Lentiviral transduction of primary myeloma cells with CD80 and CD154 generates antimyeloma effector T cells

Lenalidomide enhances antigen-specific activity and decreases CD45RA expression of T cells from patients with multiple myeloma

The aim of this study was to investigate whether the specific T cell response against the multiple myeloma Ag HM1.24 is enhanced by the immunomodulatory drug lenalidomide (Revlimid). Ag-specific CD3(+)CD8(+) T cells against the HM1.24 Ag were expanded in vitro by dendritic cells in 29 healthy donors and 26 patients with plasma cell dyscrasias. Ag-specific activation was analyzed by IFN-γ, granzyme B, and perforin secretion using ELISA, ELISPOT assay, and intracellular staining, and generation of Ag-specific T cells was analyzed by tetramer staining. Expression of T cell maturation markers (CD45RA, CD45R0, CCR7, and CD28) was investigated by flow cytometry. We found that activation of HM1.24-specific T cells from healthy donors and patients with plasma cell dyscrasias was enhanced significantly by lenalidomide and furthermore that the impact of lenalidomide on T cells depends on the duration of the exposure. Notably, lenalidomide supports the downregulation of CD45RA on T cells upon activation, observed in healthy donors and in patients in vitro and also in patients during lenalidomide therapy in vivo. We showed for the first time, to our knowledge, that lenalidomide enhances the Ag-specific activation of T cells and the subsequent downregulation of CD45RA expression of T cells in vitro and in vivo.

In vitro expansion of gamma delta T cells with anti-myeloma cell activity by Phosphostim and IL-2 in patients with multiple myeloma

T-cell-mediated immunotherapy is a promising therapeutic option for multiple myeloma (MM). Gamma-delta T cells (gammadelta T cells) recognize phosphoantigens and display strong anti-tumour cytotoxicity. The synthetic agonist Phosphostim (bromohydrin pyrophosphate, BrHPP) has been shown to selectively activate Vgamma9Vdelta2 T cells. This study aimed to evaluate the expansion capacity and anti-myeloma cell cytotoxicity of circulating gammadelta T cells from MM patients at different time points throughout the disease, using Phosphostim and interleukin 2 (IL-2). Circulating gammadelta T cell counts in patients with newly diagnosed MM or in relapse did not differ from those in healthy donors. A 14-d culture of peripheral blood mononuclear cells with Phosphostim and IL-2 triggered a 100-fold expansion of gammadelta T cells in 78% of newly diagnosed patients. Gammadelta T cells harvested at the time of haematopoietic progenitor collection or in relapsing patients expanded less efficiently. Expanded gammadelta T cells killed 13/14 myeloma cell lines as well as primary myeloma cells, but not normal CD34 cells. Their killing efficiency was not affected by 2-d IL-2 starvation. This study demonstrated the ability of Phosphostim and IL-2 to expand gammadelta T cells from MM patients, and the efficient and stable killing of human myeloma cells by gd T cells.

B7-1 and 4-1BB ligand expression on a myeloma cell line makes it possible to expand autologous tumor-specific cytotoxic T cells in vitro

OBJECTIVE

The aim of this study was to confer an antigen-presenting cell (APC) ability on multiple myeloma cell lines (HMCLs) using B7-1 and/or 4-1BBL gene transfer.

MATERIALS AND METHODS

HMCLs were retrovirally transduced with B7-1 and/or 4-1BBL cDNAs. Allogeneic or autologous T cells were stimulated by coculture with B7-1- and/or 4-1BBL-transduced HMCLs in the presence of interleukin-2. T cell clones were obtained by limiting dilution. T-cell activation was assessed by interferon-gamma Elispot assays and cytotoxicity by (51)Cr release assays.

RESULTS

Neither primary multiple myeloma cells (MMCs) nor HMCLs expressed B7-1 or 4-1BBL, and these molecules could not be induced by CD40 triggering. HMCLs failed to stimulate allogeneic or autologous T cells. Transduction of HMCLs with B7-1 and/or 4-1BBL retroviruses induced a high expression of B7-1 and 4-1BBL molecules and a strong T-cell activation ability. Long-term cultured CD8(+) T-cell lines could be obtained by stimulation with the autologous B7-1/4-1BBL XG-19 HMCL. These cytotoxic T lymphocytes (CTL) efficiently killed the autologous parental XG-19 HMCL as well as autologous primary MMCs and allogeneic HMCLs. They did not kill autologous CD34 cells and autologous EBV cell line or natural killer target K562 cells. Cloned CTL could recognize allogeneic HMCLs, demonstrating that a shared anti-MMC repertoire was expanded.

CONCLUSION

Transduction with B7-1 and 4-1BBL retroviruses turned HMCLs into efficient APCs. It permitted the long-term expansion of autologous anti-tumor CTL with a shared anti-MMC repertoire, for one HMCL. These data suggest developing an immunotherapy using modified tumor cells in patients with multiple myeloma.