Lecture 3

Question 1

Leukocytes

Answer 1

DNA, nucleus, internal organelles and can reproduce

Clonal expansion of antigen specific lymphocytes in lymph nodes is central feature of immune response

Question 2

Prior knowledge (immune system ‘database’)

Answer 2

Memory bank of the shapes of all possible foreign molecules is called the immune system repertoire.
Consists of millions of diff molecules like antibodies, Y shaped proteins which recognise a specific foreign antigen and T cell receptors

Question 3

Response

Answer 3

Specific antibody production (antibodies bind to and neutralise pathogens, label pathogens for destruction)
Phagocytes ingest foreign cells and destroy them
Cytotoxic T-cells destroy other infected cells
Complement attack (bacteria tagged with Ig can be destroyed by plasma molecules collectively called the complement system)

Question 4

Binding of antibodies to antigens inactivates antigens by:

Answer 4

-Neutralisation (blocks viral binding sites, coats bacteria and or opsonisation)
-Agglutination of antigen bearing particles
-Precipitation of soluble antigens
ALL ENHANCE PHAGOCYTOSIS
-complement fixation leads to CELL LYSIS

Question 5

Experimental tools for immunology

Observations

Answer 5

Microscopy assays for immune response, specific antibody levels

Question 6

Experimental tools for immunology

Purifying immune system component

Answer 6

Centrifugation
Cell sorting
Laboratory cell culture
Protein purification

Question 7

Experimental tools for immunology

Experiments

Answer 7

Mice- infected, irradiated and cloned - transgenic mice

Cell line experiments

Question 8

White Blood Cells - phagocytes

Answer 8

Cells that can digest other cells
Neutrophils (enter infection site and destroy bacteria then die)
Monocytes (enter tissue then transform into macrophages, destroy bacteria then report back to control centre)

Question 9

White Blood Cells- lymphocytes

Answer 9

• B cells
• T cells - T helpers and T cytotoxic
• 20-25% of WBC in blood
• mostly located in lymph nodes
• process, store info about possible infections

Question 10

White Blood Cells- macrophages

Answer 10

Phagocytes
Blood monocytes circulate for ~5-8 days before developing into macrophages
Recognise crude features of bacteria, or bound antibody, present or display antigen and migrate to lymph nodes

Question 11

Who is Metchnikoff

Answer 11

Discovered phagocytosis

Nobel prize 1908

Question 12

B cells

Answer 12

Each genetically programmed to encode for surface receptor for particular antigen
After recognising antigen, they multiply and transform into plasma cells which make specific antibody for that antigen

Question 13

T cells

Answer 13

Express antigen specific T cell receptor molecules
T helper cells assist and control B cell expansion
T cytotoxic cells kill virus infected cells