Antitumor effect of new multiple antigen peptide based on HLA-A0201-restricted CTL epitopes of human telomerase reverse transcriptase (hTERT).

Abstract

The development of peptide vaccines aimed at enhancing immune responses against tumor cells is becoming a promising area of research. Human telomerase reverse transcriptase (hTERT) is an ideal universal target for novel immunotherapies against cancers. The aim of this work was to verify whether the multiple antigen peptides (MAP) based on HLA-A0201-restricted CTL epitopes of hTERT could trigger a better and more sustained CTL response and kill multiple types of hTERT-positive tumor cells in vitro and ex vivo. Dendritic cells (DC) pulsed with MAP based on HLA-A0201-restricted CTL epitopes of hTERT (hTERT-540, hTERT-865 and hTERT-572Y) were used to evaluate immune responses against various tumors and were compared to the immune responses resulting from the use of corresponding linear epitopes and a recombinant adenovirus-hTERT vector. A 4-h standard (51) Cr-release assay and an ELISPOT assay were used for both in vitro and ex vivo analyses. Results demonstrated that targeting hTERT with an adenovector was the most effective way to stimulate a CD8(+) T cell response. When compared with linear hTERT epitopes, MAP could trigger stronger hTERT-specific CTL responses against tumor cells expressing hTERT and HLA-A0201. In contrast, the activated CTL could neither kill the hTERT-negative tumor cells, such as U2OS cells, nor kill HLA-A0201 negative cells, such as HepG2 cells. We also found that these peptide-specific CTL could not kill autologous lymphocytes and DC with low telomerase activity. Our results indicate that MAP from hTERT can be exploited for cancer immunotherapy.

• Authors: Zhong-Li Liao, Xu-Dong Tang, Mu-Han Lü, Yu-Yun Wu, Ya-Ling Cao, Dian-Chun Fang, Shi-Ming Yang, Hong Guo
• Journal: Cancer science (Cancer Sci) Vol. 103 Issue 11 Pg. 1920-8 (Nov 2012) ISSN: 1349-7006 [Electronic] England
• PMID: 22909416 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Japanese Cancer Association.

Chemical References

• Antineoplastic Agents
• Cancer Vaccines
• Epitopes, T-Lymphocyte
• HLA-A*02:01 antigen
• HLA-A2 Antigen
• Peptides
• Vaccines, Subunit
• TERT protein, human
• Telomerase

Topics

• Animals
• Antineoplastic Agents (immunology, pharmacology)
• CD4-Positive T-Lymphocytes (immunology)
• CD8-Positive T-Lymphocytes (immunology)
• Cancer Vaccines (immunology, pharmacology)
• Cell Line, Tumor
• Dendritic Cells (immunology)
• Epitopes, T-Lymphocyte (immunology)
• Genetic Vectors (immunology)
• HLA-A2 Antigen (immunology)
• Hep G2 Cells
• Humans
• Mice
• Mice, Inbred C57BL
• Neoplasms (immunology, therapy)
• Peptides (immunology, pharmacology)
• T-Lymphocytes, Cytotoxic (immunology)
• Telomerase (immunology)
• Vaccines, Subunit (immunology)