L1- Introduction

Question 1

Immune system Evolution:

Name the organisms whose immune systems are based on phagocytic cells only

Answer 1

sponge - porifera
Starfish - Echinoderms
Tunicate - Primitive chordates

Question 2

Immune system Evolution:

Name the organisms whose immune systems are based on phagocytic cells and appearance of lymphocytes

Answer 2

Jawless fish - lamprey

Question 3

Immune system Evolution:
Name the organisms whose immune systems are based on phagocytic cells and lymphocytes that separate into B cells and T cells

Answer 3

Sharks- cartilaginous fish
Bony fish
Frog - amphibians
snake - reptiles
Duck - birds
humans - mammals

Question 4

In mammals, where is the centre of haematopoiesis?

Answer 4

The bone marrow

Question 5

What is RAG?

Answer 5

Recombinant activated genes.

RAG mediated immunity is incredibly important in mammals

Question 6

In mammals, what % of immune cells are in the gut

Answer 6

70%

Particularly dendritic cells

Question 7

Where do young T cells travel to mature?

Answer 7

The thymus

Question 8

What cells do the spleen synthesise?

Answer 8

B antibodies (about 50% are monocytes)

Question 9

What type of cells are dendritic cells?

Answer 9

Phagocytic and antigen presenting cells

Question 10

What is the number of different cells in the immune system?

Answer 10

10 to the power of 12

Question 11

How many cell types are involved in the immune system?

Answer 11

> 10

Question 12

What is the number of cells in the brain?

Answer 12

10 to the power of 11

Question 13

What is the number of different cells in the brain?

Answer 13

2

Question 14

Where is the immune system?

Answer 14

• in the blood

- in the lymphatics and lymph organs

Question 15

How much of the blood is plasma?

Answer 15

55%

Question 16

How much of the blood is WBC

Answer 16

1%

Question 17

How much of the blood is RBC?

Answer 17

44%

Question 18

What is serum?

Answer 18

plasma without clotting factors

Question 19

Where do WBC circulate?

Answer 19

Within the blood

Question 20

Where does cellular interaction of immune cells occur?

Answer 20

In the lymphatic system (not in the blood)

Question 21

Some WBC and a bit of plasma leave capillaries in tissues

Answer 21

As overleaf

Question 22

What does the circulation of WBC and plasma through interstitial space/tissues and back via lymphatics to lymph nodes allow?

Answer 22

Surveillance of tissues for foreighn molecules and pathogens

Question 23

What do neutrophils, basophils and eosinophils do?

Answer 23

Attack a variety of pathogens by phagocytosis (phagocytic cells) or with anti-microbials and histamine released after degranulation

Question 24

What do plasma cells (derived from B-lymphocytes) do?

Answer 24

Secrete large amounts of antibodies

Question 25

What is the role of monocytes and macrophages?

Answer 25

Phagocytose (phagocytic cells) and regulate many aspects of innate and adaptive immune responses

Question 26

What is the role of B and T-lymphocytes

Answer 26

Orchestrate the adaptive immune response and provide immunological memory

Question 27

What does the immune system do?

Answer 27

It discriminates between self and non-self and protects us against pathogens bacteria, fungi, parasites and viruses.

Question 28

What molecules are pathogens usually covered in to have its own molecular signature (antigens)?

Answer 28

PAMPS

Question 29

What do immune cells have to recognise PAMPS?

Answer 29

Immune cells have PRR that recognise the pathogen PAMPS

Question 30

What are an example of PAMPS recognised by the innate immune system PRR?

Answer 30

Nucleic acid - CpG motif DNA (bacteria), ssRNA (viruses), dsRNA (viruses) Conserved stress proteins - heat shock proteins (bacteria) Conserved surface proteins - Flagellin (bacteria) Cell wall components - Peptidoglycan (bacteria), LPS (G+ bacteria) and Galactomannans (fungi)

Question 31

Name the soluble receptors

Answer 31

- Natural antibodies - Complement - Pentraxins - Collectins - Ficolins (all PRRS)

Question 32

Name the cell receptors

Answer 32

- TLR - NOD-like receptors - RIG-like receptors - C-type lectin-like receptors - Scavenger receptors - N-formyl met-leu-phe receptors

Question 33

Describe the Innate immunity

Answer 33

- Descriminate self and non-self - Receptors encoded in germline - Typically recognise structures common to different microbes Binding of PAMPS to PRR on phagocytic cells leads to innate immune response, which is fast and does not require immunological memory.

Question 34

Describe adaptive immunity

Answer 34

- Can discriminate self and non-self - Receptors encoded by gene recombination - massive diversity - Typically recognise structures unique to different microbes Adaptive is slower than innate and is activated by a cascade of chemical signals from site of infection, and physical interactions betweenphagocytic cells of innate immune system known as DENDRITIC cells that migrate from site of infection into the lymphatic system to activate lymphocytes

Question 35

Cytokines and chemokines are released where?

Answer 35

At the site of infection by resident macrophages and recruit neutrophils from the bloodstream leading to localised inflammation (look at picture)

Question 36

Lymphocytes and adaptive immune response - T-lymphocytes and B-lymphocytes: What they express?

Answer 36

A vast repitoire of recognition receptors: B-lymphocytes express antibodies as B cell receptors (BCRs) while T-lymphocytes express T cell receptors (TCRs). During adaptive immune response, B and T lymphocytes with receptors specific for particular pathogen molecules proliferate. Clonal selection and expansion forms the basis of protective immunity and immunological memory through which the body is protected against future attack.