The document discusses various topics related to immunology including innate immunity, acquired immunity, active immunity, passive immunity, factors influencing innate immunity, a comparison of active and passive immunity, the mechanisms of innate immunity, local immunity, herd immunity, adoptive immunity, vaccines, cell-mediated immunity, and antibody-mediated immunity. It also briefly mentions severe combined immunodeficiency disorder, otherwise known as "bubble boy disease".

1. IMMUNOLOGY
Aruni Puthuppally
Asst Professor
Noorul Islam Dental College
Trivandrum

2. Immunology
s The group of cells, tissues and molecules that are
associated with the resistance to microbial
invasion is called immune system.
s The coordinated reaction of immune system
towards the microbes is known as immune
response.

3. s The immune system is made up mainly of
lymphoid organs and reticuloendothelial cells.
s The RE cells consisting of lymphocytes and
plasma cells are the key mediators of the immune
response.

4. MALT
The Organs of the Immune System

5. The Cells of the Immune System

6. s Lymphocytes originated from thymus are known
as T-lymphocytes and are responsible for Cell
Mediated Immunity (CMI).
s Lymphocytes originated from bone marrow are
known as B-lymphocytes and are responsible for
Antibody Mediated or Humoral Immunity (AMI).

7. CMI
AMI

8. Antibody Mediated Immunity
s Antibody mediated immunity (AMI) provides primary
defense against most extracellular bacterial pathogens and
their toxins.
s Abs are present in blood, lymph and mucus secretions.
s B cells are responsible for the production of Abs.
s AMI helps in defense against viruses that infect through the
RT and GIT.
s It participate in the pathogenesis of immediate type 1,2 and 3
HS and certain autoimmune diseases.

9. Cell Mediated Immunity
s CMI protects against infection by fungi, viruses
and facultative intracellular bacterial pathogens.
s CMI participate in the rejection of homograft and
GVH reaction.
s It provides immunological surveillance and
immunity against cancer.
s CMI mediates the pathogenesis of delayed type 4
HS and certain autoimmune diseases.

11. Immunity
s Host resistance against microorganisms & other substances.
s Immune response : Rxn of the body against foreign antigen.

13. Immunity
Innate
½ Acquired

14. Innate Immunity
s Inborn resistance present
s Genetic and constitutional make up
s Does not require prior exposure
s Not modified significantly by repeated exposure

15. Innate Immunity
Species Racial Individual

16. Plant Virus
X
Physiological and Biochemical Differences

17. Innate Immunity
Species Racial Individual

18. More su
sceptibl
e
for TB
X Algerian sheep

19. Innate Immunity
Species Racial Individual

20. Show similar sensitivity or resistance
Do not show such similarity

21. Factors influencing level of immunity
Factors influencing level of immunity
m es
xtre
o E
Tw

22. Components of Innate Immunity
Physical barriers Chemical barriers Biological barriers

23. Physical Barriers
1. Skin and Mucous Membranes
Form a ‘wall’ between deep tissues and pathogens.
2. “Flushing” mechanisms
a. Salivary flow  Prevents bacterial overgrowth
b. Coughing & Sneezing  Clears respiratory tract
c. Urination  Flushes the urinary tract
d. Lacrimation  Cleanses eyes
e. Ciliary action  Expels bacteria

24. Chemical Barriers
1. pH of body fluids  Inhibits growth of many pathogens
2. Lysozyme  Breaks down cell walls of bacteria
3. Interferon  Inhibits viral replication

25. Biological Barriers
1. Natural resistance  Species resistance to microbes
2. Normal flora  Competes with invaders
3. Inflammation  Localizes & destroys pathogens
4. Complement  Cell lysis and phagocytosis
5. Phagocytosis  Engulfment of pathogens

28. Mechanisms of Innate Immunity
A. Non immunological defenses
B. Immunological defenses
A B
• Antibacterial agents in blood & tissues
• Epithelial surface • Cellular factors
• Microbial antagonism • Fever
• Acute phase proteins
• Inflammation

29. Immunologic Defenses
s Antibody mediated - IgM, IgG, IgA
s Cell mediated - T lymphocytes
s Phagocytosis - Neutrophils, Macrophages
s Complement - Lysis & enhances phagocytosis

30. Acute Phase Proteins
Activate alternate pathway of complement
• C reactive protein
• Mannose binding protein
• Alpha – 1- acid glycoprotein
• Amyloid P

31. Fever
s A rise in temperature following infection is a
natural defense mechanism.
s Pathogens like Treponema pallidum will be
destructed at high temperature.
s It stimulate the production of interferon and aids
recovery from viral infections.

