1. The Immune system

2. The Immune system is the body’s defense system
Against:
Bacteria
Viruses
Protists
Other living invaders
Toxins
Foreign debris
Cancerous cells
The immune system is complex
Defends against threats known and unknown

3. Elements of the Immune system
Many lines of defense, for many kinds of threats
Skin
Blood
Thymus
Spleen
Lymphatic system
Mucous membranes
Bone marrow

4. Innate vs. Adaptive immunity
Innate Immunity
Adaptive Immunity
Non-specific
Defends against known invaders
Skin, lysozyme
Pre-existing
Cannot adapt to changing threats
Mechanisms which fight specific invaders
For unknown threats
Responsive
Requires time to build defense (days)
Cannot anticipate threats
Remembers previous threats

5. Humoral vs. Cell-mediated Immunity
Humoral immunity
Live cells kill invaders
Innate: Phagocytic cells (e.g. macrophages, neutrophils)
Adaptive: B lymphocytes and T lymphocytes create specific responses to unique invaders
Proteins in blood (“humors”)
Innate- complement system, clotting factors, cytokines, etc.
Adaptive: Antibodies

6. Blood is a mixture of cells and plasma
Human Blood after centrifugation
~55% Plasma
~45% Red blood cells
<1% White blood cells and platelets (“buffy coat”)

7. Blood plasma Water Nutrients Solutes- Na+, Cl-, wastes, CO2, etc.
Contains humoral immune elements
Some innate immunity

8. All blood cells are part of the hematopoetic stem cell lineage

9. Hematopoetic stem cells differentiate into all blood cells
Pluripotent- able to become any one of many cell types
Includes T cells, B cells, macrophages, etc.

10. Red blood cells carry oxygen and CO2
Lose nucleus in development
Short-lived, no repair
Packed solid with hemoglobin
Membranes designed to maximize surface area
Facilitate gas transfer

11. Hemoglobin The oxygen-carrying protein Heterotetrameric protein
2 alpha subunits, 2 beta
Each subunit holds a Heme group
Each heme holds an Fe++ ion
Each Fe++ can bind an O2

12. Hemoglobin binding curve
In areas of High O2 (e.g., lungs)- binds O2 very well (picks up O2)
In areas of Low O2 (e.g., muscles) binds O2 poorly (drops off O2)
Myoglobin binds O2 in muscle & organ tissues

13. Platelets assist with blood clotting
Recruit plasma protein fibrinogen to a cut
They release clotting factors
Clotting factors convert fibrinogen to fibrin
Fibrin net prevents blood loss

14. The liquid part of blood is called  
A) water.  
B) plasma.  
C) serum.  
D) extrastitial fluid.  
E) anionic fluid.  

15. White blood cells come in a great variety of types

16. Elements of Innate Immunity

17. Lysozyme- an innate enzymatic defense
Enzyme that cuts bacterial cell walls
Also cuts chitin, a constituent of fungal cell walls and arthropod exoskeleton
Found in mucous, tears, egg whites

18. Complement- humoral defense against non-specific invaders
A biochemical cascade
Non-specific
Signalling pathway to cause cell lysis
Also Recruitable by adaptive immune system

19. Interferons are nonspecific anti-viral signalling molecules

20. Phagocytic white blood cells devour bacteria

21. Which of the following, produced by virus-infected cells, diffuses to neighboring cells to help them fight a viral infection?
A) lysozyme
B) interferon
C) histamine
D) antigen
E) interleukin-2

22. The Inflammatory response

23. Keeping the body safe comes at a cost
Inflammation implicated in heart disease, etc.
Gum inflammation linked to heart attacks

24. The lymphatic system collects lymph and houses white blood cells in nodes

25. Adaptive Immunity contains humoral and cell-mediated components

26. Adaptive Immunity is learned, and has memory

27. Antibodies- the Key component of humoral adaptive immunity
Two light chains, two heavy chains
Each contains a variable region and a constant region

29. Antigen- anything which can be bound by an antibody

30. B Cells- the source of antibodies

31. Clonal selection musters B-cell defense forces against specific antigens

32. Adaptive Immunity is learned, and has memory

33. Immune cells are the only cells with different DNA
VDJ recombination of light and heavy chains generate antibody diversity
Change is permanent
A form of Russian Roulette for the cell
Successful recombination creates a binding antibody- cell survives
Unsuccessful- cell is destroyed
Finding a good cell takes time

34. Bound antibodies are the mark of death for invaders

35. Breast milk contains maternal antibodies
Infants have no acquired immunity
Mother’s acquired immunity is transferred to the baby through nursing
Passive immunity
Is not retained by the baby

36. Vaccination gives the body active immunity
An antigen sample is given to a person
Person’s immune system mounts a response to the antigen
Antigen can be deactivated/destroyed virus particles, etc.
No waiting time for body to develop 2o immune response

37. Antibodies can be used as therapy
Some growth factors are overactive in certain cancers
Antibody binds to growth factors, or their receptors

38. Polyclonal Antibodies
From multiple B cells
Bind to different epitopes of an antigen

39. Monoclonal antibodies
Obtained from a single B cell
Bind to a single epitope
A single B cell is fused to a myeloma cell
Myeloma cells are immortal

40. Mouse antibodies can be humanized
Constant regions of mouse antibody are gradually replaced with human sequences

41. Fluorescent antibodies can be used in scientific experiments
Fluorescent molecules can be linked to antibodies
Antibodies show us where proteins exist in vivo

42. In an ELISA, Horseradish Peroxidase is linked to a 2o antibody

43. Indirect ELISA To detect the presence of an antibody
Primary Antibody
Secondary Antibody
Wash
Block
Wash
Substrate

44. Home pregnancy tests utilize antibodies

45. Antibodies are
A) amino acids.
B) lipids.
C) carbohydrates.
D) proteins.
E) nucleic acids.

46. The transfer of antibodies from breast milk to an infant is an example of __________ immunity.
A) nonspecific
B) passive
C) humoral
D) active
E) cell-mediated

47. T cells are the primary cell-mediated adaptive immune response

48. Major Histocompatibility Complex (MHC or HLA)
MHCI
Found on all cells, recognized by TC cells
MHCII
Found on B cells and Macrophages recognized by TH cells

49. When presented with antigen, Helper T cells recruit other immune cells

50. The basic function of T cells is to identify and destroy invaders in our
A) blood or lymph.
B) interstitial fluid.
C) cells.
D) immune system.
E) brain.

51. CD4 on the surface of TH cells is the site of HIV binding

53. Any known stage of the HIV life cycle is a potential point for therapy

54. Protease inhibitors prevent formation of HIV capsids

55. AZT is a nucleoside analog reverse transcriptase inhibitor
Thymine

56. Cytotoxic T cells destroy infected body cells

57. In Autoimmune disease, the immune system attacks the self

58. Allergies are immune responses to harmless antigens

59. A substance that can elicit an immune response is called a(n)
A) complement.
B) interferon.
C) histamine.
D) antibody.
E) antigen.

60. Which one of the following statements about HIV is false?
A) The genome of HIV consists of RNA.
B) HIV attacks helper T cells.
C) New HIV are produced inside helper T cells.
D) HIV is transmitted by body fluids transporting infected cells.
E) Some antibiotics have proven effective in combating the spread of AIDS.

61. Which type of immune response is always disadvantageous to a person?
A) cell-mediated
B) inflammatory
C) humoral-mediated
D) autoimmune
E) All immune responses are advantageous.