The defense mechanism of gingiva includes GCF, Saliva, epithelial barrier and connective tissue cells. All these protect the periodontium from bacterial invasion.

1. DEFENCE MECHANISM
OF GINGIVA
Achi joshi
MDS II

2. CONTENTS
1. INTRODUCTION
2. GINGIVAL CREVICULAR FLUID
1. Introduction
2. Formation
3. Functions
4. Method of collection
5. Amount and measurement
6. Composition
7. Clinical Significance
3. SALIVA
1. composition
2. Functions
3. Role of SALIVA in Defense of
Gingiva.
4. EPITHELIAL BARRIER
1. Epithelial BARRIER
2. Functions and features of
epithelia
3. Keratinocyte formation
4. Cell junctions
5. Langerhans CELLS
6. Junctional epithelium
5. CONNECTIVE TISSUE
connective tissue cell
1. Macrophages
2. Plasma cells
3. Mast cells
4. Lymphocytes

3. INTRODUCTION
DEFENSE
MECHANISM
OF GINGIVA
EPITHELIAL
SURFACE
SALIVA
GCF
CONNECTIVE
TISSUE

4. GINGIVAL CREVICE FLUID
GCF is an altered serum transudate found in the gingival sulcus.
Genco
• Gingival crevice fluid (GCF) is a complex mixture of substances derived
from serum, leukocytes, structural cells of the periodontium and oral
bacteria.
Uitto 2003

5. HISTORY
• GCF , its composition and possible role in oral defense mechanisms were
elucidated by the pioneering work of Waerhaug in 1950s
• Brill and Krasse – (1959) indicated that the passage of fluid from the
bloodstream through the tissues and exiting via the gingival sulcus.

6. • Löe et al. contributed to the use of GCF as an indicator of periodontal
diseases (Periodontics 1965)
• Egelberg continued to analyze GCF and focused his studies on the
dentogingival blood vessels and their permeability as they relate to GCF
flow.
• Presence and functions of proteins, especially enzymes in GCF were first
explored by Sueda, Bang and Cimasoni (1974)

7. FORMATION
• The initial investigations of GCF by Brill
and Krasse and Egelberg relate its
formation to the inflammatory
changes in the connective tissues
underlying the sulcular and junctional
epithelia.

8. • Brill and Krasse (1959) introduced filter paper into the gingival sulci of dogs
previously injected intramuscularly with fluorescein; within 3 minutes the
fluorescent material was recovered on the paper strips.
• Flow of gingival fluid increased markedly following stimulation of the gingiva
by tooth brushing , chewing, after intravenous injection of histamine or the
development of inflammation .
• This led to the conclusion that some irritation , whether chemical or
mechanical, was necessary to induce the production of GCF and that it
should therefore be considered as a pathological phenomenon.

9. PERMEABILITY OF THE JUNCTIONAL
EPITHELIUM
• Permeable to substances with a molecular weight upto 1000kD
• Albumin
• Endotoxin
• Thymidine
• Histamine
• Phenytoin

10. • Alfano (1974) –hypothesis – flow of gingival fluid might be osmotically
mediated
• Pashley (1976) developed the concept, mathematically describing fluid
flow across capillaries. The model assumes that when the production of fluid
by the capillaries exceed its uptake by the lymphatics -oedema results - and
gingival crevicular fluid leaves the area.

11. EXUDATE V/S TRANSUDATE
Mathematical model of Pashley, illustrated within the gingival
crevice. Cross-section of two capillaries and lymph vessel with
arrows showing the passage of fluid.
(a)Absence of inflammation: low vascular permeability and low
permeability of the basement membrane results in low GCF
flow and high % uptake by lymph vessels.
(b) Macromolecules of plaque result in an osmotic gradient,
increased vascular permeability and basement membrane
changes, resulting in increased passage of fluid into the
tissues and increased GCF production.

12. • GCF protein concentration suggested that inflamed gingivae had a protein
concentration similar to that of serum.
• Most proteins were significantly lower in GCF, but with a strong co-variation
between the proteins studied in the two fluids, suggesting that GCF
represents an inflammatory exudate of serum.
CURTIS 1990

13. FUNCTION
1. It washes the crevice carrying out shed epithelial cells, leukocytes and
bacterias and debris.
2. It contains plasma proteins which may influence epithelial attachment to
tooth.
3. It contains
1. Antimicrobial agents- lysozymes.
2. PMNs macrophages
3. Immunoglobulins IgG

14. METHOD OF COLLECTION
Gingival
washing
methods
Capillary tubing
or
micropipettes
Absorbent filter
paper strips

15. GINGIVAL WASHING METHODS
In this technique the gingival crevice is perfused with an isotonic solution of
fixed volume. The fluid collected then represents a dilution of crevicular
fluid and contains both cells and soluble constituents such as plasma
proteins.

