Immunologic Memory and Vaccines

Question 1

Two major types of immune memory

Answer 1

T and B cell

Question 2

Immune memory is induced by

Answer 2

antigen exposure via infection or vaccination

Question 3

Immune memory can be (length)

Answer 3

short and require boosting, or long lasting

Question 4

Difference between Memory responses and innate immune response

Answer 4

more rapid, quantitatively greater and higher quality

Question 5

Memory t and b cells arise by

Answer 5

clonal expansion and contraction after encountering an antigen

Question 6

When we say higher in quality and quantitatively greater secondary memory response, what does that mean?

Answer 6

quantitatively greater- frequency of antigen-specific B cells in primary response = 1 in 10^4- 1 in 10^5; secondary response = 1 in 10^2- 1 in 10^3
higher quality- primarily IgG, A, and E (not M) with the secondary response, high affinity for antigen and high somatic hypermutation

Question 7

Immune memory is characteristic of

Answer 7

adaptive but not innate immunity

Question 8

First exposure to a pathogen vs. second (later on)

Answer 8

you have this lag time the first ime and then you get an increase in the memory response effectors, the antibodies and effector T cells, and then it kind of trickles off. But the second time youre exposed, it’s a rapid spike, hits a peak effector T cell/ antibody level that is much higher, and lasts for longer before trickling off

Question 9

Diptheria = 19 years
Small pox = 75 years
Measles ~200 years

Answer 9

Immune memory can vary in duration

these are half lives of various vaccines

Question 10

Why do you need to get the flu vaccine over and over?

Answer 10

Memory responses protect, but many pathogens evolve ways to evade them (they make different antigenic features/spots that the antibody epitopes cannot recognize)

Question 11

Pathways to becoming a memory cell

Answer 11

either directly from a naive cell or from an effector cell after the effector response has contracted and the cell then differentiates into a memory cell

Question 12

Pathway to memory cell from naive cell

Answer 12

T cell gets exposed to antigen
Memory cell comes directly from activated naive cell- central express ccr7 and stay in lymphoid tissue; effector do not have ccr7 and migrate to tissues

Question 13

Pathway to memory cell from effector cell

Answer 13

T cell gets exposed to antigen
Effector T cell differentiates, secretes cytokines, and expresses cytokine receptors
Some effector cells become quiescent memory cells; others of them die after a few days