Humoral immune responses induced by anti-idiotypic antibody fusion protein of 6B11scFv/hGM-CSF in BALB/c mice.
BACKGROUND
We have previously developed and characterized a monoclonal anti-idiotype antibody, designated 6B11, which mimics an ovarian carcinoma associated antigen OC166 - 9 and whose corresponding monoclonal antibody is COC166 - 9 (Ab1). In this study, we evaluate the humoral immune responses induced by the fusion protein 6B11 single-chain variable fragment (scFv)/human granulocyte macrophage colony-stimulating factor (hGM-CSF) and 6B11scFv in BALB/c mice.


METHODS
The fusion protein 6B11scFv/hGM-CSF was constructed by fusing a recombinant single-chain variable fragment of 6B11scFv to GM-CSF. BALB/c mice were administrated by 6B11scFv/hGM-CSF and 6B11scFv, respectively.


RESULTS
The fusion protein 6B11scFv/hGM-CSF retained binding to the anti-mouse F (ab) 2' and was also biologically active as measured by proliferation of human GM-CSF dependent cell TF1 in vitro. After immunization with the 6B11scFv/hGM-CSF and 6B11ScFv, BALB/c mice showed significantly enhanced Ab3 antibody responses to 6B11scFv/hGM-CSF compared with the 6B11scFv alone. The level of Ab3 was the highest after the first week and maintained for five weeks after the last immunization. Another booster was given when the Ab3 titer descended, and it would reach to the high level in a week.


CONCLUSIONS
The fusion protein 6B11scFv/hGM-CSF can induce humoral immunity against ovarian carcinoma in vivo. We also provide the theoretical foundation for the application of the fusion protein 6B11scFv/hGM-CSF for active immunotherapy of ovarian cancer.
Chang
Xiao-hong
XH
Gynecologic Oncology Center, Peking University People's Hospital, Beijing 100044, China.
Ye
Xue
X
Cui
Heng
H
Feng
Jie
J
Li
Yi
Y
Zhu
Hong-lan
HL
Yang
Wen-lan
WL
Fu
Tian-yun
TY
Cheng
Hong-yan
HY
Guo
Hui-fang
HF
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000097:blood*; D019496:Cancer Vaccines / Q000276:immunology*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D007114:Immunization; D007128:Immunoglobulin Fragments / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010051:Ovarian Neoplasms / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D000912:Antibodies, Neoplasm; D019496:Cancer Vaccines; D007128:Immunoglobulin Fragments; D011993:Recombinant Fusion Proteins; C055966:immunoglobulin Fv; D016178:Granulocyte-Macrophage Colony-Stimulating Factor