Induction Of Cytotoxic T Lymphocytes(CTLs)with Multiple Myeloma Based On Dendritic Cells And Its Immunobiological Characteristics

ABSTRACT Multiple myeloma is a malignant disease involving plasma cells, usually accompanied by the production of an Ig paraprotein of a defined idiotype. Until recently, it was clear that optional management of the disease involved relatively low-dose chemotherapy (eg. Melphalan and prednisone), resulting in a median survival of approximately 3 years. It has become clear that more intensive chemotherapy, followed by autologous stem cell transplantation, prolongs median survival, but is unlikely to be curative. Allogeneic BMT in suitable candidates can achieve a satisfactory outcome, with complete remissions and prevention of disease progression, attesting to an immunological graft-versus-myeloma effect. The Ig paraprotein provides a natural TAA for multiple myeloma immunotherapy. MM patients are capable of generating T lymphocytes and antibody-mediated responses to Ig idiotype. In vitro studies suggest that plasma cells are targets for cytotoxic I lymphocytes and animal models show that vaccination strategies, based on Ig idiotype, eradicate plasmacytoma. Some studies of DC biology in MM patient have begun. Dentritic cells are known to be the most competent APCs. They initiate T cells, especially na飗e T cells to proliferate, and induce the generation of cytotoxic T lymphioctyes (CTL) both in vitro and in vivo. MDDC (monocyte-derived dentritic cells)presented from MM patients have been reported to have normal activities. MDDC pulsed with idiotype administered to individual patients induced a T lymphocyte proliferative response and an anti-idiotype antibody response. Because MM patients are highly applicable to the MRD (minimal residual disease) state being achieved after autologous stem cells transplantation, DC-based vaccination strategies, or Id-Specific CTL infusion after transplantation may prolong disease-free survival and postpone the inevitable relapse. KIRs (killer inhibition receptors) expressed mainly on natural killer cells, and also on I cells. Such subsets of T cells have two different types of -6- MHC-recognizing recepors on their surface-TCRs and KIRs. TCR recognizes antigen-MHC complex and induce positive signals for activities proliferation whereas KIRs mediates the opposite negative, signals for effector function and cell growth. Until recently, there is no published data demonstrating KIR expression on CTLs with MM patient. Objective The present study aimed at the in vitro induction of CTLs with MM and its immunobiological characteristics, including the following 4 sections: 1. the isolation, culture and characterization of DCs from peripheral blood with MM patients; 2. In vitro induction of CTLs with MM patients; 3. The study of KIR expression on CTLs with MM patients; 4. The in vivo immunological effect of CTLs with MM patients. Method and Results 1. To set up an in vitro culture procedure obtaining DCs from peripheral blood of MM patients. Plastic-adherent peripheral blood mononuclear cells (PBMNCs) or sorted cells by immmunomagenetic separation method were cultured in AIM-V serum-free medium containing GM-CSF and IL-4 at 37C, 5%C02 humidified atmosphere.After 5?7 days of culture, a large quantities of cells exhibiting a typical characteristic dentritic cell morphology were collected. No significant difference in yield existed between two separation met...