Reconstruction of SEA-B7.1 double signals on human hepatocellular carcinoma cells and analysis of its immunological effect

Citation
Zs. Li et al., Reconstruction of SEA-B7.1 double signals on human hepatocellular carcinoma cells and analysis of its immunological effect, BIOC BIOP R, 288(2), 2001, pp. 454-461
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
ISSN journal
0006-291X → ACNP
Volume
288
Issue
2
Year of publication
2001
Pages
454 - 461
Database
ISI
SICI code
0006-291X(20011026)288:2<454:ROSDSO>2.0.ZU;2-T
Abstract
Since transfection of established tumors with immunostimulatory genes, such as superantigens (SAg), a family of bacterial and viral proteins with stro ng immunostimulatory properties, can elicit antitumor immunity, direct tran sfection of tumors with genes of staphylococcal enterotoxin A (SEA) could p robably set up a new way of immunological pathway. In our study, human hepa tocellular carcinoma (HCC) cell lines stably transduced with SEA and B7.1/S EA fused genes, HHCCSEA and HHCCBS, were obtained by using the method of re troviral mediated gene transduction. The results showed that human HCC cell s could express SEA gene. Although a tiny quantity of expression was detect ed, a robust immune response was promoted. The cytotoxicity of CTL on HHCCB S was the same as that on HHCCSEA. But the Km value of the reaction of the former was lower than that of HHCCSEA. Furthermore, the activity assay of T cells by ELISPOT demonstrated that HHCCBS could elicit more CTL activity t han HHCCSEA and HHCCB7.1. It suggested that the affinity of T cells to HHCC BS was higher and the maxim velocity of reaction could be attained at an ea rly stage of the reaction. Transduced HCC cells were also analyzed for HLA expression, and it was found that a majority of the cells expressed HLA-I m olecules but no HLA-DR molecules. After blocking the IIIA-I molecules by HL A-I mAb, the cytotoxicity of T lymphocytes dropped remarkably. The results suggested that SEA were mainly presented by HLA-I molecules, and that B7.1 and SEA could have synergistic action at the early stage of the reaction, b ut the relationship between them in the consequent process needs to be clar ified. (C) 2001 Academic Press.