title: Human monoclonal antibody inhibits Porphyromonas gingivalis hemagglutinin activity.
abstract: BACKGROUND
  Porphyromonas gingivalis has been implicated as an important pathogen in the development of chronic periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. One potential virulence factor, hemagglutinin, may mediate bacteria attachment onto and penetration into host cells, as well as agglutinate and lyse erythrocytes to intake heme, an absolute requirement for growth. We previously cloned the gene encoding the 130 kDa hemagglutinin domain (130k HMGD) and identified its functional domain. The construction of a human monoclonal antibody that is capable of inhibiting the hemagglutinating ability is significant and important toward the development of passive immunotherapy.
  
  
  METHODS
  Human lymphocytes isolated from a donor, who had high antibody titer against the recombinant 130k HMGD (r130k HMGD), were immortalized by Epstein-Barr virus, and specific antibody-producing B cells were established by panning using the r130k HMGD.
  
  
  RESULTS
  The constructed HuMAb-HMGD1, IgG subclass, recognized the r130k HMGD as well as the 43 and 49 kDa major bands in P. gingivalis cells and vesicles. The HuMAb-HMGD1 significantly inhibited hemagglutinating activity of P. gingivalis vesicles in a dose-dependent manner. Furthermore, the HuMAb-HMGD1 recognized the synthetic peptide, EGSNEFAPVQNLTGSSVG, which contains the functional domain of 130k HMGD.
  
  
  CONCLUSIONS
  The newly constructed HuMAb-HMGD1 may prove to be useful for the development of passive immunization against periodontal diseases caused by P. gingivalis infection, pending the results of fertility study in disease mode.
authors.affiliation: Department of Biochemistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Kaizuka
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Hosogi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hayakawa
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Shibata
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Abiko
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000821:virology; D001422:Bacterial Adhesion; D015153:Blotting, Western; D002908:Chronic Disease; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005822:Genetic Vectors; D006388:Hemagglutinins / Q000235:genetics / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D010518:Periodontitis / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D011994:Recombinant Proteins; D014774:Virulence
chemical_list: C117707:130k-HMGD protein, Porphyromonas gingivalis; D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D006388:Hemagglutinins; D007074:Immunoglobulin G; D011994:Recombinant Proteins