Linking Innate & Adaptive Immunity

Question 1

What are white blood cells?

Answer 1

A minor constituent of blood but they are the main cells involved in immunity

Question 2

Where are dendritic cells present?

Answer 2

In major organs

Question 3

What do dendritic cells do?

Answer 3

Phagocytose (gobble up) antigen and process it down to peptides

Question 4

Where do dendritic cells migrate?

Answer 4

From organs (skin) to draining lymph node

Question 5

What do dendritic cells present?

Answer 5

Peptides on MHC to other which blood cells (called T cells)

Question 6

What can antibodies do?

Answer 6

Block the interaction between a molecule and its receptor

Question 7

What can cytotoxic T cells do?

Answer 7

Come along and recognise an infected cell

Question 8

What is APC?

Answer 8

Antigen presenting cell (includes any cell which can present antigen to T cell) lump

Question 9

What are the two types of T cell?

Answer 9

CD4 and CD8

Question 10

What is CTL?

Answer 10

Killer cells which produce molecules that can kill virus infected cells (perforin/granzyme)

Question 11

What are TCR?

Answer 11

T cell receptors

Question 12

What are CD4/CD8?

Answer 12

Co-receptors

Question 13

What are MCH-I and MCH-II?

Answer 13

Major histocompatibility complex class 1 and 2

Question 14

What does CD4 do?

Answer 14

Send chemical signals/cytokines to other cell types (B cells and CD8)

Question 15

What do B cells do?

Answer 15

Differentiate into plasma cell which produces lots of antibody

Question 16

What does CD8 do?

Answer 16

Make CTL killer cells

Question 17

What do perforin/granzyme do?

Answer 17

Cause lysis of infected cells (virus/cancer)

Question 18

What is an antigen?

Answer 18

Anything that has the potential to be recognised by the immune system

Question 19

What is a foreign antigen?

Answer 19

Anything from outside- transplants, pathogens and some chemicals

Question 20

What is auto (self)-antigen?

Answer 20

Immune system is normally tolerant of self-antigen. Self-antigen may be recognised in autoimmune disorders (rheumatoid arthritis or type 1 diabetes)

Question 21

What is the purpose of antigen uptake (innate response)?

Answer 21

Clearance of pathogens

Question 22

What is the purpose of antigen uptake (adaptive response)?

Answer 22

For presentation to T cells

Question 23

when did adaptive immunity evolve in vertebrates?

Answer 23

500 million years ago

Question 24

Why did phagocytes evolve?

Answer 24

To keep remnants of pathogens and display these to other cells of the immune system (beginning of adaptive immune response)

Question 25

What do invertebrates have?

Answer 25

Innate immunity only

Question 26

What do vertebrates have?

Answer 26

Both innate and adaptive systems

Question 27

What do jawless fish have?

Answer 27

They are vertebrates with both innate and adaptive systems but their adaptive system is based off different structures compared with other vertebrates

Question 28

What happens with peptides from antigens?

Answer 28

They are loaded onto MHC molecules for immune surveillance (waiting to be recognised by T cells)

Question 29

What does MHC-I present?

Answer 29

Endogenous (intracellular) antigen

Question 30

What is MHC-I expressed on?

Answer 30

All nucleated cells (not red blood cells as they don't have a nucleus)

Question 31

What does MHC-II present?

Answer 31

Exogenous (extracellular) antigen

Question 32

What is MHC-II expressed on?

Answer 32

Only on antigen presenting cells

Question 33

What happens first in MHC-I antigen processing?

Answer 33

Antigenic proteins are degraded to peptides in cytoplasm

Question 34

What happens after antigenic proteins are degraded to peptides in the cytoplasm?

Answer 34

Peptides are imported into endoplasmic reticulum (ER)

Question 35

What happens after peptides are imported into endoplasmic reticulum?

Answer 35

Peptide loading of MHC-I takes place in ER

Question 36

What happens first in MHC-II antigen processing?

Answer 36

Antigenic proteins are degraded in acidic phagolysosome

Question 37

What happens after antigenic proteins are degraded in acidic phagolysosome?

Answer 37

Peptide loading of MHC-II takes place in phagolysosome