FUNCTIONAL ROLE OF IGA ANTIBODIES TO STREPTOCOCCUS MUTAN

Project: Research project

Description

The overall objective of this proposal is to investigate the functional
aspects of naturally occurring human salivary IgA and serum IgG and IgM
antibodies in inhibiting virulence factors of Streptococcus mutans which
are important in dental caries formation. Our laboratory and others have
shown that oral immunization of humans and experimental animals with S.
mutans or pruified S. mutans antigens induces increased levels of specific
salivary IgA antibodies, reduced numbers of plaque-adherent S. mutans and
decreased numbers of carious lesions suggesting that IgA antibodies inhibit
some or all of the essential steps in S. mutans-induced cariogenicity such
as adherence, aggregation, formation of Alpha 1-3 (insoluble) and Alpha 1-6
(soluble) linked glucans or synthesis of lactic acid. Populations of
caries-resistent and caries-active subjects will be recruited and parotid
saliva and serum will be collected. The salivas and sera will be
clarified, the immunoglobulins precipitated with 50% (NH4)2SO4 and purified
by affinity chromatography and used to treat S. mutans cells and culture
supernatant enzymes (serotypes c and g) in vitro in order to determine if
the purified antibodies will inhibit S. mutans growth, adherence to glass
surfaces, aggregation, acid production from sucrose and glucose, synthesis
of insoluble and soluble glucans and/or glucosyltransferase (GTF),
fructosyltransferase (FTF), lactate dehydrogenase (LDH), phosphotransferase
(PTS), dextranase and invertase activities. Previously we have shown that
saliva and serum from rabbits and rats immunized with S. mutans whole cells
or ribosomal preparations inhibited S. mutans growth, acid production from
sucrose and glucose-PTS activity suggesting that salivary and serum
antibodies inhibit growth and production of acids by interfering with PTS
and/or other S. mutans enzyme activities. Furthermore, the levels,
specificities and isotypes of parotid salivary and serum antibodies from
caries-resistent and caries-active subjects to various S. mutans antigens
will be established using an enzyme-linked immunosorbent assay. These
studies should provide valuable information on the function of Anti-S.
mutans antibodies important in caries protection and the nature of the S.
mutans antigen(d) most relevant in inducing protective immunity.
StatusFinished
Effective start/end date12/1/848/31/03

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health

Fingerprint

Streptococcus mutans
Antibodies
Immunoglobulin A
Glucans
inulosucrase
Serum
Phosphotransferases
Dextranase
Antigens
Enzymes
Growth
Glucosyltransferases
Acids
Dental Caries
Virulence Factors
Immunoglobulin G
L-Lactate Dehydrogenase
beta-Fructofuranosidase
Glucose
Immunity

ASJC

  • Medicine(all)
  • Dentistry(all)