Introduction to immunology

Question 1

What are the body’s physical barriers to pathogen?

Answer 1

Skin and epithelial mucosa
Secretions
Normal flora
Physiological (temperature, pH)

Question 2

What are the mechanisms of innate immunity?

Answer 2

Inflammation 
Recruitment of immune cells 
Activation of complement
Opsonisation
Phagocytosis (and endocytosis)

Question 3

What are some of the common causes of inflammation?

Answer 3

Damage to tissues (burns) 
Allergens 
Microbial infection 
Complement activation 
Autoimmunity

Question 4

What is the mechanism of inflammation?

Answer 4

Vasodilation
Loosening of endothelial tight junctions
Increased cell adhesion molecules
Chemotaxis
Smooth muscle contraction

Question 5

What are the different complement pathways?

Answer 5

Classical (via antibodies bound to microbe/antigen)
Lectin
Alternative (direct activation ny microbe)

Question 6

What is the function of the complement pathways?

Answer 6

Activation of C3

Question 7

What is opsonisation?

Answer 7

Reduces repellent negative charge of cell membrane to allow phagocyte to come closer. Opsonins include complement, antibodies and plasma proteins

Question 8

What is the process of phagocytosis?

Answer 8

Phagocyte moves towards microbe
Phagocyte attaches to microbe via opsonin
Endocytosis of microbe within phagosome
Phagosome fuses with lysosome
Oxygen-dependent species result in microbe death
Release of microbe products

Question 9

What are the antigen presenting immune cells?

Answer 9

Monocytes
Macrophages
Dendritic cells

Question 10

What are the functions of neutrophils?

Answer 10

Phagocytosis

Degranulation

Question 11

What are the neutrophil receptors?

Answer 11

Toll like receptors
Complement
IgG 
Chemokine IL-8
Chemoattractant C5a
ICAM + VCAM - adhesion to endothelium

Question 12

What are the functions of eosinophils?

Answer 12

Extracellular killing via degranulation, especially of mast cells and basophils

Question 13

What is the function of basophils?

Answer 13

Degranulation of histamines, prostaglandins and cytokines

Question 14

What are the basophil receptors?

Answer 14

Surface bound IgE
C3a, C5a
Toll-like receptors

Question 15

What is the function of mast cells?

Answer 15

Degranulation through cross linking of IgE receptors

Question 16

What are the mast cell receptors?

Answer 16

Surface bound IgE
C3a and C5a
Damage associated molecular patterns
Toll like receptors
Complement

Question 17

What are the functions of macrophages?

Answer 17

Phagocytosis
Antigen presenting to T cells
Release TNF alpha, IL2 and IL6

Question 18

What are the macrophage receptors?

Answer 18

Toll like receptors
Fc for IgG and IgA
C3b
MHC class I and II

Question 19

What are the functions of dendritic cells?

Answer 19

Phagocytosis
Antigen presenting cells to CD4+ T cells via MHCII
Secrete TNF alpha

Question 20

What are the functions of the natural killer cells?

Answer 20

Bind to and kill virus-infected and cancerous cells
Release of perforin and granzymes from granules
Induce apoptosis
Release INF alpha and TNF alpha

Question 21

What are the natural killer cells receptors?

Answer 21

Killer activation receptors
Killer inhibitory receptors – recognise MHC class I
Toll-like receptors
Fc receptors
Adhesion molecules
FasL