title: A novel system for simultaneous in vivo tracking and biological assessment of leukemia cells and ex vivo generated leukemia-reactive cytotoxic T cells.
abstract: To determine the mechanisms by which adoptive immunotherapy could reduce lethality to acute myelogenous leukemia (AML), a novel technique was developed to track both leukemic blasts and adoptively transferred cytotoxic T cells (CTLs) independently and simultaneously in mice. To follow the fate of ex vivo generated anti-AML-reactive CTLs, splenocytes obtained from enhanced green fluorescent protein transgenic mice were cocultured with AML lysate-pulsed dendritic cells, which subsequently were expanded by exposure to anti-CD3/CD28 monoclonal antibody-coated magnetic microspheres. To track AML cells, stable transfectants of C1498 expressing DsRed2, a red fluorescent protein, were generated. Three factors related to CTLs correlated with disease-free survival: (a). CTL L-selectin expression. L-Selectin high fractions resulted in 70% disease-free survival, whereas L-selectin low-expressing CTLs resulted in only 30% disease-free survival. (b). Duration of ex vivo expansion (9 versus 16 days). Short-term expanded CTLs could be found at high frequency in lymphoid organs for longer than 4 weeks after transfer, whereas long-term expanded CTLs were cleared from the system after 2 weeks. Duration of expansion correlated inversely with L-selectin expression. (c). CTL dose. A higher dose (40 versus 5 x 10(6)) resulted in superior disease-free survival. This survival advantage was achieved with short-term expanded CTLs only. The site of treatment failure was mainly the central nervous system where no CTLs could be identified at AML sites.
authors.affiliation: University of Minnesota Cancer Center and Department of Pediatrics, Minneapolis, Minnesota 55455, USA.
authors.forename: Martin G
authors.initials: MG
authors.lastname: Sauer
authors.forename: Marna E
authors.initials: ME
authors.lastname: Ericson
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Weigel
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Herron
authors.forename: Angela
authors.initials: A
authors.lastname: Panoskaltsis-Mortari
authors.forename: Betsy T
authors.initials: BT
authors.lastname: Kren
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Levine
authors.forename: Jon S
authors.initials: JS
authors.lastname: Serody
authors.forename: Carl H
authors.initials: CH
authors.lastname: June
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Taylor
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Blazar
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000276:immunology; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D019041:L-Selectin / Q000096:biosynthesis / Q000276:immunology; D007951:Leukemia, Myeloid / Q000276:immunology* / Q000628:therapy*; D008221:Lymphoid Tissue / Q000276:immunology; D008546:Melanoma, Experimental / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism
chemical_list: D019041:L-Selectin