Immunopathology of caries and host Immunity Flashcards
inflammatory innate response at mucosal surface
via phagocytes: neutrophils, macrophages & esoinophils
dental caries and periodontal diseases caused by
endogenous microbes
regulation of commensal bacteria by
sIgA
carries characterized by
- complex interactions
- microbial products
- salivary constituents
- dietary carbs on tooth
formation of biolfims
dental plaque
caries eventually lead to
loss of mineralized tooth enamel
eclogical collision
infectious microbes and a lot of sugar in diet
immune regulation of oral commensals
mi
- bacterial effects immune sytems
caries
description
microorganisms
- decay of enamel and dentin (dental caries) or root carries
- streptococcus Lactobacillus
- Actinomyces (root caries)
Gingivitis
description
microorganisms
- redness and swelling (inflammation) of gums
- Actinomyces
- Fusobacterium
- Bacteroides
- Prevotella
periodontitis
description
microorganisms
- inflammation either rapid (aggressive) of slower (chronic) destruction of tissue supporting tooth
- Aggregatibacter (rapid)
- Porphyromonas
- Treponema
- tannerlla
- fusobacterium
- prevotella
Etiologic agents of dental carries
- lactic acid bacteria
- heterogenous family of bacteria
- high pop. of S. mutans
- GTF enzyme
lactic acid
- ferminted sugar
- chelates calcium
what facilitates bacterial adherence
glucosyltransferase (GTF)
Plaque Microbiota
- streptococcus mutans sterotype C (main)
- mom to child
- gram positive coccus
other
- streptoccus sorbinus
- lactobacillus species
- actinomyces
tooth with highest microbial diversity are more
susceptible to caries
gram+
promotes gingival health
promotes gingival health
- plaque reduction
- reduced inflmammation
- low GCF flow
- gram +
three types of dental carries
enamel
dentin
roots
enamel carries
smooth surface
- S. mutans
- S. salivarius
pit+fissures
- S.mutans
- Lactobacilli
Dentin carries
- lactobacilli
- anerobic gm+ rods
Root carries
Actinomyces
S. mutans fermentation
- glucose is the most fermented
- more acid production leads to larger drop in oral pH
Sucrose metabolism for S. mutans
- glucosyltransferase (GTF) enzyme creates glucans & dextrans polymers
- generates excess lactate
- creates plaque
glucans and dextrins
- sticky gelatinous
- traps bacteria
- feed plaque microbial community
- attaches to tooth surface
surface protein antigens of S. mutans
Antibodies against SA I/II prevent colonization of
S. mutans on teeth
Polysaccharide antigens of S. mutans
- antibodies against carb antigens are protective and prevent binding of GTF to cell prohibiting caries formation
what is proposed as targets for caries vaccine antigen
GTF
immunological control of cariogenic streptococcal and dental carries
- Immunity to oral pathogens is principally mediated by sIgA in salivia
- Systemic immunity cia IgG and IgM in GCF
majority of pathogens invade via
(flu, HIV)
mucosal structures
Salivia antibodies
- majority
- IgA
- GCF
- IgG
- IgM
gingival crevice antibodies
- lymphocytes
- macrophages
- PMN
caries are associated with which antbodies
for S.mutans
increased sIgA
(reseach has not confirmed)
Development of sIgA specific to S. mutans
newborn-infant
1 year
10 years
- newborn-infant
- no Ab to S. mutans
- 1 year
- start developing Ab against S. mutans
- 10 years
- IgA levels = to an adult
correlation of sIgA or serum IgG or IgM
correlate levels of sIgA or IgG and IgM Abs to S. mutans with resistance to dental caries
Immunological host defenses in caries
- production of slgA
- not understood well
- salivary abs interact with bacterial surface proteins
- bacteria opsonize bacteria
immune response to root suface carries
complement-IgG-PMN immune activation
- IgG-complement activation via classical pathway
- C3a, C5a generation
- Inflammation-phagocyte PMN
root surface bacteria
Actinomyces , S. mutans , lactobacillus
goal for vaccination against caries
- prevention of attachment
- reduce number of pathogens
- interfere with metabolic activity
dental vaccination approaches targetins specific pathogen
S. mutans
(difficult to get sIgA to generate long term response)
problems with vaccine against carries
development of rheumatic fever, acute glomerulonephritis
vaccine identification candidate
GTF or GTB
generate sIgA or serum IgG protective
Dental caries and periodontal diseases are the resilt of an
ecological imbalance between resident microbiota and host immunoity
- what provudes host defense in the oral cavity
innate and adaptive immunity
Innate immunity is primarly imparted via
mucosal and dental barriers
soluble antimicrobial mactors in saliva and GCF make up
the first line of defense (innate immunity)
saliva flushes
mucosal and dental surfaces of the mouth
GCF flushes the
oral cavity
inflammatory innate response at the mucosal surface is rendered by phagocytes
neutrophils. macrophages, and eosinophils
what provides adaptive immunity
- sIgA in saliva
- IgG and IgM in GCF
- effector T lymphocytes
diveristy and richness of microbial communites of the tooth surface directly releate to
- caries risk
- more diverse more at risk to caries
with established caries acid environment reduces the
diversity and richness of local microbiota
plaque accumulation triggers
inflammatory host response
change in the local environment condition favoring growth of proteolytic
gram-bacteria
host dendenses in caries
not understood well
bacteria in mouth…
(steps)
- swallow bacteria
- stimulation of b cells in peyer’s patch in gut-assoicated lymphoid tissue
- gereration of plasma cells in salivary glands
production sIgA
(6 effects)
- salivary Abs interact with bacterial surface proteins
- interfere with bacterial adhesion, colonization and caries formation
- Abs opsinize bacteria
- promote phagocytosis by PMNs and macrophages
- release of chemokines and trigger inflammation
- activation of lymphocytes
vaccine against caries
- whole pathogen vaccination with S.mutans in humans does not work
S.mutans Ag is crossreactive with
- S. pyogenes Ag molecular mimicry
- can induces Abs cross reactive to human heart, joints and kidney tissues
Bad effect of vaccine against caries
- generation of auto antibodies
- induction of autoreactive T cells to myocardium , heart valves, joint, blood vessels and kidney
what is a possible type of caries vaccine ?
synthetic vaccine without epitopes shared with human Ag is a possibility
