cs1-peptide and Multiple-Myeloma

We evaluated a cocktail of HLA-A2-specific peptides including heteroclitic XBP1 US184-192 (YISPWILAV), heteroclitic XBP1 SP367-375 (YLFPQLISV), native CD138260-268 (GLVGLIFAV) and native CS1239-247 (SLFVLGLFL), for their ability to elicit multipeptide-specific cytotoxic T lymphocytes (MP-CTLs) using T cells from smoldering multiple myeloma (SMM) patients. Our results demonstrate that MP-CTLs generated from SMM patients' T cells show effective anti-MM responses including CD137 (4-1BB) upregulation, CTL proliferation, interferon-γ production and degranulation (CD107a) in an HLA-A2-restricted and peptide-specific manner. Phenotypically, we observed increased total CD3(+)CD8(+) T cells (>80%) and cellular activation (CD69(+)) within the memory SMM MP-CTL (CD45RO(+)/CD3(+)CD8(+)) subset after repeated multipeptide stimulation. Importantly, SMM patients could be categorized into distinct groups by their level of MP-CTL expansion and antitumor activity. In high responders, the effector memory (CCR7(-)CD45RO(+)/CD3(+)CD8(+)) T-cell subset was enriched, whereas the remaining responders' CTL contained a higher frequency of the terminal effector (CCR7(-)CD45RO(-)/CD3(+)CD8(+)) subset. These results suggest that this multipeptide cocktail has the potential to induce effective and durable memory MP-CTL in SMM patients. Therefore, our findings provide the rationale for clinical evaluation of a therapeutic vaccine to prevent or delay progression of SMM to active disease.

Topics: Adult; Aged; Aged, 80 and over; Cell Proliferation; Disease Progression; DNA-Binding Proteins; Epitopes; Female; Humans; Immunologic Memory; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Multiple Myeloma; Peptides; Regulatory Factor X Transcription Factors; Syndecan-1; T-Lymphocytes, Cytotoxic; Transcription Factors; X-Box Binding Protein 1

Multiple myeloma (MM) remains mostly incurable despite the recent progress in the treatment strategy. One of novel fields for anti-MM therapeutic strategy is the development of immunotherapy using monoclonal antibodies (MoAbs) against myeloma-specific antigens. This article focuses on the basic and clinical aspects of several emerging and promising novel MoAbs for MM, such as elotuzumab which targets CS1 and daratumumab which targets CD38. Both antigens are highly expressed in more than 90% of MM patients, and the clinical trials have shown promising anti-MM effects, especially in combination with immunomodulatory agent lenalidomide. We also discuss the characteristics and the results of clinical trials of other MoAbs, such as tabalumab against B cell activating factor or dacetuzumab against CD40, being developed for MM.

Topics: ADP-ribosyl Cyclase 1; Antibodies, Monoclonal; B-Cell Activating Factor; Humans; Intercellular Signaling Peptides and Proteins; Multiple Myeloma; Peptides

Although CD138 expression is a hallmark of plasma cells and myeloma cells, reduced CD138 expression is occasionally found. However, the mechanisms underlying CD138 downregulation in myeloma cells remain unclear. Previous reports suggest that the bone marrow microenvironment may contribute to CD138 downregulation. Among various factors in the tumor microenvironment, hypoxia is associated with tumor progression, poor clinical outcomes, dedifferentiation and the formation of cancer stem cell niches in solid tumors. Since recent findings showed that progression of multiple myeloma (MM) delivers hypoxia within the bone marrow, we hypothesized that CD138 expression may be regulated by hypoxia. In the present study, we examined whether the expression of CD138 and transcription factors occurred in myeloma cells under hypoxic conditions. MM cell lines (KMS-12BM and RPMI 8226) were cultured under normoxic or hypoxic conditions for up to 30 days. Changes in the phenotype and the expression of surface antigens and transcription factors were analyzed using flow cytometry, RT-PCR and western blotting. All-trans retinoic acid (ATRA) was used to examine the phenotypic changes under hypoxic conditions. The expression levels of CD138, CS1 and plasma cell-specific transcription factors decreased under hypoxic conditions, while those of CD20, CXCR4 and B cell-specific transcription factors increased compared with those under normoxic conditions. Stem cell-specific transcription factors were upregulated under hypoxic conditions, while no difference was observed in ALDH activity. The reduced CD138 expression under hypoxic conditions recovered when cells were treated with ATRA, even under hypoxic conditions, along with decreases in the expression of stem cell-specific transcription factor. Interestingly, ATRA treatment sensitized MM cells to bortezomib under hypoxia. We propose that hypoxia induces immature and stem cell-like transcription phenotypes in myeloma cells. Taken together with our previous observation that decreased CD138 expression is correlated with disease progression, the present data suggest that a hypoxic microenvironment affects the phenotype of MM cells, which may correlate with disease progression.

Topics: Aldehyde Oxidoreductases; Antigens, CD20; Antineoplastic Agents; Apoptosis; Boronic Acids; Bortezomib; Cell Differentiation; Cell Hypoxia; Cell Line, Tumor; Down-Regulation; Humans; Intercellular Signaling Peptides and Proteins; Multiple Myeloma; Neoplastic Stem Cells; Oxygen; PAX5 Transcription Factor; Peptides; Pyrazines; Receptors, CXCR4; Syndecan-1; Tretinoin; Tumor Microenvironment

The efficacy of peptide vaccines may be enhanced by stimulating immune cells with multiple peptides derived from distinct tumor-associated antigens. We have evaluated the heteroclitic XBP1-US(184-192) (YISPWILAV), heteroclitic XBP1-SP(367-375) (YLFPQLISV), native CD138(260-268) (GLVGLIFAV), and native CS1(239-247) (SLFVLGLFL) peptides, which have strong HLA-A2 affinity and immunogenicity in combination, for their ability to elicit multiple myeloma antigen-specific responses.. Multipeptide-specific cytotoxic T lymphocytes (MP-CTL) were generated by the stimulation of CD3(+) T lymphocytes from HLA-A2(+) individuals with either autologous mature dendritic cells or T2 cells pulsed with a cocktail of these four peptides.. The peptide cocktail did not compromise tumor antigen-specific activity of CTLs. MP-CTLs displayed increased total, effector memory (CCR7(-)CD45RO(+)), and activated (CD69(+)) CD3(+)CD8(+) T lymphocytes. In addition, MP-CTL showed IFN-γ production, cell proliferation, and cytotoxicity against HLA-A2(+) multiple myeloma cells, including cells of HLA-A2(+) patients with multiple myeloma. Importantly, MP-CTLs showed specific responses in functional assays to each relevant peptide but not to an irrelevant HLA-A2-specific CMV pp65 (NLVPMVATV) peptide.. These results highlight the potential therapeutic application of vaccination with a cocktail of HLA-A2-specific peptides to induce CTLs with a broad spectrum of immune responses against multiple myeloma antigens.

Topics: Antigens, Neoplasm; Cell Line, Tumor; Cell Proliferation; DNA-Binding Proteins; HLA-A2 Antigen; Humans; Intercellular Signaling Peptides and Proteins; Multiple Myeloma; Peptide Fragments; Peptides; Regulatory Factor X Transcription Factors; Syndecan-1; T-Lymphocytes, Cytotoxic; Transcription Factors; Vaccines, Subunit; X-Box Binding Protein 1