1. Immune System Mr. Karns Biology
Chapter 40
Immune System
Mr. Karns
Biology

2. Color Coding Red – most important Orange – next most important
Yellow – it is o.k. to write it down
White – you likely do not need to write it down
Taking notes is about deciding what is important and deciding if you can look it up later or not

3. Infectious diseases Pathogenic (disease-causing)
Methods of transmission
Airborne droplets: chicken pox, flu, influenza
Direct contact: cold sores, Hepatitis B, C
Exchange of bodily fluids: STD’s –
HIV/AIDS, syphillis, gonorrhea
Objects Contaminated H2O: polio, cholera
Contaminated food: botulism, E. coli (some
strains only)
Vectors: Lyme disease (ticks), malaria (mosquitoes),
bubonic plague (fleas)

4. SNEEZE VIDEO
Just Watch and Enjoy 

5. Determining cause of a disease
Koch’s
Postulates

6. SCIENTIFIC METHOD - Koch’s Postulates
1. Identify pathogen every time
2. Isolate & grow
3. Infect healthy organism
4. Isolate from new host
(and grow it again if you need to)
[Note: This method doesn’t work with syphilis organisms nor viruses.]
(Viruses can’t be grown outside of a living cell, so #2 above won’t work)

7. Reservoirs of infectious organisms
Human beings
Carriers: people who contain pathogens and pass them on to others before any symptoms show in themselves.
Incubation period = time during which organisms are multiplying and before any symptoms show up.
Animals
Birds, insects, mammals
Soil
Botulism and tetanus bacteria, anthrax
(or in poorly processed canned food)

8. What do pathogens do to cause disease?
Bacteria produce toxins
Cause fever, inhibit protein production, destroy RBCs and blood vessels, cause spasms (by disrupting nervous system impulses)
Ex. tetanus toxin: causes uncontrolled muscle contractions -- eventually paralysis and death
Viruses multiply in cells, lyse (burst) some cells as they multiply and thereby injure tissues.

9. Spread of disease know these three terms
Endemic disease: low-level of infection which is constantly present in a population
Epidemic: a localized outbreak of a disease
Polio outbreak during 1950s
Pandemic: world-wide outbreak of a disease
Influenza of the early 1900s

10. How to treat infections
Antibiotic: chemical substance produced by a microorganism which can inhibit the growth and reproduction of other microorganisms.
Produced by many bacteria and fungi, sponges
Work on gram positive bacteria
Cause the cell wall to breakdown (lysis)
Nothing good available to inhibit viruses (AZT is a reverse transcriptase inhibitor used to treat HIV infections with AIDS)

11. A Potential Problem
The overuse of antibiotics kills off all the sensitive pathogens -- only the mutant resistant pathogens remain to repopulate.
Penicillin-resistant syphillis organisms (produce penicillinase)
Drug-resistant strains of tuberculosis bacteria already exist

13. Non-Specific Immunity
Skin
Inflammation
Phagocytosis (Innate Immunity)
Macrophages (1st line phagocytic defense)
Neutrophils (2nd line of phagocytic defense)
Monocytes (3rd line of phagocytic defense)

14. Nonspecific immunity Innate immunity: “inborn” immunity 1. Skin
Physical barrier
Secretions (skin, nose, lungs, etc.)
Mucus
Sweat (some enzyme lysozyme)
Tears (much enzyme lysozyme) (Alexander Flemming discovered)
Saliva (some enzyme lysozyme)
Gastric juice (HCl and other chemicals kill lots of bacteria)
the skin has a pH between 3 and 5, which is acidic enough to prevent colonization of many microbes

15. 2. Inflammation process Caused by Histamine release!
a. Reddening of area because blood vessels dilate
b. Swelling c. Pain d. Heat

16. Phagocytes
Phagocytes are white blood cells that ingest and destroy pathogens.
What are the three phagocytes?
Phagocytosis is
the process by which phagocytes ingest and destroy pathogens

17. 3. Some White blood cells are phagocytes (“eating” cells)
Microbes
MACROPHAGE
Vacuole
Lysosome
containing
enzymes
3. Some White blood cells are phagocytes (“eating” cells)
Tissue macrophages (“big eaters”)
– Neutrophils (WBC) can phagocytose bacteria
– Monocytes (large WBC which become macrophages)
– Macrophages and neutrophils die after “eating” pathogens;
along with dead tissue cells and plasma, they make pus!

18. Phagocytosis Video

19. Puncture Wound Video
Be prepared to draw a diagram of the process!

20. Lymphatic system Lymph capillaries Lymph vessels Lymph Nodes Thymus
T cells mature
Spleen
Storage of WBC & RBC
Tonsils

21. Purpose of Lymph System
Return tissue fluid (previously blood plasma) back to heart and into circulation
Tissue fluid is called lymph once it enters lymphatic vessels

22. General arrangement of capillaries and lymphatic vessels (green)

23. Lymph nodes Contain lymphocytes (WBCs) which...
Defend body against foreign substances
Filter lymph of most bacteria

24. White Blood Cells = Leukocytes
Phagocytes:
Macrophage
Neutrophil
Monocytes
Lymphocytes
T cells (Helper, Cytotoxic and Memory T-cells)
Mature in the thymus
B cells (Memory B cells and plasma cells)
RED and WHITE blood cells are produced in bone marrow

25. Specific Immunity Acquired Immunity Passive Active
Antibody Immunity (Humoral Immunity)
Cellular Immunity (for viruses, cancer cells, tumors)

26. Antibodies react with antigens and do several things

27. Antibody (humoral) Immunity
Be prepared to draw the process of humoral immunity.

28. .Helper T cells are important !

