The effect of co-expression costimulatory molecule CD80 on uptake of antigen peptide-MHC class I-GFP complex by specific T cells.
CD80, a costimulatory molecule, plays an important role in eliciting antitumor immunity. Without costimulation, recognition of antigens by T cells may not cause a response, even if tumor cells express MHC class I molecules and specific antigens. On the basis of the recombinant GFP-tagged Kb molecule, we constructed a co-expression vector of CD80 and GFP-tagged Kb molecules. The recombinant fusion was transfected into mouse melanoma B16 cells by electroporation; positive cells were obtained by G418 screening. Highly expressing monoclonal cells, irradiated by 137Cs, were used to immunize mice to obtain specific T cells, which were then cultivated with tumor cells in vitro and examined with a laser confocal microscope. The evident and intense uptake of the antigen peptide-MHC class I-GFP complex by specific T cells was visualized from the culture of B16/CD80-Kb-GFP and T cells. However, little uptake was observed from the culture of B16/Kb-GFP and T cells. These results show that co-expression of CD80 molecules with Kb, an MHC class I molecule, on the surface of B16 tumor cells can enhance the response of specific T cells and thus increase the uptake of the antigen peptide-MHC class I-GFP complex. The absorbed green fluorescence was concentrated mainly on the T cell surface, and this result might pave the way to eluting specific antigen peptides directly from T cells to find and isolate novel tumor-specific antigen peptides.
Liu
Xia
X
Research Center for Human Gene Therapy, Department of Biochemistry and Molecular Biology, School of Medicine, Shanghai Jiao Tong University, Shanghai, PR China.
Zhang
Leilei
L
Zhang
Xingqian
X
Yu
Hai
H
Zhao
Xiaoping
X
Lu
Jian
J
Qian
Guanxiang
G
Ge
Shengfang
S
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D018122:B7-1 Antigen / Q000276:immunology* / Q000378:metabolism; D018274:Electroporation; D005260:Female; D005434:Flow Cytometry; D049452:Green Fluorescent Proteins / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D018613:Microscopy, Confocal; D011993:Recombinant Fusion Proteins / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
D018122:B7-1 Antigen; D015395:Histocompatibility Antigens Class I; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins