Exam 2 (Lecture 15) - Comparative Immunity

Question 1

List the two most conserved immune protective mechanisms in insects up through mammals.

Answer 1

TLRs (toll-like receptors; type of PRR)

Antimicrobial peptide (defensins)

Question 2

Explain how birds transfer immunity to their young.

Answer 2

IgG from the blood is concentrated into the yolk
- as the chick develops, it absorbs the yolk sac
so the IgG is absorbed into the chick’s blood

IgA is produced in the oviduct
- as a fertilized ovum passes through the oviduct
it acquires IgA in the albumin
- as the chick develops, it swallows the albumin so
the IgA coats the intestinal tract

Question 3

Explain what immersion vaccination in fish is and list several factors that influence the efficacy of immersion vaccination.

Answer 3

Vaccine is put into water and the fish are then put into that water.
- Solubilized or suspended vaccine antigen
- Antigen is taken up through the gills (as well as
by the gut and lateral line of skin)

Factors that influence efficacy:
- water pH
- length of immersion time
- size of fish
- how many fish are immersed at one time
- stress level of fish

Question 4

Provide one mechanism that provides immunity in a crustacean.

Answer 4

They only have innate immunity
- antimicrobial peptides like defensin

Question 5

Provide one mechanism that provides immunity in a honey bee.

Answer 5

They only have innate immunity
- defensins/PRRs

The create “social immunity” by inducing bee fever.
- this causes the entire colony to produce
immunity

Question 6

Explain the major differences between the protective immune response induced by vaccines in mammals, avians, and higher-level aquatic animals compared to crustaceans and insects.

Answer 6

When vaccinating mammals, avians, and higher-level aquatic animals, we are inducing the adaptive immune response.

This can’t be done in crustaceans and insects, because they only possess innate immunity, so when we vaccinate them, we are just boosting their innate immunity.