16. SEMIQUANTITATIVE SKAPSKI AND
LEHNER (1976)
• Useful for studying the number and
functional state of cells and bacteria
from the crevicular fluid.
• Injection and reaspiration of a known
amount of solution into the interdental
gingival crevice, Does not permit
absolute quantitative measurements
Collection of crevicular fluid by
means of gingival washings; 10ml of
fluid (Hank’s balanced salt solution)
is ejected from a microsyringe and
re-aspirated.

17. • Proposed by Takamori(1963) and Oppenheim (1970)
• Based on use individual acrylic appliances.
• It involved the construction of a customized acrylic stent which isolated the
gingival tissues from the rest of the mouth. The tissues were then irrigated for
15min, with a saline solution, using a peristaltic pump, and the diluted GCF was
removed.

18. CAPILLARY TUBING OR
MICROPIPETTES
Capillary tubing of known
diameter is placed at the
entrance of the crevice and the
fluid migrates up the tube by
capillary action.
This technique appears to be ideal as it provides an
undiluted sample of ‘native’ GCF whose
volume can be accurately assessed.
DISADVANTAGES
1. collection time- from an individual site may
exceed 30min.
2. difficulty of removing the complete sample
from the tubing.
Sueda T, Bang J, Cimasoni 1969

19. ABSORBING PAPER STRIPS
• Used in 2 different ways
• Intracrevicular
• Brill (1962)
• End of strips inserted into the
sulcus or pocket until
minimum resistance is felt.
• Extracrevicular-
Loe and Holm Pederson
(1965)

20. EVALUATION OF THE FLUID COLLECTED
• The amount of GCF collected is extremely small.
• Measurements performed by Cimasoni showed that a strip of paper 1.5mm
wide & inserted 1mm within the gingival sulcus of a slightly inflamed gingiva
absorbs about 0.1mg of GCF in 3 min.

21. 1.Direct viewing or staining
• Under a microscope fitted with a graticule for determining the wetted area
2. Stain the strip with alcoholic solution of ninhydrin
• Stained area is measured with
• Ordinary transparent ruler
• Sliding caliper
• Calibrated magnifying glass
• Microscope with eyepiece graticule
• Photometric techniques

22. 3. Weighing the strip
• Weinstein et al (1967) inserted preweighed twisted thread into the gingival
crevice ,weighed the sample.
4. Electronic device- periotron

23. PERIOTRON
• An electronic measuring device which allows accurate determination
of the GCF volume and subsequent laboratory investigation of the
sample composition.
• It measures the affect on the electrical current flow of the wetted
paper strips.
• It has two metal ‘jaws’ which act as the plates of an electrical
condenser.

24. • If a dry strip is placed between the ‘jaws’, the capacitance is translated
via the electrical circuitry and registers ‘zero’ on the digital readout.
• A wet strip will increase the capacitance in proportion to the volume of
fluid and this can be measured as an increased value in the readout.
• The technique is rapid and has no detectable affect upon the GCF
sample.

25. MEASURES SHOWING PERIOTRON INDICES IN RESPECT TO GINGIVAL DISEASES
Periotron
Reading
Level of Gingival
Inflammation
Gingival Index
0-20 Healthy 0
21-40 Mild 1
41-80 Moderate 2
81-100 severe 3
Brochure from the
original PeriotronA 600
Loe H, Holm
Mann et al

26. COMPOSITION

27. CELLULAR ELEMENTS
• Originate from blood , host
tissue and subgingival plaque,
Bacteria from adjacent plaque
mass, desquamated epithelial
cells
• Transmigrating leukocytes
• PMN’s
• Monocytes/macrophages
• lymphocytes

28. • Bacteria with in bacterial plaque
• Microscopic observations
• Some bacteria free float in GCF
• Attached to host cells
• Some engulfed by neutrophils.
• Epithelial cells
• Shed from junctional epithelium or sulcular epithelium
Lange and Schroeder
a. From sulcular epithelium
• Extremely flattened
• Greater amounts of cytoplasmic filaments
b. From junctional epithelium
• Contain lysosome like bodies-bottom of sulcus
• Engulfed coccoid material- greater vacuolisation and karyolysis
• Turnover
• OSE 10 to 14 days
• JE 4 to 6 days

29. • Leukocytes – in 1960 Sharry and Krasse determined that 47% of cells
obtained from gingival sulcus are leukocytes
• 95- 97% neutrophils
• 1-2% lymphocytes
• 2-3% monocytes
• Numerous at the base and decrease coronally.

