Tumor protein D52 (TPD52): a novel B-cell/plasma-cell molecule with unique expression pattern and Ca(2+)-dependent association with annexin VI.
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.
Tiacci
Enrico
E
Section of Physiopathology, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy.
Orvietani
Pier-Luigi
PL
Bigerna
Barbara
B
Pucciarini
Alessandra
A
Corthals
Garry L
GL
Pettirossi
Valentina
V
Martelli
Maria P
MP
Liso
Arcangelo
A
Benedetti
Roberta
R
Pacini
Roberta
R
Bolli
Niccolò
N
Pileri
Stefano
S
Pulford
Karen
K
Gambacorta
Marcello
M
Carbone
Antonino
A
Pasquarello
Carla
C
Scherl
Alexander
A
Robertson
Helen
H
Sciurpi
Maria Teresa
MT
Alunni-Bistocchi
Giovanni
G
Binaglia
Luciano
L
Byrne
Jennifer A
JA
Falini
Brunangelo
B
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
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