Immunology I

Question 1

What is immunity?

Answer 1

The state of being insusceptible or resistant to a noxious agent or process.

Question 2

What are first defences?

Answer 2

• Skin
• Tears, mucus, Saliva
• Stomach acid
• Cilia
• Urine flow
• ‘Friendly’ bacteria

Question 3

What occurs in innate immunity?

Answer 3

LPS on bacteria only, these are known as PAMPs (pathogen associated molecular patterns)
TLRs detect PAMPs
Signal downstream effectors

Question 4

What are Myeloid white blood cells?

Answer 4

Such as macrophages, express TLRs.

Question 5

What are dendritic cells?

Answer 5

Specialised phagocytic cells
Express TLRs
Migrate to lymphoid tissues and stimulate T cells

Question 6

What does activation of the immune system trigger?

Answer 6

• Inflammation: dilated blood vessels, sticky endothelium to catch WBCs. Fever stops pathogen proliferation and speeds up reactions.
• Recruitment of phagocytic cells: neutrophils (short lived), macrophages (long lived) eosinophils (attack larger objects)

Question 7

What cells are used in innate immune system?

Answer 7

Neutrophils, mast cells

Question 8

What cells are used in the adaptive immune system?

Answer 8

B cells, T cells

Question 9

What cells are used in both the innate and adaptive immune systems?

Answer 9

Dendritic cells, macrophages

Question 10

What is adaptive immunity?

Answer 10

A specific response for a specific pathogen.

Question 11

Where are B lymphocytes produced?

Answer 11

Bone marrow

Question 12

Where are T lymphocytes produced?

Answer 12

Thymus

Question 13

What do B cells do?

Answer 13

Produce immunogoblins which are secreted by plasma cells and bind to antigens.

Question 14

What types of T cells are there?

Answer 14

• Cytotoxic T cell: kill infected host cells
• T helper cells: release cytokines, to activate dendritic cells, B cells, cytotoxic T cells, macrophages.
• Regulatory T cells: suppress immune response.

Question 15

What happens when an antigen binds to a specific cell?

Answer 15

Clonal expansion, proliferation, lots of antibodies produced.

Question 16

What does immune tolerance mean?

Answer 16

Cells transplanted into adults are rejected and destroyed by T cells
Cells transplanted into babies are accepted

Question 17

What percent of protein in plasma is antibodies?

Answer 17

20%

Question 18

How many binding sites do antigens have?

Answer 18

2

Question 19

What do constant domains do in antibodies?

Answer 19

Interact with the immune system

Question 20

What do variable domains do in antibodies?

Answer 20

Make up the antigen binding sites.

Question 21

What is the primary antibody repertoire?

Answer 21

Generates 1x10^12 antibodies

Question 22

What is junctional diversification?

Answer 22

During joining of the gene segments, nucleotides are lost or inserted from the ends of the segments.
This may cause a frame shift.

Question 23

What are the domains of a heavy chain in an antibody?

Answer 23

40 V domains
25 D domains
6 J domains
5 C domains

Question 24

What are the domains of a light chain in an antibody?

Answer 24

40 V domains
5 J domains
1 C domain

Question 25

Are T and B cells diploid or haploid?

Answer 25

Developing B and T cells are haploid, then they choose one allele to recombine (allelic exclusion)