immunology 4

Question 1

homeostasis

Answer 1

balance between pathogen and immune response

Question 2

hypersensitivity, autoimmune disease

Answer 2

immune response outweighs the pathogen

Question 3

infectious disease

Answer 3

pathogens outweighs immune response

Question 4

Innate immune defense

Answer 4

epithelial barrier
secretion
endogenous microflora
resident phagocytes
pattern recognition receptor

Question 5

epithelial barrier

Answer 5

skin, respiratory epithelium and enterocytes

Question 6

secretion

Answer 6

mucus, sweat, sebum, cerumen, acid, enzymes, defensin, polyreactive antibodies surfactant (IgA)

Question 7

TLR2

Answer 7

peptidoglycan and gram positive bacteria

Question 8

TLR3

Answer 8

dsDNA and viruses

Question 9

TLR4

Answer 9

lipoplysaccharide and gram negative bacteria

Question 10

TLR6

Answer 10

peptidoglycan and lipoteichonic acid and gram positive bacteria

Question 11

TLR7, 8

Answer 11

ssRNA and viruses

Question 12

TLR9

Answer 12

non-methylated DNA and viruses and bacteria

Question 13

adaptive immune response

Answer 13

cell mediated and humoral

Question 14

cell mediated

Answer 14

mediated by TH1 cells
most important intracellular pathogen

Question 15

humoral

Answer 15

mediated by TH2 cells
most important extracellular pathogen

Question 16

viral infection

Answer 16

bind to cell receptor (Absoption)
virions enter cell
nucleic acid released into cytoplasm
replication
protein production
assembly
release
spread

Question 17

what triggers the innate immune response to viral infection

Answer 17

recognition of viral patterns by Pattern recognition receptor (PRR)
RIG-1, MDA5 (cytoplasmic)
TLR3, 7, 8, 9 (endosomal)
cell damage

Question 18

interferons

Answer 18

glycoproteins
three types
type 1-alpha dendritic cells, beta any virally infected cells
type 2-gamma activated TH1 cells
type 3-various, mucosal epithelial cells
regulate protein expression

Question 19

type 1 interferons

Answer 19

produced upon recognition of TLR7 and TLR9 ligands
activate JAK/STAT pathways
increased production of antiviral and immunoregulatory protein
directly inhibit viral uptake, replication
induce apoptosis
produced withing hours (before antibodies)

Question 20

humoral immunity in viral infections

Answer 20

antiviral antibodies against viral proteins
antibody binding prevents viral infection by-blocking viral invasion
stimulating phagocytosis
triggering complement-mediated virolysis
promoting viral clumping
not by direct virus destruction
ADCC target infected cells for destruction
nk cells and cytotoxic t cells

Question 21

cell mediated immunity to viral infection

Answer 21

cytotoxic t cells recognized infected cells prior to rupture
induce apoptosis
recognized peptide MHC-1 complexes and kill cells
sensitized by type 1 interferons
macrophages are activated by Th1 cells and cause phagocytosis

Question 22

immune evasion by viruse

Answer 22

RNA viruses rely on antigenic variation
DNA viruses use immunoregulatory genes-proteins that block IFN signaling
proteins that interfere with MHC-1 associated antigen presentation
evasion of NK cells
alteration in humoral immunity
antigenic variation

Question 23

antigenic variation

Answer 23

point mutation and poor editing
sporadic recombination of strains
influenza A

Question 24

bacterial infection

Answer 24

presence of bacteria does not indicate bacterial disease
development of disease depends on-bacterial virulence factors
dose of bacteria
concurrent disease or tissue damage
normal flora
immune system function

Question 25

mechanism of bacterial colonization/invasion

Answer 25

opportunistic bacteria-break in epithelium pathogenic bacteria-wide range of mechanism simple-induce phagocytosis complex-inject proteins into the host cells to create a receptor

Question 26

innate immune system response to bacteria

Answer 26

bacteria are recognized through PRR (TLR1, 2, 4, 5, 6, 9) cytokine release, complement activation, inflammation and phagocytosis sequestration of nutrients (iron and tryptophan)

Question 27

adaptive immunity in bacteria infection-extracellular

Answer 27

humoral immunity-neutralization of toxin opsonization by antibodies killing by classical complement pathway phagocytosis by activated macrophages

Question 28

adaptive immunity in bacterial infection-intracelluar

Answer 28

cell mediate immunity macrophage activation and killing destruction by cytotoxic T cells

Question 29

neutralization

Answer 29

important for toxogenic bacterial antibodies generated against toxin blind prevent interaction with receptor can be IgG or IgA (mucosal surfaces)

Question 30

opsonization and phagocytosis

Answer 30

opsonization increased efficiency of phagocytosis antibodies against surface antigens bacteria coated in antibodies and complement fragments are primed for phagocytosis IgM is the most efficient antibody in opsonization

Question 31

destruction by activated macrophages

Answer 31

some bacteria can replicate inside macrophages Th1 cells activate macrophages by secreting interferon gamma acidification of phagosomes intracellular bacterial destruction NK and cytotoxic T cells can also kill cells infected with intracelluar bacteria

Question 32

bacteria evasion of innate defenses

Answer 32

interfere with TLR signaling-modify PAMPS and interfere with intracellular signaling resistance to antibacterial peptides block phagocytosis intracellular bacteria

Question 33

evasion of adaptive defense

Answer 33

antigenic variation secrete proteases to destroy antibodies or cytokines