Lecture 2: innate and adaptive immunity

Question 1

What is the process of phagocytosis and killing of pathogen?

Answer 1

Pathogen recognition Zipping of membrane around microbe Ingestion of microbe Fusion of phagosome with lysosome Phagocyte Activation Killing of microbe

Question 2

What are the cytokines for macrophage and NK Cell Activation?

Answer 2

IL 12 and IFN Gamma

Question 3

What are the cytokine for inflammatory induction?

Answer 3

TNF, IL1 and chemokines

Question 4

What are the cytokines for antiviral effects?

Answer 4

IFN type I IFN alpha IFN beta

Question 5

What are the cytokines for differentiation of T cell subpopulation?

Answer 5

IL-12

Question 6

What are the order of events in an infection?

Answer 6

Entry of pathogen Recognition of the pathogen Phagocytosis and killing of a pathogen Inflammation induction Attraction of cells to infection site Initiation of adaptive immunity

Question 7

What are the 3 signals between T cells and DC ?

Answer 7

1) MHC-TCR 2) CD80/86-CD28 3) IL-12

Question 8

What is the role of innate immunity in stimulation of adaptive immune response?

Answer 8

1) pathogen or Extracellular Antigen is phagocytised by APC and placed in a vesicle. Ingested pathogens are digested by lysosomes to extract their antigens 2) the antigens bind with MHC proteins that enter vesicles 3) the MHC proteins now carrying antigens are released from vesicles and travel to the outer surface of cell membrane 4) the dendritic cell is now presenting antigens which will activate T cells that bind with MHC proteins

Question 9

What are key players of Adaptive immunity?

Answer 9

T and B lymphocytes

Question 10

What are the features of adaptive immunity?

Answer 10

Specificity Diversity Memory Clonal expansion Specialisation Contraction and homeostasis Non-reactivity to self

Question 11

What is specificity?

Answer 11

Ensures distinct antigen elicit specific responses

Question 12

What is diversity?

Answer 12

Enables immune system to respond to a large variety of antigens

Question 13

What is Memory?

Answer 13

Leads to enhanced responses to repeated exposures of the same antigens

Question 14

What is clonal expansionV

Answer 14

Increases number of antigen-Specific lymphocytes to keep pace with microbes

Question 15

What is Specialisation?

Answer 15

Generates responses that are optimal for defence against different types of microbes

Question 16

What is Contraction and homeostasis?

Answer 16

Allows immune system to respond to newly encountered antigens

Question 17

What is non-reactivity to self?

Answer 17

Prevents injury to host during responses to foreign antigens

Question 18

How is variability of antigen recognition produced?

Answer 18

Combination of gene segments during lymphocyte development

Question 19

What are the types of Adaptive Immunity?

Answer 19

1. Antibody mediated immunity (humoral) - B lymphocytes 2. Cell mediated immunity (cellular) - T lymphocytes

Question 20

What are the lymphoid tissues?

Answer 20

Lymph node, spleen, blood, lymph

Question 21

What are T cells?

Answer 21

Immune response to infected cells Viruses, bacteria, parasites Defence against cancer and transplant rejection

Question 22

Helper T cells

Answer 22

Secrete cytokines Help B cells Tc cells to divide

Question 23

Cytotoxic T cells

Answer 23

Kill infected cells

Question 24

Memory T cells

Answer 24

Remain in body

Question 25

Where are class I MHC proteins found?

Answer 25

Virtually on all body cells

Question 26

Where are class II MHC proteins found?

Answer 26

Certain cells in immune response

Question 27

What are the Antigen-presenting cells?

Answer 27

Dendritic cells Macrophages B cells

Question 28

What does Helper T cells (TH) CD4 do?

Answer 28

Stimulate proliferation of other T cells Stimulate B cells that have already become bound to antigen

Question 29

Cell- mediated immunity

Answer 29

Attack on infected cells

Question 30

Humoral Immunity

Answer 30

Secretion of Antibodies by plasma cells

Question 31

What does cytotoxic T cells (Tc) CD8 do?

Answer 31

Destroy infected cells by binding target cell and secreting perforin and granzymes B proteins - puncture cell membrane of infected cell and induce apoptosis/lysis

Question 32

What does humoral immunity target?

Answer 32

Extracellular microorganisms (bacteria and viruses circulating in the blood)

Question 33

What does the B cell activation require?

Answer 33

Helper T cells

Question 34

What is the nature of Antibodies?

Answer 34

Globular proteins (immunoglobulins) 4 polypeptide chains (2 identical light chains and heavy chains) Variable and Constant regions

Question 35

IgM

Answer 35

1st response to antigen (can’t cross the placenta)

Question 36

IgG

Answer 36

Most common - crosses placenta (passive immunity to fetus)

Question 37

IgA

Answer 37

Secreted from mucus membrane in colostrum

Question 38

IgD

Answer 38

B cell activation (can’t cross placenta)

Question 39

IgE

Answer 39

Histamine reactions and allergies (mast cells, basophils)

Question 40

What is the role of Antibodies?

Answer 40

Agglutination Complement activation Opsonisation Neutralisation Enhanced NK Cell activity

Question 41

Neutralisation

Answer 41

Antibodies block the activity of a pathogen

Question 42

Agglutination

Answer 42

Multiple pathogens are aggregated by antibody molecule

Question 43

Opsonisation

Answer 43

Pathogens bound by antibodies are more efficiently engulfed by phagocytes

Question 44

Complement activation

Answer 44

Antibodies bound to pathogen activate the complement cascade, resulting in lysis of cell

Question 45

Enhanced NK Cell activity

Answer 45

Abnormal body cells that are bound by antibodies are recognised by NK cells and are subsequently lysis

Question 46

What are the principal mechanisms of defence against microbes

Answer 46

Antibodies, phagocytes and T cells

Question 47

What is adaptive immunity stimulated by?

Answer 47

Exposure to microbe, more potent

Question 48

What are CD nomenclature?

Answer 48

Structurally defined leukocyte surface molecule that is expressed in cells of a particular lineage and recognised by a group of monoclonal antibodies called “cluster of differentiation”