Immunology
Not your usual “Notes” - How to use this to ACTIVELY RECALL:
Bullet-point Question/Answer format
Based on Chapters from Peter Parham’s “The Immune System”, 5th Edition (Chap
1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 13, 14, 16, and 17)
Colour the questions RED until you perfect them. Colour them GREEN once you’ve
mastered them. Then, ONLY practice the red question, until they’re all green.
Follow the chapters from the book/lecture slides to view images and visuals
corresponding to the notes.
Lecture 1: Chapters 1 and 3, Intro and complement
1. What is the innate immune system? This system is non-specific: it recognizes
general features of pathogens (e.g., bacterial cell walls, viral RNA). Takes 0 to 7
hours to kick in.
2. What are components of the innate immune system? Has physical barriers like
mucous and skin, immune cells (macrophages, neutrophils, etc), and
inflammation and fever.
3. What is the adaptive immune system? It is specific and has memory, meaning it
targets specific antigens (unique molecules on pathogens) and "remembers"
them for faster responses in the future. "1 to 7 days" means this part of the
immune system takes longer to activate—typically it starts within 1 day, but full
activation can take several days.
4. What are adaptive immune system components? Includes T cells, B cells and
antibody production.
Blood immunity
5. What are immune components found in the blood? Granulocytes, lymphocytes,
plasma proteins and tissue resident immune cells.
6. What are granulocytes? These are a type of white blood cell (WBC) with
granules in their cytoplasm. They are part of the innate immune system and
act quickly.
7. What are the granulocytes? Neutrophils, basophils and eosinophils
8. What are neutrophils? First responders to infection; phagocytose (engulf)
bacteria, most abundant WBC
9. What are basophils? Release histamine during allergic responses, least
common, are blue granules
10. What are eosinophils? Fight parasites; involved in allergies, Pink/red granules.
11. What are lymphocytes? These are key cells of the adaptive immune system,
though some have innate functions.
, 12. What are the lymphocytes? B cells (Produce antibodies), T cells (Helper T cells
(coordinate); Cytotoxic T cells (kill infected cells)) and Natural killer cells (NK
cells) (Kill virus-infected or cancerous cells)
13. What are plasma proteins? These are soluble proteins in the blood that play
immune roles. Include complement proteins and antibodies
14. What are complement proteins? Tag pathogens for destruction (opsonization),
create pores to lyse them (MAC)
15. What are antibodies? Produced by B cells; bind specific antigens to neutralize or
tag them
16. Which immune cells are mostly found in tissues and not as much in blood?
Macrophages, dendritic cells and mast cells.
17. What are macrophages? Engulf pathogens; release cytokines; present antigens
18. What are dendritic cells? Best antigen-presenting cells; activate T cells
19. What are mast cells? Release histamine in allergic responses.
Hematopoeisis
20. What is hematopoiesis? The process of development of immune cells from a
pluripotent hematopoietic stem cell.
21. What are the 2 main precursor pathways for hematopoiesis? Common Myeloid
Cell Precursor and Common Lymphoid Cell Precursor.
22. What does the common myeloid cell precursor form? Gives rise to innate
immune cells such as: Granulocytes (Neutrophils, Eosinophils, Basophils) and
Tissue-resident cells (Monocytes → Macrophages, Dendritic cells, Mast cells)
23. What does the common lymphoid cell precursor form? Gives rise to adaptive and
some innate immune cells. Adaptive lymphocytes [B cells, T cells, CD4+ T
helper subsets (Treg, TH17, TH2, TH1)]. Innate lymphoid cells (NK cells, ILC1,
ILC2, ILC3, LTi)
Physical barriers
24. What is the first line of defense against pathogens? Physical, then adaptive, then
immune
25. What are mechanical and chemicals of the skin
26. What are mechanical and chemicals of the gut?
27. What are the mechanical and chemicals of the lungs?
28. What are the mechanical and chemicals of the ENT?
Lymphatic system
29. What are the divisions of the lymphatic system? Primary and secondary.
30. What is the primary lymphatic system for? Development of adaptive immune
cells - bone marrow: B cells, Thymus: T cells
31. What is the secondary lymphatic system for? Activation of adaptive immune cells
- Lymph nodes, spleen and gut associated lymphoid tissues GALT
, 32. Secondary lymphoid organs are highly structured with specific sites for T cell and
B cell activation.
