L2.2 (L5) Recognition of AGs by AIS

Question 1

pros of innate issume system (IIS)

Answer 1

immediate

Question 2

cons of IIS

Answer 2

• has limited no of receptors

- no memory generated

Question 3

pros of AIS

Answer 3

recognition of wide range of pathogen

• have memory cells to respond to upcoming infections
• response rapid and efficient upon re exposure

Question 4

cons of AIS

Answer 4

response to primary infection is slow aorund 5 - 10 days

Question 5

relationship between AIS and IIS

Question 6

what do cells fromAIS recongise

Answer 6

specific pathogen AGs

Question 7

what are AGs

Answer 7

molevules that induce immune response through activation of AG specific lympohocytes

Question 8

structures that can act as AG s

Answer 8

proteins, DNA, lipids, carbs

Question 9

function of b cells

Answer 9

secretes specific ABs

Question 10

structure of ABs

Answer 10

• has heavy and light regions
• hinge regions for flexibility
• variable regions
• constant regions

Question 11

what is the constant region

Answer 11

stays the same no matter what the pathogen is

Question 12

what is the variable region

Answer 12

different as it’s specific to pathogens

Question 13

where are the hyper varaible regions found

Answer 13

at the sites of AG binding

Question 14

process of responses of B lymphoctes to AG binding

Answer 14

AG recognition> activation> proliferation> differentiation > outcomes like

• AB secretion
• isotype switching
• affintity maturation
• memory B cell

Question 15

what kind of AG can only T cells respond to

Answer 15

peptide due to having MHC

Question 16

what does T cell have that is similar to B lymphocytes

Answer 16

T cell receptor have a structure that is similar to to Fab section of the AB or the B cell

Question 17

what sections or subunits does T cell have in their structure

Answer 17

alpha and beta

Question 18

where are the T cell receptors found

Answer 18

on the surface

Question 19

does T cell secrete AB s

Answer 19

no

Question 20

what happens when the AG binds to T cell receptor

Answer 20

there is a signalling complex (CD3) associated with the receptor
-once the binding occur, the complezx is activated and initiates signalling casade like phopphorylation

Question 21

what is MHC

Answer 21

major histocompatibility complex containing genes coding for cell surface proteins essential for the adaptive immune system. These cell surface proteins are called MHC molecules.

Question 22

types of MHC molecules

Answer 22

class I and II

Question 23

any another glycoproteins on the surface of the T cell

Answer 23

CD4 AND CD8

Question 24

What does CD4 interact with

Answer 24

class II MHC surface molecule

Question 25

what does CD8 interact with

Answer 25

class I MHC molecule

Question 26

what cells have MHC class I on their surface

Answer 26

alomost very cell

Question 27

what cells have MHC class II

Answer 27

immune cells in the lymphoid tissues like T cells, B cells, Macrophages, dendirtic cells

Question 28

pathway of the response of T lympohcytes to AG binding

Answer 28

AG recognition>lymphocyte activation > proliferation(takes time)> differentiation> effector functions like - activation of macrophages, B cells, inflammation - killing of infected cells

Question 29

what is CDR

Answer 29

complementary determining regions | - polypeptide sequence of AB that is responsible for its recognition by lymphocytes.

Question 30

how are ABs generated from the gene to the protein

Answer 30

using germline DNA to make the seqs for the chains - the J part joins the genes for Variable and constant regions together for mRNA - makes the polypeptide chain

Question 31

how can diversity generated in the gene for ABs

Answer 31

- recombo for gene segments - an enzyme (tdt) tgat is DNA polymerase nserts N-nucleotides to the V (D) J gene segment during rearrangements of genes - somatic hyper mutation for b cells - allelic exclusion

Question 32

what is allelic exclusion

Answer 32

- process by which only one allele of a gene is expressed while the other allele is silenced) - prevents the rearrangemnt of 2nd chromosome