Lecture 2: Cell Mediated Immunity

Question 1

Immunity Tree

Answer 1

Innate vs Adaptive
Adaptive-> Natural vs Artificial
Natural-> Passive (maternal) vs Active (infection)
Artificial-> Passive (antibody transfer/infusion) vs Active (immunization)

Question 2

Passive immunity is short or long?

Answer 2

short lived/temporary/transient

Question 3

Active immunity is short or long?

Answer 3

long lived, memory cells are produced

A second infection by the same antigen triggers a stronger and faster immune response/defense

Question 4

Antibody mediated immunity

Answer 4

humoral or body fluid immunity (B cells) and antibodies

Question 5

Cell mediated immunity

Answer 5

cellular immunity dependent upon various types of T cells

Question 6

Lymphocytes are

Answer 6

T cells and B cells

Question 7

B cells attack

Answer 7

Invaders outside of cells (via antibodies)

Question 8

T cells attack

Answer 8

Infected cells

Question 9

B cells mature in the

Answer 9

Bone marrow
Differentiate in the bone marrow
Take up residence in the lymph tissues

Question 10

T cells mature in the

Answer 10

Thymus (above the heart)

Differentiate from the bone marrow

Question 11

Which lymph tissues contain B cells?

Answer 11

Tonsils, lymph nodes, spleen, MALT (mucosal associated lymphoid tissue), appendix, and peyers patches (in the GI tract)

Question 12

T cells further differentiate in the

Answer 12

Thymus

And then go on to populate/patrol the lymph

Question 13

What 3 types do immature T cells differentiate into?

Answer 13

Helper T cells
Suppressor T cells
Cytotoxic T cells

Question 14

Helper T cells

Answer 14

“Raise the alarm” by releasing cytokines that then activate other cells to kill

They can’t kill cells on their own, but can activate other killer cells

They also finish “training” naive B cells by binding to class 2 MHC/antigen complexes from things the B cell has engulfed and releasing cytoikines that activate that B cell

Question 15

How many CD molecules have we identified?

Answer 15

over 130

Question 16

Cytotoxic T cells

Answer 16

Cells that recognize infected cells and kill them, directed/regulated by helper T cells/cytokines

Cytotoxic T cells recognize dying, infected or cancerous cells based on the proteins presented by their class 1 MHCs

Question 17

Natural killer cells NK

Answer 17

Also lymphocytes
Do not have B or T cell markers
Triggers apoptosis in infected cells

Question 18

Primary Lymphoid tissue

Answer 18

Where lymphoid cells mature
Bone marrow (B cells)
Thymus (T cells)

Question 19

Secondary Lymphoid tissue

Answer 19

Sites of immune ACTION

maximize antigen trapping
Lymph nodes
spleen
MALT
tonsils
Appendix
Peyers patches

Question 20

MHC proteins

Answer 20

Major histocompatibility complex
Also called MHC antigens
Every person’s MHCs are different (tissue donation rejection)

External cell markers for identification by your immune system
Plays into recognizing self vs non-self

Question 21

MHCs are used in

Answer 21

Paternity testing
Transplants
Disease diagnosis
Immune response during antigen presentation

Question 22

MHC class 1

Answer 22

On the surface of all nucleated cells (not rbc’s which have no nucleus)

Question 23

What are some general things that T cells do?

Answer 23

Cause Inflammation
Activate Macrophages (phagocytic white blood cells)
Get other T cells fired up
Regulate much of the immune response

Question 24

Macrophages and MHCs

Answer 24

Macrophages/phagocytes engulf invaders and display the invaders’ protein components by attaching them to the cell’s external MHC proteins to visibly display those invader protein components to other immune cells in the body

Also referred to as professional antigen presenting cells

Question 25

What do class 1 MHC's do?

Answer 25

Present endogenous antigens They present short chains of amino acids (proteins) based on endogenous proteins (proteins synthesized inside that particular cell) The normal proteins on a healthy cell's class 1 MHCs tell wandering immune cells that the particular cell is healthy

Question 26

How do cancerous cells utilize MHCs?

Answer 26

A cancerous cell will present portions of its abnormal proteins on its class 1 MHCs to "ask" immune cells to destroy it->flagging itself as abnormal/for death

Question 27

What are 3 types of cells that have class 2 MHC proteins? ("professionals")

Answer 27

Macrophages Dendritic cells B cells

Question 28

What do class 2 MHCs do?

Answer 28

Bind to exogenous (from the outside) proteins/anigens that are presented by other immune cells on their class 2 MHCs such as viral or bacterial antigens/fragments

Question 29

Helper T cell specificity

Answer 29

Specific in a similar way that the antibodies of B cells work A naive helper T cells can only detect one specific combination of a specific antigenic fragment bound to a class 2 MHC of the individual in question

Question 30

What happens when a Helper T binds to its perfect class 2 MHC/antigen trigger?

Answer 30

It becomes activated, and begins rapidly dividing to produce more Effector cells including Helper T cells + Regulatory cells, as well as a few Memory T cells

Question 31

What do cytokines do?

Answer 31

They are released by Helper T cells and can trigger other helper T cells to begin dividing to rapidly ramp up the immune response The cytokines also trigger/activate Cytotoxic (killer) T cells

Question 32

Immunodeficiency

Answer 32

Impairs the production or function of immune cells and antibodies, which weakens the immune system's ability to fight off invaders or cancerous cells

Question 33

Regulatory T cells (a type of effector cell)

Answer 33

Release inhibitory cytokines that tell immune cell to stand down once the initial threat has been dealt with

Question 34

Overactive immune response

Answer 34

Body loses the ability to distinguish self from other, and starts attacking the body Such as MS multiple sclerosis resulting in degeneration of myelin sheaths of nerves Type 1 diabetes, where insulin generating pancreas cells are destroyed