Innate and adaptive immunity

Question 1

What personal history quesitons ask immunology

Answer 1

Autoimmunity
Malignancy
Immunisation history
Operations - grommets, lobectomies

Question 2

What is innate immunity

Answer 2

Pre-existing degences eg first line, immediate response
Broad types of threat responds generally
No change in repsonse w repeat exposure

Question 3

What is the adaptic immune systeme

Answer 3

Recognises and responds to specific threats
Highly tailored reponse
Takes time
Stronger/faster w repeated exposure - immunological memory

Question 4

What does germline encoded mean

Answer 4

Receptors for innate immune system coded for by DNA already possessed

Question 5

How does adaptive immune system produce receptors

Answer 5

Somatic recombiantion of gene segments

Question 6

Innate immune cells

Answer 6

Phagocytic - neutrophils, macrophages
Dendritic cells (antigen presenting)
Natural killer cells
Complement
Cytokines

Question 7

Phagocytes

Answer 7

Monocytes - macrophages
Neutrophils
Basophils
Eosinophils
Dendritic cells

Question 8

Granulocytes

Answer 8

Neutrophils
Basophils
Eosinophils

Question 9

Monocytes vs macrophage

Answer 9

monocytes - in blood stream
In tissue = macrophages

Question 10

Macrophage fucntion

Answer 10

Engul and kill pathogens by phagocytosis
Secrete cytokines
antigen presenting cell

Question 11

How does the dendritic cell link innate and adaptive immune systems

Answer 11

Phagocytosis
Ingests ECF - presents antigens on MHC molecule to TH cells

Question 12

What is a NK cell

Answer 12

Large granular lymphocyte
Kill infected cells and tumour cells

Question 13

What is an epitope

Answer 13

Paritcular part of antigen recognised by innate or adaptive immune system receptor

Question 14

Antigen presenting cells + what express

Answer 14

Dendritic cell
Macrophage
Express MHC II

Question 15

Types of addaptive immunity

Answer 15

Cell mediated eg CD4+ and CD8+ T lympgocytes
Humoral - B lymphocytes nad antibodies

Question 16

Are all B or T cell receptors on surface of one cell the same

Answer 16

YES - one B or T cell has one type of B or T cell receptor - one specificitty
Need the number of cells for variety of receptors

Question 17

What cells produce antibodies

Answer 17

B cells

Question 18

Antibody structure

Answer 18

2 heavy chains in middle
Two light cahins on outside
Identical to their partner
Variable region = antigen binding site = upper section
Constant region = lower

Question 19

Structure of T cell receptors

Answer 19

2 different polypeptide chains - alpha and beta

Question 20

When can TCRs recognise antigens

Answer 20

ONLY when attached to MHC molecule - I or II

Question 21

Which T cells are cytotoxic vs helper

Answer 21

CD8+ = cytotoxic
CD4+ = helper

Question 22

What do CD4 and CD8 determine what T cell can do

Answer 22

Which MHC class molecule can attach to =
CD4 - MHC class II on APCs
CD8 - MHC I on any cell

Question 23

How are CD4 Thcells activated

Answer 23

TCR and CD4 bind to antigen-MHCII complex on APC

Question 24

What do CD4 Th cells do after activation

Answer 24

Multiple and form effector cells -> migrate to site of inflammation and produce cytokines directing immune repsonse

Question 25

What do cytokines from daughter effector Th cells do

Answer 25

B cells produce antibodies Recruite macrophages

Question 26

Role of CD8 T cells

Answer 26

Kill infected cells preenting antigen with MHC I on surface

Question 27

What is a B cell receptor

Answer 27

Membrane bound antibody

Question 28

How are B cells activated to release antibodies

Answer 28

Antigen binds to B cell receptor -> internalises and antigen is broken down MHC II-antigen complex presented and binds to CD4 T helper cell Activates B cell

Question 29

Tissues of the immune system

Answer 29

Primary lymphoid tiseeus - bone marrow and thymus

Question 30

Where do B cells and T cells originate from

Answer 30

B cells - bone marrow T cells - thymus

Question 31

What are the peripheral lymphoid tissues

Answer 31

Lymph nodes Spleen MALT in gut

Question 32

Purpose of peripheral lymphoid tissue

Answer 32

Antigen and lymphocyte to come together - allows adaptive immunitiy Dendritic APCs migrate to here in lymph via lymphatics Naive lymphocytes circle lymph nodes via blood stream

Question 33

What is lymph and what it does

Answer 33

ECF from all tissue containing APCs bringing peripheral antigens from tissues into lymphatics

Question 34

How is lymph circuclated

Answer 34

Drains in series of afferent lymphatic vessels into seconadry lymphoid tissues Fluid/lymph leaves via efferent lymphatic vessels -> collecting duct eg thoracic duct Drains into bloodstream via heart

Question 35

Circulation of lymphocytes

Answer 35

Naive -> lymph nodes from blood ->smaple environment for antigen on APCs. If encounter activated to effector cells -> efferent lymphatics -> thoracic duct -> blood Effector cells -> site of infection Naive cells -> lymph nodes again

Question 36

Passive immunity features

Answer 36

Transfer of anitbodies Cross-placental transfer most common Transusion Gives temporary protection, only few weeks or months

Question 37

Family history to ask in immunology

Answer 37

Serious infections Immunodeficiencies AI disease Unexplained sudden deaths

Question 38

Medication history what to ask for

Answer 38

Lamotrogine - combined ID phenytoin - reduced Igs and pesudolymphoma

Question 39

What can phenytoin do to immune system

Answer 39

hypogammaglobulinaemia (reduced IGs) and enlarged lymph nodes (psuedolymphoma)