title: Tumor protein D52 (TPD52): a novel B-cell/plasma-cell molecule with unique expression pattern and Ca(2+)-dependent association with annexin VI.
abstract: We generated a murine monoclonal antibody (B28p) detecting an antigenic determinant shared by the immunoglobulin superfamily receptor translocation-associated 1 (IRTA1) receptor (the immunogen used to raise B28p) and an unrelated 28-kDa protein that was subsequently subjected to extensive characterization. The expression of the 28-kDa protein in normal lymphohematopoietic tissues was restricted to B cells and plasma cells and clearly differed from that expected for IRTA1 (selectively expressed by mucosa-associated lymphoid tissue [MALT] marginal zone B cells). Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE)/mass-spectrometry analysis identified the 28-kDa protein as human tumor protein D52 (TPD52), whose expression had been previously described only in normal and neoplastic epithelia. Specific B28p reactivity with TPD52 was confirmed by immunostaining/immunoblotting of TPD52-transfected cells. TPD52 expression pattern in normal and neoplastic B cells was unique. In fact, unlike other B-cell molecules (paired box 5 [PAX5], CD19, CD79a, CD20, CD22), which are down-regulated during differentiation from B cells to plasma cells, TPD52 expression reached its maximum levels at the plasma cell stage. In the Thiel myeloma cell line, TPD52 bound to annexin VI in a Ca(2+)-dependent manner, suggesting that these molecules may act in concert to regulate secretory processes in plasma cells, similarly to what was observed in pancreatic acinar cells. Finally, the anti-TPD52 monoclonal antibody served as a valuable tool for the diagnosis of B-cell malignancies.
authors.affiliation: Section of Physiopathology, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Tiacci
authors.forename: Pier-Luigi
authors.initials: PL
authors.lastname: Orvietani
authors.forename: Barbara
authors.initials: B
authors.lastname: Bigerna
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pucciarini
authors.forename: Garry L
authors.initials: GL
authors.lastname: Corthals
authors.forename: Valentina
authors.initials: V
authors.lastname: Pettirossi
authors.forename: Maria P
authors.initials: MP
authors.lastname: Martelli
authors.forename: Arcangelo
authors.initials: A
authors.lastname: Liso
authors.forename: Roberta
authors.initials: R
authors.lastname: Benedetti
authors.forename: Roberta
authors.initials: R
authors.lastname: Pacini
authors.forename: Niccolò
authors.initials: N
authors.lastname: Bolli
authors.forename: Stefano
authors.initials: S
authors.lastname: Pileri
authors.forename: Karen
authors.initials: K
authors.lastname: Pulford
authors.forename: Marcello
authors.initials: M
authors.lastname: Gambacorta
authors.forename: Antonino
authors.initials: A
authors.lastname: Carbone
authors.forename: Carla
authors.initials: C
authors.lastname: Pasquarello
authors.forename: Alexander
authors.initials: A
authors.lastname: Scherl
authors.forename: Helen
authors.initials: H
authors.lastname: Robertson
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Sciurpi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Alunni-Bistocchi
authors.forename: Luciano
authors.initials: L
authors.lastname: Binaglia
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Byrne
authors.forename: Brunangelo
authors.initials: B
authors.lastname: Falini
mesh_terms: D000818:Animals; D017317:Annexin A6 / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D015973:Gene Expression Regulation, Leukemic / Q000276:immunology; D015448:Leukemia, B-Cell / Q000175:diagnosis / Q000503:physiopathology; D013058:Mass Spectrometry; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D010950:Plasma Cells / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000276:immunology; D011961:Receptors, Fc
chemical_list: D017317:Annexin A6; D000911:Antibodies, Monoclonal; D018985:Epitopes, B-Lymphocyte; C423544:FCRL4 protein, human; D009363:Neoplasm Proteins; D011956:Receptors, Cell Surface; D011961:Receptors, Fc; C114751:TPD52 protein, human; D002118:Calcium