29. .Cytotoxic T cells are Killer T cells

30. Steps of Antibody Immunity
Displayed
antigens

31. Cellular Immunity for Viral Defense
Be prepared to draw the process of cellular immunity

32. Draw a diagram of the cellular immune response.
You may work in groups of three, but everyone needs to draw the diagram.

33. Cellular Immunity (Cytotoxic = Killer) Lesion = opening
Perforin = cluster of
proteins which make a
Lesion (hole).

34. Interferon Proteins Produced by virus-infected cells
Interferons are host-specific (human proteins only work for humans, etc.)
Interferon act as an “alarm” molecule to uninfected cells
Uninfected cells produce antiviral proteins which prevent viruses from entering them.
[Summary note: cells of innate (nonspecific) immune system constantly monitor tissues for foreign invaders and attempt to suppress the “invasion”.]

35. Allergy (can be specific or non-specific)
Is an exaggerated reaction to antigens
A 2nd exposure to an environmental Ag causes the typical allergic reaction
Histamines affect tissues throughout whole body similar to an inflammatory reaction.
(pollen grain)

36. 1983: HIV -- is a retrovirus (RNA virus;
1983: HIV -- is a retrovirus (RNA virus; contains reverse transcriptase to reproduce itself in a host cell)
HIV infects and kills helper T cells
Nearly all HIV carriers will have AIDS and will die from cancers or opportunistic infections.

37. HIV structure
and infection
of helper T cell

38. HIV / AIDS / Immune System
1981: rare types of pneumonia and skin cancer (Karposi’s sarcoma) noticed in San Francisco
Nonfunctioning immune systems in patients
Purple splotches common in Karposi’s sarcoma

39. HIV budding from helper T cell

40. HIV

41. End
It’s time for TEST Review

42. 1. A general type of “eating” cell is called a __________ .
phagocyte
2. A specialized type of big “eating”
cell in the immune sytesm is called
a ________ and is usually considered
to be part of nonspecific immunity.
macrophage

43. 3. AIDS is a disease of the immune system
because HIV infects and kills the
___________ cells which are important
in developing an immune response.
Helper T
4. Organ transplants procedures require
the patient’s immune system to be
suppressed before the procedure begins?
Why?
To prevent cellular immunity methods
from rejecting the donated organ.

44. Easy
questions

45. Question 1
Diseases that are constantly present in the population are called _____
A. endemic diseases
B. epidemic diseases
C. immunity diseases
D. resistant diseases

46. Question 2
Who first proved that a specific microbe caused a particular disease?
Jenner
B. Mendel
C. Darwin
D. Koch

47. Question 3
While in the lymphatic vessels, tissue fluid passes through structures called _____ that filter the fluid.
A. lymphocytes
B. lymph nodes
C. thymus glands
D. mucus traps

48. Question 4
Which of the following are part of the nonspecific defense (innate immune system) against diseases?
A. B cells
B. T cells
C. plasma cells
D. macrophages

49. Question 5
Which cells are attacked by HIV?
B cells
B. T cells
C. plasma cells
D. macrophages

50. Medium Difficulty
questions

51. Question 1
A baby is born lacking a thymus gland. What cells are missing in the child?
B cells
B. T cells
C. plasma cells
D. macrophages

52. Question 2
What is the relationship between tissue fluid and lymph?
A. Tissue fluid leaks out of blood vessels and is called lymph when it enters lymphatic vessels.
B. Tissue fluid surrounds the body cells, and lymph circulates throughout the body in the lymphatic system.
C. Lymph leaks out of the blood. It is then
called tissue fluid.
D. Tissue fluid is the liquid portion of the blood. When it leaks out of the capillaries, it is called lymph.

53. Question 3
What is the function of a booster shot?
A. Some individuals are allergic to the first
shot, so they need more than one shot.
B. The booster vaccines contain different
materials.
C. When the body is re-exposed to a disease agent, it forms more memory cells for immunity.
D. A booster shot will activate different cells of the immune system from those activated by the first vaccine.

54. Question 4
Why do patients with AIDS continually battle infectious diseases?
A. AIDS patients are infected with the HIV virus.
B. AIDS causes the production of interferon.
C. AIDS destroys the plasma cell response to infectious diseases.
D. AIDS weakens a patient's immune response to infectious diseases.

55. Question 5
Why does a vaccination give long-lasting
protection against a disease?
A. Vaccines increase the level of antibodies in the bloodstream.
B. Vaccines contain dead or weakened
disease agents.
C. Vaccines prevent the body from responding to disease agents.
D. Vaccines cause the body to create memory cells that are prepared to fight any future encounters with the disease organism.

