antibodies

Question 1

where do t cells arise and mature

Answer 1

thymus

Question 2

two types of effector t cells

Answer 2

cytotoxic and helper

Question 3

cytotoxic t cells

Answer 3

they have a cd8 glycoprotein associated with their membrane and lyses foreign or infected host cells

Question 4

helper t cells

Answer 4

they have a cd4 glycoprotein associated with their membrane and secrete cytokines which regulate both b and t cells

Question 5

how are t cells activated

Answer 5

t cell receptros bind to mhc-antigen complexes

Question 6

where do b cells arise and mature

Answer 6

bone marrow

Question 7

naive b cells

Answer 7

when they encounter a foreign antigen they divide into memory and effector cells

Question 8

what can b cells do that t cells cannot

Answer 8

bind to soluble antigens

Question 9

clonal selection theory

Answer 9

it states that an individual b cell expresses receptors specific to the distinct antigen determined before the antibody ever encounters the antigen

Question 10

lymphocytes and their receptors

Answer 10

they each have a single type of receptors with a unique specificity

Question 11

what happens to lymocytes with receptors that are self reactive

Answer 11

they are deleted at an early stage in lymphoid cell development

Question 12

primary immune response

Answer 12

when specific b cells bind their corresponding antigen they proliferate to form effector and memory cells

Question 13

duration of primary immune response

Answer 13

5-10 days

Question 14

secondary immune response

Answer 14

when memory cells are eposed to the same antigen a second which shortens the reponse time to 3-5 days

Question 15

what do hv regions determine

Answer 15

antigen specificity

Question 16

epitope

Answer 16

the region of an antigen ehich interacts with an antibody

Question 17

affinity

Answer 17

measure of strength of binding of an epitope to an antibody

Question 18

epitope types

Answer 18

conformational and linear

Question 19

conformational epitope

Answer 19

they are composed of amino acids from different parts of a polypeptode chain

Question 20

linear epitope

Answer 20

they are composed of amino acids from a single segment of polypeptide chain

Question 21

polyclonal antibodies

Answer 21

they are a heterogenous mix of antibodies derived from b cells

Question 22

what is the main difference between polyclonal and monoclonal antibodies

Answer 22

monoclonal antibodies recognize the same epitope while polyclonal antibodies recognize multiple epitopes of the same antigen

Question 23

what is the process of pAb production

Answer 23

it involves the immunization of the host species with an antigen to induce an immune response

Question 24

which animals are commonly used for isolating polyclonal antibodies

Answer 24

rabbits are mainly used but if large amounts are required sheeps or horses are used

Question 25

why are boost injections provided to host species

Answer 25

if the antibody titre concentrations levels are declining

Question 26

how is the polyclonal antibody isolated

Answer 26

blood is harvested from the animal and centrifuged to isolate the serum containing the antibody. the serum is also purfied

Question 27

advantages of polyclonal antibody production

Answer 27

quick and inexpensive process have a choice of producing antibodies in different animals easy purification process using high-affinity chromatography methods

Question 28

disadvantages of polyclonal antibody production

Answer 28

can only be produced in limited volumes each antiserum is different from others even if isolated from identical animal and uses same protocol and antigen cross reactions can occur even after separation and purification

Question 29

adjuvants

Answer 29

they are substances that increase the immunogenicity of the antigen reducing the amount of antigen required

Question 30

example of adjuvants

Answer 30

freunds complete adjuvant (FCA)

Question 31

monoclonal antibody

Answer 31

they are antibodies that are made by identical immune cells belonging to a single parent cell

Question 32

what is the process of monoclonal antibody production

Answer 32

they are produced by fusing immunized mouse b cells to myeloma cells

Question 33

what does fusing an activate b cell and. myeloma cell produce

Answer 33

it creates hybridoma that can grow continuously in culture and produce antigen-specific antibodies

Question 34

examples of monoclonal antibodies

Answer 34

okt3 and campath-1h

Question 35

okt3 function

Answer 35

okt3 can suppress the immune response in organ transplantation

Question 36

what type of monoclonal antibody is okt3

Answer 36

igG2

Question 37

how does okt3 works

Answer 37

it binds to inhibits cd3 on the surface of circulating t cells

Question 38

campath 1-h function

Answer 38

it targets cd52 antigen found in malignant leukemia cells

Question 39

bl22

Answer 39

helps target cd22 expressing cells

Question 40

hairy-cell leukemia

Answer 40

expresses cd22 at high levels

Question 41

advantages of monoclonal antibodies

Answer 41

high specific recognition of only one epitope of an antigen high consistency in experiments minimal cross reactions

Question 42

disadvantages of monoclonal antibodies

Answer 42

slow rocess and requires high technical skills can be seen as foreign and needs to be humanised

Question 43

tools used for diagnosing monoclonal antibodies

Answer 43

cell staining immunoassay immunoblots

Question 44

what protein is expressed in cell proliferation

Answer 44

ki-67

Question 45

how does ki-67 work

Answer 45

ki-67 is present in the active phases in the cell cycle which can help determinea growth fraction of a given cell population

Question 46

immunoassays

Answer 46

biochmical tests used to detect presence or concentration of specific antigen in a solution

Question 47

immunoblots

Answer 47

the cell is broken down into proteins and separated using electrophoresis. the proteins are transferred to nitrocellulose membrane and overlay with antiserum. antibodies bound to proteins and are detected with enzyme-linked antihuman antibodies

Question 48

antibody purification methods

Answer 48

ammonium sulfate precipitation protein affinity chromatography ion-exchange chromatography

Question 49

ammonium sulphate precipitation

Answer 49

antibodies can be precipitated by salting with ammonium sulphate which separates the antibody from the serum

Question 50

how can ammonium sulphate be removed

Answer 50

dialysis or gel filtration

Question 51

affinity chromatography

Answer 51

isolates antibodies from serum by exploiting antigen-antibody binding based on ligand specificity

Question 52

ion exchange chromatography

Answer 52

antibodies are separated based on the differences in their charge serum flows thorugh a column with positively charged beads and antibodies with a negative charge bind to the beads