33. Point to the B cell and T cell sites in the lymph node.
Innate IS and Inflammation
34. What immune components are fast responders upon bacterial infection?
Macrophages and neutrophils
35. What do macrophages and neutrophils do upon bacterial infection? Induce
inflammation. Macrophages recruit neutrophils from the bone marrow to
collaborate and clear bacterial infection using phagocytosis.
36. How does inflammation occur? Surface wound, bacteria infect, which activates
effector cells to secrete cytokines (signalling molecules for activation).
Vasodilation increases permeability of capillary wall. Fluid, proteins and cells
leave the blood to enter the tissue. Infected tissue becomes inflamed - redness,
heat and swelling.
37. What happens when macrophages recruit neutrophils? Neutrophils are stored in
the bone marrow and released when infection happens. Go to the sit and kill
bacteria. Neutrophils then die and are degraded by macrophages.
38. How do innate immune cells distinguish self from non-self cells? Innate immune
cells use Pattern Recognition Receptors (PRRs) to Distinguish self from
non-self, Become activated, and Engulf pathogens (pathogen uptake).
39. What are features of the PRRs in innate IS? Equally expressed on each type of
innate immune cell (e.g., macrophages, dendritic cells), Capable of recognizing
general features of pathogens — not specific strains, Able to detect entire
classes of pathogens (e.g., bacteria, viruses, fungi)
40. What is a limitation of innate IS PRRs? No antigen-specific memory or precision
targeting. If only the innate system is involved and there's no specific adaptive
response, pathogens may win the battle.
Adaptive IS
41. What happens while inflammation is going on? Dendritic cells initiate adaptive
immunity in secondary lymphoid organs. The pathogen is transported to the
organ, where T cells are activated by dendritic cells to create B cells and T helper
cells, producing plasma cells and antibodies.
42. What are the receptors on adaptive IS cells? TCR (T cell receptor) and BCR.
Can differentiate within major pathogen species.
43. How do adaptive IS receptors have specificity? They use antigens specific to
each pathogen.
44. How does T cell and B cell activation work, also based on specificity? Each T
cell or B cell expresses many receptors, but all with one unique antigen
specificity per cell. Only those cells with receptors that match the current
infection get activated in secondary lymphoid organs (e.g., lymph nodes,
spleen). Activated cells undergo clonal expansion.
, 45. What is clonal expansion? All daughter cells have the same receptor for one
specific epitope - takes about 1 week.
46. What is an epitope? the specific part of a pathogen (antigen) that is recognized
by a receptor on a T cell or B cell.
47. What is the humoral response of B cells? The humoral immune response is the
branch of adaptive immunity that involves B cells and the antibodies they
produce to fight pathogens in body fluids (the "humors") like blood, lymph, and
mucus. B cells get activated by: Direct antigen binding and Help from T helper
cells. Once activated: B cells differentiate into plasma cells and Plasma cells
produce antibodies.
Complement system
48. What is the complement system? a part of the innate immune system that
enhances (complements) inflammation and pathogen elimination.
49. What is a key component of the complement system? Central to all complement
pathways. Cleaved by C3 convertase into:
C3a → Anaphylatoxin: promotes inflammation and recruits immune cells
C3b → Opsonin: tags pathogens for phagocytosis and helps form more C3
convertase (amplification loop)
50. What are the 3 complement system pathways? Alternative pathway, Lectin
pathways and Classical pathway
51. What is the alternative pathway? Starts with spontaneous hydrolysis of C3.
Leads to formation of a soluble C3 convertase. Amplifies itself through more C3
cleavage. Fastest and first to act
52. What is the lectin pathway? Triggered by mannose-binding lectin (MBL) binding
to sugars on pathogen surfaces. Leads to cleavage of complement proteins and
formation of membrane-bound C3 convertase
53. What is the classical pathway? Triggered by: Antibodies (from adaptive
immunity) OR C-reactive protein (CRP). Complement factor C1 binds to
antibody/CRP and cleaves more complement proteins Also forms membrane-
bound C3 convertase
Lecture 2: Chapter 3 Innate cells
Macrophages and neutrophils as first line of defense
Not your usual “Notes” - How to use this to ACTIVELY RECALL:
Bullet-point Question/Answer format
Based on Chapters from Peter Parham’s “The Immune System”, 5th Edition (Chap
1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 13, 14, 16, and 17)
Colour the questions RED until you perfect them. Colour them GREEN once you’ve
mastered them. Then, ONLY practice the red question, until they’re all green.
