1. MCMP 422 Tony Hazbun RHPH 406D Hazbun@pharmacy.purdue.edu
Include MCMP 422 in the subject line

2. MCMP422 Immunology
Immunology is important personally and professionally!
Learn the language - use the glossary and index
RNR - Reading, Note taking, Reviewing
All materials in Chapters 1-5 are examinable (with exceptions) plus extra material from class

3. What and why?
Immunology: Science of how the body responds to foreign agents
Immune system: the organs, cells and molecules that defend and respond to pathogens/allergens
Organ transplantation, cancer, immunodeficiency diseases, infectious diseases

4. Pharmacy and Therapy Perspective
Immunology
How do we recognize foreign structures?
How do we recognize self vs non-self?
How do we stop and remove invading agents?
Pharmacy and Therapy Perspective
How can we use the immune system as a therapeutic agent?
How do drugs affect the immune system?

5. Chapter 1 Concepts What components make up the immune system?
Cells, organs, cytokines and other molecules involved in the immune system
What is the goal of the immune system?
To clear pathogens in our body
How do we classify immune responses?
Innate and adaptive immune responses
What are the side effects of the immune system?
Autoimmune diseases, Allergies, Transplantation Rejection

6. Machinery of the Immune system
1. Tissues/organs
bone marrow, thymus, spleen, lymph nodes
2. Cells
lymphocytes, dendritic cells, macrophages, natural killer cells, granulocytes (neutrophils, basophils, eosinophils), mast cells
Blood-borne proteins
complement and mannose-binding proteins

7. Origin of Immunology - individuals who survived a disease seemed to be untouched upon re-exposure
Vaccination/Immunization - procedure where disease is prevented by deliberate exposure to infectious agent that cannot cause disease.
Vaccinia - mild disease caused by cowpox
Edward Jenner - first demonstration of vaccination

8. Pathogen - any organism that can cause disease
Figure 1-2

9. Diversity of Pathogens
Four Classes
Bacteria
Fungi
Viruses
Parasites
Opportunistic pathogens
e.g. Pneumocystis carinii
Pathogen-Host relationship

10. How Clean are You? Part of body Bacteria Head (scalp) 1,000,000 /cm2
Surface of skin /cm2
Saliva ,000,000 /g
Nose mucus 10,000,000 /g
Faeces over 100,000,000 /g

11. Defenses against Pathogens
Physical Defenses
1. Skin
- Tough water-proof Barrier
- Pathogen Penetration is difficult
- Breached by wounds/mosquito
2. Mucosal surfaces
- line body cavities
- epithelial cells covered with mucus
- mucus thick fluid layer containing glycoproteins, proteoglycans and enzymes
- e.g. mucus in lungs traps pathogens
Immune Defenses
1. Innate - physical defenses are part of innate immunity
2. Adaptive

12. Physical Barriers Lungs: Mucus, cilia trap and move pathogens
Nose: Mucus traps pathogens which are then swallowed or blown out
Mouth: Friendly bacteria, Saliva
Eyes: lysozyme
Stomach: acid neutralization
Intestine: Friendly bacteria
Urogenital tract: Slightly acid conditions

13. Immunity: Three Basic Parts
Pathogen
Recognition
(Binding event)
(Foreign)
Signal
Effector mechanisms
(Self)
Immune
disorders
Effector Cells
Complement
Two types of Immunity - Innate or Adaptive

14. Innate Immunity Ancient system - present in invertebrates
naïve, immediate, everyday immunity
Molecules recognize common features of pathogens
Lectin
Phagocytes, large lymphocytes (NK cells)
Complement

15. Adaptive Immunity specialized, late, immunity
Newer system - present in fish, birds, human
specialized, late, immunity
Molecules recognize specific features of pathogens
Antibodies
B and T cells - small lymphocytes
Immunological memory

16. Figure 1-5 part 1 of 2 Example of Innate Immunity
Complement - blood borne (serum) proteins that tag pathogens or attack them directly
Effector cell - engulf bacteria, kill virus infected cells, attack pathogens
Endocytosis - process by which extracellular material is taken up

17. One type of effector cell is the phagocyte

18. Figure 1-6 Innate Immunity
Cytokines = signaling molecules --> inflammation/adaptive immunity
Phagocytosis = “phagos” means to eat
Inflammation is sometimes an unwanted by-product!
Inflammatory cells = WBC’s contributing to inflammation

19. Inflammation
Inflammation - local accumulation of fluid and cells involved in the immune response
What happens when inflammation is induced
Blood capillary dilation => heat (calor) & redness (rubor)
- Local dilation of blood capillaries = increase of blood to the area (DOES NOT increase blood flow)
Vascular dilation (vasodilation) => swelling (tumor) & pain (dolor)
Extravasation - movement of cells/fluid into connective tissue.
A) change in adhesiveness of the endothelial tissue allowing immune cells to attach and migrate into the connective tissue
B) vascular dilation - gaps in endothelial cells

20. Example of inflammation gone bad: Sepsis
Systemic inflammatory response syndrome (SIRS)
Results from the body's systemic over-response to infection
Treatment: broad-spectrum antibiotics and supportive therapy
Disturbance of innate immunity during sepsis and multiorgan dysfunction syndrome (MODS) probably linked to uncontrolled activation of the complement system
Future Drug therapies could be used that modulate pro-inflammatory and anti-inflammatory factors

21. Innate and Adaptive responses
Pathogen independent
Immediate (hours)
Neutrophils
Macrophages
Mast cells
Eosinophils
Basophils
NK cells
“Large Lymphocytes” = NK cells
Adaptive
Pathogen-dependent
Slower (days)
Dendritic cells
B cells
T cells (CD4 or CD8)
“Small Lymphocytes” = B & T cells
Both systems “talk” to each other to modulate response
Both systems use leukocytes = white blood cells

22. What if Innate Immunity is not Enough?
Innate immunity keeps us healthy most of the time
Some pathogens escape the innate immune process
Need a specific system to adapt to a specific pathogen
- Hence vertebrates evolved the Adaptive immune response

23. Principles of Adaptive Immunity
Lymphocytes each with different specificity generated by gene rearrangements
Small fraction of total pool of lymphocytes can recognize the pathogen
Pathogen recognizing lymphocyte is amplified - Clonal amplification
Pathogen recognizing lymphocyte can persist providing long-term immunological memory
Primary vs Secondary immune response
eg. Influenza/Measles/Vaccination

24. Figure 1-7 Characteristics of Innate vs Adaptive Immunity INNATE
= genes are constant
= genes are rearranged
Leukocytes - white blood cells that increase the immune response to ongoing infection

26. Innate vs Adaptive Molecular Recognition
Most important difference: Receptors used to recognize pathogens
Innate immunity: Receptors recognize conserved structures present in many pathogens (usually a repetitive pattern)
Pathogen-associated Molecular Patterns (PAMPs): LPS, peptidoglycan, lipids, mannose, bacterial DNA and viral RNA
e.g. Mannose-binding Lectin (MBL)
Adaptive immunity: Receptors recognize a specific structure unique to that pathogen
e.g. Antibodies

27. Figure 1-11 part 1 of 2 Flowchart of Hematopoiesis
Pluripotent stem cell
Self-renewal

28. Flowchart of Hematopoiesis
Figure 1-11
Leukocytes

29. Myeloid Lineage

30. Figure 1-9 part 3 of 6 Granulocytes (Myeloid progenitor)
Polymorphonuclear leukocytes (PMLs)
Figure 1-9 part 3 of 6
Neutrophils:
Most abundant
Phagocyte
Effector cells of Innate Immunity
Short-lived - Pus
Eosinophils:
Worms/intestinal parasites
Amplify inflammation
Bind IgE
Very Toxic - Pathogen and host
Chronic asthma
Basophils:
Rare
Unknown function
Bind to IgE

31. Figure 1-9 part 5 of 6 Circulate in blood Bigger than PMLs
Look similar
Immature form of macrophage
Scavengers
Phagocytose pathogens, cells, debris
Secrete cytokines

32. Figure 1-13

33. Macrophages respond by two mechanisms - use 2 different receptors.
Phagocytosis - Phagosome fuses with lysosome - toxic small molecules and hydrolytic enzymes kill/degrade the bacteria
Signaling - bacterial component binds receptor - initiates transcription - inflammatory cytokines synthesized and secreted

