Lecture 17 - comparative immunology

Question 1

What is a toll-like receptor?

Answer 1

A pattern recognition receptor (PRR) of the innate immune system that recognizes conserved microbial patterns.

(Fun fact - toll in German means ‘great’)

Question 2

What is a defensin

Answer 2

Molecule that polymerizes to form a pore in bacterial membranes, similar to the MAC.

Question 3

Learning Objective 1

Describe the most conserved immune protective mechanisms present in insects up through mammals.

Answer 3

Toll-like receptors

Antimicrobial peptides (e.g. defensins)

Alternative complement pathway not present in insects, but is present in many higher species.

Question 4

Which species possess an adaptive immune system?

Answer 4

Agnathans through mammals

Question 5

Learning Objective 2

Explain how birds transfer immunity to their young.

Answer 5

IgG passed in the yolk

IgA passed in the albumin

Question 6

True or False

Birds have higher levels of Gamma Delta T cells than humans and mice.

Answer 6

TRUE

Similar levels to bovine and swine

Question 7

Where do B cells mature in the bird?

Answer 7

Bursa of Fabricius

Question 8

List the primary lymphoid tissues in the bird.

Answer 8

Thymus

Bursa of Fabricius

Question 9

List the secondary lymphoid tissues in the bird

Answer 9

Chickens do not have lymph nodes, but do have lymphoid nodules.

Spleen

Peyer’s patches

Question 10

True or False

Crustaceans possess an adaptive immune system

Answer 10

FALSE

For this reason, you cannot vaccinate shrimp in the traditional sense.

Question 11

What is the term for the jawless fish?

Answer 11

Agnatha

Question 12

What is the term for the cartilaginous fish?

Answer 12

Chondrichthyes

Question 13

Do the chondrichthyes have bone marrow?

Answer 13

No

Question 14

Do the bony fish have bone marrow?

Answer 14

No

Question 15

Jawed fish have most of the same immune mechanisms as mammals. However, unlike mammals, they are exothermic (cold-blooded). What is the implication for the immune system?

Answer 15

The immune system of fish must be able to function in a broad range of temperatures.

Question 16

Which fish species possess NK cells?

Answer 16

Teleosts

Question 17

In fish, which cells are responsible for humoral immunity (antibody production)?

Answer 17

B cells

Question 18

How does antibody affinity of fish compare to that of birds and mammals?

Answer 18

Lower affinity

Also less diversity and weaker memory

Question 19

What is the most common method for vaccinating fish?

Answer 19

Immersion vaccination

Question 20

Learning Objective 3

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

Answer 20

Accomplished by placing fish in water with solubilized vaccine. Antigen can be taken up by gill, gut or skin.

Efficacy can be improved by ultrasounding the water.

Many factors affect efficacy. Antigen concentration, immersion time, water temperature, size of the fish, etc.

Question 21

What is the most common method for vaccinating birds?

Answer 21

In ovo vaccination

Question 22

Learning Objective 4

Compare and contrast the properties of antibodies in fish, birds, and mammals.

Answer 22

All species have IgM

Fish have only IgM. Shows some diversity, but not a lot of specificity.

Birds have IgM and IgG, and an IgA similar to mammals. Do not have IgE.

Mammals got it all, bro.

Question 23

Learning Objective 5

List the immune system components of crustaceans and explain the challenges of vaccinating this species.

Answer 23

Crustaceans only have an innate immune system. Thus, there can be no memory response.

Tend to rely on fibrin encapsulation, phagocytic cells, and antimicrobial peptides.

Cannot vaccinate this species. Can only temporarily enhance the innate immune system response.