Immunodiagnostics + Vaccines - TOKA Flashcards
What are polyclonal Ab?
Many different clones of B cells that are specific for several epitopes of an Ag
*** found in serum, used for Anti-serum
What are monoclonal Ab?
Ab specific for 1 epitope
products of a single B cell clone
** can not be produced in animals
How are monoclonal Ab produced?
- Injecting an Ag over 3 boosters
- Collecting spleen cells from the animal bc germinal centers with differentiated B cells
- Fuse spleen cells and myeloma cells
- Makes a hybridoma - B cell + tumor cell
** B cell contributes Ab, Tumor cell allows endless replication !!
- Dilute hybridomas so there is only 1 cell, then culture to amplify cell
What does an indirect ELISA detect?
Antibodies
What is happening in an indirect ELISA?
- plate is coated w Ag
- Add primary Ab in serum
- Add 2nd Ab FROM A DIFFERENT SPECIES (Ex: Anti dog Ab) which is labeled w an enzyme
- Add substrate to bind to enzyme on 2nd Ab
- Look for color change
What does a sandwich ELISA detect?
Antigens
What is an example of when you would use immunoprecipitation assay?
To detect Type III hypersensitivity
** gives qualitative or quantitative results
How is precipitates formed?
Using equal amounts of Ab and Ag
*** Too much Ag or Ab = no precipitation
** Ab-Ag complex will form but rapidly dissociate
Is gel based immunoprecipitation a qualitative or quantitative assay?
Qualitative
How does gel based immunoprecipitation work?
Ag and Ab are put on seperate wells in an agar gel
- They diffuse towards each other
- At zone of equivalence Ag-Ab complexes form a precipitate in an arc or straight line
How can you tell blood groups in dogs and cats?
Blood typing
Ex: RBC containing A antigen on it is mixed with
Why are blood transfusions difficult in cats?
Because they naturally have anti-blood group antibodies
Ex: If type B blood - cats have high titers of Anti-A antibodies
If a cat w B blood gets a transfusion with A blood its game over , cat will have a strong rxn against it
What are the main blood groups in cats?
Types A, B and AB
** and Mik
What are clinically important RBC antigens in horses?
Aa
Qa
Ca
What techniques are available for blood typing?
- Typing cards
- Typing gels
- Membrane dipsticks
When is passive immunity necessary?
- During primary or secondary immunodeficiency
- When active immunity doesn’t develop to prevent disease
- In infections where best immunity is achieved through transfer of Ab
What diseases are examples of when passive immunity is administered?
- Rabies
- Botulism
- Measles
- Snake bites
-Diphtheria
What are the disadvantages of passive immunity?
- High possibility of a Type 1 or 3 hypersensitivity
- Immunity wanes with time
- No memory
How is hyperimmune serum made?
From serum collected from horses, sheep, and goats
What are the advantages of active immunity?
- Long lived immunity + effector T and B cells with memory
What are the advantages of a live-attenuated vaccine?
- Longer lasting effect than killed vax
- Replication of the pathogen increased the amt of Ag required to generate IR
- Antigenic epitopes are presented to T and B cells for Ab production
How is attenuation achieved?
- Passaging - virulent pathogen is cultured under conditions that dont support virulence (reduces virulence)
- Genetic engineering - by site directed mutagenesis or by removing genes responsible for virulence
What are methods used to kill or inactivate a pathogen intended for vaccine?
Heat, radiation, chemicals, antibiotics
What are subunit / component vaccines?
Made from purified Ag obtained from the pathogen
- Toxoids - purified toxins inactivated with formaldehyde but retain immunogenicity
- Bacterial polysaccharides - Ab against polysaccharides can opsonize bacT and result in efficient phagocytosis by neutophils + macrophages
What are recombinant vaccines?
Immunogenic proteins are cloned and expressed in prokaryotic or eukaryotic cells
What are naked DNA vaccines?
Cloning an immunogenic gene + inserting it into a plasmid vector, then admin of the plasmid DNA into the animal
What are vector vaccines?
Gene is cloned then inserted into a virus vector
Vaccinated host will be infected with the vector that does not cause disease but induces IR
What is the DIVA vaccine used for?
Able to tell between IR induced by the vaccine or from natural exposure
What are adjuvants?
Part of a vaccine that enhances the IR and immunogenicity to an antigen
