[T lymphocytes with chimeric receptor induce carcinoembryonic antigen-positive specific gastric carcinoma cells apoptosis].
OBJECTIVE
To develop a method to generate T lymphocytes that identify tumor specific carcinoembryonic antigen (CEA), and induce anti-tumor response such as apoptosis.


METHODS
Peripheral blood samples were collected from 10 healthy persons and peripheral blood mononuclear cells (PBMCs) were isolated. 1, then CD8(+) T cells were isolated from the PBMCs by magnetic activated cell sorting (MACS) using magnetic beads-conjugated anti-CD8 monoclonal antibodies. Then the recombinant vector anti-CEA-scFv-CD3zeta-pcDNA3.0 was transfected into the CD8(+) T cells by lipofectamine 2000 and T lymphocytes with chimeric receptor were generated and cultivated. The T lymphocytes' activation was assessed by detecting the expression of CD69, an early signal of T cell activation. Human gastric carcinoma cells of the lines HGC-27 (CEA(+)) and SGC-7901 (CEA(-)) were cocultivated with the T lymphocytes with chimeric receptor. Flow cytometry (FCM) with annexin V-FITC/PI double staining was used to detect the expressions of annexin V, a signal of cell apoptosis, so as to observe the apoptosis of the gastric carcinoma cells. T cells activated by phytohemagglutinin (PHA) were used as positive controls, and T cells transfected with blank vector pcDNA3.0 were used as negative controls.


RESULTS
T lymphocytes with chimeric receptor directed towards CEA(+) gastric carcinoma cells were generated. 12 and 24 hours after the co-culture of these T cells and HCG-27 cells, the CD69 expression rates were 40.5% +/- 3.4% and 48.3% +/- 2.8% respectively. However, the CD69 expression rates of the HGC-27 and SGC-7901 cells transfected with the T lymphocytes transfected with blank vector were both 0%. FCM showed that the apoptotic rates of the CEA(+) gastric tumor HGC-27 cells was 47.8% +/- 4.2%, significantly higher than that of the CEA(-) gastric tumor SGC-7901 cells (18.7% +/- 2.8%, P < 0.05).


CONCLUSIONS
T lymphocytes with chimeric receptor targeting CEA specifically identify CEA positive gastric carcinoma cells and promote the apoptosis thereof, thus providing a promising method of cellular immunotherapy for gastric carcinomas.
Hepatobiliary General Surgery, Hospital No. 451 of Chinese People's Liberation Army, Xi'an 710054, China. hongyongxu@medmail.com.cn
Hong-yong
HY
Xu
Li
L
Xu
Jian-hong
JH
Gao
Kai-zong
KZ
Li
Ke-feng
KF
Dou
D000911:Antibodies, Monoclonal / Q000276:immunology; D017209:Apoptosis / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000235:genetics / Q000276:immunology*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D013274:Stomach Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D014162:Transfection / Q000379:methods
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins