1. Branches of Microbiology Bacteriology Virology Mycology Parasitology Immunology Recombinant DNA technology

2. Vaccines & Vaccination Vaccines =are products produced from microorganisms ### when introduced into a host ### stimulate immune system ### defense against particular microbial disease

3. Immunology Is a science dealing with immunity Immunity = the body’s defense against particular pathogenic microorganism Or = the ability to wardoff disease through body defenses Susceptibility = lack of immunity

4. Immunology Immune system = is a set of mechanisms that protect an individual from infection, by recognizing, killing, & eliminating foreign pathogens or particle Antigen(Ag) = any substance that causes antibody formation (=immunogen) Antibody(Ab) = a protein produced by the body in response to an Ag & capable of combining specifically with that Ag

5. Immunology There are two types of immunity Innate immunity (non specific) = an individual genetically predetermined resistance to certain disease Adaptive immunity (specific) =immunity obtained during the life to produce specific response

6. Innate immunity Defenses that are present at birth The are always present & available to provide rapid responses to protect us against diseases First line Second line

7. Innate immunity Two components First line of defense skin & mucous membrane normal microbiota

8. Innate immunity Second line of defense phagocytosis inflammation fever Antimicrobial substances

9. Innate immunity first line of defenses Skin & mucous membranes Physical factors :: barriers to entry or processes that remove microbes from the body surface Chemical factors :: substances made by the body that inhibit microbial growth or destroy them

10. The Body’s Surfaces (from a microbe’s persepctive)

11. First line of defenses skin & mucous membrane /Physical factors  The skin is the most difficult surface to penetrate.  some microbes can penetrate mucous membranes but--------  Saliva ----- washes microbes  Respiratory tract– ciliary action remove microbes ---coughing & sneezing

12. First line of defenses skin & mucous membrane / Chemical factors Oil glands of skin ---- inhibit the growth of microbes Perspiration --- washes microbes Lysozyme (tears, nasal secretions, & perspiration) High acidity of gastric juice – inhibit microbial growth in stomach

13. First line of defenses Normal microbiota Change the environment & prevent the growth of pathogens ## competing for essential nutrients ## production of inhibitory substances that suppress the growth of potential pathogen

14. First-Line Defense

15. Second line of defenses If a microbe penetrates the first line of defense phagocytosis inflammation fever Antimicrobial substances

16. Second line of defenses Phagocytes = a cell capable of engulfing & digesting particles that are harmful to the body Phagocytosis = the ingestion of microorganisms by a cell phagocytosis

17. Second line of defenses Phagocytosis Phagocytes ==== WBC (=granulocytes, lymphocytes, monocytes) ## granulocytes (= neutrophils, basophils, eosinophils)

18. Leukocytes = White Blood Cells

19. Phagocytic Leukocytes

20. The mechanism of phagocytosis

21. Second line of defenses Phagocytosis The mechanism of phagocytosis 1– the phagocytes are attracted to microorganism 2—then adheres to microorganism ## the adherence may be facilitated by Opsonization (= coating the microorganism with serum proteins == opsonins==

22. Second line of defenses Phagocytosis 3– pseudopods of the phagocytes engulf the microorganism & enclose it in a phagocytic vesicle 4– the microorganisms are killed by lysosomal enzyme & oxidizing agent inside the phagocytes

23. Second line of defenses inflammation **** a host response to tissue damage characterized by redness, pain, heat, & swelling, & some time loss of function

24. Inflammation

26.  Inflammation gives rise to localized reddening, swelling, increased temperatures, and pain.  The function of inflammation is to localize tissue damage, localize responses, and then to restore tissue function.  The action of localized leukocytes is enhanced via the attraction of neutrophils and monocytes normally found in circulation.  Microbial materials such as LPS, flagellin (making up bacterial flagella), and even bacterial DNA serve as indicators of infection which in turn activates the production of pro-inflammatory cytokines (= immune- system activating chemicals).  In addition to the cell-to-cell interactions underlying inflammation, the inflammatory response involves localized increases in blood flow, leakage of blood vessels, and attraction of leukocytes from the blood.

27. Second line of defenses fever *** is an abnormally high temperature produced in response to a bacterial or viral infection ** fever is considered a defense against disease

28. Second line of defenses fever High body temp. ** intensifies the effect of antiviral interferon ** increases production of transferrins that decrease the iron available to microbes Also high temp. ** speeds up the body's reaction it may help body tissue repair them self's more quickly ** Ab. production have been shown to be enhanced at elevated temp.

29. Second line of defenses antimicrobial substances *** the body produce certain antimicrobial substances that lyse microorganism *** the most important of these are the protein of the & Complement system interferon

30. Interferon: An Antiviral dsRNA normally is not present in cells.

31. Complement system *** it is a group of steps which composes a large number of components = serum proteins which activated each other in a sub sequential manner) to produce a specified action destroy invading microorganism

32. complement

33. Toll-Like Receptors Including phagocyte- attracting cytokines. Danger, I’m infected! signal.

34. Complement 1. Inactive complement proteins are in constant circulation. 2. Complement proteins are activated by various mechanisms. 3. These are the consequences...

35. Adaptive immunity Obtained during the life of the individual to produce specific response **particular pathogen & antigen **it takes time in days **cell-mediated & humoral components **exposure leads to immunological memory **lymphocytes, antigen-specific receptors & antibodies

36. Adaptive immunity Cell-mediated response (immunity) Is based on T-cells (=type of lymphocytes) Humoral response (immunity) Is based on antibodies

37. Adaptive immunity Antigen (Ag) = immunogen Ags = are the foreign particles which stimulate the immune system to secrete antibodies When Ag is introduced into the host, host cell induces the formation of specific antibody & T-lymphocytes that are reactive against the Ag (bacteria, viruses, pollen grains, dust…..)

