title: Cell membrane associated free kappa light chains are found on a subset of tonsil and in vitro-derived plasmablasts.
abstract: The monoclonal antibody, MDX-1097, is currently progressing through clinical trials as a possible therapy for multiple myeloma. MDX-1097 targets a cell membrane bound form of free immunoglobulin kappa light chain (FκLC), termed kappa myeloma antigen (KMA), which is found on the surface of malignant plasma cells. The clinical potential of MDX-1097 highlights the need to characterise the expression of its cognate antigen, KMA, in normal tissue. In this study, we have analysed the expression of KMA on B cell subsets found in tonsils, peripheral blood and bone marrow. We found KMA expression on a small population of tonsillar and in vitro derived plasmablasts. In contrast, no KMA expression was observed on peripheral blood or bone marrow resident B cell subsets. This study yields important insights into the possible subsets of B cells that might be depleted as a result of an immunotherapy targeting KMA.
authors.affiliation: School of Medical and Molecular Biosciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Centre for Health Technologies, University of Technology Sydney, Ultimo, NSW 2007, Australia; The iThree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia; Centre for Biomedical Research, Burnet Institute, Melbourne, VIC 3004, Australia. Electronic address: andrew.hutchinson@uts.edu.au.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Hutchinson
authors.affiliation: School of Medical and Molecular Biosciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Darren R
authors.initials: DR
authors.lastname: Jones
authors.affiliation: School of Medical and Molecular Biosciences, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Padraig
authors.initials: P
authors.lastname: McCauley Winter
authors.affiliation: Immunology Research Program, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, University of NSW, Darlinghurst, NSW 2010, Australia.
authors.forename: Stuart G
authors.initials: SG
authors.lastname: Tangye
authors.affiliation: School of Medical and Molecular Biosciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Centre for Health Technologies, University of Technology Sydney, Ultimo, NSW 2007, Australia.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Raison
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000276:immunology / Q000378:metabolism; D018941:Antigens, CD19 / Q000276:immunology / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D014066:Palatine Tonsil / Q000276:immunology* / Q000378:metabolism; D010950:Plasma Cells / Q000276:immunology* / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology / Q000378:metabolism
chemical_list: D018941:Antigens, CD19; D007145:Immunoglobulin kappa-Chains; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D051997:ADP-ribosyl Cyclase 1
keywords: Free light chain; Immunoglobulin; MDX-1097; Plasmablasts