title: Renewal of natural killer cells in mice having elevated natural killer cell activity.
abstract: The present study was designed to examined the dynamics of splenic natural killer (NK) cells under two conditions of enhanced NK cell activity: (1) CBA/J mice given polyinosinic-polycytidylic acid (poly-I:C), an NK-cell-enhancing agent, and 62) untreated athymic nude (nu/nu) mice. The 'total NK cell activity' of the spleen (percentage specific lysis corrected for changes in organ cellularity) increased 5-fold and 2.7-fold after poly-I:C treatment for 1 day and 4 days, respectively. An injection of hydroxyurea (HU), a cell-cycle-toxic drug, given together with either poly-I:C or saline to CBA/J mice resulted in both cases in a 25% reduction in total NK cell activity 1 day later. This suggests that the renewal rate of nondividing NK cells is similar in poly-I:C-treated and saline-injected mice, and that the NK-enhancing effect of poly-I:C is not due to a stimulation of proliferation among NK cell precursors. HU administered simultaneously with poly-I:C or saline for 4 days eliminated NK cell activity in both cases, indicating that spleen NK cell activity is mediated almost entirely by newly formed (less than or equal to 4 days) cells. In nude mice, NK cell activity was assayed at various intervals after an HU depletion period of 2 days. NK depletion was initially more rapid in nu/nu mice than in control (nu/+) mice, although equally profound, and the subsequent recovery of NK cell activity after cessation of HU was also more rapid than in control (nu/+) mice.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anatomy, McGill University, Montreal, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Nassiry
authors.forename: S C
authors.initials: SC
authors.lastname: Miller
mesh_terms: D000818:Animals; D002452:Cell Count; D002453:Cell Cycle; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D005260:Female; D006918:Hydroxyurea / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D008819:Mice, Nude; D011070:Poly I-C / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D011070:Poly I-C; D006918:Hydroxyurea