[In vitro stimulation of specific antileukemia T-cell response by dendritic cells derived from CD14+ acute monocytic leukemia cells].
OBJECTIVE
Dendritic cells (DCs) or DC-like cells had been successfully induced in vitro from leukemia cells, which may provide a promising immunotherapeutic protocol for leukemia. This study was designed to investigate the efficiency of in vitro generation of dendritic cells from CD14+ acute myelomonocytic (M4) or monocytic (M5) leukemia cells and their ability of stimulating specific antileukemia T-cell response.


METHODS
Bone marrow mononuclear cells (BMMNCs) were isolated from 5 M4/M5 leukemia patients with high CD14 expression, and then divided into 3 groups: adherent leukemia cells, nonadherent blasts, and total unfractioned blasts. CD14 expression of the 3 groups was evaluated by flow cytometry (FCM). When cultured with or without granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) for 7-10 days, monocytic leukemia cell-derived dendritic cells (Mo-LDCs) were identified through morphologic observation and immunophenotype analysis using FCM. The immune function of Mo-LDCs was detected through allogeneic mixed lymphocyte reaction (Allo-MLR) and cytotoxicity assay of antileukemia cytotoxic T lymphocytes (CTLs). The leukemic origin of Mo-LDCs was confirmed by chromosomal karyotype analysis combined with the aberrant expression of myeloid antigens.


RESULTS
The amount of CD14+ cells, which could differentiate into CD83+ mature DCs under induction of the cytokine combination, was higher in adherent leukemia cells than in nonadherent blasts and total unfractioned blasts. Regarding each 3 cell groups of the same patient or the unfractioned blasts of various patients, initial CD14 expression was positively related to the yield of CD83+ DCs after induction (r = 0.967, P = 0.007). Mo-LDCs exhibited typical morphology and phenotype as mature DCs, induced potent proliferation of homogeneous T cells in Allo-MLR, stimulated the expansion of leukemia-specific CTLs, and continued to possess the cytogenetic abnormalities of the original leukemia, as well as the aberrant expression of myeloid antigens.


CONCLUSIONS
In M4/M5 subtype of AML, CD14+ cells could differentiate into immune-competent Mo-LDCs under the induction of the cytokine combination. CD14 expression level may predict the DCs differentiation ability of monocytic leukemia. Mo-LDCs, which possess the classical phenotype and function of DCs, as well as the abnormal leukemic antigens, may be useful for the immunotherapy of M4/M5 AML.
Department of Hematology, The Third Affiliated Hospital, Soochow University, Changzhou, Jiangsu, 213000, PR China.
Li-Xia
LX
Sheng
Xiao-Bao
XB
Xie
Guo-Qiang
GQ
Qiu
Wei-Ying
WY
Gu
Zhi-Lin
ZL
Wang
Hao-Qing
HQ
Wu
D000293:Adolescent; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D007948:Leukemia, Monocytic, Acute / Q000276:immunology / Q000473:pathology*; D018950:Lipopolysaccharide Receptors / Q000032:analysis*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008875:Middle Aged; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D000097802:CD83 Antigen
D015703:Antigens, CD; D007136:Immunoglobulins; D018950:Lipopolysaccharide Receptors; D008562:Membrane Glycoproteins; D000097802:CD83 Antigen