Immunology

Question 1

What leukocytes have Fc and complement receptors?

Answer 1

• Neutrophils
• Monocytes
• Macrophages

Question 2

Neutrophils

Answer 2

• Important phagocytic role in innate immunity
• primary lysosomes combine with phagosomes (digest them)
• kill microbes by secreting superoxides

Question 3

Eosinophils

Answer 3

• Associated with parasitic infection and allergic reaction
• Granules contain MBP (toxic to worms)
• Granules stain for acidic dyes

Question 4

Basophils

Answer 4

• similar to mast cells
• high affinity IgE receptors –> IgE binding = degranulation = histamine = allergic reaction
• parasitic infection and allergic reaction

Question 5

What are the polymorphonuclear leukocytes (granulocytes)?

Answer 5

• Neutrophils
• eosinophils
• basophils
• mast cells

Question 6

What are the mononuclear leukocytes (agranulocytes)?

Answer 6

• monocytes –> macrophages

- lymphocytes (B&T)

Question 7

Monocytes

Answer 7

• in blood
• innate and adaptive immunity (phagocytosis and Ag presentation)
• remove microbes and dead self
• lysosomal peroxidase = kill microbes

Question 8

Macrophages

Answer 8

• in tissue (liver = kupffer; brain = microglia)
• innate and adaptive immunity (phagocytosis and Ag pres to T-cells)
• 1st line of non-self recog.
  removes microbes and dead self

Question 9

T lymphocytes

Answer 9

• mature in thymus; travel to LNs, blood and spleen
• adaptive immunity!
• recognise peptide Ag displayed by APCs

Question 10

Types of T lymphocytes

Answer 10

• T-reg = regulate immune responses
• Th1 (CD4) = help intracellular pathogen response
• Th2 (CD4) = help make Ab for extracellular pathogen response
• CTL (CD8) = kill cells directly

Question 11

B lymphocytes

Answer 11

• adaptive immunity!
• secrete membrane-bound Ab once differentiated into plasma cells
• mature in BM; travel to LNs, blood and spleen
• recognise Ag displayed by APCs

Question 12

Mast cells

Answer 12

• mature cells only in tissues (precursor in blood)
• similar to basophils
• high affinity IgE receptors –> IgE binding = degranulation = histamine = allergic reaction
• parasitic infection and allergic reaction

Question 13

Natural killer cells

Answer 13

• found in spleen and tissues

- recognise and kill virus-infected cells and tumour cells via apoptosis

Question 14

What are the soluble factors of the immune system?

Answer 14

• complement
• Abs/Igs
• cytokines

Question 15

What are the complement pathways?

Answer 15

• classical –> antibody binds to microbe
• alternative –> complement binds to microbe
• lectin –> MBL binds to microbe

Question 16

Define antibody

Answer 16

• protein produced in response to Ag
• binds specifically to Ag that induced its formation
• adapter that links microbe to phagocyte

Question 17

Define antigen

Answer 17

molecule that reacts with preformed Ab and specific receptors on T-cells and B-cells

Question 18

Define epitope

Answer 18

the part of the antigen that binds to the AB-receptor binding site

Question 19

Define affinity

Answer 19

measure of binding strength between an epitope and an Ab-binding site