Immunology Lab Flashcards
Describe the diagnostic uses of antibodies
Determining blood groups
Immunoassays
Immunodiagnosis
What can immunoassays be used to measure
Hormones
Antibodies
Antigens
What can immunodiagnosis assist in diagnosing
Infectious diseases
Autoimmunity
Allergy (IgE)
Malignancy (myeloma)
What are the therapeutic uses of manufactured antibodies and give examples of each
Prophylactic protection against microbial infection e.g. IV-IG , synagis (anti-RSV)
Anti-cancer therapy e.g. anti-HER2
Removal of T-cells from bone marrow grafts e.g. anti-CD3
Block cytokine activity e.g. TNF-α in rheumatoid arthritis
What can be attached to antibodies’ constant region for diagnostic testing
Enzymes: e.g. peroxidase, alkaline phosphatase
Fluorescent probes: dyes, beads of different sizes
Magnetic beads: e.g. purification of cell types
Drugs: e.g. Kadcyla, anti-HER2 linked to emtansine
What feature of antibodies make them useful in diagnostics
unique specificity of antibodies for their target antigens
Can be raised against almost any antigen (often but not always proteins), including immunoglobulins from other species (anti-antibodies)
Can perform indirect labelling using anti-antibody
What are the sources of antibodies
Produced by the patient (autoimmune disease or defence against infection)
Manufactured
antisera from immunised animals (polyclonal)
Monoclonal antibodies
Genetically engineered antibodies
Explain how monoclonal antibodies are generated
- Immunise an animal with the antigen for the desired antibody
- Take the spleen cells – source of antibody-producing b cells
- Fusion of the B cells and myeloma cells to form hybridomas
- Culture in HAT medium,
- Select for the positive cells and grow hybridomas with enzyme
- Clone by limiting dilution: put single cells in wells à screen clones for those that produce antibody
How are antibodies produced using recombinant DNA technology
- Isolate population of genes encoding antibody variable regions
- Construct fusion protein of V region with a bacteriophage coat protein
- Cloning a random population of variable regions to give rise to a mixture of bacteriophages (phase-displat library)
- Select phage with desired V regions by specific binding to antigen
What is ELISA
Enzyme Linked Immunosorbent Assay
Use of anti-antibodies for rapid diagnosis
Describe rapid ELISA testing
- Antigen/antibody is immobilised in a well
- Antibodies added to bind to antigen
- Complex moves down and binds a second antibody on the test line
- Complex moves further to the control line (where only 1st antibodies bind to show sample has moved down)
What feature of myeloma cells make them useful for monoclonal antibody production
Grow indefinitely and do not produce own antibodies, no particular enzymes
What are the features of hybridomas used in monoclonal antibody production
Immortal
Have enzyme
Produce desired antibodies
What does the suffix -omab suggest
mouse monoclonal
e.g. Muronomab = anti-CD3, transplant immunosuppression
What does the suffix -imab suggest
chimeric or partly humanised
e.g. Infliximab (Remicade) = anti-TNFa, Rituximab = anti-CD20