CSIM 1.29 - Principles of Immunology

Question 1

Describe the major characteristics of innate immunity?

Answer 1

Rapid (0-4 hours)
Non-specific
No memory

Question 2

Describe the major characteristics of adaptive/acquired immunity?

Answer 2

Specific
Delayed (>96 hours)
Memory

Question 3

Where does humoral immunity operate and what is the major unit involved?

Answer 3

Extracellular space

Antibodies

Question 4

Name the co-stimulatory signals required to activate T-cells?

Answer 4

CD28 (T-cell)
CD80 (APC)
CD86 (APC)

Question 5

Define the term ‘vaccine’?

Answer 5

Antigenic preparation whose administration in a subject induces an immune response specific to the given infectious agent/Ag

Question 6

Describe passive immunity and provide examples?

Answer 6

Protection transferred as antibody form (temporary)
Placental transfer of IgG
Breast-feeding transfer of IgA (gut lumen only)

Question 7

Describe active immunity?

Answer 7

Protection produced by person’s OWN immune system (permanent) - immunological memory similar to post-infection with out the disease

Question 8

What are the two types of vaccines?

Answer 8

Live attenuated

Inactivated

Question 9

Describe thymus dependent B-cell activation?

Answer 9

1st signal - B-cell and specific Ag = clustering of Ig(X) receptors = intracellular Ig-alpha and Ig-Beta interactions
2nd signal - CD4 Th2 cell help class switching

Question 10

Describe thymus independent B-cell activation?

Answer 10

Antibody response without T-cell
Carbohydrate/polysaccharide Ag mediates IgM and IgG.2
1st signal - specific Ag and B-cell receptor interaction
2nd signal - TLR//extensive BCR cross-linking

Question 11

Describe thymus independent Ag type 1?

Answer 11

Intrinsic activity directs B-cell division
Increased concentration = Non Ag specific activation
Decreased concentration = Ag specific concentration

Question 12

Describe thymus independent Ag type 2?

Answer 12

Stimulate B-cells appearing later in life - IgM production

If concentration is too high - B-cell becomes anergic

Question 13

Why must care be taken when vaccinating small children in particular with polysaccheride vaccinations?

Answer 13

The polysaccheride surrounding some pathogens = Type 2 thymus independent Ag. If young children are vaccinated with a polysaccheride vaccine as they DON’T have any of these specific B-cells they may in fact become anergic to the high concentration

Question 14

What type of vaccination is used in children under that age of 2 years?

Answer 14

Conjugate vaccine