BIOL 435 Ch. 4 Part Three (Innate Immunity)

Question 1

MHC class 1

Answer 1

• binds inhibitory receptor on NK cell=inhibits
• none=inhibition OFF, NK cell lysis
• must match (ex. transplants)

Question 2

defects in PRRs and signalling pathways

Answer 2

• increase susceptibility to infections

* regulation includes both positive and negative feedback mechanisms

Question 3

abnormally “turned on” defects

Answer 3

-contribute to inflammatory disorders

>more and more of good things, ends up being unhealthy and damaging

Question 4

pathogens evolve strategies

Answer 4

-avoid detection by PRRs
-block PRR signalling pathways
>prevent activation of responses
-prevent killing or replication inhibition

Question 5

interplay between two systems

Answer 5

-several innate systems have been co-opted by adaptive immunity to contribute to Ab-mediated pathogen elimination
>opsonization
>complement activations

Question 6

some lymphocytes express TLRs

Answer 6

-but use them as costimulatory receptors

Question 7

dendritic cells are a key bridge

Answer 7

-bring Ag from site of infection and present them to T-cells in lymph nodes
-activates T-cells, allowing them to differentiate
>T-helper cell subsets
>cytotoxic T cells

Question 8

naive T-cell at dendritc bridge

Answer 8

-different IL producted due to differentiation of T-helper cells
>varying roles and responses

Question 9

innate “age”

Answer 9

• evolutionarily older
• TLRs unique to animals
• PRRs with LRRs are found in virtually ALL plants and animals