sprent
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002455:Cell Division; D002460:Cell Line; D005434:Flow Cytometry; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D010641:Phenotype; D013154:Spleen / Q000166:cytology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D013934:Thymectomy; D013950:Thymus Gland / Q000166:cytology
chemical_list: D001973:Bromodeoxyuridine