Immunology - Lecture 1 - Introduction

Front 1

What is the function of an immune system?

Back 1

Distinguish self from non-self

Front 2

What are 3 chemical barriers and 2 physical barriers to infection?

Back 2

Chemical
1. Lysozyme - in secretion, split cell wall of gram positive bacteria
2. Spermine - in semen, prevents growth of gram positive bacteria
3. acid pH of stomach - prevents colonization of bacteria

Physical Barriers
1. skin
2. mucosal lining

Front 3

Fill in the Cytokines.

Back 3

Front 4

Innate Immunity

Back 4

- First line of defense
- very fast
- Not very specific (recognize classes)
- Principle Cells - Phagocytes, macrophages, neutrophils
- Soluble Molecules - Cytokines, Chemokines

Front 5

What are the principle cells of the innate immune system?

Back 5

Phagocytes, macrophages, neutrophils

Front 6

Adaptive Immunity

Back 6

- Cells = lymphocytes. need to be matured or trained to recognize & kill antigens
- slower. needs to be trained.
- evolves with exposure
- Specific. - limited to recognition repertoire from epitome of antigen
- memory cells. will respond faster the next time around.
- Soluble molecules - Antibodies, Cytokines, Chemokines

Front 7

Tolerance

Back 7

The ability to distinguish self from non-self.

Central - in T cells (thymus) and B cells (bone marrow)

Peripheral - everywhere else

Front 8

What occurs if there is a loss of tolerance?

Back 8

Autoimmunity
- "self" antigens are recognized as foreign

Front 9

What is considered Primary Immune Tissue?

Back 9

Bone Marrow and Thymus. This is where B cells and T cells are produced and developed.

Front 10

What is considered secondary immune tissue?

Back 10

- Lymph nodes
- Tonsils and Adenoids
- Spleen
- Mucosal Associated Lymph Tissue (MALT)

Front 11

What does GM-CSF stand for?

Back 11

G - Granulocyte
M - Monocyte
CSF - Colony Stimulating Growth Factors

Front 12

Bursa of Fabricius

Back 12

the first place B cells were discovered. (in a chicken).
- Bone marrow was first referred to as 'bursa equivalent'

Front 13

tolerance induction

Back 13

screening process in which potentially autoreactive cells are deleted or inactivated (anergized)

Front 14

Epitope

Back 14

Portion of antigen that interacts with receptors on cells of the
immune system (recognize)

AKA Antigenic determinate or Determinant

Front 15

Where is the site of primary immune responses?

Back 15

Secondary lymphoid tissue

Front 16

Describe Mucosal Associated Lymphatic Tissue (MALT)

Back 16

Definition diffuse system of small concentrations of lymphoid tissue

-unencapsulated. (Diffuse)

- found in gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin.

- populated by T cells & B cells, plasma cells and macrophages

Different Types:
GALT - Gut Associated Lymphoid Tissue - Peyers Patches

BALT - Bronchus

Front 17

Primary Follicle

Back 17

- contain mostly mature resting B cells
- no germinal centers

- Located in outer cortex of lymph nodes

Front 18

Secondary follicles

Back 18

- contain germinal centers
- antigen activated B cells

- Located in outer cortex of lymph nodes

Front 19

What is contained in the medulla of lymph nodes?

Back 19

macrophages
dendritic cells
plasma cells

Front 20

Whats is contained in the outer cortex of the lymph nodes?

Back 20

primary and secondary follicles

Front 21

What are plasma cells and where are they located?

Back 21

Plasma cells are differentiated B cells that secrete antibodies
- located in medulla of lymph nodes and secrete antibodies into circulation

Front 22

White pulp of the spleen

Back 22

- functions as secondary lymphoid tissue
-contains majority of lymphoid tissue (T-cells, B-cells)

- function: to mount an immunological response to antigens within the blood

- in the periarteriolar lymphoid sheath

Front 23

Where are the T Cells found in the spleen? Where are the B cells found?