34. Star-shape
In tissue
Cellular messenger
Cargo cell
Connective tissue
Unknown progenitor
Granules
Degranulation major contributor to inflammation and allergies

35. Lymphoid Lineage Cells
Large lymphocytes
NK cells
Innate immunity
Small lymphocytes
B cells
T cells
Adaptive immunity

36. Figure 1-9 part 2 of 6 Lymp Large lymphocyte with granular cytoplasm
Effector cell of innate immunity
1) kill viral infected cells
2) secrete cytokines that interfere with virus infections

37. Adaptive IR
Small and immature
Activated by pathogen
Two types
- B cell
- T cell
B cells have B cell receptors and secrete Ab
T cells have T cell receptors

38. Erythroid Lineage

39. Figure 1-9 part 6 of 6 Giant nucleus Resident of bone marrow
Fusion of precursor cells
Fragments to make platelets
Figure 1-9 part 6 of 6
Gas transport
Infected by Plasmodium falciparum

40. Lymphoid
Myeloid
Erythroid
Neulasta (Amgen): Granulocyte Colony-Stimulating Factor (G-CSF)
Recovery from Neutropenia & protect against Bacterial disease
Leukine (Schering-Plough): Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF), Recovery from Neutropenia and protection against Bacterial/fungal/parasitic disease

41. Centrifuged blood sample
Plasma
Red blood cells
White blood cells

42. Figure 1-12

43. High WBC could be a sign of infection or leukemia
Low WBC bone marrow diseases or HIV
Polys = polymorphonucleocytes - mainly neutrophils
High lymphocyte count indicates the bacterial or viral infection

44. Figure 1-15 The lymph system and sites of lymphoid tissue
Primary (Red) and Secondary (yellow)
GALT, BALT, MALT
Thoracic Duct
Lymphpatic vessels - fluid collection
Lymph nodes - junctions of vessels

45. Recirculation
Draining Lymph node
Edema - is worse when patient is inactive
Afferent (entry)
Efferent (exit)

46. Figure 1-17 part 1 of 2 Communications Center
Afferent vessels bring in the lymph from infected tissue
Efferent vessels place of exit for non-activated lymphocytes

47. B-cell area
(follicle)

48. Lymphocyte not activated T-cell area Afferent lymph
Lymphocytes
Efferent lymph
artery
Lymphocyte not activated
T-cell area
Afferent
lymph
Pathogen
Dendritic cells
Activated by dendritic cell
T helper cell (lymph node)
T helper cell
(Infection site)
Cytotoxic T cell (Infection site)
Activate B cells
Activate Macrophages
Kills infected host cells
Make Antibodies

49. Lymphocytes enter node through artery
Tcells migrate to the T-cell area and if they meet a dendritic cell that is carrying pathogens from an infection site they get activated - to divide into functional effector cells.
Some T-cells stay in the lymph node and become T-helper cells - secrete cytokines (soluble proteins) and have receptors that contact B-cells. This helps the B-cells differentiate into plasma cells.
Plasma cells stay in the lymph or leave and pump out large amount of antibodies - a soluble form of their cell surface receptor
A second type of activated T-cell is the T-helper cell that leaves the node to the infected area and interacts with macrophages and amplify inflammation
Third type of T-cell is the cytotoxic T-Cell which kill cells infected with pathogen
Remember 5 million lymphocytes are entering node every minute and only a few are activated in response to an infection.

50. Figure 1-19 Anatomy of immune function in the Spleen
Blood filtering organ - remove old/damaged red cells (red pulp)
Blood-borne pathogens e.g. malaria
White pulp (Immune system)
- similar to lymph node (except pathogens enter and leave by blood)

51. Activated lymphocytes
Figure 1-20
M cells
Activated lymphocytes
M cells - specialized cells lining mucosal epithelium that deliver pathogen => activate lymphocytes

52. Adaptive Immunity
Vertebrates only
Specificity
- recognition modules - BCR, Ab and TCR
- gene rearrangement is the source of diversity
- clonal selection
Small lymphocytes
- types and sub-types
- functions

