monoclonal antibodies

• Monoclonal antibodies:


  Identical copies of a single antibody, produced from clones of one antibody-producing cell in a lab.

  They are identical in structure

  They are made to bind a specific target antigen. E.g. cancer cells

  • "mono-" = single
  • "clonal" = clone

  
• Antibodies:


  Small proteins produced by special white blood cells called B-lymphocytes, used to help fight disease as:

  • They bind to antigens with a complementary shape, on the surface of foreign material, such as bacteria. 
  • This marks the foreign material for destruction by our immune system. 

  
• Hybridoma


  A hybrid cell, Combined by B lymphocytes and tumour cells.

  • Produces lots of antibodies like a B lymphocyte.
  • Divides rapidly like a tumour cell.

  
• Steps in producing monoclonal antibodies:

  • Inject an animal with the antigen that we want our antibodies to bind to.
  • Let the animal develop an immune response, and then isolate some of their B-lymphocytes (which will produce the antibody we want).
  • Combine those B-lymphocytes with fast-dividing tumour cells to form hybridoma cells. 
  • Let these hybridoma cells divide rapidly in a petri dish. 
  • Collect and purify the monoclonal antibodies they produce

  
• How To make lots of monoclonal antibodies:


  • B lymphocyte don't divide very quickly.
  • To fix this, fuse them with fast dividing tumour cells, grown in culture & B lymphocytes to form a hybridoma cell.
  • Leave the hybridoma cell to divide for a while in a petri dish.
  • To end up with an army of hybridoma cells.
  • Then collect and purify the monoclonal antibodies (as they are produced by the identical offspring of a single, cloned antibody producing cell) that they produce.

  
• How To get B lymphocytes to produce the correct antibody in the first place:

  • Inject a mouse's spleen with the antigen for the monoclonal antibody to bind to.
  • The antigen is now within the mouse.
  • The mouse’s immune system generates a response & produce loads of B lymphocytes that's specific to that antigen.
  • Isolate the lymphocytes from the mouse's spleen & combine them with fast dividing tumour cells to form a hybridoma cell.

  
• Monoclonal antibodies:

  • Always bind to one specific thing.
  • So by choosing the right B-lymphocyte.
  • It can effectively create antibodies that bind to anything.

  
• Monoclonal antibodies can bind to:

  • A particular protein / cell within our body.
  • A harmful pathogen / chemical.

  
• The bottom of monoclonal antibodies we can attach substances like:

  • Fluorescent proteins
  • Drugs
  • Radioactive material

  To locate or destroy specific types of cells.

  
• If some monoclonal antibodies were specific to an antigen on cancer cells:

  • Then we can locate and destroy the cancer.
  • By attaching drugs / radioactive material onto the monoclonal antibodies.
  • Then injects them into the patient.
  • Where they’d find their way to the cancer cells & destroy them.

  
• Lymphocytes first divide, then produce antibodies.


  • it takes a while for it to divide, so that's when we feel symptoms.
  • once it starts to make antibodies, it can't divide anymore.
• Monoclonal antibodies uses:

  • Disease treatment & detection
  • pregnancy test
  • In labs
  • In research
  • Cancer treatment & detection
  • locate blood clots
  • delivery of drugs to specific cells
• Monoclonal antibodies are used In labs:


  To measure the levels of hormones and other chemicals in blood, or to detect pathogens.
• Monoclonal antibodies are used in research:


  To locate / identify specific molecules in a cell or tissue by binding them with a fluorescent dye.
• Monoclonal antibodies are used for treatment of diseases:


  To carry specific drugs to the target cells

  • because they bind to the antigen in a tumour.

  For example, the monoclonal antibody can be bound to:

  • a radioactive substance
  • toxic drug
  • a chemical

  It delivers the substances to the cancer cells to stop them from growing & dividing, without harming other cells in the body.
• Advantages of monoclonal antibodies:

  • Side effects can be treated and reduced by using mice-human hybrid cells or by using fractions of antibodies.
  • They bind to specific diseased / damaged cells needing treatment.
  • can find certain target cells among healthy body cells
  • They treat a wider range of conditions
  • They are used to detect diseases.
  • They can deliver toxic drugs to specific cells.
  • They can detect pregnancy.
• When monoclonal antibodies are used in cancer treatment, it has some advantages over radiotherapy & chemotherapy:

  • The treatment of cancer is that healthy body cells are unaffected.
  • Because monoclonal antibodies only binds with specific cancer cells being treated.
  • Unlike drugs & radiotherapy treatments, which are less targeted.
  • They avoid the use of more destructive treatments.
• Disadvantage of Using monoclonal antibodies is that it creates more side effects than expected (in humans) including:


  • Chills or fever
  • Itchy rashes
  • Nausea
  • Headaches
  • Breathlessness or wheezing
  • Changes in blood pressure
• Disadvantages of monoclonal antibodies:

  • Very expensive for NHS to produce safe and consistent monoclonal antibodies.
  • Difficult to get the right antibodies with a compound to it.
  • It can be harmful to cells, as they are made by mouse cells.
  • They require animal testing.
• Monoclonal antibodies in Herceptin bind to the cancer cells but not to healthy body cells.

  As Cancer cells have different antigens, the monoclonal antibodies only match the antigens on the cancer cells.
• Chlamydia is an infectious disease caused by a bacterial infection.

  Injecting monoclonal antibodies for the bacteria could help treat the condition:

  • As Monoclonal antibodies are complementary to the antigen on the bacteria.
  • so they bind to the bacteria, causing white blood cells to engulf the bacteria and destroy it.
• Injecting monoclonal antibodies, with a toxic drug attached, could help reduce the number of cancerous cells.

  As Monoclonal antibodies are complementary to the antigen on the cancer cells.

  • so they bind to the cancer cells, delivering the drug directly to the cancer cells, killing the damaged cells.
• • The shape of the antibody is complementary of the A antigen.
  • The B antigen has a different shape
  • So it will only bind to the A antigen & not the B antigen.

  
• • isolate an antigen from the pathogen, which causes the STI.
  • inject the antigen into a mouse
  • collect lymphocytes producing an antibody to the STI antigen
  • fuse the B-lymphocyte with a tumour cell for a hybridoma cell that produces monoclonal antibodies against the antigen of the STI
  • Attach the monoclonal antibody to coloured beads into a test strip.