Back 23

T-Cells - Periarterial Lymphatic Sheath (PALS)
B-Cells - outgrowths out of PALS

Front 24

What are the 2 functions of the lymph nodes:

Back 24

- phagocytic cells act as filters for particulate matter and micro-organisms

- antigen is presented to the immune system

Front 25

Red pulp of the Spleen

Back 25

Filters damaged or old blood out of circulation

Front 26

Peyer's Patches

Back 26

aggregates of follicles in GALT (Gut-Associated Lymphoid Tissue)

Front 27

M cells

Back 27

- sample antigen from the lumen and deliver it to the lymphoid tissue.
(bring antigen to immune system so it can learn how to kill pathogen)

- found in Follicle Associated Epithelium

- very few lysozymes (phagocytosis not its role)

Front 28

Follicle Associated Epithelium

Back 28

- M Cells found here
- In Peyer's Patches, where there is no mucus layer or goblet cells

Front 29

Cytokines

Back 29

- small peptides secreted by active leukocytes
- Pleiotropic and redundant
- can mediate numerous seemingly unrelated effects

Front 30

Chemokines

Back 30

Chemoattractant -
attract cells to particular region

Front 31

Antibodies

Back 31

- aka Immunoglobulins (Igs)

- polypeptide chains define the antigen binding site and its isotype

- expressed on surface of B cells

- when stimulated, secrete plasma cells. secreted cells are effector molecules for functioning innate or adaptive immune response

Front 32

Complement

Back 32

family of proteins that facilitate elimination of microorganisms (esp. extracellular bacteria)

Front 33

What 3 general classes of molecules activate lymphocytes?

Back 33

1. monoclonal activators - activate single clone
2. polyclonal activator - activate most or all clones
3. activate more than one clone but not all clone.

Front 34

Antigen

Back 34

- recognized by lymphocytes and elicit immune response
(aka immunogen)

Front 35

What factors make an antigen potent?

Back 35

1. Complexity
2. High molecular weight (> 5kd
3. Foreignness

Complexity hierarchy
- proteins
- polysaccharides
- nucleic acid and lipids

Front 36

T-independent antigens

Back 36

- polysaccharides
- activates B cells.
- T cells don't recognize them

Front 37

Carrier Effect

Back 37

Hapten - (small molecules) can bind to large proteins and become immunogenic.

Front 38

What does spermine (in semen) do?

Back 38

prevents growth gram + bacteria

Front 39

When does clonal expansion occcur?

Back 39

during primary response

Front 40

APCs display antigen on what receptors?

Back 40

class II MHC

Front 41

Name the 3 types of phagocytes?

Back 41

monocyte, macrophage, neutrophil

Front 42

Name 3 antigen presenting cells?

Back 42

dendritic, macrophage, B cell

Front 43

When do NK cells become LAK cells?

Back 43

In presense of high concentrations of IL-2

Front 44

Where are mast cells found? Basophils?

Back 44

Mast Cells - gut, lung, around vessels Basophils - Everywhere

Front 45

Plasma cells are differentiated from what type of cells?

Back 45

B cells

Front 46

What soluble mediators induce hematopoiesis

Back 46

C-kit ligand, IL-3, IL-7, CSF

Front 47

What is a primary immune tissue?

Back 47

Lymphocyte Development Site

Front 48

What is a secondary immune tissue?

Back 48

Lymphocyte Activation Site

Front 49

Whats happens at the thymus

Back 49

T-cell maturation.

Front 50

Where is blood thymus barrier found?

Back 50

Between Brain and cortex

Front 51

If you are exposed to an antigen via blood, what is the site of initial immune response?

Back 51

Spleen

Front 52

If you are exposed to an antigen via lymphatics, what is the site of initial immune response?

Back 52

Lymph nodes

Front 53

If you ate an antigen, where is the site of initial immune response?

Back 53

mucosa-associated lymphoid tissues (MALT)

Front 54

Which is the only lymphatic tissue that has afferent lymphatics?

Back 54

Lymph nodes into subcapsular sinuses

Front 55

What cells are in the Medulla of a lymph node?

Back 55

Macrophages, dendritic cells, and (plasma cells secrete antibodies into blood)

Front 56

How do lymph nodes clear antigen from blood?

Back 56

Lymph perculates through medulla where phagocytes “eat” them

Front 57

Which system has periarterial lymphatic sheaths?

Back 57

Spleen

Front 58

What cells are found in the marginal zone of the spleen?

Back 58

Dendritic and macrophages

Front 59

Function of M Cell

Back 59

Transport antigen from lumen to basolateral surface (not phagocytosis since no lysosomes)

Front 60

What are those regions in gut where mucus is absent called?

Back 60

Follicle associated epithelium (FAE)

Front 61

What is a complex antigen?

Back 61

Antigen with more than one epitope

Front 62

What is more immunogenic proteins, carbs, lipids or nucleic acids?

Back 62

Proteins > carbs > the other 2

Front 63

Why are T independent associated bacteria hard to destroy?

Back 63

No isotype switching, only IgM