Immunology 1

Question 1

what are the four major features of the immune system?

Answer 1

• tolerance
• specificity
• memory
• diversity (10^6)

Question 2

describe the layers of the immune response and the time taken to respond

Answer 2

• mechanical defense (skin, saliva, mucous membranes, immediate/continuous)
• innate immunity (minutes to hours)
• adaptive immunity (3-4 days)

Question 3

what components of the immune system are not cells?

Answer 3

cytokines and prostaglandins are proteins, bone marrow, spleen and thymus are organs

Question 4

what common cell type do immune cells derive from?

Answer 4

pluripotent hematopoietic stem cells

Question 5

where do pluripotent hematopoietic stem cells reside?

Answer 5

in the bone marrow

Question 6

what do pluripotent hematopoietic stem cells give rise to?

Answer 6

myeloid and lymphoid derived cells (all cells of the immune system and other blood cells)

Question 7

what are examples of myeloid cells?

Answer 7

such as granulocytes, monocytes, erythrocytes and megakaryocytes

Question 8

describe the potency of the cells that the pluripotent hematopoietic stem cells divide into

Answer 8

divides asymmetrically into one more HSC and one either myeloid stem cell or a lymphoid stem cell

Question 9

myeloid and lymphoid stem cells are?

Answer 9

multipotent

Question 10

what ensures correct differentiation of HSC and etc is occuring?

Answer 10

cytokines

Question 11

what are the four types of cytokines?

Answer 11

• chemokines
• interleukins
• interferons
• Tumor necrosis factor (cell death or T cell stimulation)

Question 12

describe the timeline of a viral infection

Answer 12

interferons immediatley respond, NK cells begin to increase with viral titer
after 3 days cytotoxic T cells increase, and after 5 days antibodies begin to rise

Question 13

why does tissue damage increase with cytotoxic T cell levels?

Answer 13

because the cytotoxic T cells are killing virally infected cells in those tissues

Question 14

what is the generalised response to infection/injury?

Answer 14

inflammation to eliminate cause of infection and create environment for the adaptive immune response

Question 15

what are the tissue resident APCs?

Answer 15

dendritic cells and macrophages

Question 16

what are the phagocytes of the tissues?

Answer 16

dendritic cells, macrophages and neutrophils (from blood)

Question 17

what mechanisms do phagocytes have/use to recognise pathogens?

Answer 17

• pattern recognition receptors (TLRs and C-type lectin receptors)
• FC receptors
• complement receptors

Question 18

what feature of dendritic cells is the link between innate and adaptive immunity?

Answer 18

PRRs such as TLR4 which recognise PAMPs (common features of microbes)
- then dc activation leads to adaptive or

Question 19

what happens when a dendritic cell/APC PRR binds PAMPs?

Answer 19

DC activation - inflammatory cytokine secretion, upregulation of co-stimulatory molecules, movement to lymph nodes to activate adaptive immunity

Question 20

how do NK cells recognise infected cells?

Answer 20

through a balance of activating and inhibitory receptors
- if an NK cells binds its killing activating receptor to an NK ligand on target cell

Question 21

what are NK cell roles?

Answer 21

Anticancer agents
Keep virus infections contained while adaptive T cell response is initiated

Question 22

what is the inhibitory ligand for NK cells?

Answer 22

MHC class 1 (dont kill this cell signal)

Question 23

how do NK cells kill?

Answer 23

perforin and granzymes

Question 24

what are the four functions of pro-inflammatory cytokines

Answer 24

1. recruit cells to area
2. cell differentiation and activation
3. increase vascular permeability
4. coordination of response to virus/bacteria