Immunology 2

Question 1

antigen

Answer 1

any substance that can induce an immune response (B or T cell immune response)

Question 2

2 main categories of antigens

Answer 2

infectious (multiply) and non infectious

Question 3

size of antigens and strength of immune response

Answer 3

• large antigen: strong immune response (bacterial toxins, viruses, protazoal membranes, hormones, venoms)
• small: poor response
• very small: no response

Question 4

antigen complexity and antigens and strength of immune response

Answer 4

most complex = good immune response
* proteins

simple substances = poor antigens (do not induce strong immune response
* lipids, polymers

Question 5

antigen stability and strength of immune response

Answer 5

more stable/less flexibility= stronger immune response
ex: flagellin are flexible

Question 6

antigen degradibility and strength of immune response

Answer 6

high degradability = poor immune response
non degradable = also poor antige (steel pins, plastic heart valve implants)

needs medium degradibility to be good antigen

Question 7

antigen foreigness and immune response

Answer 7

more foreign = stronger response
remember immune system differentiates self vs non self

Question 8

antigen concentration and immune response

Answer 8

low concentration = T cells unresponsive = tolerance
moderate = good immune response
excessive concentration = T and B cells unresponsive = tolerance

Question 9

epitope (antigenic determinant)

Answer 9

region of the antigen where the immune system (antibody) acts (binds) on it

Question 10

hapten

Answer 10

• small molecule that by itself cannot induce an immune response
• can induce strong response when bound to protein

binding of hapten to a large molecule (eg protein) = immune response

Question 11

cross reactive epitopes

Answer 11

common epitope found on different antigens
ex: brucella and yersenia
ex: molecular mimicry: share epitope between microbe and “self”

Question 12

which part of the immune system deals first with antigens and handles >95% of them?

Answer 12

innate immune system (non specific)

Question 13

physical barriers (1st line of defense)

Answer 13

• skin
• GI system
• respiratory
• urogenital
• mammary gland

Question 14

chemical barriers (first line of defense)

Answer 14

• lysozyme
• complement-C
• lysins
• chemokines
• opsonins
• acute phase proteins

Question 15

skin as an physical and chemical barrier

Answer 15

• sebum from sebaceous glands (low pH, toxic to pathogens)
• natural desquamation (sloughing off)
• non pathogenic bacteria occupy surface of skin

Question 16

mouth as a barrier

Answer 16

has saliva
flushing action (spitting out)

Question 17

stomach and intestine as a barrier

Answer 17

• low pH
• lysozyme
• normal bacterial flora (secrete acids, aid in digestion, compete for space, regulate health/disease)

Question 18

urogenital tract as a barrier

Answer 18

urine:
* flushing action (urination)
* low pH

vagina:
* epithelium rich in glycogen: promotes growth of lactobacillus- makes lactic acid

Question 19

urogenital tract as a barrier

Answer 19

urine:
* flushing action (urination)
* low pH

vagina:
* epithelium rich in glycogen: promotes growth of lactobacillus- makes lactic acid

Question 20

respiratory tract as a barrier

Answer 20

• suspended particles cleared by tubulence (bumps pathogens against mucus)
• walls of upper resp tract has mucus (produced by goblet cells, has lysozymes and slgA)
• alveolar macrophages
• ciliary action

Question 21

mammary glands as a barrier

Answer 21

flushing action
lacteins
* lactoperoxidase
* lysozyme
* lactoferrin

Question 22

Complement (C’)

Answer 22

• complex series of proteins (many are enzymes/proteases)
• can bind to antibody or work independently
• consists of ~30 proteins starting with C (ex C1)

Question 23

C3 and C5

Answer 23

very important in inflammation and eliminating antigen

Question 24

Where are complement components produced?

Answer 24

• liver (parenchyma)
• marcophages
• monocytes
• GI, urinary tracts
• neutrophils store complements

Question 25

main functions of complement

Answer 25

• complement mediated chemotaxis
• complement mediated oponization
• complement mediated inflammation
• removal of immune complexes
• regulation of immune system

Question 26

complement mediated oponization

Answer 26

1. complement binds to bacteria
2. macrophages with receptor for the complement bind to complement-bacteria complex
3. macrophage eats complement and bacteria (more efficient)