Antigenicity and immunogenicity of a synthetic peptide derived from a glucan-binding domain of mutans streptococcal glucosyltransferase.

AUTOR(ES)

Smith, D J

RESUMO

The immunogenicity and antigenicity of a multiply antigenic peptide construct containing four copies of the synthetic peptide TGAQTIKGQKLYFKANGQQVKG were measured in rodents and humans, respectively. The composition of this peptide construct (termed GLU) was derived from a major repeating sequence in the C-terminal region of mutans streptococcal glucosyltransferases that synthesize water-insoluble glucan (GTF-I). The GLU peptide elicited high levels of serum immunoglobulin G antibody to GLU after subcutaneous injection into Sprague-Dawley rats. These antisera also reacted with intact GTF isozymes from Streptococcus sobrinus and Streptococcus mutans (by enzyme-linked immunosorbent assay [ELISA] and Western blot [immunoblot] analyses) and with an 87-kDa glucan-binding protein from S. sobrinus (by Western blot). The synthesis of filter-retained glucan by GTF-Sd of S. sobrinus could be inhibited (30%) by preincubation with anti-GLU rat serum. Splenic and lymph node lymphocytes from rats injected once with S. sobrinus GTF isozymes demonstrated significant proliferation after 5 days of culture with GLU. The GLU peptide reacted with 4 of 29 human parotid saliva samples and 5 of 29 human serum samples (by ELISA). These results suggest that the GLU peptide contains B- and T-cell epitopes that are similar to those of intact mutans streptococcal GTFs and possibly certain other glucan-binding proteins as well. Furthermore, since antibody to this epitope(s) appears to inhibit GTF function, sequences within this peptide construct may have value for inclusion in a synthetic dental caries vaccine.

Documentos Relacionados

• Immunization of rats with synthetic peptide constructs from the glucan-binding or catalytic region of mutans streptococcal glucosyltransferase protects against dental caries.
• Purification and antigenicity of a novel glucan-binding protein of Streptococcus mutans.
• Glucan-binding domain of a glucosyltransferase from Streptococcus sobrinus: isolation of a 55-kilodalton peptide from a trypsin digest of glucosyltransferase prebound to insoluble glucan.
• Immunological characteristics of a synthetic peptide associated with a catalytic domain of mutans streptococcal glucosyltransferase.
• Isolation of a glucan-binding domain of glucosyltransferase (1,6-alpha-glucan synthase) from Streptococcus sobrinus.