38. Adaptive immunity Immunogenicity Is the ability to induce a humoral & cell mediated immune responses

39. Adaptive immunity Antibody (Ab) Abs = are proteins present on the surface of B-cells & secreted by plasma cells circulate in the blood where they search & kill the microbes Abs reside on the serum

40. Adaptive immunity

41. each Ab molecule consists of 4 peptides chains-----2 identical heavy chains -----2 identical light chains binds with disulphide bond The first a.a of both chains are highly variable from which it binds with the Ag

42. Adaptive immunity Immunoglobulin classes 5 classes based on the structure of their heavy chain constant region IgG IgM IgA IgE IgD

43. Adaptive immunity

44. IgG == Is the most abundant class ==Has the ability to cross the placenta (= provides a major line of defense against infection for the newborn) ==complement activator ==bind on phagocyte & mediate opsonization ==neutralization of bacterial toxins

45. IgM == the first immunoglobulin class produced in a primary infection or primary response == is the first immunoglobulin to be synthesizes by the neonate

46. IgA == it is the predominant immunoglobulin class in external secretion (saliva, tears, breast milk & mucus of the bronchial, genitourinary & digestive tract) ==it protect the external surfaces of the body from microbial attack (= prevent the adherence of microorganism to the surface of mucosal cells)

47. IgE == bind to mast cells & basophiles degranulation Histamine Hay fever & asthma immediate hypersensitivity

49. hypersensitivity

50. IgD == involved with the differentiation of B-cells where it seems to be interacting with Ag

51. Adaptive immunity Active immunity =developed after Ag enter the body & the immune system responds with Abs ##### long lasting protection or Passive immunity =developed when Ab enter the body from an outside source #### short lived protection

53. Passive immunity Naturally acquired passive immunity (==immunoglobulin transferred from mother to baby to protect the fetus Or Artificially acquired passive immunity (==direct artificial injection of Ab into the host) Hepatitis Ig, serum containing antitoxin (tetanus)

55. Adaptive immunity Active immunity Naturally acquired active immunity (==follows a short time illness) ) Or Artificially acquired active immunity (==vaccination)

56. Active immunity illness vaccination

57. Active immunity ###memory cells in the lymphoid tissues are responsible for producing Ab,the cells remain active for many years & produce IgG immediately after Ag entry (=secondary immune response

62. Adaptive immunity Humoral immunity (response) Is based on antibodies Cell-mediated immunity(response ) Is based on T-cells ( = type of lymphocytes)

63. Humoral response Abs bind to the Ag & facilitate their elimination ##forming clusters ingested by phagocytes ##binding of Ab to m.o. can activate complement system lyses of m.o. ##Ab bind to toxins or viruses prevent their binding to host cell (neutralization)

65. Cell-mediated response Based on T-cells = type of lymphocytes T-cells are of 2 types T-helper & T-cytotoxic

66. Cell-mediated response When T-h interact with Ag molecule it becomes activated & begins to secrete cytokines activate B-cells Ab activate phagocytes kill activate T-c kill cells that display pathogen (virus)

68. Autoimmunity Results from a loss of self-tolerance The ability of a host to recognize & not make Abs against self

69. Immune diseases === damage to ones own organs due to action of the immune system Rheumatoid arthritis =IgG, IgM & complement deposited in joints severe pain Insulin dependent diabetes mellitus = destruction of insulin-secreting cells of the pancreas=cell-mediated autoimmune reaction

70. Immunodeficiency === the absence of an adequate immune response Congenital = inherited Or Acquired = drugs, cancers, infectious disease AIDS

71. vaccination immunization the process of conferring immunity by administering a vaccine

72. Vaccines = are preparations of killed, inactivated or attenuated m.o or toxoids to induce artificially acquired active immunity Are the safest & most effective means of controlling infectious diseases

74. The effects of vaccination The response of the body to the first contact with an Ag is called the primary response, it is characterized by the appearance of IgM followed by IgG Subsequent contact with the same Ag results in a very high Ab titer & called the secondary or memory response, the Ab is primarily IgG

76. Attenuated ( living but weakened microbes) Long life immunity Humeral & cell mediated response Reversion to virulence Inactivated (killed microbes) Short life immunity Antibody only Not reverse to virulance

77. Subunit (antigenic fragments of microbes) Subunit Recombinant vaccines a cellular vaccines disrupted bacterial cell

80. Vaccination program

81. 6y. 18-24 m 12 m 10m120d90d.60d.1m *BCG DT****DTP OPV OPV IPV IPV Polio.v ***HiB ***HBV ** Measles **MMR

82. Polio vaccines IPV =inactivated polio vaccine (killed) === injection OPV = attenuated polio vaccine == orally intestine

83. HiB = Haemophilus influenzae B == injection DTP = combination vaccines diphtheria tetanus pertusis == injection HiB + DTP === combination

84. HBV = hepatitis virus type B = HBV surface antigen == biotechnology BCG = tuberculosis == Bacillus Calmett-Guerin MMR = measles virus + mumps virus + rubella virus

85. Other vaccines Pox virus Cholera Chicken pox Influenza virus Endemic area Travelling to endemic area

86. === vaccines should not given to pregnant women === illness === immunocompromized individuals

87. Booster === to increase the power of effectiveness Booster dose=== active immunizing agent usually smaller than the initial dose given to maintain immunity

88. Final Exam Good Luck