30. ELECTROLYTES
• Sodium
• 207-222 mEq/l
• Potassium
• Exceeds that of serum
• 69mEq/l
• Fluoride
• Other ions
• Calcium , magnesium and phosphate

31. ORGANIC COMPOUNDS1. Carbohydrates
• Glucose, hexosamine and hexuronic acid
• Glucose 3-6 times that of serum
2. Proteins
• Around 6.9g/100ml (much less than serum)
• γ,β,α1,α2 -globulins and albumin
3. Immunoglobulins – IgG, IgA, IgM
4. Other proteins
• Albumin, fibrinogen, transferrin
5. Lipids
• Phopholipids
• Sources – serum, salivary, bacterial and tissue sources

32. METABOLIC AND BACTERIAL
PRODUCTS
• Lactic acid
• Hydroxyproline – breakdown of collagen
• Prostaglandins – PgE2
• Urea
• Endotoxin
• Cytotoxic substances- hydrogen sulphide
• Antibacterial factors

33. ENZYMES
• Acid phosphatase
• Connective tissue catabolism
• Attack teichoic acid –one of the components of bacterial cell wall
• Sources – PMN’s, desquamating epithelial cells
• Alkaline phosphatase
• Sources – PMN’s
• Pyrophosphatase
• Βeta glucouronidase
• Hydrolases found in azurophilic or primary granules
• Responsible for final degradation of oligosaccharides
• Source-Macrophages , fibroblasts, endothelial cells.

34. • Lysozyme
• Hydrolyses β-1,4 – glycosidic bonds of peptidoglycans of bacterial cell wall
• Increased in areas of increased destruction
• Hyaluronidase
• Proteolytic enzymes
• Exopeptidases
• Aminopeptidase
• Endopeptidases
• Cathepsin D
• Elastase
• Collagenases
• Lactic dehydrogenase

35. GCF FLOW
• It is the process of fluid moving into and out of the gingival crevice or pocket
• Shallow pockets – 3 to 8µl/hr
• Intermediate periodontal disease - 20µl/hr
• Advanced periodontal disease- 137µl/hr
• Is an important determinant in the ecology of the periodontal pocket.
• Flushing action
• Substances put in the pocket are rapidly flushed out.
• Controlled release antibacterial therapy, compensates for the rapid removal of
substances from the sulcus
(UITTO, PERIO 2000: 2003)

36. Isolation effect
• Substances from outside do not penetrate the sulcus easily
• GCF is relatively isolated from saliva--Salivary amylase – low levels in GCF
• Concentration of IgG is 100 times that of in saliva
• Outward GCF flow inhibits retrograde salivary flow
• Salivary contents do not generally enter the pocket

37. CLINICAL SIGNIFICANCE
• Circadian periodicity
• Greater in the evening and minimal in the morning –Bissada et al (1967)
• Gingival fluid and sex hormones
• Pregnancy, menstrual cycle, puberty
• Increase in vascular permeability
• Drugs in GCF
• Drugs that are excreated through GCF- periodontal therapy.
• Tetracycline and metronidazole.

38. • Gingival fluid as a sign of subclinical inflammation
• Flow from crevice was demonstrated before clinical gingivitis was observed
• Increase in vascular permeability of the venular type vessels in the connective tissue
• Influence of mechanical stimuli
• Increase in GCF
• Periodontal therapy
• Decrease in GCF – scaling and root planing
• Increase in GCF – surgical procedures
• Result of inflammatory reaction and loss of intact epithelial barrier

39. • GCF and diabetes
• β glucouronidase – higher in diabeteics with poorer metabolic control
• β glucouronidase is a predictor of periodontal disease activity
• GCF and pregnancy
• PGE2 is increased
• PGE2 is a marker for current periodontal disease activity and decrease in birth
weight

40. SALIVA
• Saliva is clear, tasteless, odourless slightly acidic (ph6.8) viscid fluid,
consisting of secretions from the parotid, sublingual and submandibular
salivary glands and the mucous glands of the oral cavity.

41. SALIVA
WATER (99.5%) SOLIDS (0.5%)
ORGANIC (0.3%) INORGANIC (0.3%)
GAMMA-GLOBULIN CATIONS ANIONS
PTYLIN SODIUM CHLORINE
MUCIN POTASSIUM BICARBONATE
KALLIKREIN CALCIUM PHOSPHATE
BRADIKYNIN MAGNESSIUM THIOCYNATE
LYSOSOME FLUORIDE
IMMUNOGLOBULIN IgG
BLOOD GROUP ANTIGEN
NERVE GROWTH FACTOR
VIT C AND VIT K
UREAAND URIC ACID
CELLULAR COMPONENTS
COMPOSITION

42. FUNCTIONS OF SALIVA
1. Fluid flow helps to remove bacteria and food debris.
2. Bio-carbonates and phosphate buffer the bacterial acid
3. Lubrication of oral mucosa
4. Antibacterial enzymes- lysozyme
5. Antibody – IgA
6. Maintains the tooth integrity.
7. Exchange of calcium and phosphate ions- remineralization of enamel
8. Contains coagulation factors.
ELEY AND MANSON

43. ROLE OF SALIVA IN DEFENCE OF GINGIVA
• Saliva exerts a major influence on plaque initiation, maturation and metabolism.
• It also influences calculus formation, periodontal disease and caries.
• Salivary secretions are protective in nature, because they maintain the tissue in
normal Physiologic state.
• Saliva exerts major influences:
a) on plaque by mechanically cleansing the exposed oral surfaces.
B) by buffering acids produced by bacteria.
C) by controlling bacterial activity.

44. 1. Antibacterial factors
Saliva contains lysozymes, myeloperoxidase, lactoperoxidase, glucoproteins, mucins
& antibodies etc.
(a) Lysozyme:
Lysozyme is a hydrolytic enzyme that cleavage linkage beta-1, 4- glycosidic bond of
peptidoglycans of bacterial cell wall. eg. Actinobacillus actinomycetemcomitans.
(b) Lacto- peroxidase – thiocyanate:
Bactericidal to some strains of lactobacillus & streptococcus by preventing
accumulation of lysine & glutamic acids both of which are essentials for bacterial
growth. Lactoferrin also effective against actinobacillus species.

45. (c) Myeloperoxidase: enzyme released by leucocytes and is bactericidal for
actinobacillus.
(d) Glycoproteins & mucin: It forms coating layer over tissue structures & provide lubrication
& physical protection. The glycoprotein-bacteria interactions facilitate bacterial
accumulation on the exposed tooth surface. (by making acquired pellicle to which
bacteria attach)
• Other salivary glycoproteins inhibit the sorption of some bacteria to the tooth surface
and to epithelial cells of the oral mucosa.

46. 2. Salivary Antibodies:
1) Saliva IgA, IgG and IgM antibodies.
2) IgA Immunoglobulin found in Saliva.
IgA
• The predominant immunoglobulin in saliva is secretory IgA (sIgA) which is derived from
plasma cells in the salivary glands.
• Parotid gland are responsible for the majority of the IgA found in saliva (Bienenstock et
al. 1980, Nair 1986).
• sIgA -important in maintaining homeostasis in the oral cavity. It may control the oral
microbiota by reducing the adherence of bacterial cells to the oral mucosa and teeth
(Marcotte & Lavoie 1998).

47. IgG
• Salivary IgG is primarily derived from serum via GCF and is present in low
concentrations.
• Consequently, the IgG concentration in saliva should increase as inflammation of
the periodontal tissues becomes more severe and vascular permeability increases,
resulting in increased flow of GCF (Wilton et al. 1989, Shapiro et al. 1979)

48. • Proteolytic enzymes in the saliva are generated by both the host and oral
bacteria. These enzymes have been recognized as contributors to the
initiation and progression of periodontal disease.
• To combat these enzymes , saliva contains antiproteases that inhibit
cysteine proteases such as cathepsins and anti-leucoproteases that inhibit
elastase.
• Another antiprotease identified as a tissue inhibitor of matrix
metalloproteinase (TIMP) has been shown to inhibit the activity of collagen-
degrading enzymes.
ENZYMES

49. • The enzymes normally found in the saliva are derived from the salivary glands, bacteria,
leukocytes, oral tissues,and ingested substances; the major enzyme is parotid amylase.
• Certain salivary enzymes have been reported in increased concentrations in
periodontal disease; these are-
• hyaluronidase
• lipase
• ß-glucuronidase
• chondroitin sulfatase
• amino acid decarboxylases,
• catalase,peroxidase, and
• collagenase.

50. 2. Buffers & coagulation factor
• Salivary buffer bicarbonate – carbonic acid system maintains the physiologic pH of
oral cavity.
• Saliva contains coagulation factor- factor viii, ix, x, PTA & hagman factor that hasten
blood coagulation & protect wound from bacterial invasion.
3. Leukocytes:
• Leukocytes reach the Oral Cavity migrating through the Gingival Sulcus.
• Poly Morpho Nuclear Leukocytes chiefly found in Saliva mainly causes the
Phagocytosis of Bacteria.

51. • Living PMNs in saliva are referred to as orogranulocytes, and their rate of
migration into the oral cavity is termed the orogranulocytic migratory rate.
• Some investigators think that the rate of migration is correlated with the
severity of gingival inflammation and is therefore a reliable index for
assessing gingivitis.

52. INTRODUCTION
DEFENSE
MECHANISM
OF GINGIVA
EPITHELIAL
SURFACE
SALIVA
GCF
CONNECTIVE
TISSUE

53. EPITHELIUM

54. EPITHELIAL BARRIER
• When active disease is present, the
epithelial barrier function fails , results in
bacterial invasion, inflammation and
destruction of the connective tissue, with
subsequent bone loss and possible tooth
loss.
54

55. Now, it is well established that while the epithelial compartment does
provide a physical barrier to infection, it also has an active role in
innate host defence.

56. FEATURES OF EPITHELIUM
Architectural integrity
1. Cell–cell attachments
• Desmosome , Adherent
junctions, Tight junctions, Gap
junctions
• Keratin cytoskeleton
2. Cell to tooth attachment
• Basal lamina - hemidesmosome
junction
Cell types important in
defence
Keratinocyte
Langerhans cells
Melanocyte
56

57. GINGIVAL EPITHELIAL Cell types
Keratinocytes
Langerhans cell
immunity )
Melanocyte
to make & transfer pigment
Merkel cell
(sensory)
dead
alive
Nerve cell represented
by its axon

58. EPITHELIUM :BARRIER FUNCTION
1. KERATINOCYTE FORMATION
3. CELL JUNCTIONS
2. LANGERHANS CELLS
58

59. 1. Cell–cell attachments and the overall integrity of the tissue as well as
the process of differentiation (keratinization) of the tissue leading to
the toughened, mechanically resistant surface.
2. Desmosomes mediate keratinocyte cell–cell attachment, and
hemidesmosomes mediate keratinocyte–basal lamina attachment.
3. Langerhans cells within the epithelium do not have desmosomal
attachments.
4. Constant cell renewal is critical to tissue turnover and continual
differentiation. Cell migration is critical to wound healing and re-
epithelialization.
5. Antimicrobial peptides contribute to the barrier to microbial invasion
59FUNCTION

60. Keratinocyte formation
• Following cell division in the
basal layer and the resultant
birth of a new keratinocyte,
about 30 days are required for
the new cell to traverse the
epithelium to reach the stratum
corneum.
• This time interval interval is
known as the epithelial cell
turnover time .

61. They are found in oral epithelium & in smaller amounts in sulcular epithelium & are
absent from JE
They are characterized by Birbeck granules
FUNCTION
• Role in the immune reaction as antigen-presenting cells for lymphocytes.
• Langerhans cells penetrate the epithelium in response to antigenic challenge by
bacterial plaque and Act as shuttle between epithelium and regional lymph nodes.
Langerhans Cells

62. UNDER ELECTRON
MICROSCOPE
Basement
membrane
Lamina Lucida (400 Å – wide) is in
immediate contact with the
epithelial cells of the stratum
basale, to which it is connected
via hemidesmosomes, containing
proteoglycan laminin.
Lamina densa contacts the
connective tissue
compartment and is
attached firmly to it via
anchoring fibrils (1 m in
length)
EPITHELIAL–CONNECTIVE TISSUE JUNCTION

63. DESMOSOMES
• Play a decisive role in the firm attachment
of the cells to the internal basal lamina on
the tooth surface.
• Act as specific sites of signal transduction
and, thus, participate in regulation of gene
expression, cell proliferation and cell
differentiation.

64. • Desmosomes have a typical structure consisting of
two dense attachment plaques into which
tonofibrils insert and an intermediate, electron-
dense line in the extracellular compartment.
• Tonofilaments, are the morphologic expression of
the cytoskeleton of keratin proteins, radiate in
brush-like fashion from the attachment plaques
into the cytoplasm of the cells.
• The space between the cells shows cytoplasmic
projections resembling microvilli that extend into
the intercellular space and often interdigitate.

65. ZONA OCCLUDENS (TIGHT JUNCTIONS)
• Membranes of the adjoining cells
fuse and allow ions & small molecules
to pass from one cell to other.
• It is probably a typical structure in
the uppermost layer of oral gingival
epithelium, is and functions as
barrier
(Hatakeyama et al.2006JPR)

66. • FUNCTIONS:
HOLDS CELLS TOGETHER
BLOCK MOVEMENT OF INTERGRAL MEMBRANE PROTEIN

67. ZONA ADHERENS (GAP JUNCTIONS )
-
• Intercellular space narrows to 2 – 3 nm.
• Transmembrane proteins (connexin) in
adjacent cells fuse to form a channel
for movement of molecules from one
cell to another.
• THESE ARE ABLE TO OPEN AND CLOSE

68. JUNCTIONAL EPITHELIUM
• The junctional epithelium consists of a collar like band of stratified squamous
non-keratinizing epithelium.
• It is three to four layers thick in early life, but the number of layers increases with
age to 10 or even 20 layers.
• It tapers from its coronal end, which may be 10 to 29 cells wide to one or two
cells at its apical termination, located at the cementoenamel junction in healthy
tissue

70. Junctional
Epithelium
internal basal lamina
to tooth surface
(epithelial attachment)
external basal lamina.
to gingival connective
tissue –

71. JE
• The basal cells and the adjacent 1 to 2 suprabasal cell
layers are cuboidal to slightly spindle-shaped.
• All remaining cells of the suprabasal layer are flat,
oriented parallel to the tooth surface, and closely
resemble each other
• The innermost suprabasal cells (facing the tooth surface)
DAT cells
(Salonen et al., 1989).
• They form and maintain the ‘internal basal lamina’ that
faces the tooth surface.

72. JE
• Basal lamina of the junctional epithelium resembles that of endothelial and epithelial
cells in its laminin content
• It differs in its internal basal lamina, having no type IV collagen.
• Cells of the junctional epithelium are involved in the production of laminin and play
a key role in the adhesion mechanism.
• Lysosomal bodies are found in large numbers which help in bacterial eradication.
• JE have wide intercellular spaces compared to sulcular and oral epithelium

73. 76
WIDE INTERCELLULAR SPACE
MAY BE A DOUBLE ENDED SWORD
widened spaces ALLOW the
transmigration of GC fluid
and leukocytes , and thus prevent
the entry of bacteria (Hatakeyama et .al,2006)
at the same time it provides passage
for bacterial products ,into
the connective tissue

74. 77
JE : ROLE IN DEFENCE
• In contrast to most other epithelia, there is no keratinizing epithelial cell layer at
the free surface of the junctional epithelium that could function as a physical
barrier.
• Other structural and functional characteristics of the junctional epithelium must
compensate for the absence of this barrier.

75. 78
ATTACHMENT APPARATUS
• consists of hemidesmosomes at the
plasma membrane of the cells
directly attached to the tooth (DAT
cells) and a basal lamina-like
extracellular matrix, termed the
internal basal lamina, on the tooth
surface

76. 79
• DAT cell shows the structural and molecular composition of the
epithelial attachment apparatus (EAA).
• The hemidesmosomes at the plasma membrane are
associated with the α6β4 integrin that communicate with Ln-5
= laminin 5 located mainly in the internalbasal lamina,
• the extracellular domain (?) for BP180 is a collagenous protein
(perhaps type VIII), that has not yet been definitely
characterized.
• N = nucleus of a DAT cell,
• IF = cytoplasmic keratin filaments
• LL = lamina lucida,
• LD =lamina densa,
• SLL = sublamina lucida,
• IBL =internal basal lamina.
• BP =bullous pemphigoid
(PERIO 2000: 2003)
The interaction between the different components of the extracellular
matrix and the cell surface molecules linked to the intracellular
cytoskeleton is fundamental for cell adhesion, cell motility, synthetic
capacity, tissue stability, regeneration and responses to external signals
Uitto, 1991

77. TURNOVER OF JUNCTIONAL
EPITHELIAL CELLS
• Previously it was thought that only epithelial cells facing the external basal
lamina were rapidly dividing.
• Evidence indicates that a significant number of the DAT cells are, like the
basal cells along the connective tissue, capable of synthesizing DNA, which
demonstrates their mitotic activity. (Tonetti )
• DAT cells have a more important role in tissue dynamics and reparative
capacity of the junctional epithelium.

