Properties of practical oral liposome‐Streptococcus mutans glucosyltransferase vaccines for effective induction of caries protection

Abstract

Here we report the effectiveness of various liposome vaccines containing Streptococcus mutans glucosyltransferase (GTF) in protecting against dental caries after oral immunization. Rats were immunized by gastric intubation of the appropriate liposome vaccine at weaning and boosted 3 times. Rats were infected with S. mutans following initial immunization and fed cariogenic diet (Diet 305). Saliva and serum were collected during the study and assessed for antibody activity by enzyme-linked immunosorbent assay. Mandibles were removed on day 47 and assessed for S. mutans levels and then for caries. Animals immunized with sonicated, filtered and microemulsified GTF liposome preparations had decreased levels of dental caries compared with control animals given empty liposomes. Rats given dehydrated/rehydrated or purified liposomal GTF also had significantly less caries than control group (GTF alone). Because of economy, ease of preparation and efficiency in amount of antigen used, filtered, dehydrated/ rehydrated and purified liposomal GTF preparations are most practical for use in further assessing the efficacy of liposomal GTF in oral immunization.

Dental Caries Vaccines: Prospects and Concerns

“…Liposomes are thought to improve mucosal immune responses by facilitating M cell uptake and delivery of antigen to lymphoid elements of inductive tissue (Childers et al, 1990). Gastric intubation of rats with GTF-liposome vaccines induced responses which diminished dental caries caused by subsequent infection with S. mutans (Childers et al, 1996). Clinical studies comparing intranasal immunization with GTF-liposomes vs. GTF alone showed that both vaccines increased local (nasal) and salivary IgA antibody responses to GTF up to fivefold (Childers et al, 1999).…”

“…Liposomes, which are phospholipid membrane vesicles manufactured to contain and deliver drugs and antigens, have been used to enhance mucosal responses to mutans streptococcal carbohydrate (Childers et al, 1990(Childers et al, -1991 and GTF (Childers et al, 1996). Liposomes are thought to improve mucosal immune responses by facilitating M cell uptake and delivery of antigen to lymphoid elements of inductive tissue (Childers et al, 1990).…”

Adjuvant Activity of Monophosphoryl Lipid A for Nasal and Oral Immunization with Soluble or Liposome-Associated Antigen

“…An ELISA was used to determine relative concentrations of antibodies to C-GTF as previously described (11). Briefly, one-half of a polyvinyl chloride 96-well, flat-bottom microtiter plate (Dynatech Laboratories Inc., Chantilly, Va.) was coated overnight at room temperature with goat or rabbit anti-mouse IgA or IgG diluted in PBS, while the other half was coated with C-GTF (5 g/ml in borate buffer [pH 9.6]).…”

Secretory Immunity in Defense against Cariogenic Mutans Streptococci

“…Liposomal GTF has been shown to induce protective immune responses in the rat model after oral immunization Childers et al, 1996], and salivary IgA anti-GTF responses in humans after oral or i.n. immunization .…”