Follow the chapters from the book/lecture slides to view images and visuals
corresponding to the notes.
Lecture 1: Chapters 1 and 3, Intro and complement
1. What is the innate immune system? This system is non-specific: it recognizes
general features of pathogens (e.g., bacterial cell walls, viral RNA). Takes 0 to 7
hours to kick in.
2. What are components of the innate immune system? Has physical barriers like
mucous and skin, immune cells (macrophages, neutrophils, etc), and
inflammation and fever.
3. What is the adaptive immune system? It is specific and has memory, meaning it
targets specific antigens (unique molecules on pathogens) and "remembers"
them for faster responses in the future. "1 to 7 days" means this part of the
immune system takes longer to activate—typically it starts within 1 day, but full
activation can take several days.
4. What are adaptive immune system components? Includes T cells, B cells and
antibody production.
Blood immunity
5. What are immune components found in the blood? Granulocytes, lymphocytes,
plasma proteins and tissue resident immune cells.
6. What are granulocytes? These are a type of white blood cell (WBC) with
granules in their cytoplasm. They are part of the innate immune system and
act quickly.
7. What are the granulocytes? Neutrophils, basophils and eosinophils
8. What are neutrophils? First responders to infection; phagocytose (engulf)
bacteria, most abundant WBC
9. What are basophils? Release histamine during allergic responses, least
common, are blue granules
10. What are eosinophils? Fight parasites; involved in allergies, Pink/red granules.
11. What are lymphocytes? These are key cells of the adaptive immune system,
though some have innate functions.
, 12. What are the lymphocytes? B cells (Produce antibodies), T cells (Helper T cells
(coordinate); Cytotoxic T cells (kill infected cells)) and Natural killer cells (NK
cells) (Kill virus-infected or cancerous cells)
13. What are plasma proteins? These are soluble proteins in the blood that play
immune roles. Include complement proteins and antibodies
14. What are complement proteins? Tag pathogens for destruction (opsonization),
create pores to lyse them (MAC)
15. What are antibodies? Produced by B cells; bind specific antigens to neutralize or
tag them
16. Which immune cells are mostly found in tissues and not as much in blood?
Macrophages, dendritic cells and mast cells.
17. What are macrophages? Engulf pathogens; release cytokines; present antigens
18. What are dendritic cells? Best antigen-presenting cells; activate T cells
19. What are mast cells? Release histamine in allergic responses.
Hematopoeisis
20. What is hematopoiesis? The process of development of immune cells from a
pluripotent hematopoietic stem cell.
21. What are the 2 main precursor pathways for hematopoiesis? Common Myeloid
Cell Precursor and Common Lymphoid Cell Precursor.
22. What does the common myeloid cell precursor form? Gives rise to innate
immune cells such as: Granulocytes (Neutrophils, Eosinophils, Basophils) and
Tissue-resident cells (Monocytes → Macrophages, Dendritic cells, Mast cells)
23. What does the common lymphoid cell precursor form? Gives rise to adaptive and
some innate immune cells. Adaptive lymphocytes [B cells, T cells, CD4+ T
helper subsets (Treg, TH17, TH2, TH1)]. Innate lymphoid cells (NK cells, ILC1,
ILC2, ILC3, LTi)
Physical barriers
24. What is the first line of defense against pathogens? Physical, then adaptive, then
immune
25. What are mechanical and chemicals of the skin
26. What are mechanical and chemicals of the gut?
27. What are the mechanical and chemicals of the lungs?
28. What are the mechanical and chemicals of the ENT?
Lymphatic system
29. What are the divisions of the lymphatic system? Primary and secondary.
30. What is the primary lymphatic system for? Development of adaptive immune
cells - bone marrow: B cells, Thymus: T cells
31. What is the secondary lymphatic system for? Activation of adaptive immune cells
- Lymph nodes, spleen and gut associated lymphoid tissues GALT
, 32. Secondary lymphoid organs are highly structured with specific sites for T cell and
B cell activation.
