W1/Q1 Immunology intro

Question 1

Study of the molecules, cells, organs (immune system) responsible for responding to foreign material

Answer 1

Immunology

Question 2

How does immunology/immune system work?

Answer 2

The immune system recognizes and eliminates foreign/”non-self” material

Question 3

Activation - TCR bind and recognize cognate ligand antigen from MCH 2.
Creates cytokines -> Role - Activation of B and Tc cells

Answer 3

TcR-CD4+ T helper cells : Activation/Role

Question 4

Activation - TCR bind and recognize cognate ligand antigen from MCH 1.
Role - kill infected/damaged cells

Answer 4

TcR-CD8+ T cytotoxic cells : Activation/Role

Question 5

• non-specific- responds to groups, not individual pathogens
• fast - full capacity ready, many cells present, deployed rapidly
• no memory - multiple exposures create no memory, response is not augmented

Answer 5

Innate immune system characteristics

Question 6

• specific - responds to a pathogen / foreign element
• slower - few cells have potential to respond, need activation and expansion
• memory - secondary exposures -> robust and fast response

Answer 6

Adaptive immune system characteristics

Question 7

activation - B cells proliferate -> plasma cells secrete antibodies which combines with antigen; allows for immune system to Identify and neutralize pathogens aka antibodies

Answer 7

BcR

Question 8

1st line of defense
Polymophonuclear cells (PMNs)
Segs (segmented)
Innate immunity
Circulating granulocyte
50-75% of WBCs
- Primary phagocyte and initiator of inflammation after a cut/scrape
- Main component of pus - yellow/white
- Granules w/toxic reactive oxygen species (ROS) to kill pathogens

Answer 8

Neutrophils
Foot soldiers - kill pathogens

Question 9

Tissue specific
Expansions of outer membrane -> “decoration”
Innate immunity
Bridge between innate and adaptive immunity
Myeloid line
CD11C
- Phagocytosis of antigens and presentation to helper T lymphocyte
- Most potent phagocytic cell in tissue

Answer 9

Dendritic cells (Dcs) 
Foot soldiers/informants - Present and kill pathogens

Question 10

Kill and present pathogens
Clean up
Innate immunity
Non-granulocytic myeloid cell
4-10% of WBCs
CD11b, CD14
- Phagocytes eat pathogens
- Present pathogen bits (antigens) to T cells
- Clean up debris from immune “fights”

Answer 10

Monocytes/Macrophages (MACs)
Foot soldiers / informants

Question 11

Direct or stop B cells and CD8 Tc cells
TCR***

Answer 11

T lymphocytes (CD4 T helper)

Question 12

Kill infected cells
Adaptive immunity

Answer 12

T lymphocytes (CD8 T cytotoxic)

Question 13

Produce antibodies that neutralize/kill pathogens long distance
adaptive immunity
Archers/drone controllers

Answer 13

B lymphocytes

Question 14

Circulating granulocyte
Myeloid line
0-2% WBCs
- Release histamines and other inflammatory mediators in allergic disease
- Regulate some T helper cell responses and stimulate B cells to produce IgE
* Mast cells are similar but in tissues

Answer 14

Basophil/Mast Cells

Question 15

Myeloid line
1-3% WBCs
- Primary phagocyte against multicellular microbes (parasites)
-Neutralize basophil and mast cell products
- Regulation of mast cell function

Answer 15

Eosinophils

Question 16

lymphoid line
10-15% of WBCs
CD56
- Kill tumor/infected target cells (does not need earlier exposure to them)
- Can be directly activated by no inhibitory signal or ADCC

Answer 16

Natural Killer Lymphocytes/Cells

Question 17

MHC class 1 protein is expressed on healthy self cells and creates an inhibitory signal

• diseased/cancerous cells tend to lose MHC class 1 proteins -> killing of cells
• activating receptors engage with target cells and will result in killing unless inhibitory receptors are engaged

Answer 17

NK activation by Lack of inhibition

Question 18

IgG binds to target cell through Fc portion and CD16 receptor -> IgG coated cells are bound and destroyed
- NK cells can recognize and lyse antibody - coated cells

Answer 18

NK activation by ADCC

(Antibody dependent cell cytotoxicity)

Question 19

Perforins and granzymes are injected into cells (after activation)
- Cytokines produced (tumor necrosis factor)

Answer 19

NK Killing

Question 20

Proteins that form channels (pores) in the target cell membrane

Answer 20

Perforins

Question 21

Packets of enzymes that may enter through the channels and mediate cell lysis

Answer 21

Granzymes