Lecture 9

Question 1

What are the attributes of the adaptive immune system?

Answer 1

1. Specificity
   - responds to specific pathogens
2. indelibility
   - elicits specific immune responses against those pathogens
3. Memory
   - remembers pathogens
4. Unresponsive to self
   - can differentiate between self and pathogen (does not attack own cells)

Question 2

Mechanism of Humoral-mediated immunity

Answer 2

Antibody mediated

Question 3

Mechanism of Cell-mediated immunity

Answer 3

Cell mediated

Question 4

Cell type of Humoral immune system

Answer 4

B lymphocytes

B cells

Question 5

Cell type of cell mediated immunity

Answer 5

T lymphocytes

cytotoxic T cells

Question 6

Purpose of Humoral immuity

Answer 6

• Primary defense against extracellular pathogens

ex: extracellular pathogens (not inside the cell,)

Question 7

Purpose of Cell mediated immunity

Answer 7

• Primary defense against intracellular pathogens (cells that have infected our body)
  (kills zombie cells)

Question 8

6 Different Leukocytes:

Answer 8

Granulocytes

• Neutrophils
• Eosinophils
• Basophils/Mast Cells

Agranulocytes

• Macrophages
• Lymphocytes
• Dendritic Cells

Question 9

Lymphocytes

Answer 9

• NK cells
• • innate immunity
• T Cells
• B Cells

Question 10

Dendritic Cells

Answer 10

APC
- primary role not to kill pathogen but to sample it and report its finding to T Cells and B cells (which initiate a immune response)

Question 11

Two primary lymphoid organs, and what is their function?

Answer 11

• Bone marrow
• • B cells mature here
• Thymus
• • Kills self reactive T cells

Question 12

What is and antigen and what is it’s function?

Answer 12

• Antigen is any macromolecule (flagella, cell wall, protein, DNA, RNA, etc) that can be used to accurately recognize pathogens.

Question 13

What is an epitope?

Answer 13

• a unique chemical group on an antigen that elicits a specific immune response
• There can be a lot of epitopes on a single antigen

Question 14

What are BCR and what is their function?

Answer 14

• B-cell Receptor
• it is an antibody that resided in the membrane of a B cell and recognize an array of various pathogens (used for the adaptive immune system)

Question 15

BCR are composed of _____ and _____ proteins

Answer 15

• light chain

- heavy chain

Question 16

The unique region of an antibody is _____ and the common region of the antibody is _____

Answer 16

• variable region (this binds to epitope)

- stem (Fc region)

Question 17

What is TCR and how is it different from BCR

Answer 17

• T-cell Receptors

- they only bind to epitopes presented to them by MHC (TCR have a thing for MHC)

Question 18

What is MHC and what is its function?

Answer 18

• Major histocompatibility complex
• a ubiquitous protein
• all cells have specific MHC unique to each individual (a way to tell apart self from non-self)

func:
aids T cells in recognition of epitope (T cell need to bind to MHC to so that TCR can probe for epitope)

Question 19

Which tissue contains no MHC

Answer 19

blood

Question 20

MHC I present ________ antigen for T cells and binds to ____

Answer 20

• presents endogenous antigens

- binds to CD8 (found on Tc cell)

Question 21

MHC I is found on:

Answer 21

• found on all cells of body

Question 22

MHC II present ________ antigen and binds to _____

Answer 22

• presents exogenous antigen

- binds to CD4 (found on Th cell)

Question 23

MHC II is found on:

Answer 23

Professional Antigen Presenting Cells (APC)

• Dendritic cells
• B cells
• Macrophages

Question 24

What is Cross-presentation of?

Answer 24

• dendritic cells can take up exogenous antigens and present them in MHC I and MHC II pathways
• which allows for activation of Tc and Th cells

Question 25

________ cells can present exogenous antigen in both MHC I and MHC II

Answer 25

Dendritic

Question 26

How does cell mediated immunity begin?

Answer 26

- Dendritic cells engulf pathogen and display their epitope on MHC I and MHC II complex

Question 27

Cells associated with Cell-Mediated Immunity, and their function:

Answer 27

- Dendritic Cells: Present antigen (epitope) to T cells - Th 1 Cells: Activate Tc cells - Tc Cells: target and kill infected cells using TCR (cells that have the epitope presented on their surface due to infection are killed)

Question 28

Dendritic cells release ______ when the both Tc and Th cells bind to the epitope the dendritic cell is presenting

Answer 28

Interleukins

Question 29

What role do interleukins play in activation of Tc cells?

Answer 29

- help undifferentiated helper T cells become type Th 1 | - signal Tc cells to multiply and produce memory T cells

Question 30

How do Tc cells kill infected cells?

Answer 30

- Tc cells recognize infected cell by the presence of pathogen epitope on MHC I - after recognition, Tc cell releases Perforin and Granzymes

Question 31

What is the function of Perforin and Granzymes?

Answer 31

- Perforin: tunnel like proteins that pokes holes in membrane of infected cell - Granzyme: travel through perforin and signals infected cell to commit apoptosis

Question 32

How do NK cells recognize/kill infected cells?

Answer 32

- some infected cells will have low (or no) MHC | - NK cells are able to recognize absence of MHC and delivers perforin/granzymes

Question 33

Cells associated with Humoral-Mediated Immunity, and their function:

Answer 33

- Dendritic Cells: Present antigen (epitope) to T cells - Th 2 Cells: Activate the specific B cells with the BCR that can recognize the epitope from the dendritic cell - B Cells: secrete antibodies

Question 34

IgM (name and function)

Answer 34

- Macroglobulin - first antibody made after activation of humoral immune system - 5 individual antibodies are chained together (looks like star)

Question 35

IgG (name and function)

Answer 35

- Gamma-globulin - replaces IgM - is produced by memory cells, thus it is quickly produced upon secondary infection (infected for a second time by the same pathogen)

Question 36

Five functions of an antibody:

Answer 36

1. Neutralization 2. Opsonization 3. Agglutination 4. ADCC (antibody dependent cellular cytotoxicity) 5. Activation of complement