3: L14

Question 1

what is inflammation characterised by

Answer 1

o	Swelling (tumor) 
o	Redness (rubor) 
o	Heat (calor) 
o	Pain (dolor)

Question 2

What organs are immune privileged and what does that mean

Answer 2

o Developed own strategies to control
o Susceptable to tissue damage // cannot repair
o Immune response may actually damage structures resulting in loss of function

Question 3

2 Types of immune suvrailence

Answer 3

Humoral + cellar

Question 4

what are the two divisions of cellular immuntiy

Answer 4

innate + adoptive

Question 5

Neutrophil Granulocytes & Macrophages function

Answer 5

take foreign particles and destroy them in lysosomes

Question 6

Difference between neutrophil and macrophage

Answer 6

N= mobile, die after phagocytosis, 24hr life

M= months life, can engulf many pathogens, act as antigen presenting cells to T cells

Question 7

Eosinophilic & Basophilic Granulocytes Mast cells , NK-cells function

Answer 7

deliver substances
kill parasites/tumur cells
induce or support inflammatory responses

Question 8

function of M cells

Answer 8

• Transport antigens from lumen to lamina propria AG not normally allowed to cross lining

Question 9

function of dendritic cells

Answer 9

• DCs Take up antigens from their environment

• Activate phagocytic cells
• Present antigens on MHC surface molecules to T-lymphocytes

Question 10

follicular dendritic cells function

Answer 10

present antigen to B-lymphocytes

Question 11

what are b lymphocytes also called

Answer 11

plasma cells

Question 12

how are early b cells activated and their function

Answer 12

activated according to surface receptor (specific to AG) – = cells then “primed”
o Recognised with help of T cells and FDC they mature into plasma cells

Question 13

plasma cell function

Answer 13

• Plasma cells: antibody production in lymphatic or migrate to other tissues
o Some ABs expressed on surface (eg IgA important in gut etc)
• Plasma cells make IgM / IgG

Question 14

what do memory b cells do

Answer 14

react faster to same AG, mature cells, FDC not required activate

Question 15

• Function of Antibodies

Answer 15

o Bind to antigenic (AG) molecules , Neutralize toxins
o Help phagocytosis, virus neutralisation
o Vaccines work by specific AB produced over long time

Question 16

where is IgA, G and M distributed to

Answer 16

• IgA - Added to secretion of glands , Tears , Nasal cavity , Bronchial surface , Gastrointestinal surface
• IgG & IgM - Delivered to blood and extracellular liquid
• Light chains + heavy chains (small/large connected by bonds)

Question 17

the production of antibodies is the main function of what system

Answer 17

humeral

Question 18

describe the ‘constant region;

Answer 18

Bottom of Y connects to cell surface (if antibody expressed on cell surface, this is what membrane binds tw), morphology more common to other antigens)
o Top arms of the Y= binds to antigen itself (each antigen= specific antigen site)

Question 19

what’s a light/heavy chain

Answer 19

on antibody- light chain is singular piece, heavy chain connect bottom of y to top

Question 20

Describe the primary AB response- first encounter antigen

Answer 20

• B cells differentiate and activate- produces IgM (penta structure), + small amount of IgA (bc of 5 binding sites // mop up more antigen (despite being weaker immune response than IgG)

Question 21

Describe the secondary AB response- second encounter antigen

Answer 21

larger IgG response as stronger immune response

Question 22

describe why the antibody class switch from primary (M) to secondary (G)

Answer 22

o Within B cell germline, different parts of chromosome responsibly for particular parts
o V region (AB binding site)= V, D, J cites = splicing
• Different antibody combine DVJ in different sequences= permeablity + almost endless variation

Question 23

what are the two types of lymphocytes

Answer 23

Cytotoxic T-cells (CD8+)

Helper T-cells (CD4+)

Question 24

what do Cytotoxic T-cells (CD8+) do

Answer 24

• Recognise foreign bodies – activated CTL
• Kill virus infected cells
• Kill tumour cells

Question 25

what do Helper T-cells (CD4+) do

Answer 25

• Produce cytokines = hormone-like soluble factors
• Regulate immune response through cell surface molecule interaction (cell:cell)
• Regulate and Support B-cell differentiation (recognise same AG)
• Recognise different parts of same AG (epitopes)
• Support cytotoxic T-cell function (CD8+ must be activated (c.f. NK cells))

Question 26

describe the steps of Cytotoxic T-cells (CD8+)

Answer 26

1. Infected cell= presentation of antigen molecule with CD8 marker + class 1 MHC (t cell recognises not normal cell + extra markers)
2. Responds to these = production of active cytotoxic t cells
3. = Produce lymphotoxin etc =designed to puncture and degrgade cell
   • Main driver= t cell receptor and CD8 molecule= complex created

Question 27

describe the steps of Helper T-cells (CD4+)

Answer 27

1. Other cell degrade infected cell and presents antigens to T helper cells (presents Class II MHC co-localised with CD4)
2. = activated + cell division > release cytosine
3. Targets cell to destroy
4. And memory cells primed and activated

Question 28

describe MHC protein role in ummuno

Answer 28

cell phagocytise pathogen/abnormal peptides and bind MHC to the unusual product (MHC Class II on the antigen presenting cell, and Class I on the peptides)

abnormal fragments displayed on membrane by MHC

Question 29

What does class 1 MHC activate

Answer 29

abnormal cell= CD8 T cells

Class II= presence of pathogen // CD4

Question 30

What are cytokines

Answer 30

Chemical messengers released by tissue cells:
• to coordinate local activities
• to act as hormones to affect whole body
Stimulate T cell divisions:

Question 31

difference between Th1 and 2 cytokines

Answer 31

TH1= Pro inflamm
Th2= antinflamm

Question 32

what do alpha, beta and gamma interferons do

Answer 32

• Released by activated lymphocytes and macrophages (usually by virus)
• Alpha interferons: produced by leukocytes stimulate NK cells
• Beta interferons: secreted by fibroblasts slow inflammation
• Gamma interferons: secreted by T cells and NK cells, stimulate macrophage activity