Immune evasion Flashcards
What is an infectious agent’s goal
acquire what they need from the host, and survive long enough to reproduce and be transmitted
Cattle use this kind of Ig diverstiy
Gene conversion
Humans use what type of Ig diversity
Somatic recombination
Where does phase variation occur
bacteria
Why should you use invariant antigens when testing
Improve sensitivity and predictive value of a test
What are the two boundries an infectious agent balance between
lethality and transmission
Is variability genetically encoded
Not always
Where is antigenic variation found
only in bacterial and protozoal pathogens
What is antigenic drift
Slow accumulation of mutations that eventually result in protein isoform that is no longer recognized in pre-existing immune response
Sheep use what kind of Ig diversity
somatic hypermutation
what does an MHC class 1 molecule contain
2 separate polypeptides
What is antigenic variation
mechanism that specifically targets multigene family for variation at 2-3x faster than random mutation (BABESIAAA)
How do you determine total potential diversity of an immune system
product of the number of alleles for each part multiplied together
What is cytoadhesion
parasites (BABESIAAAA) and bacteria adhere to host cells, grow and develop without circulating through the spleen
What is an epitope
Chemical structure capable of eliciting an immune response and being specifically recognized by molecules of immune recognition
What immune tactic does BABESIA bovis
cytoadhesion
What immune regulatory cells are very specific
Immunoglobulins and T-cells
What does an MHC class 2 molecule contain
2 full sized transmembrane polypeptides
What are combinatorial genetics
multiple parts of immunity are assembled in any different combinations to make a whole
What is molecular mimicry
the production by an infectious agent of a component that resembles and behaves similarly to normal host componenet
What is Dr. Alred’s favorite thing on earth
babesia
What is antigenic shift
sudden change in phenotype brought about by mixing genomes from two microbes of different genotypes
What is the immune evasion tactic, viral latency
Virus inserts itself into host genome, virus becomes active or latent, virus can emerge from latency (herpies)
What is a confirmational epitope
contiguous structures made of discontinuous structural elements
What immune regulatory cells are very promiscuous
MHC class 1 and 2
What does phase variation result in
on/off regulation of transcription of individual genes
What does somatic hypermutation do
diversifies the specificity and enhances the affinity of antibodies produced
What is antigen masking
microbes bind host components to mask their own surface.
What is a linear epitope
continuous contiguous chemical structure usually part of a larger molecule
What is a major example of antigenic shift
Influenza virus
