Lec 1: Basic Concepts in Immunity

Question 1

What is the goal of immunity?

Answer 1

• to return the body to a state of homeostasis

Question 2

What 3 things stem from the goal of immunity?

Answer 2

• defending the host
• cleaning up debris/spent cells
• controlling tissue damage

Question 3

What are the 10 principles?

Answer 3

1. The goal of immunity is to help return the body to a state of homeostasis
2. Host-pathogen interactions are strong drivers for evolution of immune defence mechanisms
3. Immune conservation occurs across two dimensions
4. Conservation is not consistent across the spectrum of immune responses
5. Comparative models govern veterinary immunology
6. Immunity can also contribute to disease progression
7. Microorganisms are not just the bad guys
8. Each host cell must properly control several functions
9. Protein expression dictates the cellular response that results
10. The immune system acts in the context of an overall host response

Question 4

What is the challenge for invading microbes?

Answer 4

• devise clever evasion strategies to overcome immune defence mechanisms and increase potential for survival and spread

Question 5

What is the ultimate goal for the animal host?

Answer 5

• to avoid death from infection

Question 6

Define functional redundancy.

Answer 6

capacity of immune tools to exert similar and overlapping functions on specific cells to provide extra safeguards if one layer of the system were to fail or be overcome by pathogen invasion strategies

Question 7

Define functional pleiotropy.

Answer 7

capacity of immune tools to exhibit a wide variety of biological functions on various tissues and cells

Question 8

What are the ‘two dimensions’ across immune conservation?

Answer 8

phylogeny and ontogeny

Question 9

What is phylogeny?

Answer 9

evolution over millions of years

Question 10

What is ontogeny?

Answer 10

• development from embryo to fetus to adult

Question 11

Is conservation consistent across immune responses?

Answer 11

• no

Question 12

Describe innate immunity.

Answer 12

• not affected by prior contact with infectious agents
• non specific
• wide range
• localized
• ready to go
• phagocytosis and complement cascades

Question 13

Describe adaptive immunity.

Answer 13

• specific
• adaptable
• systemic
• includes antibodies, antigen presentation, recognition of self/non self
• forms basis of memory

Question 14

What is a pro of conservation of immune response?

Answer 14

• time proven strategy for elimination of infiltrating pathogens

Question 15

What is a con of conservation of immune response?

Answer 15

• many pathogens can jump from species to species

Question 16

What is comparative immunology?

Answer 16

• the study of immune responses across all animals

Question 17

What choices could have been made during evolution?

Answer 17

• change in environment
• differences in intrinsic physiological tools available to host
• changes in energy sources and expenditures
• acquisition of new antimicrobial mechanisms
• random mutations

Question 18

What is an example of autoimmunity?

Answer 18

• systemic lupus erythroumatosus

- combo of type 2 and 3 hypersensitivities

Question 19

Some autoimmune diseases can stem from what?

Answer 19

• prior pathogenic infections

Question 20

What are some functions of gut microflora?

Answer 20

• aid in breakdown of otherwise undigestible food components
• provide vitamins
• contribute to development of intestine
• compete with incoming pathogens
• promote development of host immune repertoire

Question 21

What are some examples of host cell functions?

Answer 21

• proliferation
• take in nutrients
• migrate
• repair DNA
• apoptosis
• differentiate (mature)

Question 22

How do immune cells decide what to do?

Answer 22

• signalling pathways help integrate extracellular and intracellular signals
• these pathways converge at level of gene expression

Question 23

What dictates the cellular response the results?

Answer 23

• protein expression

Question 24

The immune system acts in the context of what?

Answer 24

an overall host response