Construction and characterization of a novel superantigen fusion protein: bFGF/SEB.
BACKGROUND
As one of the bacterial superantigens, Staphylococcal enterotoxins (SEs) are potent activators of T cells, especially for those expressing T cell receptor V(beta) chains, and can induce the production of cytokines such as IFN-gamma, TNF-alpha, IL-1, IL-2, IL-6, IL-12, etc. Thus, SEs could be used in tumor-targeting therapy when cooperated with the vectors that can specifically recognize the tumor cells.


METHODS
The coding sequences of Staphylococcal enterotxin B (SEB) was amplified and fused with human basic fibroblast growth factor (bFGF). Recombinant protein SEB and fusion protein bFGF/SEB were expressed and purified. The biological activity was detected, including splenocytes proliferation, cytokine production, and cytotoxicity in tumor cells in vitro. In addition, the binding of bFGF/SEB with tumor cells and the tumor cell apoptosis were also tested by immunofluorescent technique.


RESULTS
The fusion protein bFGF/SEB had similar biological activities compared with natural SEA and recombinant SEB, including tumor-inhibition ratio.


CONCLUSIONS
The recombinant bFGF/SEB-fusion protein was shown to retain the superantigenic activity of SEB, and might be a novel promising immunotherapeutic agent for the treatment of some carcinomas.
Wang
Lichan
L
Serum Division, National Institute for Control of Pharmaceutical and Biological Products, Beijing, China.
Zhang
Huajie
H
Zhang
Shumin
S
Yu
Mosong
M
Yang
Xiaoming
X
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D019073:HT29 Cells; D006801:Humans; D018796:Immunoconjugates / Q000494:pharmacology*; D007167:Immunotherapy / Q000379:methods*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D018089:Superantigens / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013997:Time Factors
D016207:Cytokines; D004768:Enterotoxins; D018796:Immunoconjugates; D011993:Recombinant Fusion Proteins; D018089:Superantigens; D016222:Fibroblast Growth Factor 2; C031818:enterotoxin B, staphylococcal