24. Passive immunoglobulin Y immunotherapy targeting oral diseases

Abstract

Dental caries and periodontal disease have a bacterial component in their etiology. Chicken egg yolk immunoglobulin Y (IgY) antibodies directed Streptococcus mutans, Porphoromonas gingivalis or Fusobacterium nucleatum have been investigated for their ability to intercept or modulate the infectious component of these diseases. IgY antibody was prepared to S. mutans adhesins, glucosyltransferase (Gtf) or glucan binding protein B, components associated with adhesion or accumulation of S. mutans. Dietary administration of these IgY reagents in experimental rodent models for dental caries has shown reductions in dental caries, even when IgY was added to the diet only in the first phase of infection. In short-term clinical trial delivery of lozenges containing IgY antibody to cell-associated Gtf was associated with reduced colonization of potentially cariogenic S. mutans. IgY antibody was also prepared to whole cells or virulence components of two putative periodontal pathogens, P. gingivalis and F. nucleatum. IgY antibody to P. gingivalis hemagglutinin A or outer membrane protein interfered with hemagglutinating activity of P. gingivalis vesicles or coaggregation of P. gingivalis with S. gordonii, respectively. Two clinical trials using IgY antibody to P. gingivalis gingipains suggested that direct application of this antibody to the periodontal pocket or periodic oral administration in tablets could improve periodontal health and reduce numbers of P. gingivalis. Passive antibody therapy might also be useful in humans in whom the anti-bacterial properties of their saliva has been compromised by autoimmune or radiation-induced ablation of salivary flow. Challenges for use of IgY as an immunotherapeutic for these oral diseases are the timing of application, appropriate delivery vehicle and likelihood that more than one microorganism may contribute to the pathogenic effects observed.