Project: Research project

Project Details


The major objective of this grant is to determine the levels of antibodies
in saliva and serum from caries-defined and periodontal disease-defined
subjects to immunoglobulin A1 (IgA1) and IgG proteases isolated from
culture supernatants of Streptococcus sanguis and Capnocytophaga ochracea,
respectively. Naturally occurring antibodies to IgA1 protease in saliva
and serum have recently been reported; however, it is not known if there
are differences in the levels of these antibodies between various groups of
individuals. IgA1 protease cleaves a particular proline/threonine linkage
in the hinge region of the IgA1 subclass of IgA rendering it nonfunctional
and it therefore is an important virulence factor which is produced by
several different mucosal pathogens. IgG protease also cleaves the
immunoglobulin which abrogates its' functional activity, however, much less
is known about this enzyme than IgA1 protease. The purity and activity of
the IgA1 and IgG protease antigens to be used to establish antibody levels
will be determined by sodium dodecyl sulfate-polyacrylamide gel
electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA).
Salivary and serum antibody levels will be determined using SDS-PAGE and
ELISA and homogenous preparations of S. sanguis IgA1 and Capnocytophaga IgG
proteases. Caries-resistant and -susceptible and periodontal
disease-resistant and -susceptible individuals will be recruited using
strict criteria. It is anticipated that caries-resistant and periodontal
disease-resistant subjects will have higher levels of salivary and serum
antibodies, respectively, to IgA1 and IgG proteases than caries-susceptible
and periodontal disease-susceptible subjects. The higher levels of
antibodies to IgA1 and IgG proteases in resistant individuals may prevent
the enzymes from cleaving IgA1 and IgG, whereas the lower antibody levels
in susceptible subjects may not neutralize the enzymes sufficiently to
prevent them from cleaving IgA1 and IgG. The IgA1 and IgG proteases in the
oral cavities of susceptible individuals may then cleave more potentially
protective IgA and IgG antibodies and thus these subjects may be more at
risk from disease than those having higher levels of enzyme-neutralizing
antibodies. These proposed studies will significantly advance our
understanding of the action of AgA1 and IgG proteases and their
immunological properties.
Effective start/end date2/1/861/31/87


  • National Institutes of Health


  • Medicine(all)
  • Dentistry(all)

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