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Flashcards in Monoclonal antibodies 2 Deck (25)
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1
Q

uses of monoclonal antbodies

A
  • diagnostic pathology
  • in vitro diagnostic asses based on e.g. ELISA, lateral flow assay etc
  • affinity purification and characterisation of antigen
2
Q

there was a limited use of mouse mABs in vivo until fairly recently due to

A

not having phage display or hybridomal technology

3
Q

diagnostic pathogly

A

cytology and histology- ca identify cancerous cells e.g. breast cancer screen-specific abnormalities on antigens of cancerous cells, which can be targeted by specific antibodies

4
Q

there is a need to

A

‘humanise’ monoclonal antibodies

5
Q

why is there a need to humanise monoclonal antibodies

A

have to be disguised as human- otherwise human immune system will recognise them as foreign and destroy them

6
Q

if yu put a mouse antibody into a human you have

A

around 5 days until it will be destroyed

7
Q

immunogenicity of mouse antibodies in humans

A

most mAbs used in vivo are of mouse orpine and therefore XENOGENEIC resulting in HAMA reactions-

8
Q

HAMA

A

Human antibody mouse antibody

9
Q

Origin of antibody

A

mouse origin dimishd their ability to elicit effector mechanisms such as complement, mediated lysis or ADCC

10
Q

humanisation

A

use of xenanoantibodies in human patients has proved severley limiting owing to their being foreign proteins- recognised by the patients immune system

11
Q

strategies adopted to increase the human content of antibodies which have been proven in clinical trial include

A

1) production of human hybridomas and human B lymphocytes
2) replacement of the constant regions of mouse mAbs (powerful) with those of human antibodies yielding CHIMERIC antibodies
3) replacement of CDRs of human antibody with those of a mouse antibody via CDR gifting to make humanised antibodies
4) production of fully humanised mAbs in transgenic mice

12
Q

production of human hybridomas

A

ethical issues and low efficiency

13
Q

replacement of constant regions of mouse mAbs (powerful) with those of human antibdoies- yielding chimeric antibodies

A

leaving really important VH/VL parts of the Fab fragments from the mouse

14
Q

replacement of CDR of human antibody with those of a mouse antibody via CDR grafting to make a

A

humanised antibody

15
Q

genetic engineering of monoclonal antibodies

A

take a human IgG1 antibody, the constant region of a human antibody and replace the VH/VL with that of the mouse- chimeric
- contains some mouse proteins- specific binding - still have all the human parts which will react with complement, ADCC etc

16
Q

chimeric antibodies

A

replacement of all constant regions with those of a human antibody e.g. constant regions of Fab and Fc

17
Q

Herceptin is

A

humanised- CD grafting

18
Q

rituximab

A

chimeric

19
Q

difference between chimeric and humanised antibodies

A

chimeric antibodies- constant regions ar humaan, variable regions are mouse

Humanised- the antibody is human, but CDRs from specific mouse antibody has been grafted

20
Q

CDR grafting

A

take a human antibody nd swap out the CDRs with the CDRs of a mouse- so the hyperaribale egoism are specific to the antigen of interest

21
Q

CDRs are the

A

part of the variable chain in immunoglobulins and T cell receptors- generated by ba nd T cells respectively
- where these molecules bind tot heir specific antigen

22
Q

a set of CDRs constitutes a

A

paratope

23
Q

as the most variable part of the molecules CDRs are..

A

crucia to the diverts f antigen specificcies generated by lymphocytes

24
Q

antibody expression in chinese hamster ovary (CHO) cells

A

1) mouse monoclona cell line
2) mRNA for variable domains extracted
3) cloned nto mammalian expression vector
4) transfected into CHO cell line
5) constant domains can be any human or murine isotopes
6) these will grow in vitro and will produce human antibodies with CDRs of the mouse

25
Q

drug which uses phage display synthetic antibodies

A

Adalimumab