IMMUNOLOGY - Basic (B-cells/T-cells, Immunoglobulins, MHC

Question 1

Which immunoglobulin passes through the placenta to assist foetal immunity?

Answer 1

IgG

Question 2

What is the main immunoglobulin in human tears?

Answer 2

IgA

Question 3

What receptors do macrophages have? (3)

Answer 3

1. pattern recognition receptors which recognise microbial components
2. surface receptors that recognise Fc portion of immunoglobulin and complement components. Binding of these receptors to their ligands enhances phagocytosis of antigen (opsonisation)
3. MHC class II molecules on surface when activated - present antigen to helper T-cells. Secrete IL-12 which directs T-cell differentiation to Th1 subset.

Question 4

What pro-inflammatory cytokines do macrophages produce?

Answer 4

IL-1, IL-6, and TNF

Question 5

Which complements are involved in the terminal pathway (membrane attack complex) and its deficiency predisposes to Neisserial infections?

Answer 5

C5-C9 (C3 is also associated)

Question 6

IL-2 is produced by what cells?

Answer 6

CD4+ cell

Question 7

HLA Class I Antigens vs
HLA Class II Antigens

Answer 7

Class I : all nucleated cells, allows CD8+ cytotoxic T cells to recognise and eliminate virus infected cells

Class II: macrophages, dendritic cells, B cells, endothelial cells, allows initiation of immune response by interaction with T-helper CD4+ cells

Question 8

difference in structure between class 1 and class II HLA

Answer 8

picture

Question 9

What cytokines do TH1 produce?
What cytokines do TH2 produce?

Answer 9

1. TH1 : IFN-gamma, IL2 –> B cells, NK cell and macrophage activation
2. TH2: IL3, IL4, IL5, IL6 –> mast cell and eosinophil activation

Question 10

What are the main functions of interferon? (3)

Answer 10

1. activation of NK cells and macrophages
2. directive antiproliferative action on tumour and virus infected cells
3. increased expression of Class 1 HLA on infected/tumour cells

Question 11

What cells produce interferon?

Answer 11

T lymphocytes & macrophages

Question 12

Which immunoglobulin is the first antibody to appear in infection?

Answer 12

IgM

Question 13

What pathway does IgA activate?

Answer 13

Activates the alternative complement pathway (unlike other antibodies that activate the classical pathway)

Question 14

What are the main types of eicosanoids? (3)

Answer 14

1. Prostaglandins
2. Leukotrienes
3. Thromboxanes

Question 15

What is the role of thromboxanes? (3)

vs

What is the role of leukotrienes? (3)

Answer 15

thromboxanes:
vasoconstriction, platelet aggregation and bronchoconstriction

leukotrienes
Bronchoconstriction, vasocontriction and increased vascular permeability

Question 16

What is the cyclo=oxygenase pathway?

Answer 16

See diagram.

Question 17

What is the effect of prostaglandin I2?

Answer 17

causes vasodilation and reduced platelet adhesion

Question 18

What are the effects of prostaglandin E2? (5)

Answer 18

1. vasodilation
2. bronchodilation
3. Release of pituitary hormones, adrenal cortex steroids and insulin from pancreas
4. Macrophage activation
5. Uterine contraction