Immunization with truncated sequence of Telomerase Reverse Transcriptase induces a specific antitumor response in vivo.
To select the MHC-I-binding epitope-rich sequence of mice telomerase reverse transcriptase (mTERT) and study the antitumor immune response induced by truncated TERT through mRNA-transfected dendritic cells (DCs) immunization in mice. The MHC-I-binding epitopes of TERT were predicted using bioinformatics software. The selected sequence of TERT (Truncated mTERT, TERT(t), mTERT cDNA 1776 bp-2942 bp encoding 584 aa-969 aa) was cloned from B16 mouse melanoma cells and inserted into pBluescriptIIKS(+) plasmid downstream of the T7 promoter. TERT(t) RNA was prepared through in vitro transcription. Bone marrow-derived DCs were electroporated with TERT(t) RNA and used to immunize syngeneic naïve mice. The quantity and cytotoxic activity of TERT-specific cytotoxic T lymphocytes (CTLs) in mice spleen were evaluated using IFN-gamma enzyme-linked immunospot (ELISPOT) and Lactate dehydrogenase release assay. The immunoprophylactic effects against TERT positive tumor induced by TERT(t) RNA transfected DC in vivo were evaluated through an immunized-challenged mouse model. TERT(t) was cloned and in vitro transcribed into TERT(t) mRNA. As shown in FCM analysis, the efficiency of DC electroporation is 35.1% (29.7-41.2%). After electroporation, a subtle increase of costimulator and MHC-II molecules were expressed on the cell surface. Immunization of TERT(t) mRNA transfected DCs induced IFN-gamma-secreting CTLs which manifested specific cytotoxic activity against TERT-positive target cells. In a cancer mouse model, vaccination of TERT(t) mRNA-transfected DCs suppressed the growth of TERT positive tumors (p=0.001) and prolong the survival time of tumor-bearing animals (p=0.029). TERT(t) evokes an antitumor immune response in vivo which is targeted to TERT. TERT(t) can be used as an antigeneic sequence to produce anti-TERT tumor vaccine.
Qiu
Jian
J
Department of General Surgery, Shaanxi Provincial People's Hospital, The Third Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, China. qiujian263@126.com
Li
Guo-Wei
GW
Sui
Yan-Fang
YF
Sun
Yu-Jing
YJ
Huang
Ya-Yu
YY
Si
Shao-Yan
SY
Ge
Wei
W
D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology* / Q000637:transplantation; D018274:Electroporation; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D007114:Immunization; D016056:Immunodominant Epitopes / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D017384:Sequence Deletion; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019098:Telomerase / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D014162:Transfection; D014611:Vaccination
D000970:Antineoplastic Agents; D015395:Histocompatibility Antigens Class I; D016056:Immunodominant Epitopes; D019098:Telomerase