immunity Flashcards

Question

problems with monoclonal antibodies

Answer 1

The problem with using mouse-derived (murine) mAbs in humans is that they may be recognized as foreign. This will trigger an immune response, which quickly inactivates the mAbs. The immune response can be minimized by using genetic engineering to create humanized mAbs. These consist of mainly human polypeptide chains, with only the amino acids at the antigen-binding site derived from mice.

Answer 2

This technique is performed to detect the presence and/or amount of a target protein/antigen of interest. Or it can be used to detect if a person contains antibodies for a certain antigen. This process can be used to detect for allergies or infection. An antibody is used which has an enzyme attached to it; this will catalyse the conversion of a substrate to a coloured product. The intensity of the colour can be an indicator of the quantity of antigen/antibody

Answer 3

The antigen for the infection that is being tested for is immobilised to the bottom Wash the well several times to remove any antigen molecules that did not stick Add an antibody which is specific for our antigen We wait to allow the antibody molecules to stick to the antigen molecules Wash the well several times to remove any excess antibody Molecules A second antibody is added. The 2nd antibody specifically binds to the 1st. The second antibody is attached to an enzyme molecule Next, we wash again to removed any unbound antibody Add substrate for the enzyn The enzyme converts the substrate into a product molecule which is coloured The intensity of the colour can be used to determine the amount of antigen. This makes the ELIZA a quantitative test

Answer 4

pregnancy tests treating cancer HIV ELIZA test

Answer 5

• Creating monoclonal antibodies requires the use of mice to produce antibodies and tumour cells which leads to ethical debates as to whether the use of animals is justified to enable the better treatment of cancers in human and to detect diseases.

Answer 6

• Is produced by the introduction of antibodies into individuals from an outside source. • No direct contact with the pathogen or its antigen is necessary to induce immunity.

Answer 7

• Is produced by stimulating the production of antibodies by the individuals own immune system. • Natural/ artificial immunity.

Answer 8

Vaccines stimulate the production of antibodies and memory cells against the target pathogen without causing illness.

Answer 9

envelope protein envelope viral genome nucleocapsid viral tegumant

Answer 10

• This means it contains RNA (ribonucleic acid) rather than DNA (deoxyribonucleic acid •Viral DNA is made from viral RNA by reverse transcription using the viral enzyme reverse transcriptase. • Viral DNA is incorporated into host DNA in the nucleus by viral enzyme integrase

Answer 11

1. p120 molecules on the HIV bind to CD4 receptor proteins on T helper lymphocytes and macrophages. 2. The Virus outer envelope fuses with the cell membrane 3. Viral RNA + enzymes from the HIV are injected into the T cell 4. The viral DNA is transcribed and translated by the host cell to produce new viral proteins. (10° new viruses can be produced per day!) 5. Transcribed RNA plus viral proteins are assembled together to form new viruses 6. The new viruses leave the cell by budding, taking some of the host cell membrane to form the viral envelope. This kills the T helper cells

Answer 12

• T cells are killed when the HIV virus exits the T cell via budding. • Infected T helper cells are also destroyed by T killer cells. • So the number of T helper lymphocytes decreases over time. • Loss of T helper cells results in the loss of activation of both B and T cells so the effectiveness of the specific immune response to combat infection is subsequently reduced.

immunity Flashcards

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