title: Anti-idiotypic antibody facilitates scFv chimeric immune receptor gene transduction and clonal expansion of human lymphocytes for tumor therapy.
abstract: Chimeric immune receptors (CIR) transduced into lymphocytes link target recognition by single chain antibody Fv (scFv) to activation through CD28/TCRzeta signaling. As surrogate antigens, anti-idiotypic antibodies may facilitate gene-transduction and clonal expansion of human lymphocytes for in vivo tumor therapy. The murine monoclonal antibody (MAb) 8H9 reacts with a novel antigen widely expressed on solid tumors. A CIR consisting of human CD8-leader sequence, 8H9-scFv, CD28 (transmembrane and cytoplasmic domains), and TCR-zeta chain was constructed, ligated into the pMSCVneo vector, and used to transfect the packaging line GP + envAM12 bearing an amphotropic envelope. Rat anti-idiotypic MAb 2E9 (IgG2a) was used to clone retroviral producer line as well as to expand gene-modified primary human lymphocytes. Sequential enrichments using either affinity chromatography or cell sorting using anti-idiotypic MAb 2E9 significantly improved the percentage of producer clones positive for surface 8H9-scFv and the efficiency of their supernatant in transducing the indicator cell line K562. By 3 weeks of in vitro culture, >95% of transduced primary human lymphocytes were CIR-positive. Upon periodic stimulation with 2E9, these lymphocytes underwent >10(6)-fold expansion by 6 months in culture. They mediated antigen-specific non-MHC restricted cytokine release and tumor cytotoxicity, and inhibited human xenograft engraftment in SCID mice. Anti-idiotypic antibody may provide a useful tool for optimizing gene transduction of CIR fusion constructs into primary human lymphocytes and their continual expansion in vitro.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002999:Clone Cells / Q000276:immunology; D003001:Cloning, Molecular; D005822:Genetic Vectors; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics* / Q000276:immunology; D016219:Immunotherapy, Adoptive; D008213:Lymphocyte Activation; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D051381:Rats; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D015398:Signal Transduction; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors; D014162:Transfection; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D007135:Immunoglobulin Variable Region; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins