This document discusses the cells of the immune system that are involved in the host response to periodontal pathogens. It describes the main immune cells, including lymphocytes (B cells, T cells, natural killer cells), phagocytes (neutrophils, macrophages, dendritic cells), mast cells, basophils, and eosinophils. It explains the functions of these cells, such as phagocytosis, antigen presentation, and secretion of inflammatory mediators. The document also discusses innate immunity, cell-mediated immunity, and their roles in periodontal disease.

1. 1

2. PRESENTED BY :
DR. VARTIKA SRIVASTAVA
CELLS OF
IMMUNE SYSTEM
2

3. CONTENT
INTRODUCTION
CELLS OF IMMUNE SYSTEM
Lymphocytes ,B cells ,T cells , Natural killer cell
Dendritic Cells, Monocytes, Macrophages, Neutrophils, Eosinophils, Basophils , Mast Cells
TYPES OF IMMUNITY
INNATE & CELL MEDIATED IMMUNITY IN PERIODONTAL DISEASE
CLINICAL IMPLICATION OF IMMUNE RESPONSES
REFERENCES
3

4. INTRODUCTION
 The state of periodontal health or disease
depends upon the interaction between the
resident microbiota and the host response.
 Periodontal pathogens trigger both inflammatory
reaction and host immune response.
4

5. What Is Immunity
 The ability of the body to defend itself against
specific invading agents such as bacteria, toxins,
viruses, and foreign tissue is called immunity.
5

6.  The immune system plays a key role in limiting the
infections to the gingival crevice.
 The main function of the immune system is to
defend the body against a wide variety of
pathogenic infectious agents with vastly differing
natures, i.e. viruses, bacteria, fungi, protozoa and
parasitic worms.
6

7. what is the importance of immunity? 7

8.  The complexity of this task requires a
sophisticated repertoire of mechanisms for the
recognition of, and defense of the body against,
these pathogens.
 This is achieved by an array of cells and molecules
which they secrete which are dispersed through-
out the body and collectively constitute the
immune system
8

9.  Most of the major cell types of the immune
system are derived from progenitors (stem cells)
in the bone marrow.
 Many of the mature cells circulate in the
bloodstream and are dispersed throughout tissues
of the body, while some also congregate in
specialized lymphoid tissues.
9

10.  Furthermore, in order to generate effective
immunity, the various cell types cooperate with
each other by means of direct interactions
between cell surface molecules and via the
molecules that they secrete.
10

11. 11
Lymphocytes B cells T cells
Natural killer
cell
Dendritic Cells Monocytes
Macrophages Neutrophils Eosinophils
Basophils Mast Cells
CELLS OF IMMUNITY

12. 12

13. 13

14. 14

15. NEUTROPHIL
 Comprise the majority of white blood cells (60–70%).
 They are also known as polymorphonuclear leucocytes
because of their multi lobed nuclei and are larger than
most mononuclear blood cells.
 Derived from myeloid progenitors in the bone marrow,
granulocytes are released at a rate of seven million per
minute, but are short-lived (2–3 days).
15

16.  They contain azurophilic lysosomal granules which,
in addition to myeloperoxidase, lysozyme and acid
hydrolases, contain other antimicrobial proteins
(e.g. defensins and serprocidins).
 They also possess secondary specific granules
which contain the iron-binding protein lactoferrin
as well as lytic enzymes
16

17.  The main function of neutrophils is the
phagocytosis and intracellular digestion of
particulate antigens (e.g. bacteria) and to produce
reactive oxygen intermediates (ROI) with
antimicrobial potential.
17

18. 18

19.  In addition to producing classical effector
molecules, such as ROI and cytokines , neutrophils
can extrude extracellular fibrillary networks
termed neutrophil extracellular traps (NETs)
 These networks are composed mainly of DNA, but
also contain proteins from neutrophil granules
19

20.  NETs act as a mesh that traps microorganisms
and, in turn, facilitates their interaction with
neutrophil-derived effector molecules.
 NETs have been shown to trap microorganisms —
such as Escherichia coli, Staphylococcus aureus,
Shigella flexneri, Salmonella enterica subspecies
enterica serovar Typhimurium, Candida albicans
and Leishmania amazonensis and promote the
interaction of these pathogens with granule
derived proteins and their subsequent disposal
20

21. 21

22. DENDRITIC CELL
 Dendritic cells are antigen-presenting cells (APCs)
which play a critical role in the regulation of the
adaptive immune response.
 DCs were first described by Ralph Steinman
nearly forty years ago.
 He found a population of striking dendritic-shaped
cells in the spleen.
22

23.  Dendritic cells are so called because, when they
are mature, their cytoplasm extends into
transient spiny dendrites and sheet-like veils.
 This provides a large surface area for their main
function of antigen presentation to T
lymphocytes.
23

24.  All dendritic cells are derived from bone marrow
stem cells, but appear to be heterogeneous, with
various precursors (including monocytes)
differentiating into dendritic cells when stimulated
by appropriate combinations of cytokines.
 Immature dendritic cells are found in tissues
throughout the body and are very efficient at
capturing and processing antigens.
24

25.  Mature DCs are defined by key morphological features
and by the presence or absence of various molecules on
the cell surface.
 The key morphological characteristic of DCs is the
presence of numerous membrane processes that
extend out from the main cell body (similar to
dendrites on neurons).
25

26.  An additional morphological feature of DCs is that they
contain abundant intracellular structures relating to
antigen processing including endosomes, lysosomes, and
Birbeck granules of Langerhans cells of the epidermis.
26

27.  Recently, subsets of DC were recognized based on their
function in immune responses. DC1 cells, also called
myeloid DCs, express different Toll-like receptors
(TLR)-2, -3, -4, and -7.
 After encountering different natural ligands or
pathogens for these TLRs in the blood, DC1 cells
become activated and mature into antigen-presenting
cells (APC) that can secrete Th-1 or Th-2 cytokines and
prime naive T cells for a proper immune response.
27

28. 28

29. What is the function of dendritic
cells?
The function of DCs falls broadly into three categories, each
of which involve antigen presentation.
29

30. 30
• The first category of DCs function is antigen presentation
and activation of T cells.
• The second category of DC function is not as well
established, but it has been suggested that a different
class of DCs exist with the function of inducing and
maintaining immune tolerance.
• The third category of DCs, known as follicular DCs, appear
to work to maintain immune memory in tandem with B cells.

31. EOSINOPHIL
 The granulocytes whose granules stain with acidic
dyes are called eosinophils.
 They comprise 2–5% of white
blood cells and have bilobed nuclei.
31

32.  In contrast to the phagocytosis and intracellular
digestion normally displayed by neutrophils, eosinophils
secrete their granule contents for extracellular
digestion of infectious pathogens which are too large
to be engulfed.
 Eosinophils also produce cytokines, prostaglandins and
leucotrienes, and enzymes which can inhibit the
inflammatory products of mast cells
32

33.  Eosinophils have Fc receptors for IgG and IgE
antibodies and for C3b, enabling them to bind to
opsonized targets.
 They then secrete their antibiotic granule
contents (including major basic protein and
eosinophil cationic protein) and reactive oxygen
species to bring about damage to the target.
33

34. Monocytes and Macrophages
 Monocytes, which constitute 5–10% of mononuclear
leucocytes in the blood, differentiate into
macrophages when they migrate into tissues.
 Monocytes are larger than most lymphocytes and
have a kidney-shaped nucleus: they possess
azurophilic lysosomal granules containing lysozyme,
acidhydrolases and myeloperoxidase.
34

35.  The blood monocytes arise from myeloid progenitors in
the bone marrow.
 Macrophages can be resident in tissues for prolonged
periods of time where they take on various morphologies,
and are known by different names, depending on their
tissues of residence, e.g. Kupffer cells in the liver,
mesangial cells in the kidney and microglial cells in the
brain.
35

36. Macrophages also participate in the effector phase of humoral immunity. Macrophages
efficiently phagocytose and destroy microbes that are opsonized (coated) by IgG or C3b.
They are key effector cells in certain forms of cell-mediated immunity, the reaction that serves
to eliminate intracellular microbes. In this type of response, T cells activate macrophages and
enhance their ability to kill ingested microbes .
Macrophages that have phagocytosed microbes and protein antigens process the antigens and
present peptide fragments to T cells. Thus, macrophages function as APCs in T-cell activation.
The important functions of macrophage are in the induction and effector phases of adaptive
immune responses.
36

37. 37

38.  Phagocytic activity increases when there is tissue
damage and inflammation, which releases
substances that attract macrophages.
 Activated macrophages migrate more vigorously in
response to chemotactic factors and should enter
sites of inflammation.
38

39.  The activity of mononuclear phagocytes against cancer
cells in humans is less well understood than the
phagocytosis of microorganisms.
 Phagocytes are thought to suppress the growth of
spontaneously arising tumors.
39

40.  The ability of these cells to control malignant cells
may not involve phagocytosis but may be related to
secreted cellular products such as lysosomal
enzymes, oxygen metabolites, proteinases, and TNFα
 The proteolytic enzymes present on the surface
membrane of monocytes also may play a role in tumor
rejection
40

41. Basophils
 Basophilic granulocytes (basophils) derive their name
from the affinity of their cytoplasmic granules for
certain basic dyes.
 They constitute less than 1% of white blood cells.
 Basophils are of hematopoietic origin.
 Typically mature in the bone marrow and then circulate
in the peripheral blood, from where they can then be
recruited into the tissues
41

42. Basophils have a short life-span of several days.
Interleukin-3 (IL-3) promotes the production and survival of human basophils in vitro and
can induce basophili in vivo.
Mediators stored preformed in the cytoplasmic granules of basophils include chondroitin
sulphates, proteases and histamine
Chondroitin sulphates probably contribute to the storage of histamine and neutral
proteases, and basophils are the source of most of the histamine found in normal human
blood.
42

43.  A mast cell (also known as a mastocyte or a labrocyte) is a
resident granulocyte of several types of tissues that contains
many granules rich in histamine and heparin.
 The mast cell is very similar in both appearance and function to
the basophil. However, they are not the same, as they arise
from different cell lines.
 Mast cells were first described by Paul Ehrlich in 1878.
43Mast cell

44.  Two types of mast cells are recognized,
A. connective tissue mast cell
B. mucosal mast cells.
 Mast cells are present in most tissues
characteristically surrounding blood vessels and nerves,
and are especially prominent near the boundaries
between the outside world and the internal milieu, such
as the skin, mucosa of the lungs, and digestive tract, as
well as the mouth, conjunctiva, and nose.
44

45.  Mast cells and basophils may have particularly
important roles as effector cells in initiating and
or amplifying IgE-dependent inflammatory
reactions
 Both cells play an important protective role as
well, being intimately involved in wound healing and
defense against pathogens
45
Role Of Basophil And Mast Cell

46. 46

47.  Basophils appear in many specific kinds of
inflammatory reactions, particularly those that cause
allergic symptoms.
 They contain anticoagulant heparin, which prevents
blood from clotting too quickly.
 They also contain the vasodilator histamine, which
promotes blood flow to tissues.
 They can be found in unusually high numbers at sites
of ectoparasite infection.
47

48.  Basophils have protein receptors on their cell
surface that bind IgE, an immunoglobulin involved in
macroparasite defense and allergy.
 It is the bound IgE antibody that confers a
selective response of these cells to environmental
substances, for example, pollen proteins or helminth
antigens.
 Recent studies in mice suggest that basophils may
also regulate the behavior of T cells and mediate
the magnitude of the secondary immune response
48

49.  Mast cells are important in immediate
inflammation.
 It is best known for their role in allergy and
anaphylaxis.
 They possess receptors for complement
components (C3a and C5a) as well as receptors for
the Fc portion of the antibody molecules IgE and
IgG .
49

50.  The stimulation of these receptors can result in
activation and secretion of vasoactive substances
that increase vascular permeability and dilation,
two important signs of anaphylaxis
 Mast cells can synthesize, de novo, other
inflammatory mediators, such as the slow-reacting
substances of anaphylaxis (SRS- A), tumor
necrosis factor-a (TNF-a), and leukotriene C4.
50

51. 51

52. CARRANZAS Clinical Periodontology-10th Edition.
Periodontics-grant,stern,listgarten-8th Edition.
Robbins And Cotran Pathologic Basis Of Disease - 7th and 8th Edition
Guyton - Textbook Of Medical Physiology 11th Ed - 2005
Cells Of The Immune System ENCYCLOPEDIA OF LIFE SCIENCES / & 2001 Nature Publishing Group ;Ian Todd ,
University Of Nottingham, Nottingham, UK
Neutrophils In The Activation And Regulation Of Innate And Adaptive Immunity Alberto Mantovani, Marco
A. Cassatella, Claudio Costantini And Sébastien Jaillon NATURE REVIEWS IMMUNOLOGY VOLUME 11 AUGUST
2011
Mast Cells And Basophils In Acquired Immunity Jochen Wedemeyer And Stephen J Galli ; British Medical Bulletin
2000; 56 (No. 4): 936-955
Cells And Cellular Activities Of The Immune System: Granulocytes And Mononuclear Cells
52REFERENCES

53. 53

54. What Is Azurophilic Granules ?
 An azurophil is an object readily stained with an azure stain.
 Neutrophils in particular are known for containing azurophils loaded
with a wide variety of anti-microbial defensins that fuse with
phagocytic vacuoles.
 Azurophils may contain myeloperoxidase, phospholipase A2, Acid
Hydrolases, Elastase, defensins, neutral serine proteases,
bactericidal/permeability-increasing protein, lysozyme, cathepsin
G, proteinase 3, and proteoglycans.
 Azurophil granules are also known as "primary granules.
54

55. CONTENTS
Cells of immune system
Lymphocytes ,B cells ,T cells , natural killer cell
Types of immunity
Innate & cell mediated immunity in periodontal disease
Clinical implication of immune responses
Conclusion
References
55

56. LYMPHOCYTE
 Lymphocytes are 20-40% of WBC, 99% of cells in
lymph.
 Only cells of immune system exhibit specific receptor
for antigen .
 Bridge between various parts of immune system
 Small, round 5-12 m diameter spherical densely
compact nucleus occupies almost entire cell & scanty
cytoplasm.
56

57. Lymphocytes includes three types of cells.
 T-lymphocytes or T cells, which are derived from
the thymus and play a role in cell-mediated
immunity.
 B-lymphocytes or B-cells which are derived from
liver, spleen and bone marrow are the precursors
of plasma cells and play a role in humoral immunity.
 Natural killer (NK) and killer (K) cells.
57

58. Development Of
Cells
58

59. 59

60. Function Of Cells
60

61. 61

62. T Cell
 About 70% of human blood lymphocytes are T cells.
 Those cells destined to be T cell which leave the bone
marrow via the blood stream and move to the thymus.
 There the T cell become able to differentiate between self
and nonself antigens.
62

63.  The main functions of T lymphocytes are to exert
effects on other cells, either regulating the
activity of cells of the immune system or killing
cells that are infected or malignant.
 T cells have surface antigen receptors, but there
is no secreted form of these equivalent to
antibodies.
63

64.  Furthermore, T cells cannot recognize antigens in
their native forms, but only when they are
presented on the surface of antigen-presenting
cells (APCs).
 The antigen receptors of most T cells (ab T cells)
are composed of two polypeptides called a and b
chains, and they interact with peptides derived
from the degradation (processing) of foreign
antigenic proteins
64

65. The T lymphocytes are associated with two types of
immunological functions,
65
EFFECTOR REGULATORY

66.  The effector functions include activities such as
killing of virally infected cells and tumors.
 The regulatory function are represented by their
ability to amplify or suppress through cytokines or
other effector lymphocytes including B and T
cells.
66

67.  T cells receptor has two parts TCR and CD3.
 CD3 is present on all T cells .
 Presently two types of TCR are defined:TCR-1 &
TCR-2
 Both receptors are associated with a complex of
a polypeptides making up the CD3 complex.
67

68.  Thus a T cell is defined either by TCR-1 or TCR2
which is associated with CD3.
 Approximately 95% of blood T cells express TCR-
2.
 TCR-2 bearing cells can be further divided into
CD4+ T cells and CD8+ cells .
68

69. HELPER T CELLS
 Helper T cells are the major driving force and the
main regulators of the immune defense.
 Their primary task is to activate B cells and killer T
cells.
 However, the helper T cells themselves must be
activated.
69

70.  This happens when a macrophage or dendritic cell,
which has eaten an invader, travels to the nearest
lymph node to present information about the
captured pathogen.
 The phagocyte displays an antigen fragment from
the invader on its own surface, a process called
antigen presentation.
70

71.  When the receptor of a helper T cell recognizes
the antigen, the T cell is activated.
 Once activated, helper T cells start to divide and
to produce proteins that activate B and T cells as
well as other immune cells.
71

72. T-INDUCER CELLS :
 Some T cells induce other T cells to become
suppressor T cells and involve in regulation of the
immune response.
 These cells have common phenotypic
characteristics.
 Examples are Ly1a and Ly2 cells in mice.
72

73. T-suppressor cells
Suppressor effector T cells bind antigen and
release factor that inactivate T-helper cells.
 T-suppressor cells can:
 Suppress delayed –type hypersensitivity
reactions,
 Prevent proliferation and antibody secretion by
antigen-binding B cells,
 Suppress antibody secretion by some types of B
cells.
73

74. T-CYTOTOXIC CELLS :
 These cells recognize certain histocompatibility
antigens and are capable of killing foreign cells
(i.e., virus) and altered self-cells (i.e. tumor
antigens).
 T-cytotoxic cells are important in the
cytotoxicity of graft reactions and graft-versus-
host reactions.
74

75.  Cytolysis requires direct contact between the T-
cytotoxic cell and the target cell, occurs as a
result of antigen specific receptors on the T-cells.
75

76. T-CONTRASUPPRESSOR CELLS
 These cells present the inactivation of T-helper
and T-inducer cells by the action of suppressor
effector T-cells.
 They are antigen specific and may be important in
immunologic memory.
76

77. B cells
 B lymphocytes represents 3 to 15% of circulating
lymphoid cells and are primarily defined by
surface immunoglobulins (Ig).
 The B lymphocytes are common in areas of
antibody production, such as the germinal centers
of the lymph nodes and diffuse lymphoid tissue of
mucosal systems.
77

78.  The main function of a B cell is to secrete soluble
recognition molecules called antibodies which
specifically bind to an antigen recognized by that
B cell.
 Throughout the life, bone marrow remains the
major repository of stem cells for B lymphocytes.
78

79. A B cell will only produce antibodies when it has
been activated by binding antigen; this activation
process also usually requires help from T cells. The
activated B cell undergoes multiple divisions and
some of the resulting cells differentiate into
antibody-secreting cells.
These are known as plasma cells, and they possess
copious rough endoplasmic reticulum involved in
antibody synthesis.
79

80.  An important aspect of antigen recognition by B
cells is that these lymphocytes, and the
antibodies they produce, bind to antigens in their
natural or native form, i.e. as they occur as
constituents of pathogens
80

81. 81

82. Natural Killer Cells
 Natural killer (NK) cells constitute up to 15% of human
blood lymphocytes.
 Together with δ T cells and about 50% of CD8+ T cells
they are known as large granular lymphocytes because,
compared with most T and B lymphocytes, they have
more cytoplasm and contain prominent granules.
82

83.  In contrast to all T and B cells, NK cells do not
express antigen-specific receptors and do not
possess the adaptive property of memory cell
development; they are therefore considered to
form part of the innate immune system.
 Their main function is to kill infected cells and
tumor cells by inducing apoptosis of their targets.
83

84. 84

85.  Since they lack antigen receptors, NK cells do not
recognize specific antigens on the surface of a
target cell.
 Instead, they detect molecular changes in the
surface of a cell which are indicative of that cell
being abnormal and therefore a potential threat to
the body.
 They kill cells with reduced expression of MHC
class I molecules, as can result from viral infection
or malignant transformation.
85

86.  NK cells express surface ligands for MHC class I
known as killer inhibitory receptors (KIRs)
because their binding to MHC class I on the
surface of a potential target cell inhibits the
cytotoxic activity of the NK cell.
 This prevents NK cells from killing normal tissue
cells with normal levels of MHC class I expression
86

87. 87

88. 88

89. TYPES OF IMMUNITY
Natural / Innate
Immunity
Acquired /
Adaptive
Immunity
89

90. 90

91. Acquired Or Adaptive Immunity
 Specific
 Resistance that an individual acquires during his
life time
 May be weak / absent on first exposure
 Increases with subsequent exposures to same
specific pathogen
91

92. Acquired immunities are of two types:
92
ACTIVE PASSIVE

93.  Active immunity is the resistance developed by an
individual as a result of an antigenic stimulus.
 Involves the synthesis of antibodies and/or the
production of immunologically active cells.
93

94.  Passive immunity is the resistance that is
transmitted to a recipient in a readymade form as
passive immunity.
 Preformed antibodies are administered
94

95. 95
There are two types of effecter mechanisms that
mediate specific immune response:
• Immune responses are those mediated by a cell
product of the lymphoid tissues referred to as
antibody.
• Associated with the fluid phase of blood (plasma
or serum.
Humoral Immunity
• Immune reactions reside in cells of the lymphoid
system,
• Are mediated by specifically sensitized
lymphocytes themselves
Cell Mediated
Immunity

96. 96

97. NATURAL OR INNATE
(NON SPECIFIC)
 First line of defense against invasion by microbes.
 Inborn resistance .
 First time a pathogen is encountered.
 Does not require prior exposure .
 Not modified significantly by repeated exposures.
 Eg: phagocytosis by leukocytes, natural killer cells,
tissue secretion and complement.
97

98. Mechanism involved in innate immunity are :
Epithelial surfaces :
 Intact skin and mucous membrane
 Protection against invasion by microorganism.
Eg: mucosa of respiratory tract, mucopolysaccharides capable
of neutralizing the bacterial products.
 The mouth is constantly bathed in saliva, contain antibodies, iga,
t-helper and suppressor cell, macrophages.
98

99. Antibacterial substance in blood and tissues :
 The complement system possess bactericidal activity .
 Destroys pathogenic bacteria invading the blood and tissues.
 Substances possessing antibacterial property include:
a) Beta lysine – active against anthrax, and related bacteria
b) Basic polypeptides such leukins.
c) Acidic substances such as lactic acid found in muscle tissue,
has anti bacterial action.
99

100. Cellular factor in innate immunity :
Inflammation :
 Tissue injury and irritation by the entry of
pathogens or other irritation
 Causes inflammation, which is an important non-
specific mechanism of defence.
 Help in the initial defense.
100

101. 101

102. Fever :
 Rise in temperature following infection is a natural
defense mechanism.
 Help not merely to accelerate physiological
processes but many in some cases.
 Actually destroy the infecting pathogens.
102

103. Acute phase proteins :
 Infection or injury leads to a sudden increase in plasma
concentration of certain proteins, collectively called acute
phase proteins.
 Include c-reactive protein, mannose binding protein, alpha 1-
acid glycoprotein, serum amyloid p component and many
others.
 Believed to enhance host resistance,
 Prevent tissue injury .
 Promote repair of inflammatory lesions.
103

104. Innate Mechanisms Of Defence Against Periodontal Disease
Salivary secretions are protective
Exerts a major influences on plaque
Mechanically cleanse the exposed oral surfaces
By buffering acids produced by bacteria
By controlling bacterial activity
104

105. Morphology And Physiology Of The Dento-gingival Region Contributing To
Gingival Defense :
 High turnover rate of the junctional epithelium.
 The constant renewal of these epithelial cells.
 The ability of junction epithelium to produce
attachment to the tooth - counteract subgingival
plaque growth.
105

106.  Intercellular material, by the epithelial cells may
prevent the penetration of bacteria into the
epithelium.
 The loose arrangement of the junctional epithelial
cells, facilitates the transport of phagocytic cells
and antimicrobial substances from the vascular
system into this region.
106

107.  In 1971 Lange and Schroeder demonstrated that
the epithelial cells in the base region of the sulcus
contain lysosomes and cells also showed
phagocytic activity toward bacteria.
 Epidermal cell, mainly keratinocytes, to a lesser
extent melanocytes and Langerhan cells, release a
variety of regulatory proteins (cytokines) which
may assist local defense by recruitment and
enhancement of phagocyte functions. (E.g- IL-3,
TGF-alfa and beta, TNF-alpha etc.,)
107

108. Functions Of Innate Immune Mechanisms In Periodontal Diseases
 Various factors and cells make up the innate
immune system.
 Include complement, acute-phase proteins, and
interferons.
 The complement system appears to be down-
regulated in patients with periodontal diseases.
108