53. Recognition concept
Receptor or Antibody molecule
Antigen - structure recognized by an Ab, BCR or TCR
Epitope - particular sub-structure of the Ag that is bound
Affinity - how much a molecule likes to bind to a structure

54. Small lymphocyte sub-types
B-cells
BCR is Immunoglobulin (Ig)
Plasma cells - effector cells that secrete Ab
T-cells
Tc = cytotoxic (CD8+)
TH = helper T-cells (CD4+)
Th1 (inflammation)
Th2 (help B-cells make AB)

55. Recognition modules of Adaptive immunity
B-cell receptor (BCR)
T cell receptor (TCR)
B cells
T cells
Antibody is a secreted form of BCR
TCR is membrane bound

56. Native vs Denatured
Antigen processing
Major Histocomp-atibility (MHC)
B-cells
T-cell

57. MHC APC - Antigen Presenting Cells Professional APC - macrophages
- B cells
Dendritic cells
MHC I
- all nucleated cells
- intracelluar pathogens e.g. virus
MHC II
- immune cells - APC
- extracellular
Interact with cytotoxic T cells
Interact with helper T cells

58. MHC class I communicates with cytotoxic T cells (Tc cells)
Cellular ribosomes are subverted into making more virus proteins
Some of those proteins are degraded in the cytoplasm and transported to ER
MHC1 bind to these peptides and help to display them on the cell surface
Cytotoxic T cells = Tc cells, Cytotoxic T-lymphocytes (CTLs)

59. MHC class II communicates with TH cells (TH1 or TH2)
Also: Dendritic cells interact with naïve T-cells to initiate differentiation

60. Antibodies Produced by B-cells
Humoral Immunity - Humor = “body fluids”
Passive immunity - serum transferred to another individual can confer passive reistance due to transfer antibodies

61. Expel and/or destroy pathogen
Antibodies
Parasitic infection
Parasite +
Mast cell
Neutralization
Opsonization
Inflammation
Inflammation
Mast cell activated
Expel and/or destroy pathogen

62. Principles of Adaptive Immunity
Diversity
Specificity
Memory
Self-tolerance

63. Gene Rearrangement is the source of Diversity
Germline configuration - the exact form of genes you inherit
Somatic cells - all the cells of the body except germ cells
Diversity
Alternative combinations
Imprecise joints
Different types of chains
B-cells - somatic hypermutation
All this can happen in the absence of antigen

64. Clonal Selection
Each cell = one receptor
Millions of lymphocytes are generated
Small subset will recognize a pathogen
Proliferation and differentiation
Acquired immunity - the adaptive immunity provided by immunological memory

65. Antibodies are usually very specific
Figure 1-22

66. Concept Behind Vaccination
Some memory lymphocytes
Many lymphocytes
Few specific lymphocytes

67. Pre-industrialization infants built immunity naturally
Post-industrialization polio rate increased in adults hence a need for vaccination

68. Polio Vaccine - Inactive vs Oral “live” version
VDPV - vaccine derived polio virus, cheap and easy to administer
- mutations can lead to polio at extremely low rate
- immunocompromized individuals can be carriers of VDPV

69. Principle of Self-tolerance
B-cells with BCR that bind to self will undergo Apoptosis
More complicated scheme of selection for T cells

70. Selection of T cells
Thymocytes - immature T-cells
Positive selection
-Self MHC
-cortex (epithelial cells)
Negative selection
Mechanism of Self-tolerance

71. Immunodeficiencies Inherited deficiencies e.g. Bubble boy disease
Stress induced
nutrition, emotional
Pathogen caused deficiencies
HIV - attacks CD4 T lymphocyte

72. Figure 1-32 Cells and molecules involved in Hypersensitivity Diseases
IgE
IgG
CD4 TH1
CD8 CTL

73. Insulin-Dependent Diabetes Mellitus
Beta cells of the islets of Langerhans in the pancreas are attacked
Symptoms don’t show up for a long time
Infection by a specific virus has been correlated with higher rate of IDDM
Some of the activated CTL and Th1 cells will attack the healthy beta cells
IDDM also has been correlated with certain polymorphisms (types) of the MHC molecule

74. Inflammatory Adaptive Immune Response
Hygiene Hypothesis or Global Warming Hypothesis