Leukemia-derived immature dendritic cells differentiate into functionally competent mature dendritic cells that efficiently stimulate T cell responses.
Primary acute myeloid leukemia cells can be induced to differentiate into dendritic cells (DC). In the presence of GM-CSF, TNF-alpha, and/or IL-4, leukemia-derived DC are obtained that display features of immature DC (i-DC). The aim of this study was to determine whether i-DC of leukemic origin could be further differentiated into mature DC (m-DC) and to evaluate the possibility that leukemic m-DC could be effective in vivo as a tumor vaccine. Using CD40L as maturating agent, we show that leukemic i-DC can differentiate into cells that fulfill the phenotypic criteria of m-DC and, compared with normal counterparts, are functionally competent in vitro in terms of: 1) production of cytokines that support T cell activation and proliferation and drive Th1 polarization; 2) generation of autologous CD8(+) CTLs and CD4(+) T cells that are MHC-restricted and leukemia-specific; 3) migration from tissues to lymph nodes; 4) amplification of Ag presentation by monocyte attraction; 5) attraction of naive/resting and activated T cells. Irradiation of leukemic i-DC after CD40L stimulation did not affect their differentiating and functional capacity. Our data indicate that acute myeloid leukemia cells can fully differentiate into functionally competent m-DC and lay the ground for testing their efficacy as a tumor vaccine.
Laboratory of Cancer Immunology, Institute for Cancer Research and Treatment, Candiolo, Italy. alex.cignetti@unito.it
Alessandro
A
Cignetti
Antonella
A
Vallario
Ilaria
I
Roato
Paola
P
Circosta
Bernardino
B
Allione
Laura
L
Casorzo
Paolo
P
Ghia
Federico
F
Caligaris-Cappio
D023201:CD40 Ligand / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015470:Leukemia, Myeloid, Acute / Q000276:immunology*; D018950:Lipopolysaccharide Receptors / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D008297:Male; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology*
D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D023201:CD40 Ligand