Monoclonal antibodies Flashcards
Monoclonal antibody
Proteins that are used to target specific antigens in the body.
How do monoclonal antibodies work against cancer?
Bind to tumour markers on the surface of antigen to show doctors where it is
Combined with radioactive substance so once binded they stop it growing
Combine to antigen and alert the immune system
Block chemicals that stimulate tumour growth
How to make a monoclonal antibody?
Inject antigen into a mouse, eg cancer
Mouse produces lymphocytes targeted for antigen
Combine that with tumour cells to form hybridoma cells
Select singular hybridoma cell to divide a lot to make many identical clones
Collected then purified
What is a hybridoma?
Cells created during the production of monoclonal antibodies by the fusion of an antibody specific lymphocyte and a tumour cell.
Disadvantages of MABs
Expensive to produce
Not as successful as other treatments
Large number of side effects eg allergic reaction to mouse cell
Producing right MAB is difficult
Ethics: using animals that can’t consent is wrong
Advantages of MABs
Specifically targeted, don’t attack other cells
Large number of diseases can be treated
Large number of uses
How do pregnancy tests use MABs?
Contains MABs which combine with hormone HCG
Only found in urine of pregnant women = produced in placenta
If she is pregnant, they combine and cause a change of colour to show a positive test.
How do doctors use MABs to diagnose disease ie cancer?
MABs combine to these antigens to locate where in the body the tumor is, making it easier to identify
Other uses of MABs
Screening donated blood for STI infection
Drug tests for athletes
COVID tests
Blood tests to detect pathogens and hormone levels
How do scientists research MABs?
They produce MABs linked to molecules with a fluorescent dye. They observe the build up of fluorescence once they are combined to test what happens.
Why use tumour cells?
They divide easily whereas the lymphocytes don’t
What are MABs made of?
Tumor cells (divide easily) + specially made lymphocytes who target the chosen disease.
Hybridoma
The fused cells of a spleen cell and tumour cells
How does hybridoma cells divide?
By mitosis
Why do monoclonal antibodies only target specific diseases?
Because they consist of lymphocytes that target a specific binding site of an antigen
Thus they are specific to one disease only
