Study On Antitumor Role Of MICA-induced γδT Cells

Human MHC class I chain-related A (MICA) is a nonclassic HLA I polymorphic gene, which is expressed on many kinds of epithelial tumors and can be recognized by the Vδ1 subset of γδ T cells. The objective of this study was aimed at whether MICA could induce expansion of human ovarian epithelial carcinoma (OEC)- or colonic carcinoma (CC)- derived γδ T cells of the Vδ1 phenotype in vitro, and identifying whether MICA-reacting Vδ1 γδ TILs are cytotoxic towards epithelial carcinomas. Because under the condition of without MHC restriction and antigen presentation, Vδ1 γδ T cells could recognize MICA expressed on the surface of tumor cells, this simple and quickly way maybe a new approach for adoptive cellular therapy of tumors. Our results will make foundation for adoptive cellular therapy of tumors.First, total RNA was obtained from SKOV₃ ovary tumor cells and whole length cDNA of MICA was amplified by RT-PCR. The recombinant MICA (rMICA)*008 contain α1-α3 domains was expressed in prokaryocyte and purified successfully. The eukaryotic expressed vector transfected to Daudi cells transient also successfully. All these works make foundation for further researches.Secondly, the anti-MICA monoclonal antibodies (mAbs) 5G11, 4D2, 3E8, 1F10, 2D10 and rabbit antiserum were produced by immunization with purified rMICA. The specificity of the antibodies was tested by ELISA, immunofluorescence staining and western blot. The results of flow cytometry showed that the mAbs 3E8 and 5G11 also reacted with native MICA on HeLa cells. The antibodies obtained give us more tools for following researches.