title: Myeloma bone marrow plasma cells: evidence for their capacity as antigen-presenting cells.
abstract: Myeloma plasma cells constitute 10% to 90% of the total bone marrow cell count in patients with multiple myeloma (MM). These cells express a variety of cell surface markers, such as HLA-ABC and HLA-DR, and surface antigens that are necessary for professional antigen-presenting cells, including adhesion and costimulatory molecules. In this study, we examined the expression of major histocompatability complex (MHC) and costimulatory molecules on CD38(bright,++) plasma cells in bone marrow aspirates from eight MM patients. Small percentages of plasma cells expressed weak but detectable levels of HLA-DR, HLA-DQ, CD40, CD80, and CD86, which could be upregulated by interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha. CD38++ plasma cell and CD38(dim,+) cells were sorted from freshly isolated bone marrow mononuclear cells and tested for their capacity to act as antigen-presenting cells. Indeed, both CD38++ plasma cells and CD38+ cells were able to stimulate allogeneic T cells and present the soluble antigens purified protein derivative and tetanus toxoid to autologous T cells. Recognition of the antigens led to T-cell proliferation and secretion of IFN-gamma and was MHC class-I and -II restricted. Antigen processing and presentation by CD38++ and CD38+ cells were abolished by treatment of the cells with chloroquine. Hence, our study provides for the first time evidence that myeloma plasma cells may act as antigen-presenting cells. Further studies are warranted to examine in detail the molecules required for inducing T-cell stimulation.
authors.affiliation: Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
authors.forename: Q
authors.initials: Q
authors.lastname: Yi
authors.forename: S
authors.initials: S
authors.lastname: Dabadghao
authors.forename: A
authors.initials: A
authors.lastname: Osterborg
authors.forename: S
authors.initials: S
authors.lastname: Bergenbrant
authors.forename: G
authors.initials: G
authors.lastname: Holm
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000368:Aged; D000369:Aged, 80 and over; D017951:Antigen Presentation; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D005260:Female; D006683:HLA-DQ Antigens / Q000096:biosynthesis / Q000276:immunology*; D006684:HLA-DR Antigens / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D009101:Multiple Myeloma / Q000276:immunology* / Q000473:pathology; D009244:NAD+ Nucleosidase / Q000276:immunology*; D010950:Plasma Cells / Q000276:immunology* / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D016207:Cytokines; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1