Lecture 2

Question 1

Who discovered that cowpox vaccine also had protection against smallpox?

Answer 1

Edward Jenner in 1796

Question 2

What term did he coin?

Answer 2

Vaccination: inoculation of healthy individuals with weakened or attneuated strains of disease

Question 3

What did Metchnikoff discover in 1890?

Answer 3

Many microorganisms can be engulfed by phagocytic cells called macrophages. They are front line components of innate immunity

Question 4

What is an antigen?

Answer 4

A foreign material that induces response

Question 5

What is Innate Immunity?

Answer 5

any bacterial pathogen that anyone can relate to

Question 6

What is adaptive immunity?

Answer 6

Is generated from vaccines
- varies from person to person
- one person getting covid means they have more adaptive immunity for that

Question 7

Where do the cells of the immune system derive from?

Answer 7

Pluripotent hematopoietic stem cells in the bone marrow

Question 8

What are the different levels in the bone marrow?

Answer 8

Innate: common lymphoid progenitors and common myeloid progenitor

Adaptive: granulocytes/macrophages, megakaryocyte and erythrocyte progenitor, erythoblast and megakaryocyte

Question 9

What levels are in the Blood?

Answer 9

Innate: B cell, T cell, NK cell, ILC, immature dendritic cell

Adaptive: neutrophil, eosinophil, basophil, monocyte, platelets, erythocytes

Question 10

What levels are in the lymph nodes/tissues?

Answer 10

Innate: B cell, T cell, NK cell, ILC, mature dendritic cell

Adaptive: (tissues) immature dendritic cells, mast cell, macrophage

Question 11

What are in Effector cells in the innate immune system?

Answer 11

B cell -> plasma cell
Activated T cell
Activated NK cells
Activated ILC

Question 12

What is a pathogen?

Answer 12

Anything harmful causing a disease

Question 13

What are the levels of defense when a pathogen enters?

Answer 13

Anatomic Barriers
- skin, oral mucosa, respiratory epithelium, intestine

Complement/antimicrobial proteins:
- cascade of proteins to remove pathogen

Innate immune cells:
- macrophages, granulocytes, NK cells, epithelial cells

Adaptive immunity:
- B cells/antibodies, T cells

Question 14

How long does adaptive immunity take to kick in?

Answer 14

4 days which is why innate response is so crucial. Antigen recognition in adaptive immunity is important and is memory specific

Question 15

What is the cell mediated immunity process ? (1)

Answer 15

Inflammatory inducers: bacterial lipopolysaccharides, ATP, urate crystals

Question 16

What is the cell mediated immunity process ? (2)

Answer 16

Sensor cells: macrophages, neutrophils, dendritic cells
- these cells engulf material and are activated by inflammation

Question 17

What is the cell mediated immunity process ? (3) What is the cell mediated immunity process ? (3)

Answer 17

Mediators: cytokines, cytotoxicity

Question 18

What are cytokines?

Answer 18

Proteins with immune functions from cells

Question 19

What is cytotoxicity?

Answer 19

Damage for the cell

Question 20

What is the cell mediated immunity process ? (4)

Answer 20

Target tissues: production of antimicrobial proteins, induction of intracellular antiviral proteins, killing of infected cells

Question 21

What are the three phases of immune response?

Answer 21

Innate immune response, Adaptive immune response, and immunological memory

Question 22

Innate Immunity

Answer 22

Inflammation, complement activation, phagocytosis, and destruction of the pathogen

Question 23

How long does it take after infection for response to start?

Answer 23

Minutes, and duration is days

Question 24

What is adaptive immune response?

Answer 24

Interaction between antigen-presenting dendritic cells and antigen-specific T cells: recognition of antigen, adhesion, co-stimulation , T cell-proliferation

Question 25

What do B cells do in adaptive immune response?

Answer 25

Activation of antigen specific B cells - starts after hours and takes days

Question 26

What happens to T cells during adaptive immune response?

Answer 26

Formation of effector and memory T cells - starts after days and takes weeks to respond

Question 27

What happens with the interaction of T and B cells?

Answer 27

The formation of germinal centers, the formation of effector B cells and memory B cells, production of antibody which takes days and takes weeks to respond

Question 28

When does the pathogen become eliminated?

Answer 28

It becomes eliminated by effector cells and antibodies after a few days

Question 29

What is immunological memory?

Answer 29

Maintenance of memory B cells and T cells and high serum or mucosal antibody levels - Protection against reinfection which takes days to weeks

Question 30

What is a chemo kine?

Answer 30

Causes recruitment and is secreted from immune cells - it leads to migration and follows chemokine gradient moving something from blood to lymph

Question 31

What is a macrophage and what does it do?

Answer 31

Phagocytosis and activation of bactericidal mechanisms - antigen presentation and cytokine production

Question 32

What is an Eosinophil?

Answer 32

Killing of antibody-coated parasites

Question 33

What is a dendritic cell?

Answer 33

Antigen uptake in peripheral cites due to branching and migratory. It becomes an APC and produces cytokines

Question 34

What is a basophil?

Answer 34

Promotion of allergic responses

Question 35

What is a neutrophil?

Answer 35

Phagocytosis and activation of bactericidal mechanisms

Question 36

What is a mast cell?

Answer 36

Releases granules containing histamines

Question 37

What do macrophages express that allow them to express different pathogens?

Answer 37

Receptors: TLR1, TLR2, TLR4, mannose receptor, NOD1, glucan, scavenger receptor

Question 38

What triggers the inflammatory response?

Answer 38

Infection: 1. Bacteria triggers macrophages to release cytokines and chemokines 2. Vasodilation and increases vascular permeability cause redness, heat, and swelling 3. Inflammatory cells migrate into tissue, releasing inflammatory mediators that cause pain

Question 39

What are Natural Killer (NK) cells?

Answer 39

Innate cells that partially bridge over into adaptive - lymphoid cells that lack antigen specific receptors and are part of innate immune system - circulate in blood as large lymphocytes that contain distinctive granules - can recognize and kill some abnormal cells, such as tumor cells and virus-infected cells

Question 40

Where do lymphocytes mature?

Answer 40

In the bone marrow or the thymus and then congregate in lymphoid tissues throughout the body

Question 41

What initiates adaptive immune responses?

Answer 41

Antigen and antigen-presenting cells in peripheral lymphoid tissues

Question 42

What are the two major types of lymphocytes?

Answer 42

T cells and B cells B cells: when activated differentiate into plasma cells that secrete antibodies T cells: two main classes - one class differentiates into cytotoxic cells which kills cells with viruses

Question 43

What kind of features do T cells and B cells have

Answer 43

No functional activity until they encounter antigen as well as molecules induced by innate immunity called co-stimulatory molecules

Question 43

What do T helper cells do?

Answer 43

They make cytokines

Question 44

What are the parts of an antibody?

Answer 44

Constant region (effector function) which is the bottom of the antibody, and the variable region which is the antigen binding site

Question 45

What does the structure of the T-cell receptor?

Answer 45

constant region, variable region (antigen-binding site)

Question 46

Why do we want quaternary or more complex structures for vaccines?

Answer 46

We want to give the full breath of the longer folded protein into the vaccine, so the antibody recognizes that rather than a simple structure.

Question 47

What is an anamnestic response?

Answer 47

Quicker response to the next exposure of an antigen

Question 48

What does the course of an immune response look like?

Answer 48

First encounter: produces a primary response, slow to develop 2nd encounter: with the same antigen, produces a very rapid and intense secondary response - illustrates why we give boost injections after an initial vaccinatio