Immunological memory

Question 1

phases from entry of microorganism to clearance of pathogen

Answer 1

1. establishment of infection
2. inductive phase
3. effector phase
4. memory phase
   *duration of infection is from phases 1 to 3

Question 2

stages of a response to an infection

Answer 2

local infection - penetration of epithelium
local infection of tissues
lymphatic spread
adaptive immunity

Question 3

response to infection mechanism: penetration of epithelium

Answer 3

wound healing induced antimicrobial peptides, phagocytes and complement destroy invading microorganisms

Question 4

response to infection mechanism: local infection of tissues

Answer 4

complement activation
dendritic cells migrate to lymph nodes
phagocyte action
NK cells activated
cytokines and chemokines produced

Question 5

response to infection mechanism: lymphatic spread

Answer 5

pathogens trapped and phagocytosed in lymphoid tissue
adaptive immunity initiated by migrating dendritic cells

Question 6

response to infection mechanism: adaptive immunity

Answer 6

infection cleared by specific antibody
T-cell dependent macrophage activation and cytotoxic T cells

Question 7

types of ILC’s and the type of pathogen they respond to

Answer 7

cytotoxic ILC: viruses
group 1 ILC: intracellular bacteria
group 2 ILC: helminths (parasites)
group 3 ILC: extracellular bacteria

Question 8

cytokines and chemokines produced by innate sensor cells activate…

Answer 8

Innate lymphoid cells

Question 9

types of innate sensor cells

Answer 9

dendritic cells
macrophages
tuft cells

Question 10

what makes up immune effector modules

Answer 10

integration of ILC’s, T-cell subsets and innate effector cells

Question 11

what is the role of T-helper 1 cells

Answer 11

coordinate and amplify host response to intracellular pathogens through classical activation of macrophages

Question 12

what is the role of T-helper 2 cells

Answer 12

coordinate type 2 responses to expel intestinal helminths and repair tissue injury

Question 13

what Is the role of T-helper 17 cells

Answer 13

coordinate type 3 responses to enhance the clearance of extracellular bacteria and fungi
IL17 and IL22 induce the production of AMPs by epithelial cells

Question 14

what processes are included int he primary immune response

Answer 14

T and B cell activation
differentiation
proliferation

Question 15

properties of the primary immune response

Answer 15

type of B cell: naive
lag time: 4-7 days
time of peak response: 7-10 days
magnitude of peak response: antigen-dependent
isotype: IgM
antibody affinity: low

Question 16

properties of the secondary immune response

Answer 16

type of B cell: memory
lag time: 1-3 days
time of peak response: 3-5 days
magnitude of peak response: 1000x higher than primary
isotype: IgG
antibody affinity: high

Question 17

immunological memory is long-lived after…

Answer 17

infection or vaccination

Question 18

what are the 2 general models for memory T cell development

Answer 18

1. linear model: memory T cells arise from effector T cells as the primary immune response subsides
2. branching model: an activated naive T cell gives rise to daughter cells that commit to either effector OR memory cell program

Question 19

what are the types of memory T cells

Answer 19

central memory (Tcm)
effector memory (Tem)
tissue-resident subsets (Trm)

Question 20

Protein = CCR7
what T cells is it present in and what are its functions

Answer 20

naive T cell, central mem. T cell
chemokine receptor for getting into the lymph node

Question 21

protein = CD45RA (or CD45R0)
what T cells is it present in and what are its functions

Answer 21

all naive, effector and memory T cells
modulates T cell receptor signalling

Question 22

protein = Bcl-2
what T cells is it present in and what are its functions

Answer 22

naive, all memory T cells and some effector T cells
prevents intrinsic apoptosis, promotes cell survival

Question 23

what alters when naive T cells become memory T cells

Answer 23

the expression of certain proteins

Question 24

where do each type of memory T cell reside within our tissues

Answer 24

central memory T cell: recirculate between blood, T cell zones of SLO and lymph
effector memory T cells: recirculate between non-lymphoid tissues lymph, lymph nodes, and blood. some remain in circulation and migrate only though spleen
resident memory T cells: do not recirculate, confined to a single tissue

Question 25

circulating memory T cells acquire heightened sensitivity to which cytokines

Answer 25

IL7 and IL15

Question 26

how do memory T cells survive long-term

Answer 26

they undergo metabolic reprogramming

Question 27

what are the requirements for naive T cell survival

Answer 27

require signals from contact with self peptide:MHC complexes and the cytokine IL-7

Question 28

what are the requirements for memory T cell survival

Answer 28

need contact with cognate peptide:MHC complexes but reduced co-stimulation to undergo clonal expansion

Question 29

related to antibodies, what increases with repeated immunization

Answer 29

the affinity and amount of antibody

Question 30

what happens to lymphocytes with repeated immunization

Answer 30

• memory B cells can re-enter germinal centres and undergo additional somatic hypermutation and affinity maturation during secondary immune responses
• in immune individuals, secondary subsequent responses are mainly attributable to memory lymphocytes

Question 31

what is Fcy-RIIB1

Answer 31

an inhibitory receptor on the surface of naive B cells
interacts with Fc component of IgG

Question 32

what is RHoGAM

Answer 32

an anti-Rh Ig
it binds to the FcyRIIB1 inhibitory receptor on naive B cells that recognize Rh

Question 33

what is the original antigenic sin

Answer 33

when individuals who have been infected with one variant of a virus are infected with a different variant, they make antibodies only agains epitopes that are present on the initial virus