Dendritic cells-based T-cell immune response for the variable region of immunoglobulin light chain of myeloma and lymphoma cell lines.

The present work supported and extended a previous study (used VLIg gene segment type VkappaIV) and indicated that a considerable (P<0.001) and specific autologous T-cell proliferation, proliferative index (PI) ranged from 386.0 to 399.5 at 20% dendritic cells (DCs):T-cells ratio, restricted mainly (>80%) to the major histocompatibility complex (MHC) class-I molecules can be elicited in vitro against other different VLg gene segments (VkappaI, VkappaIII and Vlambda2) of myeloma and lymphoma cell lines through a retroviral transduction of human DCs generated from CD34+ progenitor cells by phorbol ester (PMA) and under serum-free conditions. This study also showed a lesser proliferation, but significant (P<0.05), restricted to MHC class-II molecules and specific for VLIg gene segments. The obtained proliferation was almost completely blocked (approximately 95%, P<0.001) by anti-CD86 monoclonal antibodies, which confirmed the critical role of the CD86 costimulatory molecules in the activation of naive T-cells. The resulting immune responses did not significantly differ (P>0.05) among the different types of VLIg gene segments, as VLIg-transduced DCs equally coexpressed the VLIg genes and CD86 costimulatory molecules. In conclusion, the present study could provide the basis of a VLIg-based immunotherapy in plasma cell and B-cell malignancies.