[Specific induction of anti-leukemia effects by umbilical cord cell-derived CD8+ T cytotoxic lymphocytes].
OBJECTIVE
To explore the specific anti-leukemia immune response of CD8+ cytotoxic T lymphocyte (CTL) derived from cord blood (CB) ex vivo and evaluate the feasibilities and values of the CTL for specific immunotherapy.


METHODS
Dendritic cells (DC) were induced from mononuclear cells (MNC) by combination cytokines in 10 CB samples. Loading U937 cell lysate antigen on the mature DC, they could stimulate the lymphocytes of the same origin to generate CTL. MidiMACS was used to isolate CD8+ CTL. Analysis of DC was performed by inverted microscopy, scanning electron microscopy and flow cytometry. Methyl thiazolyl tetrazolium (MTT) assay was used to evaluate the cytotoxicity of the CTL.


RESULTS
Cocultured with GM-CSF, IL-4, TNF-alpha and PGE2, CB-MNC could be induced into functional DC with typical morphology. The mean cytotoxicity of CD8+ CTL to U937 cells was significant stronger than that of CD8- CTL and TL at the same E: T ratios. The mean cytotoxicity rate of CD8+ CTL to U937 cells was higher than that to K562 cells [(66.36 +/- 12.43)% vs (41.97 +/- 14.24)%] at E: T ratio of 40: 1 (P < 0.05). The cytotoxicity of CD8- CTL to K562 cells showed no difference from that to U937 cells (P > 0.05).


CONCLUSIONS
Mature CB-DC loading U937 cell antigens could induce CB-T lymphocytes to generate leukemia-specific CD8+ CTL. The cytotoxicity of the CD8+ CTL is specific against U937 cells and is more potent than that of CD8- CTL.
Liu
Xin
X
Centre of Oncology and Hematology, First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510230, China.
Tan
Huo
H
Wang
Chun-Yan
CY
Huang
Zhen-Qian
ZQ
Zhang
Huan-Zhu
HZ
D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D020014:K562 Cells; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D020298:U937 Cells