12 Integration of Immune response

Question 1

Immune responses to Cytosolic infection

Answer 1

processed and presented on MHC1

Question 2

Immune responses Vesicular infection

Answer 2

(deliberately taken into cell by phagocytosis) – processed and presented on MHC2

Question 3

why are there different immune responses to different types of infection

Answer 3

So the right T cells (CD4/CD8 activated)

Question 4

Anatomic barriers

Answer 4

• Skin
• Oral mucosa
• Respiratory epithelium
• intestine

Question 5

Complement/antimicrobial proteins (first thing activated-lectin pathway)

Answer 5

• C3
• Defensins
• Reg-3-gamma

Question 6

Innate immune cells

Answer 6

• Macrophages
• Granulocytes
• NK cells

Question 7

Adaptive immune cells

Answer 7

• B cells/antibodies

- T cells

Question 8

Physical barriers

Answer 8

Skin
gut
lungs
eyes/nose/oral cavity

Question 9

Skin - mechanical

Answer 9

longitudinal flow of air or fluid

mechanical – epithelia cells joined by tight junctions

Question 10

skin - chemical

Answer 10

> fatty acids

> beta-defensins, Lamellar bodies, Cathelicidin

Question 11

skin - microbiological

Answer 11

> normal microbiota

Question 12

gut - mechanical

Answer 12

longitudinal flow of air or fluid

mechanical – epithelia cells joined by tight junctions

Question 13

gut - chemical

Answer 13

low pH
> enzymes (pepsin)
> alpha-defensins, Reg3, Cathelicidin

Question 14

gut - microbiological

Answer 14

> normal microbiota

Question 15

lungs - mechanical

Answer 15

mechanical – epithelia cells joined by tight junctions

movement of mucus by cilia

Question 16

lungs - chemical

Answer 16

> pulmonary surfactant

> alpha-defensins, cathelicidin

Question 17

lungs - microbiological

Answer 17

> normal microbiota

Question 18

eyes/nose/oral cavity -mechanical

Answer 18

> tears
nasal cilia
mechanical – epithelia cells joined by tight junctions

Question 19

eyes/nose/oral cavity - chemical

Answer 19

> enzymes in tears and saliva (lysozyme)

> histatins, beta-defensins

Question 20

eyes/nose/oral cavity - microbiological

Answer 20

normal microbiota

Question 21

Innate Immunity -primary immune response stages

Answer 21

1. epithelial barrier
2. immediate local response (innate):
   - complement proteins
   - macrophages

Question 22

phagocytes

Answer 22

• macrophage:
  > phagocytosis and activation of bactericidal mechanisms
  > APC
• neutrophil:
  > phagocytosis and activation of bactericidal mechanisms

Question 23

Phagocyte recognition

Answer 23

• toll-like receptors
• C-type lectin receptors
• other PRRs: NOD-like receptors scavenger receptors, Fc receptors

Question 24

Macrophage function

Answer 24

Activated macrophages produce numerous cytokines and chemokines

Question 25

TNF

Answer 25

activation of local endothelium initiation of cytokine production; upregulation of adhesion molecules

Question 26

IL-6

Answer 26

triggers production of acute phase proteins from liver, enhances antibody production from B cells; induces T-cell proliferation

Question 27

IL-8

Answer 27

triggers neutrophil chemotaxis; chemotactic for basophils and T cells; activation of neutrophils promotes angiogenesis

Question 28

IL-12

Answer 28

activates NK cells; polarization of T cells to T helper

Question 29

Early induced response

Answer 29

innate and inflammatory - inflammatory mediators from complement, macrophages, mast cells - attract leucocytes and serum proteins (more complement)

Question 30

Adaptive immune response

Answer 30

later adaptive response - antigen carriage by dendritic cells to lymphoid tissue - activation of specific T and B lymphocytes and antibody production - recirculation to site of infection

Question 31

Lymphocytes and Pathogens meet

Answer 31

Coordinated way for pathogens and cells to meet in the lymph node to activate the adaptive immune response

Question 32

transport of antigen to lymphoid organs

Answer 32

Dendritic cells take up bacterial antigens in the skin and then move to enter a draining lymphatic vessel Dendritic cells bearing antigen enter draining lymph node where they settle in the T cell areas During migrating the dendritic cell changes it function from uptake to presentation, it starts to mature

Question 33

T cell homing adhesion molecules

Answer 33

L selectin on surface To leave blood circulation the express L selectin Sit and wait in the lymph node

Question 34

Naïve T cell and B cell homing

Answer 34

Circulating lymphocyte enters the high endothelial enters high endothelial venule in lymph node Binding of L-selectin to GlyCAM-1 and CD34 allows rolling interaction LFA-1 is activated by chemokines bound to extracellular matrix Activated LFA-1 binds tightly to ICAM-1

Question 35

what is the third signal for in T cell interaction with DCs

Answer 35

what T cell it becomes

Question 36

Paracortex function

Answer 36

activation of specific T and B cells - Activation of antigen-specific T cells by dendritic cells - Activation of antigen-specific B cells by T cells

Question 37

what is lymph node structure made of

Answer 37

paracortex | germinal centre

Question 38

Germinal centre function

Answer 38

maturation of activated B cells - Division - Somatic mutation - Class switching - Formation of plasma cells and memory cells

Question 39

what does class switching cause

Answer 39

increases defence effector functions

Question 40

what does division cause

Answer 40

increases size of response

Question 41

what does somatic mutation cause

Answer 41

increases affinity of the response

Question 42

what is somatic mutation

Answer 42

immunoglobulin variable domains involves point mutations, resulting in amino acid changes that effectively increase or decrease the affinity of interaction with the antigen epitope

Question 43

Tissue homing

Answer 43

Tissue homing of activated lymphocytes is determined by their expression of particular adhesion molecules (eg. integrins) and chemokine receptors

Question 44

Leucocyte adhesion molecules involved in

Answer 44

Adhesion molecules involved in the selective homing of T cells to different tissues

Question 45

Inducers of inflammation (amplifying events)

Answer 45

- C3a and C5a (anaphylatoxins) - Mast cell products (e.g. histamine - immediate release, leukotrienes - delayed release) - Prostaglandins (e.g. from macrophages and mast cells) - Cytokines (e.g. from macrophages and T cells) - Chemokines