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World J Gastroenterol. Dec 14, 2008; 14(46): 7127-7132
Published online Dec 14, 2008. doi: 10.3748/wjg.14.7127
Bone marrow-derived dendritic cells pulsed with tumor lysates induce anti-tumor immunity against gastric cancer ex vivo
Yan-Lin Li, Yu-Gang Wu, Yong-Qing Wang, Zhong Li, Rong-Chao Wang, Liang Wang, Yan-Yun Zhang
Yan-Lin Li, Yong-Qing Wang, Department of Paediatrics, the First People Hospital of Changzhou and The Third Affiliated Hospital of Soochow University, Changzhou 213000, Jiangsu Province, China
Yu-Gang Wu, Zhong Li, Rong-Chao Wang, Department of Surgery, the First People Hospital of Changzhou and The Third Affiliated Hospital of Soochow University, Changzhou 213000, Jiangsu Province, China
Liang Wang, Department of Surgery, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
Yan-Yun Zhang, Institute of Health Sciences and Shanghai Institute of Immunology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences and Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
Author contributions: Li YL and Wu YG contributed equally to this work; Li YL, Wu YG, Wang L and Zhang YY designed the research; Li YL, Wu YG, Wang YQ, Li Z, Wang RC performed the research; Li YL, Wu YG, Wang L and Zhang YY analyzed the data; Li YL and Wu YG wrote the paper.
Correspondence to: Dr. Liang Wang, Department of Surgery, the First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China. xiaobabyee@163.com
Telephone: +86-519-86180077 Fax: +86-519-86621235
Received: June 24, 2008
Revised: September 27, 2008
Accepted: October 4, 2008
Published online: December 14, 2008
Abstract

AIM: To investigate whether bone marrow-derived dendritic cells pulsed with tumor lysates induce immunity against gastric cancer ex vivo.

METHODS: c-kit+ hematopoietic progenitor cells were magnetically isolated with a MiniMACS separator from BALB/c mice bone marrow cells. These cells were cultured with cytokines GM-CSF, IL-4, and TNFα to induce their maturation. They were analysed by morphological observation, phenotype analysis, and mixed lymphocyte reaction (MLR). Bone marrow-derived DCs (BM-DCs) were pulsed with tumor cell lysate obtained by rapid freezing and thawing at a 1:3 DC:tumor cell ratio. Finally, cytotoxic T lymphocyte (CTL) activity and interferon gamma (IFNγ) secretion was evaluated ex vivo.

RESULTS: c-kit+ hematopoietic progenitor cells from mice bone marrow cells cultured with cytokines for 8 d showed the character of typical mature DCs. Morphologically, observed by light microscope, these cells were large with oval or irregularly shaped nuclei and with many small dendrites. Phenotypically, FACS analysis showed that they expressed high levels of Ia, DEC-205, CD11b, CD80 and CD86 antigen, moderate levels of CD40, and negative for F4/80. Functionally, these cells gained the capacity to stimulate allogeneic T cells in MLR assay. However, immature DCs cultured with cytokines for 5 d did not have typical DCs phenotypic markers and could not stimulate allogeneic T cells. Ex vivo primed T cells with SGC-7901 tumor cell lysate-pulsed (TP) DCs were able to induce effective CTL activity against SGC-7901 tumor cells (E:T = 100:1, 69.55% ± 6.05% specific lysis), but not B16 tumor cells, and produced higher levels of IFNγ when stimulated with SGC-7901 tumor cells but not when stimulated with B16 tumor cells (1575.31 ± 60.25 pg/mL in SGC-7901 group vs 164.11 ± 18.52 pg/mL in B16 group, P < 0.01).

CONCLUSION: BM-derived DCs pulsed with tumor lysates can induce anti-tumor immunity specific to gastric cancer ex vivo.

Keywords: Dendritic cells, Cytokine, Gastric cancer, Cytotoxic T lymphocyte, Immunotherapy