HIV And Monochlonal Antibodies Flashcards
Describe the structure of a HIV particle
-attachment proteins
-capsid
-reverse transcriptase
-lipid envelope
-RNA
Describe the replication of HIV in helper T cells
-HIV attachment proteins attach to receptors on helper T cell
-Lipid envelope fuses with cell-surface membrane, releasing capsid into cell
-Capsid uncoats, releasing RNA and reverse transcriptase
-Reverse transcriptase converts viral RNA to DNA
-Viral DNA inserted / incorporated into helper T cell DNA (may remain latent)
-Viral protein / capsid / enzymes are produced
a. DNA transcribed into HIV mRNA
b. HIV mRNA translated into new HIV proteins
-Virus particles assembled and released from cell
Explain how HIV causes the symptoms of acquired immune deficiency
syndrome (AIDS)
● HIV infects and kills helper T cells (host cell) as it multiplies rapidly
○ So T helper cells can’t stimulate cytotoxic T cells, B cells and phagocytes
○ So B plasma cells can’t release as many antibodies for agglutination & destruction of pathogens
● Immune system deteriorates → more susceptible to (opportunistic) infections
● Pathogens reproduce, release toxins and damage cells
Explain why antibiotics are ineffective against viruses
● Viruses do not have metabolic processes (eg. do not make protein) / ribosomes
● Viruses do not have bacterial enzymes / murein cell wall
What is a monoclonal antibody?
Antibody produced from genetically identical / cloned B lymphocytes / plasma cells
● So have same tertiary structure
Explain how monoclonal antibodies can be used in medical treatments
● Monoclonal antibody has a specific tertiary structure / binding site / variable region
● Complementary to receptor found only on a specific cell type (eg. cancer cell)
● Therapeutic drug attached to antibody
● Antibody binds to specific cell, forming antigen-antibody complex, delivering drug
Explain how monoclonal antibodies can be used in medical diagnosis
● Monoclonal antibody has a specific tertiary structure / binding site / variable region
● Complementary to specific receptor /antigen associated with diagnosis
● stain marker attached to antibody
● Antibody binds to receptor / protein / antigen, forming antigen-antibody complex
Explain the use of antibodies in the ELISA test to detect antibodies
- Attach specific antigens to well
2.Add sample with potential antibodies, wash well - Add complementary monoclonal antibodies
with enzymes attached → bind to antibodies if
present - Wash well → remove unbound antibodies
- Add substrate → enzymes create products that
cause a colour change (positive result)
Suggest the purpose of a control well in the ELISA test
● Compare to test to show only enzyme causes colour change
● Compare to test to show all unbound antibodies have been washed awa
Suggest why failure to thoroughly wash the well can result in a false positive
in the ELISA test
● Antibody with enzyme remains / not washed out
● So substrate converted into colour product
Discuss some general ethical issues associated with the use of vaccines and
monoclonal antibodies
● Pre-clinical testing on / use of animals- potential stress / harm / mistreatment
○ But animals not killed & helps produce new drugs to reduce human suffering
● Clinical trials on humans- potential harm / side-effects
● Vaccines - may continue high risk activities and still develop / pass on pathogen
● Use of drug - potentially dangerous side effects