56. Difficult
questions

57. Question 1 (analogy)
Virus-infected cells are to interferon as plasma cells are to _____
A. complement
B. lysozyme
C. antibody
D. helper T cells

58. Question 2
When a patient receives a kidney transplant, the patient's immune system is suppressed by the use of prescribed drugs. Why would this be important and necessary?
A. Without this suppression, the immune system would attack the foreign transplanted tissue.
B. The suppression will stimulate the immune
system to work more efficiently.
C. The suppression will stimulate the bone
marrow to produce more white blood cells.
D. Without the suppression, the body will
secrete too many hormones.

59. Question 3
Why might a physician recommend against taking a fever-reducing medication when you have an abnormally high temperature?
A. A high temperature activates the immune system.
B. A high temperature inhibits the growth of some disease-causing bacteria.
C. A high temperature decreases blood flow, so the disease will spread more slowly.
D. A high temperature inhibits the body's
repair.

60. Do well on your test :)
That’s all . . .

61. A bit of a review and some detail follows.
Watch carefully I will move quickly.

63. Cellular immunity, cancer, & organ transplants
Cytotoxic (Tc) cells will “lock onto” any cell which presents a “foreign” molecule
Virus-infected cells present an Ag in the midst of their own self marker molecules (new markers are made continuously)
Malignant cancer cells present unusual molecules which attract Tc cells; Tc usually keep cancer cells “in check”
Some types of cancer lose their ability to continue making self marker molecules and don’t present the unusual molecules which ordinarily attract Tc cells.
Transplanted organs may contain slightly different self markers and attract Tc cells
Immunosuppressant drugs such as cyclosporin A are used before, during, and after the transplant procedure to avoid activation of helper T cells.

64. Acquired immune response
Self components of a person’s own body
Self marker is a cluster of proteins on plasma membrane surface; cluster is a “protein fingerprint” -- unique for each person (real term = major histocompatiblity complex)
Foreign substances are nonself.
Nonself molecules are called antigens
Pollens, dust particles, animal dander, bacteria, viral proteins, etc.
Acquired immune response is a process of producing specific antibodies against specific antigens
Acquiring immunity takes time (up to 2 weeks)

65. Thymus gland Immature lymphocytes mature into T cells
Gland declines in size by adolescence

66. The Spleen Contains lymphocytes Filters and destroys bacteria
Removes old RBCs from circulation; liver converts them into bile

67. Antigen-Antibody binding is specific

68. Two kinds of acquired immunity
Antibody (humoral) immunity
Antibodies circulate in the blood (humor)
Cellular immunity
Antibodies remain attached to immune cells (lymphocytes)
Acquired immunity is SPECIFIC and occurs simultaneously with Innate or non-specific immunity.

69. B T Lymphocyte: basic cell of immune system
Made in red bone marrow from stem cells T B

70. Specific immunity Occurs simultaneously with innate immune cells
Certain white blood cells (lymphocytes) “learn” to recognize foreign substances and react specifically to them.
These cells can eventually inactivate/destroy pathogens
This takes time (from days up to 2 weeks).
Immunity which results is called acquired immunity.

71. Two categories of lymphocytes
B cells -- have only been exposed to bone marrow
T cells -- spend time in and mature in thymus gland; receive additional attributes beyond B cells
May circulate in the blood or reside in lymphoid tissues/organs

72. T cells M T T B B Plasma cells
Helper T cells interacts with Antigen-presenting macrophages or Antigen-presenting B cells M
a. Macrophage with ingested pathogen,
b. In a food vacuole,
c. Presenting pathogen
d. Helper T cell binds to macrophage self
markers; T cells become stimulated by
binding to the antigens on macrophages T
e. Activated T cells bind to B cells;
f. B cells divide rapidly into plasma cells
and memory cells B B T
Memory B Cells Clone
Plasma cells Y
Antibodies in blood and tissue fluid

73. B cells can bind antigens directly
Helper T cell releases chemical
(interleukin) which activates B cell to
divide.
Memory B Cells Clone Y
Plasma cells Y

74. From nonspecific defense to production of antibodies

75. Summary Many B cells to select from Only one kind of B cell becomes
activated by a
specific antigen
Most memory cells
last our whole life.

76. Primary/Secondary Responses

77. The complement cascade
Complement = about 20 proteins in blood
Complement proteins self-assemble to make a lesion in plasma membrane; cell lyses

78. Examples of perforin lesions
Cancer cells

80. Two types of acquired immunity
1. Passive: receive antibodies from another source -- person, animal, genetically- engineered antibodies from bacteria
Ex. Antibodies from mother -- through the placenta; through breast milk
Ex. Injection of pooled serum (from many donors) and its diversity of antibodies from donors.

81. 2. Active: antibodies obtained naturally by having an infection of a pathogen OR
Receiving a Vaccine of . . .
Dead or weakened pathogens (viruses, bacteria)
Edward Jenner (1798): use cowpox virus to vaccinate against smallpox -- cowpox protein shapes are similar enough to smallpox to give immunity
Which type of immunity is longer-lasting -- passive or active?