Adaptive Immunity

Question 1

What is cytotoxic T-cell activity influenced by?

Answer 1

T-helper and T-suppressor cells

Question 2

What is genetic recombination?

Answer 2

Each Tc lymphocyte and B lymphocyte recognises a single antigen. They can collectively recognise every antigen possible.

Question 3

How is a specific response and memory ensured?

Answer 3

Through clonal selection and expansion

Question 4

What are some things that STIMULATE the immune system?

Answer 4

1) Presence of antigen
2) Th cells
3) Cytokines

Question 5

What are some things that INHIBIT the immune system?

Answer 5

1) Removal of antigen
2) Ts cells
3) Cytokine breakdown

Question 6

What does self-tolerance rely on?

Answer 6

1) Pre-natal exposure

2) Continuous/large-scale re-exposure to own antigen

Question 7

What is clonal selection?

Answer 7

Fine-tuning of immune response (increases avidity and affinity)

T & B Lymphocytes with Best Fit → Multiply → Evolve → Repeat

Question 8

What is the purpose of memory cells?

Answer 8

Improved responses to same antigen in future

Question 9

Compare the difference between a primary response and a secondary response

Answer 9

1 - Usually 5-10 day lag
2 - Usually 1-3 day lag (quicker response)

1 - Smaller peak response (amount of antibody)
2 - Larger peak response

1) Usually IgM>IgG
2) Relative increase in IgG and, under certain situations, in IgA or IgE (heavy chain isotype switching)

1 - Lower average affinity, more variable
2 - Higher average affinity (affinity maturation)

Question 10

Where does development of T cell tolerance happen?

Answer 10

In the thymus

Question 11

Define interleukins

Answer 11

12 different proteins, produced by MPS & Th cells, which stimulate various components of the immune system,
leading to proliferation, differentiation, activation & chemotaxis

Interleukins 1-12 are involved in every step of adaptive immunity
→ short-lived autocrine & paracrine effects

Question 12

Define Tumour necrosis factor

Answer 12

small protein, produced by MPS cells, which has multiple effect on various cells leading to fever, inflammation, enhanced immunity, septic shock, anorexia, cachexia

Question 13

Define Interferons

Answer 13

3 different proteins (alpha, beta and gamma), produced by virus-infected cells & T-helper cells, which activate NK cells & T-cytotoxic cells leading to cell cytotoxicity and make other host cells virus-resistant

They also activate macrophages & up-regulate antigen presentation
– thus interacting with the adaptive immune system