[Impact of CPP-Id on expression of co-stimulating molecules on dendritic cells in mice].
OBJECTIVE
Idiotypic immunoglobin (Id) derived from B-cell lymphoma, as a tumor-specific antigen, can suppress tumor development by inducing immune response. This study was to confirm the presence of Id epitope on cytotoxic T lymphocytes (Id-CTL) in mouse lymphoma cell line A20, detect the quantity and distribution of cell-penetrating peptide-loaded Id (CPP-Id) in dendritic cells (DCs) at different time points, and explore its impact on the expression of surface molecules on DCs.


METHODS
Id-CTL epitope in A20 cells was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. The quantity of CPP-Id and Id alone in DCs and the expression of DC surface molecules were detected by flow cytometry. The process of CPP-Id entering DCs was observed under confocal microscope, and its distribution was observed under fluorescent microscope.


RESULTS
A 660 bp-length fragment was amplified from A20 cells by RT-PCR, and identified as Id-CTL epitope by sequencing. CPP-Id entered DCs quickly during the initial 200 s, but few Id entered DCs. The mean fluorescent intensity (MFI) in DCs was significantly higher in CPP-Id group than in Id group (4.35+/-0.48 vs. 1.14+/-0.33, P<0.005). The expression of surface molecules CD80, CD86, CD54 and MHC-I, MHC-II were higher on the DCs loaded by either CPP-Id or Id alone than on immature DCs.


CONCLUSIONS
CPP can enhance the quantity of Id entering DCs. CPP-Id can up-regulate the expression of MHC I, MHC-II and CD80, CD86, and CD54 on DCs, and may help to activate CTLs.
Chang
Jian-Hua
JH
State Key Laboratory of Oncology in Southern China, Guangzhou, Guangdong 510060, P. R. China.
Shi
Yan-Xia
YX
Zhang
Xiao-Shi
XS
Jiang
Wen-Qi
WQ
Guan
Zhong-Zhen
ZZ
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen / Q000378:metabolism; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008223:Lymphoma / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000494:pharmacology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D007130:Immunoglobulin Idiotypes; D010455:Peptides; D018799:Intercellular Adhesion Molecule-1