Development of chimeric molecules for recognition and targeting of antigen-specific B cells in pemphigus vulgaris.
Pemphigus vulgaris (PV) is an autoimmune blistering disease characterized by circulating pathogenic IgG antibodies against desmoglein 3 (Dsg3). The purpose of this study was to develop chimeric molecules for specific recognition and elimination of autoimmune B cells in PV. Mouse hybridoma cell lines producing anti-Dsg3 antibody (5H10, 12A2) were developed as an in vitro model system for targeting B cells. Dsg3-GFP, a baculoprotein containing the entire extracellular domain of Dsg3 fused with green fluorescence protein, recognized and targeted the hybridoma cells through their surface immunoglobulin receptors in an antigen-specific way. The epitopes of these monoclonal antibodies were mapped on the amino terminal EC1 and part of EC2, a region considered functionally important in cadherins. Chimeric toxin molecules containing the mapped region (Dsg3deltaN1) and modified Pseudomonas exotoxin were produced in bacteria (Dsg3deltaN1-PE40-KDEL, PE3 7-Dsg3deltaN1-KDEL) and tested in vitro on hybridoma cell lines. The chimeric toxins, but not Dsg3deltaN1 alone, showed dose-dependent toxic activity with a reduction in hybridoma cell number to 40-60% of toxin-negative control cultures, compared with little or no effect on anti-Dsg3-negative hybridoma cells. Furthermore, these toxins showed toxic effects on anti-Dsg3 IgG-producing B cells from Dsg3deltaN1-immunized mice, with a 60% reduction in cell number compared with Dsg3deltaN1 alone. Thus, specific recognition and targeting of antigen-specific B cells in PV was demonstrated; this strategy may hold promise as a future therapeutic option for PV and other autoimmune diseases.
Proby
C M
CM
Department of Dermatology, Keio University School of Medicine, Tokyo, Japan.
Ota
T
T
Suzuki
H
H
Koyasu
S
S
Gamou
S
S
Shimizu
N
N
Wahl
J K
JK
Wheelock
M J
MJ
Nishikawa
T
T
Amagai
M
M
D036002:ADP Ribose Transferases; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology; D015820:Cadherins / Q000276:immunology; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D051184:Desmoglein 3; D018604:Epitope Mapping; D005098:Exotoxins / Q000276:immunology*; D005260:Female; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D000922:Immunotoxins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010392:Pemphigus / Q000276:immunology*; D011550:Pseudomonas aeruginosa / Q000276:immunology; D011994:Recombinant Proteins / Q000096:biosynthesis; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
D036002:ADP Ribose Transferases; D000911:Antibodies, Monoclonal; D001324:Autoantigens; D001427:Bacterial Toxins; D015820:Cadherins; D051184:Desmoglein 3; D005098:Exotoxins; D007074:Immunoglobulin G; D000922:Immunotoxins; D011994:Recombinant Proteins; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C071894:DSG3 protein, human