Effectiveness of anti-folate receptor beta antibody conjugated with truncated Pseudomonas exotoxin in the targeting of rheumatoid arthritis synovial macrophages.
OBJECTIVE
To define the distribution of folate receptor beta (FRbeta)-expressing cells in various tissues, including rheumatoid arthritis (RA) synovial tissues, and to verify the effects of an immunotoxin composed of an anti-FRbeta monoclonal antibody (mAb) and truncated Pseudomonas exotoxin A (PEA) on apoptosis and tumor necrosis factor alpha (TNFalpha) production by adherent synovial mononuclear cells from RA patients.


METHODS
Anti-FRbeta mAb were produced by immunizing mice with FRbeta-transfected murine pre-B cells. The distribution of the FRbeta antigen was examined by immunohistochemical analysis using anti-FRbeta mAb and macrophage-specific anti-CD163 mAb. Anti-FRbeta mAb was chemically crosslinked with truncated PEA. FRbeta-expressing macrophages were produced by the transfection of adenovirus vector containing the FRbeta gene. Apoptotic cells were detected by staining with propidium iodide. TNFalpha was measured by enzyme-linked immunosorbent assay.


RESULTS
FRbeta-expressing cells were not present in peripheral blood leukocytes and their activated cells. In all of the tissues examined, most FRbeta-expressing cells were CD163+. The immunotoxin significantly induced the apoptosis of FRbeta-transfected macrophages and adherent RA synovial mononuclear cells and inhibited TNFalpha production by adherent RA synovial mononuclear cells.


CONCLUSIONS
We demonstrated the limited distribution of FRbeta-expressing cells in various tissues. The immunotoxin targeting FRbeta-expressing cells will provide a therapeutic tool for rheumatoid synovitis.
Nagayoshi
Ryusaku
R
Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
Nagai
Taku
T
Matsushita
Kakushi
K
Sato
Katsuaki
K
Sunahara
Nobuhiko
N
Matsuda
Takemasa
T
Nakamura
Tadashi
T
Komiya
Setsuro
S
Onda
Masanori
M
Matsuyama
Takami
T
D036002:ADP Ribose Transferases / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D001427:Bacterial Toxins / Q000276:immunology* / Q000378:metabolism; D002352:Carrier Proteins / Q000276:immunology* / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D005098:Exotoxins / Q000276:immunology* / Q000378:metabolism; D058973:Folate Receptors, GPI-Anchored; D006801:Humans; D000922:Immunotoxins / Q000276:immunology / Q000494:pharmacology*; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D011956:Receptors, Cell Surface / Q000276:immunology* / Q000378:metabolism; D013583:Synovial Membrane / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D037521:Virulence Factors / Q000276:immunology* / Q000378:metabolism; D000097668:Pseudomonas aeruginosa Exotoxin A; D000098902:CD163 Antigen
D036002:ADP Ribose Transferases; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D001427:Bacterial Toxins; D002352:Carrier Proteins; D005098:Exotoxins; D058973:Folate Receptors, GPI-Anchored; D000922:Immunotoxins; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; D000098902:CD163 Antigen