Passive Immunization with Milk Produced from an Immunized Cow Prevents Oral Recolonization by Streptococcus mutans

Abstract

Cell surface protein antigen (PAc) and water-insoluble glucan-synthesizing enzyme (GTF-I) produced by cariogenic Streptococcus mutans are two major factors implicated in the colonization of the human oral cavity by this bacterium. We examined the effect of bovine milk, produced after immunization with a fusion protein of functional domains of these proteins, on the recolonization of S. mutans. To prepare immune milk, a pregnant Holstein cow was immunized with the fusion protein PAcA-GB, a fusion of the saliva-binding alanine-rich region (PAcA) of PAc and the glucan-binding (GB) domain of GTF-I. After eight adult subjects received cetylpyridinium chloride (CPC) treatment, one subgroup (n ‫؍‬ 4) rinsed their mouths with immune milk and a control group (n ‫؍‬ 4) rinsed with nonimmune milk. S. mutans levels in saliva and dental plaque decreased after CPC treatment in both groups. Mouth rinsing with immune milk significantly inhibited recolonization of S. mutans in saliva and plaque. On the other hand, the numbers of S. mutans cells in saliva and plaque in the control group increased immediately after the CPC treatment and surpassed the baseline level 42 and 28 days, respectively, after the CPC treatment. The ratios of S. mutans to total streptococci in saliva and plaque in the group that received immune milk were lower than those in the control group. These results suggest that milk produced from immunized cow may be useful for controlling S. mutans in the human oral cavity.

Enhanced Immunogenicity of a Genetic Chimeric Protein Consisting of Two Virulence Antigens ofStreptococcus mutansand Protection against Infection

“…These results support the importance of inducing salivary responses that could interfere with the two different stages involved in the pathogenesis of S. mutans infection (i.e., attachment to and accumulation on tooth surfaces) in developing a vaccine against dental caries. Recent studies by others using a similar fusion protein, termed "PAcA-GB," have shown that bovine milk containing antibodies against the fusion protein was effective in controlling the recolonization of S. mutans in the oral cavity of humans (37). Furthermore, passive immunization of rats with bovine milk containing antibodies against the PAcA-GB fusion protein was shown to protect against S. mutans induced dental caries in a rat model (25).…”

The Biofilm Concept: Consequences for Future Prophylaxis of Oral Diseases?

“…There are also data to show that passive immunization in humans impedes recolonization of selected target micro-organisms in both caries (Koga et al, 2002;Smith, 2002) and periodontal disease (Booth et al, 1996). As vehicles for passive immunization, both milk from immunized cows (Shimazaki et al, 2001) and transgenic plants (Ma et al, 1998) have been tested, with encouraging results. Likewise, chimeric recombinant microbial vectors that are avirulent but which express antigens from S. mutans (Huang et al, 2001;Taubman et al, 2001) or P. gingivalis (Sharma et al, 2001) have been shown to provide protection against dental caries and alveolar bone loss, respectively, in experimental animals.…”

Microbial Dynamics and Caries: The Role of Antimicrobials

“…The vehicles for passive immunization, such as milk from immunized cows (Shimazaki et al, 2001) and transgenic plants (Ma et al, 1998), have been tested with promising results. Similarly, it was shown that recombinant chimeric microbial vectors that are non-virulent, but express antigens of S. mutans (Huang et al, 2001, Taubman et al, 2001 or P. gingivalis (Sharma et al, 2001) promoted protection against tooth decay and loss of alveolar bone in experimental animals.…”