33. Point to the B cell and T cell sites in the lymph node.
Innate IS and Inflammation
34. What immune components are fast responders upon bacterial infection?
Macrophages and neutrophils
35. What do macrophages and neutrophils do upon bacterial infection? Induce
inflammation. Macrophages recruit neutrophils from the bone marrow to
collaborate and clear bacterial infection using phagocytosis.
36. How does inflammation occur? Surface wound, bacteria infect, which activates
effector cells to secrete cytokines (signalling molecules for activation).
Vasodilation increases permeability of capillary wall. Fluid, proteins and cells
leave the blood to enter the tissue. Infected tissue becomes inflamed - redness,
heat and swelling.
37. What happens when macrophages recruit neutrophils? Neutrophils are stored in
the bone marrow and released when infection happens. Go to the sit and kill
bacteria. Neutrophils then die and are degraded by macrophages.
38. How do innate immune cells distinguish self from non-self cells? Innate immune
cells use Pattern Recognition Receptors (PRRs) to Distinguish self from
non-self, Become activated, and Engulf pathogens (pathogen uptake).
39. What are features of the PRRs in innate IS? Equally expressed on each type of
innate immune cell (e.g., macrophages, dendritic cells), Capable of recognizing
general features of pathogens — not specific strains, Able to detect entire
classes of pathogens (e.g., bacteria, viruses, fungi)
40. What is a limitation of innate IS PRRs? No antigen-specific memory or precision
targeting. If only the innate system is involved and there's no specific adaptive
response, pathogens may win the battle.
Adaptive IS
41. What happens while inflammation is going on? Dendritic cells initiate adaptive
immunity in secondary lymphoid organs. The pathogen is transported to the
organ, where T cells are activated by dendritic cells to create B cells and T helper
cells, producing plasma cells and antibodies.
42. What are the receptors on adaptive IS cells? TCR (T cell receptor) and BCR.
Can differentiate within major pathogen species.
43. How do adaptive IS receptors have specificity? They use antigens specific to
each pathogen.
44. How does T cell and B cell activation work, also based on specificity? Each T
cell or B cell expresses many receptors, but all with one unique antigen
specificity per cell. Only those cells with receptors that match the current
infection get activated in secondary lymphoid organs (e.g., lymph nodes,
spleen). Activated cells undergo clonal expansion.
, 45. What is clonal expansion? All daughter cells have the same receptor for one
specific epitope - takes about 1 week.
46. What is an epitope? the specific part of a pathogen (antigen) that is recognized
by a receptor on a T cell or B cell.
47. What is the humoral response of B cells? The humoral immune response is the
branch of adaptive immunity that involves B cells and the antibodies they
produce to fight pathogens in body fluids (the "humors") like blood, lymph, and
mucus. B cells get activated by: Direct antigen binding and Help from T helper
cells. Once activated: B cells differentiate into plasma cells and Plasma cells
produce antibodies.
Complement system
48. What is the complement system? a part of the innate immune system that
enhances (complements) inflammation and pathogen elimination.
49. What is a key component of the complement system? Central to all complement
pathways. Cleaved by C3 convertase into:
C3a → Anaphylatoxin: promotes inflammation and recruits immune cells
C3b → Opsonin: tags pathogens for phagocytosis and helps form more C3
convertase (amplification loop)
50. What are the 3 complement system pathways? Alternative pathway, Lectin
pathways and Classical pathway
51. What is the alternative pathway? Starts with spontaneous hydrolysis of C3.
Leads to formation of a soluble C3 convertase. Amplifies itself through more C3
cleavage. Fastest and first to act
52. What is the lectin pathway? Triggered by mannose-binding lectin (MBL) binding
to sugars on pathogen surfaces. Leads to cleavage of complement proteins and
formation of membrane-bound C3 convertase
53. What is the classical pathway? Triggered by: Antibodies (from adaptive
immunity) OR C-reactive protein (CRP). Complement factor C1 binds to
antibody/CRP and cleaves more complement proteins Also forms membrane-
bound C3 convertase
Lecture 2: Chapter 3 Innate cells
Macrophages and neutrophils as first line of defense