78. The mechanism of DAT cell turnover is not fully
understood. Considering the fact that the DAT cells
are able to divide and migrate, three possible
mechanisms can be proposed. These are-
1. Dividing DAT cells replace degenerating cells on the
tooth surface
2. Daughter cells enter the exfoliation pathway and
migrate coronally between the basal cells and the DAT
cells to eventually break off into the sulcus
3. Epithelial cells move/migrate in the coronal direction
along the tooth surface and are replaced by basal cells
migrating round the apical termination of the
junctional epithelium

79. 83JE:ROLE IN ANTIMICROBIAL DEFENCE
In the coronal part of the JE quick cell exfoliation
1. (A) because of rapid cell division (B) and funnelling of JE cells towards
the sulcus hinder bacterial colonization
2. .Laterally, the (external) basement membrane forms an effective
barrier against invading microbes
3. Active antimicrobial substances are produced in JE cells. These include
defensins and lysosomal enzymes
4. Epithelial cells activated by microbial substances secrete chemokines,
e.g. interleukin-8 and cytokines, e.g. interleukins -1 and -6, and tumour
necrosis factor-a that attract and activate professional defence cells,
such as lymphocytes (LC) and polymorphonuclear leukocytes (PMN).
Their secreted product, in turn, cause further activation of the
junctional epithelial cells

80. 84
IMPORTANT MOLECULES IN DEFENCE
Some important molecules secreted by JE-
• Cytokines
• Cell adhesion molecules
• Growth factors

81. 85
LOCATION & FUNCTION OF CYTOKINES
Molecular Factor Location within the Junctional
Epithelium
Suggested Functions Reference
Interleukin-8 (Il-8)
In junctional epithelial cells near the sulcus bottom
Chemotaxis; guiding PMNs toward the sulcus
bottom
Tonetti et al., 1994, 1998
Interleukin-1(Il-1)
Interleukin-6(Il-6)
Tumor necrosis
factor-(TNF-a)
In junctional epithelial
cells and macrophages in
the coronal portion of the
junctional epithelium
Pro-inflammatory
cytokines that contribute
to the innate immune
defence
Miyauchi et al., 2001

82. 86
LOCATION & FUNCTION OF C.A.M’S
Molecular Factor Location within the Junctional
Epithelium
Suggested Functions Reference
Integrins Cell membrane of junctional
epithelial cells
Mediate cell-matrix and cell-
cell interactions
Hormia et al., 1992, 2001
Del Castillo et al., 1996
Thorup et al., 1997
Gurses et al., 1999
(CEA-CAM1)
Carcino-embryonic antigen
related cell adhesion molecule
-1
Cell membranes of leukocytes
and junctional epithelial cells
Adhesion between epithelial
cells; contributes to the
guidance of PMNs through
the junctional
epithelium; participates in the
regulation of cell
proliferation, stimulation, and
co-regulation of activated T-
cells; cell receptor for certain
bacteria
Odin et al., 1988
Öbrink, 1997
Hauck et al., 1998
Kammerer et al., 1998
Singer et al., 2000
Heymann et al., 2001

83. Intercellular adhesion
molecule-1 (ICAM-1
or CD54)
Cell membrane of junctional
epithelial cells
Mediates cell-cell
interactions in inflammatory
reactions; guiding PMNs
toward the sulcus bottom
Crawford, 1992
Gao and Mackenzie, 1992
Tonetti, 1997
Tonetti et al., 1998
Lymphocyte function
antigen-3 (LFA-3)
Cell membrane of junctional
epithelial cells
Mediates cell-cell
interactions in inflammatory
reactions; controls leukocyte
migration to inflammatory
sites
Crawford, 1992
Epithelial cadherin
(E-cadherin)
Epithelial intercellular
junctions
Critical in intercellular
adhesion and thus crucial for
maintaining structural
integrity
Ye et al., 2000
Molecular Factor Location within the Junctional
Epithelium
Suggested Functions Reference

84. 88
LOCATION & FUNCTION OF GROWTH FACTORS
Molecular Factor Location within the
Junctional Epithelium
Suggested Functions Reference
Epidermal growth
factor receptor
(EGFR)
Cell membrane of
junctional epithelial
cells
Signal transduction Nordlund et
al., 1991
Epidermal growth
factor (EGF)
In junctional epithelial
cells
Mitogen that participates
in epithelial growth,
differentiation, and wound
healing
Tajima et al.,
1992

