Preparation Of Mouse Anti-human ICOS Monoclonal Antibody And The Effect Of GL50-ICOS Signal On T Cell Costimulation In Vitro

The inducible costimulator (ICOS) and his ligand GL50 are a couple of the newest member of CD28/B7 family involved in regulating T cell activation. The interaction of GL50 with ICOS, the specific receptor for GL50, is critically involved in the activation, proliferation, differentiation and cytokine production of T cells as well as in the antibody secretion from B cells during the secondary immune responses. It is well-accepted that GL50/ICOS signal pathway plays a pivotal role in the regulation of inflammatory responses, in the prevention of transplantation rejection and tumor development, as well as in the modulation of autoimmune diseases. Therefore, the specific mAb against ICOS molecule, a valuable tool for modulation of GL50/ICOS signal pathway, not only provides a new perspective for a thorough understanding of the delicate regulation of the immune system, but also plays a potential role in clinical application.1 . Establishment of the hybridoma cell line specifically secreting monoclonal antibody (mAb) against ICOS and the identification of itsbiological characterizationBALB/c mice were immunized with activated T cells from hydrothorax of lung cancer patient as an immune antigen and the splenocytes were fused with murine myeloma SP2/0 cells by the cell fusion hybridoma technique. By means of multiple cell subcloning and repeated screening with ICOS-L929 as antibody screening positive cell while mock-L929 as negative control, a hybridoma cell line (named as 3F8) stably secreting anti-ICOS monoclonal antibody was obtained. Then the Ig isotype was identified with test paper.The isotope of 3F8 was mouse IgG1 while the isotope of light chain is K.The...