Effective In Vitro Clearance ofPorphyromonas gingivalisby Fcα Receptor I (CD89) on Gingival Crevicular Neutrophils

Abstract

Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P. gingivalis from disease sites. Because antibody-Fc receptor (FcR) interactions play a role in the effector functions of polymorphonuclear neutrophils (PMN), we evaluated which FcR on PMN from gingival crevicular fluid (GCF) serves as an optimal target molecule for FcR-directed immunotherapy. GCF PMN and peripheral blood (PB) PMN from adult periodontitis patients were analyzed for their immunoglobulin G (IgG) and IgA FcR (Fc␥R and Fc␣R, respectively) expression and function by studying IgG-and IgA-mediated elimination of P. gingivalis. GCF PMN exhibited higher Fc␣RI and Fc␥RI levels and lower Fc␥RIIa and Fc␥RIIIb levels than PB PMN. Functional studies revealed that GCF PMN exhibited less of a capacity to phagocytose and kill IgG1-opsonized P. gingivalis than PB PMN. IgA1-mediated phagocytosis and killing capacity was, however, comparable between GCF PMN and PB PMN. In summary, these in vitro results document that Fc␣RI represents a candidate target for FcRdirected immunotherapy for the clearance of P. gingivalis.

Salivary Enzyme Levels After Scaling and Interleukin‐1 Genotypes in Japanese Patients With Chronic Periodontitis

“…Other methods to reflect the activity of periodontal disease should be considered. We previously investigated the indicators of periodontitis activities in GCF that is in close contact with periodontal tissues 19‐21 . It is much better to determine the activity of periodontal disease using the GCF.…”

FcγRIIB gene polymorphisms in Japanese periodontitis patients

“…25 Our recent study indicated the upregulation of phagocyte FcgRI expression to be observed in periodontal lesions. 26 Furthermore, injection of intravenous gamma globulin was found to induce FcgRIIb expression, leading to inhibition of phagocytic function mediated through activating FcgR. 27 Therefore, the 232I/ T allele may alter phagocytic activity in activating FcgRbearing phagocytes in the periodontal tissue or gingival crevicular fluid.…”

The FcγRIIa polymorphism influences production of interleukin‐1 by mononuclear cells

“…Surface expression levels of FcγRIIa were analysed by flow cytometry (Kobayashi et al ., 2001). In short, purified mononuclear cells were incubated with Phycoerythrin (PE)‐conjugated anti‐CD14 monoclonal antibody (Becton Dickinson, San Jose, CA, USA) for 30 min at 4 °C.…”