The trans-chromosomic mouse-derived human monoclonal antibody promotes phagocytosis of Porphyromonas gingivalis by neutrophils.
BACKGROUND
As a safe immunotherapeutic approach, human monoclonal antibody (hMAb) may be effective in clearing periodontopathic bacteria. The trans-chromosomic (TC) technology has recently been applied to construction of the TC mouse, which enables us to incorporate entire human chromosome fragments containing immunoglobulin (Ig) gene cluster. The aim of this study is to establish TC mouse-derived hMAb, and to test the in vitro opsonophagocytic activity.


METHODS
Human Ig-producing TC mouse was immunized by recombinant 40-kDa outer membrane protein (r40-kDa OMP) of Porphyromonas gingivalis 381, and the spleen cells were fused with the mouse myeloma cell line. The specificity of antir40- kDa OMP hMAb was evaluated with the enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance assays. Flow cytometric analyses were performed to assess the opsonophagocytic activity.


RESULTS
We successfully constructed 99 IgG isotype clones (IgG1: 84; IgG2: 11; IgG4: four clones), which were specifically reactive with r40-kDa OMP. The anti-r40-kDa OMP IgG1 hMAbs promoted phagocytosis of P. gingivalis by neutrophils. Futhermore, an increased opsonophagocytic activitity of anti-r40-kDa OMP IgG1 hMAbs was observed not only in P. gingivalis 381, but also in the W50, W83, and Su63 strains.


CONCLUSIONS
Our results document the TC mouse-derived hMAb to promote neutrophil phagocytosis of P. gingivalis, suggesting an immunotherapeutic option for clearance of P. gingivalis.
Takauchi
Ayano
A
Division of Periodontology, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Kobayashi
Tetsuo
T
Tahara
Tomoyuki
T
Nakazawa
Kumiko
K
Hayakawa
Mitsuo
M
Shibata
Yasuko
Y
Ishida
Isao
I
Abiko
Yoshimitsu
Y
Yoshie
Hiromasa
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology; D051379:Mice; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology*; D016966:Porphyromonas gingivalis / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G