autoimmunity 1

Question 1

how many people in the uk have an autoimmune disease and in how many people

Answer 1

4 million
1 in 5 people

Question 2

how many people are affected by rheumatoid arthritis

Answer 2

1 in 100 people

Question 3

what are autoimmune diseases

Answer 3

a family of diseases that are chronic and disabling where the immune system attacks the body’s own tissue and organs

Question 4

what are the risk factors for an autoimmune disease

Answer 4

environmental triggers such as infectious agents
hereditary genes
lifestyle considerations

Question 5

what has a significant effect on autoimmune disease

Answer 5

b cell progression

Question 6

what is the process of a normal CD4 t cell response

Answer 6

APC recognises pathogen
internalisation and interaction with MHC
presentation by MHC
MHC interaction with a TCR complex with peptide
danger signal/ costimulation
t cell proliferation
t cell signal launches immune response via b cell and cd8 cell

Question 7

when will an autoimmune disease occur

Answer 7

when the usual control of lymphocytes are interrupted which interrupts lymphocyte impression
when there is an alteration in cells and tissue meaning they are not longer recognises as self

Question 8

what can trigger the autoimmune response

Answer 8

bacteria, viruses, toxins and some drugs

Question 9

what is tolerance and what happens when this is broken down

Answer 9

the prevention of an immune response to a particular antigen
autoimmune disease

Question 10

if a MHC is interrupted

Answer 10

the person could become more susceptible to an autoimmune disease

Question 11

what does t cell activation consist of

Answer 11

recognition of a self MHC and a foreign antigen

Question 12

what is central tolerance

Answer 12

central tolerance is the elimination of t cells that recognise the body’s self-antigens

Question 13

in central tolerance, where does positive regulation take place and what is the process

Answer 13

thymic cortex
this is where cells that have a receptor that binds with MHC molecules and selected and are allowed to survive
cells that do not interact with MHC molecules are destroyed via apoptosis

Question 14

in central tolerance, what is negative selection and where does it occur

Answer 14

this is where the cells that bind with high affinity to self-antigens and/ or self-MHCs are killed to prevent an autoimmune response
the ones that do not mature into CD8/ CD4
this occurs in the thymic medulla

Question 15

what happens to cells that have an intermediate affinity for a self-antigens

Answer 15

they work as t cell regulators to suppress any reaction to self antigens

Question 16

what is perpherial tolerance

Answer 16

is the deletion or anergy of lymphocytes located outside of the immune organs that recognise self-antigens

Question 17

what is anergy

Answer 17

anergy is the lack of response to an antigen

Question 18

what can cause anergy in t cells

Answer 18

lack of accessory signals in the present in the engagement of TCR and MCH peptide

Question 19

what do treg cells repsond to to produce an inhibitory response and why

Answer 19

antigens
to suppress t cells from self reacting

Question 20

why is anergy important when a t cell does not have accessory signals present

Answer 20

to prevent self reactivity

Question 21

what can happen to a cell with low self antigen affinity but why can this be a problem

Answer 21

they can escape tolerance
if a stimulus is strong enough, they can be activated

Question 22

how do t cells distinguish self from non-self (three wyas)

Answer 22

-they must encounter the ligand (self antigen) when the they are still immature
-when there is a high and constant concentration of ligand
-bing to the ligand without costimulation

Question 23

why do b cells need to be taught self tolerance

Answer 23

as antibodies can react to self-antigens and either trigger the complement system or opinization

Question 24

when does central tolerance occur in b cells and where

Answer 24

when the immature b cell is presenting igM
in the bone marrow

Question 25

what happens to b cells that bind to self antigens

Answer 25

cell death

Question 26

when does cell death occur in b cells during negative selection

Answer 26

if there is crosslinking of igM on immature b cells to a self antigen

Question 27

what experiment did Nemazee and Burki complete

Answer 27

testing the negative selection of b cells expressing autoimmunity

Question 28

what happens if b cells have no strong reactivity to self-antigens

Answer 28

they are allowed to mature

Question 29

how are b cells saved from negative selection

Answer 29

light chain editing