title: Overcoming immune tolerance against multiple myeloma with lentiviral calnexin-engineered dendritic cells.
abstract: The key to successful cancer immunotherapy is to induce an effective anticancer immunity that will overcome the acquired cancer-specific immune tolerance. In this study, we found that dendritic cells (DCs) from multiple myeloma (MM) patients suppressed rather than induced a cancer cell-specific immune response. We demonstrated that CD4(+)CD25(high) T cells from MM patients suppressed the proliferation of activated peripheral blood lymphocytes. Further analysis illustrated that MM cell lysates or MM-specific idiotype immunoglobulins (MM Id-Ig) specifically induced the expansion of peripheral CD4(+)CD25(high)FoxP3(high) T regulatory (Treg) cells in vitro. Supraphysiological expression of calnexin (CNX) using lentiviral (LV) vectors in DCs of MM patients overcame the immune suppression and enhanced MM-specific CD4 and CD8 T-cell responses. However, overexpression of CNX did not affect the peripheral expansion of Treg cells stimulated by MM antigens. Thus, the immune suppression effect of Treg cells in cancer patients may be overcome by improving antigen processing in DCs, which in turn may lower the activation threshold of the immune effector cells. This concept of modulating anticancer immunity by genetically engineering cancer patients' DCs may improve immunotherapeutic regimens in cancer treatment.
authors: Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida 32610-0266, USA.
authors: Shuhong
authors: S
authors: Han
authors: Bei
authors: B
authors: Wang
authors: Matthew J
authors: MJ
authors: Cotter
authors: Li-Jun
authors: LJ
authors: Yang
authors: James
authors: J
authors: Zucali
authors: Jan S
authors: JS
authors: Moreb
authors: Lung-Ji
authors: LJ
authors: Chang
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015153:Blotting, Western; D015704:CD4 Antigens / Q000276:immunology / Q000378:metabolism; D037281:Calnexin / Q000235:genetics / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007130:Immunoglobulin Idiotypes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009101:Multiple Myeloma / Q000276:immunology* / Q000473:pathology; D016415:Sequence Alignment; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism
chemical_list: D015704:CD4 Antigens; D007130:Immunoglobulin Idiotypes; D053645:Interleukin-2 Receptor alpha Subunit; D037281:Calnexin