109.  The decrease in complement function results from
both bacterial and host actions and may increase the
susceptibility of the host to periodontal disease.
 Neutrophils have a primary role in the
immunopathogenesis of at least some forms of
periodontal disease.
 The basic paradigm shift is that in some cases, PMNs
do not exhibit a decrease in function, but rather they
become hyperactive and are primed for actions that
result in tissue breakdown. ease.
109

110. Functions Of Adaptive Immunity In
Periodontal Diseases
 T lymphocytes, B lymphocytes/plasma cells, and
macrophages.
 The mechanisms of innate and adaptive immunity are
extensive, overlapping, and redundant.
 If the functions of innate immunity, do not abate the
initial infection, an inflammatory infiltrate becomes
localized to the connective tissue of the affected area.
110

111.  This infiltrate is composed mainly of lymphocytes and
macrophages, with some neutrophils, and reflects an
adaptive immune response.
 Lymphocytes, macrophages, and other immune cells
produce cytokines that drive the immune response to
clear the infection.
 The early inflammatory infiltrate is dominated by
lymphocytes; Predominantly, T cells.
 T cells have two basic subpopulations: CD4 or helper T
cells, and CD8, which are suppressor/cytotoxic T cells.
111

112.  B cells predominates at the expense of T cells when
gingivitis progresses to a periodontitis.
 There is a decreased CD4/CD8 ratio
 And an increase in memory T cells.
 B cells mature and differentiate into plasma cells,
which ultimately produce antibodies
112

113.  Antibody titers and disease severity commonly
express a positive relationship – that is, patients
with higher titers have severe disease, especially
in patients with chronic periodontitis or localized
aggressive periodontitis.
 Antibody titers decrease after resolution of
periodontal disease
113

114. Immune Responses As Markers Of Susceptibility Of Periodontal
Diseases
 IgG3 and IgG1 to A. actinomycetemcomitans were
significantly elevated in localized juvenile
periodontitis and rapidly progressive periodontitis
patients, while IgG2 was similar among the disease
groups.
 Only the rapidly progressive periodontitis
patients had IgG4 to A. actinomycetemcomitans.
114

115.  Rapidly progressive periodontitis and adult
periodontitis patient had elevated IgG2, IgG1 and
IgG4 to P. gingivalis.
 Patients with rapidly progressive periodontitis had
elevated IgG1 to P. intermedia.
 IgG2 was the primary response to C. rectus in the
localized juvenile periodontitis and adult
periodontitis.
115

116.  Serum IgG2 levels were elevated in localized
juvenile periodontitis patients compared with
healthy controls.
 The IgG2 antibody levels to A. actinomycetem
comitans were similar among adult periodontitis
and generalized juvenile periodontitis patients and
healthy controls.
116

117. CONCLUSION
 Pathogenesis of periodontal destruction involves a complex
interplay between bacterial pathogens and the host tissues.
 In order to generate effective immunity, the various cell types
cooperate with each other by means of direct interactions
between cell surface molecules and via the molecules that they
secrete.
 Recent investigation have revealed that not all strains of a
specific microbial species are equal in their capacity to cause
disease, and not all host are equal in their susceptibility to
diseases.
 The challenge for future is to be able to better identify the
more virulent bacterial strain and the more susceptible host.
117

118. 118

119. CARRANZAS Clinical Periodontology-10th Edition.
Periodontics-grant,stern,listgarten-8th Edition.
Robbins And Cotran Pathologic Basis Of Disease - 7th and 8th Edition
Guyton - Textbook Of Medical Physiology 11th Ed - 2005
Cells Of The Immune System ENCYCLOPEDIA OF LIFE SCIENCES / & 2001 ;Ian Todd ,
University Of Nottingham, Nottingham, UK
Neutrophils In The Activation And Regulation Of Innate And Adaptive Immunity Alberto
Mantovani, Marco A. Cassatella, NATURE REVIEWS IMMUNOLOGY VOLUME 11 AUGUST 2011
Mast Cells And Basophils In Acquired Immunity Jochen Wedemeyer And Stephen J Galli ; British
Medical Bulletin 2000; 56 (No. 4): 936-955
Cells And Cellular Activities Of The Immune System: Granulocytes And Mononuclear Cells
Molecular Biology of the Cell. 4th edition.
119
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