32. Opsonization – a process that facilitates phagocytosis by
coating antigens with opsonin (Eg. antibody and C3b)

33. Inflammation
Immunological response to tissue injury.
Non-specific defense mechanism.
Vascular changes & recruitment of neutrophils & macrophages.

34. Classic features of Inflammation
¢ Calor (Heat)
• Dolor (Pain)
• Rubor (Redness)
• Tumor (Swelling)

35.  Cells & Proteins in Inflammatory Reactions
s Cells s Specific proteins
• Phagocytes • CRP
• Monocyte- • Mannose binding protein
Macrophage • Amyloid protein
• Natural killer cell • Prostaglandins

36. Cytokines:
Biologically active proteins that are released during inflammation
During inflammation, they:
1) Affect the local microcirculation by causing vasodilation
and increased vascular permeability
2) Attract immune system cells to the site and activate cells
involved in tissue repair.

38. Chemotaxis – migration of cells in response to
concentration gradients of certain factors
Diapedesis – movement of blood cells between
endothelial cells lining blood vessels

39. Neutrophil Extravasation In Inflammation
Blood flow

41. Immunity
Innate Acquired
½

42. Acquired Immunity
s The resistance that an individual acquires during life.
s ↑ es dramatically with subsequent exposure to the same Ag.
s Immune response primarily refers to acquired immunity.

43. rison
Co mpa
Innate Immunity Acquired
Immunity
“Line of defense” “First” “Second”
Specificity General Specific
Improved response No Yes
upon re - exposure
Immunological No Yes
memory
Cells Phagocytes, NK Lymphocytes (B,T)
cells

44. Acquired
Immunity
Active Passive
Natural Artificial Natural Artificial

45. Types of Acquired immunity
s Active – Resistance developed as a result of antigenic stimulus
s Passive – Resistance that is transmitted in a readymade form

46. Active Immunity
s Induction of immunity by infection or with a vaccine is
called Active Immunity.
s Natural : By a clinical or inapparent infection.
s Artificial : By vaccines.

47. Passive Immunity
 The resistance that is transmitted to a recipient in a
readymade form.
 Here the recipient’s immune system plays no active role.
 There is no latent period, but immunity is transient.
 Non-immune individual can be made immune by
transferring serum or lymphocytes from an immune
individual.
 Serum constituents (antibodies) and lymphocytes are
involved in immunity.

48. Passive Immunity
s Natural : Mother to fetus.
s Artificial : Administration of antibodies. Ex: ATS, TIG
s Uses of passive immunity :
• Temporary protection of non-immunised patients
• For treatment of particular infection
• For suppression of active immunity, Eg: RhIg

49. Comparison of active & Passive immunity
Active Immunity Passive Immunity
Produced actively by host’s immune system Received passively,No active host participn
Induced by infection or by immunogens Readymade antibody transferred
Durable, effective protection Transient, less effective
Immunity effective only after lag period Immediate immunity
Immunological memory present No memory
Booster effect on subsequent dose Subsequent dose less effective
‘Negative phase’ may occur No negative phase
Not applicable in the immunodeficient Applicable in immunodeficient

50. Adoptive immunity
s Extract of immunologically competent lymphocytes:
Transfer factor, are injected
s Application- Lepromatous leprosy

51. Local immunity
s Achieved by administration of live vaccines
• Eg: Polio vaccine
s Secretory IgA produced locally by plasma cells
s These IgA are responsible for this

52. Herd immunity
s Refers to overall level of immunity in a community
s Relevant in controlling epidemic disease
s Eradication of communicable diseases depends on the
development of a high level of herd immunity

53. Immunology Your Skin
Your
T-cell
Pathogen
Your
WBC
Pathogen

54. Immunology Your Skin
Your
T-cell
Pathogen
Your
WBC
Pathogen

55. Granulocytes Agranulocyte Agranulocyte
T-Cells
B- Cells
NK Cells

59. Factors influencing level of immunity
Factors influencing level of immunity
m es
xtre
o E
Tw

60. Components of Innate Immunity
Physical Barriers Chemical Barriers Biological Barriers

63. Innate immunity
Acquired immunity
Active immunity
Passive immunity
Factors influencing innate immunity
Comparison – active and passive immunity
Mechanism of innate immunity

64. Local immunity
Herd immunity
Adoptive immunity
Vaccines
Cell Mediated Immunity
Antibody Mediated Immunity

65. In severe combined immunodeficiency, a person's ability to fight
infections is severely impaired. This condition has been dubbed "bubble
boy disease" and became widely known during the 1970s with the case of
David Vetter, who lived for 12 years sealed in a plastic, germfree
environment.

72. Thank you