85. 89
LOCATION & FUNCTION OF PROTEASES
Molecular Factor Location within the
Junctional Epithelium
Suggested Functions Reference
Tissue plasminogen
activator (t-PA)
In junctional epithelial
cells
Serine protease that converts
plasminogen into
plasmin, which in turn
degrades extracellular matrix
proteins and activates matrix
metalloproteinases
Schmid et al., 1991
MMP-7 or
matrilysin)
In suprabasal junctional
epithelial cells
Proteolytic degradation of the
extracellular matrix
Uitto et al., 2002

86. 90
NATURAL ANTIMICROBIAL PEPTIDES AND PROTEINS
Molecular Factor Location within the Junctional
Epithelium
Suggested Functions Reference
Defensins In PMNs and gingival
crevicular fluid
PMN-produced antimicrobial substances
that
contribute In PMNs and gingival crevicular
fluid to the innate immune defense
Dale, 2002
Human-defensin-1 (hBD1)
Human-defensin-2 (hBD2)
Weak expression in junctional
epithelial cells
Epithelially produced antimicrobial
substances that contribute to innate host
defense
Dale, 2002
Cathelicidin LL-37 In junctional epithelial and
inflammatory cells
Antimicrobial and chemotactic substance
produced by both PMNs and epithelial
cells; contributes to the regulation of the
innate immune defense
Dale, 2002

87. 91
CONNECTIVE TISSUE

88. CONNECTIVE TISSUE
• If the above mechanisms fail to prevent entry of pathogen, it reaches to the
connective tissue.
• Connective tissue offers a potential paradise. The abundant extracellular material
provides all the necessary nutrients as well as an ideal warm, humid, oxygenated
environment.
• Without vigorous immunological defences within the connective tissue, any small
break in the epithelium would convert the body into an excellent bacterial culture.

89. CONNECTIVE TISSUE CELLS
1. Fixed cells ( intrinsic cells)
• Fibroblasts
• Undifferentiated mesenchymal cells
• Adipocytes
• Macrophages(histiocytes)
2. Free cells( extrinsic/wandering cells)
• Free macrophages
• Plasma cells
• Mast cells
• leucocytes

91. MACROPHAGES (HISTIOCYTES)
• Derived from blood monocytes.
• Surface of the cell is thrown into numerous folds & finger like projection.
• These folds are active in phagocytosis.in that they engulf the substances to
be phagocytosed.
• When macrophages encounter large foreign bodies they fuse to form large cells
with up to 100 nuclei. These multinucleate cells are called foreign body giant cells.
• During antigenic stimulation or inflammation the fixed macrophages withdraw their
processes & become free macrophages.

92. Function-
• Defense
• Cleanup operation
• Immune reactions

93. MAST CELLS
• Ovoid connective tissue cell with spherical nucleus.
• Involved in inflammatory reactions, allergies & hypersensitivity reaction.
• Do not produce antibodies but are dependent upon plasma cells to
produce antibodies that bind to their surface.
• Substances released by mast cells
1. Histamin
2. Eosinophil chemotactic factor of anaphylaxis
3. Heparin
4. Slow reacting substance of anaphylaxis

94. LYMPHOCYTES
• They are the smallest of the free cells in the connective tissue.
• Lymphocytes circulate through both blood and connective tissue. They
possess in their secretory product and on their cell membranes the ability to
recognize and bind to foreign substances.
• Number increases dramatically at the sites of tissue inflammation & repair.

95. 99
They appear as cells having thin rim of cytoplasm surrounding a deeply stained
heterochromatic nucleus.

96. • T-lymphocytes
• Have long life span & are involved in cell-mediated immunity.
• B-lymphocytes
• have variable life-span & are involved in the production of
antibodies.

98. 102
REFRENCES
• Nanci A.Ten cate’s Oral histology
• CARRANZA’S CLINICAL PERIODONTOLOGY-10th and 11th edition
• Structure and function of interface in health and disease:Periodontology
2000, Vol. 31, 2003, 12–31
• The Junctional Epithelium: from Health to Disease
J DENT RES 2005 84: 9 AND
J DENT RES 2003 82: 158
• Expression pattern of adhesion molecules in junctional epithelium differs
from that in other gingival epithelia J Periodont Res 2006; 41; 322–328