immunity and inflammation periodontics

1. Good
morning

2. Role of immune system
in inflammation
Presented by
Dr.AyeshaGuided by
Mrs. Veena A Patil
Department of
periodontia.

24. Major Histocompatibility Complex
 Clusters of genes found in all mammals
 Its products play role in discriminating
self/non-self participants in both humoral
and cell mediated immunity.
MHC act as antigen presenting structures
In human MHC is found on chromosome 6
 Referrred to as HLA complex

28.  Defensins are small cationic proteins found in
vertebrates and invertebrates.
 They are active against bacteria,fungal and
many enveloped and non-enveloped viruses.
 Cells of the immune system contains these
peptides to assist in killing phagocytised
bacteria, for example-in neutrophil granulocytes
and almost all epithelial cells.
 Most defensins function by binding to the
microbial cell membrane and once
embedded,forming pore like membrane defects
that allow efflux of essential ions and nutrients.

29.  Definition : series of heat-labile serum proteins
 Site : serum and all tissue fluids except
urine and CSF
 Synthesis : in liver – appear in fetal circulation
 Function : Responsible for certain aspects of
immune response and
inflammatory response
 Activation : antigen-antibody complex or
endotoxin, capsule
series of proteins activated
sequentially
 Inactivation: inhibitors in plasma (short lived)
 Biological effects: either beneficial or harmful to
host

31. A) Classical pathway:
- Complement is activated by antigen –antibody
complex (IgM or IgG)
- Fc portion of the antibody form a binding site
for C1q
- The numerical sequence of the complement
factors in the classic pathway is:
C1q,r,s , C4, C2, C3, C5, C6, C7, C8, C9

34.  This pathway is initiated by:
 Bacterial endotoxin, polysaccharide capsule,
aggregates of IgE
and properdin.
 It starts at C3 then C5, C6, C7, C8, C9.
 The complement components C1, C4, C2 are
by-passed
 Antibodies are not required to initiate
activation of this
pathway.
 This pathway provides a means of non-specific
resistance

35. Classic Pathway Alternative pathway
Specific acquired immunity Non-specific innate immunity
Initiated by antibody Bacterial endotoxin, capsule
Interaction of all components C1, C4, C2 are by-passed
Properdin system not involved Properdin system is involved

36. Beneficial effects:
1) Cytolysis:
- activated complement proteins
polymerize on cell surfaces of bacteria or
erythrocyte to form pores in its membrane
(killing by osmotic lysis).

37. 2) Opsonization:
- Binding of complement proteins
opsonin (C3b)
to surfaces of foreign organisms or
particles
- Phagocytic cells express specific
receptors for
opsonins, so promote phagocytosis

39. Inflammatory response :
Small fragments released during complement
activation have several inflammatory actions:
a) C5a is chemotactic and attract neutrophiles and
macrophages
b) C5a activate phagocytes and neutrophils
C) C3,C4 and C5 are anaphylatoxins
Cause degranulation of mast cells and release of
histamine and other inflammatory mediators

40. 5-Enhancement of antibody
production:
- Binding of C3b to its receptors on
activated B cells
(CR2) greatly enhances antibody
production
- Patient who are deficient in C3b produce
much less antibody than normal
individuals and
more susceptible to pyogenic infection

41. Harmful effects:
- If complement activate systematically on
a large
scale (Gm –ve bacilli)
- If activated by an autoimmune
response to host cells

44.  Directed movement of leucocyte from blood.
 Defects in trans endothelial migration results
in aggressive periodontitis.
 8 steps before the process of chemotaxis
reflects the importance of transendothelial
migration in periodontal disease.

46.  Once leucocyte enters tissue-it must be able
to locate and migrate to the site of insult..
 Leucocytes ability to sense a chemical
gradient across in cell body and migrate in
the direction of increasing concentration.
 Receptors for chemotaxisbelong to G-protein
coupled family
 To migrate leucocytes assume an asymmetric
or polarized shape rather than rounded
morphology.

47. Movements
of
phagocytic
cells
N-formyl
methionine
Chemotaxis
Ameboid
movement
LPS
endotoxin
Bacteria initiate RNA translation with
NFM. Phagocytic receptors reacts to this,
causing the cell to move toward source of
signal.LPS endotoxin in outer membrane of
gm –ve bacteria activates compliment
cascade producing chemotaxin C5a

50.  Oxidative process:
oxidation reduction potential at or above -
160mv.
Both variables suboptimal in gingival crevice.
Neutrophils can function under aerobic
condition
Non oxidative process:
Phagosome lysosome fusion phagolysome
Neutrophil contains
specific granules :for both
extracellular and intraphagolysomal
secretion.

51. Specific granules
lysozyme lactoferrin
Bactericidal bacteriostatic
Enzyme independent domain lactoferricin
Bactericidal & fungicidal
Activity.
azurophil granules------for
intraphagolysosomal secretion

66. Neutrophils provide the first line of
defense when a micro-organism enters
the junctional epithelium and then
connective tissue. A thorough
understanding of neutrophil function is
very important to understand the disease
process of periodontal disease.