Innate Immunity -07

Question 1

immunity

Answer 1

the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells; the immune system is principally concerned w/ the maintenance of homeostasis

Question 2

Immunology

Answer 2

study of the immune system

Question 3

what does the immune system protect us against?

Answer 3

pathogens, tumours, toxins, prions, allergens

Question 4

what are the types of pathogens?

Answer 4

bacteria, virus, fungi, parasites

Question 5

vaccination

Answer 5

introducing all or subunits of an “attenuated” or “inactivated” pathogen; cheapest way to reduce disease

Question 6

what are the 3 levels of immunity?

Answer 6

intrinsic barriers, innate immunity (resident and induced defenses), adaptive immunity

Question 7

intrinsic barriers

Answer 7

pre-formed barriers to prevent invasion; mechanical, chemical, physiological and microbiological

Question 8

resident and induced defenses

Answer 8

complement, phagocytes, inflammation

Question 9

complement defense

Answer 9

exist as precursor proteins throughout the body that get cleaved for activation; activated by anti-body-pathogen-binding/mannose-binding lectin/pathogens themselves and cause opsonization, membrane attack complex formation and inflammation

Question 10

opsonization

Answer 10

an immune response in which the binding of antibodies to the surface of a microbe facilitates phagocytosis of the the microbe by a macrophage (“tagging”)

Question 11

membrane attack complex (MAC)

Answer 11

molecular complex consisting of a set of complement proteins that forms a pore in the membrane of bacterial and transplanted cells, causing the cells to die by lysis

Question 12

what are the types of phagocytes?

Answer 12

macrophages (resident in tissue), dendritic cells (resident in tissue), neutrophils

Question 13

what are the phases in phagocytosis?

Answer 13

chemotaxis, adherence, ingestion, digestion, killing/elimination

Question 14

how is inflammation initiated?

Answer 14

PRRs such as toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) expressed by microbes

Question 15

what is the primary goal of inflammation?

Answer 15

to move the required components from the blood stream to the site of tissue injury (may also recruit additional cells from bone marrow), and it also serves to remove the injurious agent, stim. and assist the immune system and promote tissue healing

Question 16

what are the three events that occur in inflammation?

Answer 16

vasodilation + increased vascular permeability, migration of leukocytes, tissue repair (healing)

Question 17

what are the cardinal signs of inflammation?

Answer 17

rubor (redness), calor (heat), tumor (swelling), dolor (pain) and funcio laesa (loss of function)

Question 18

rubor (redness)

Answer 18

vasodilation and increased blood flow

Question 19

calor (heat)

Answer 19

more blood delivered and metabolically active immune cells that release heat

Question 20

tumor (swelling)

Answer 20

plasma leaked out into tissue

Question 21

dolor (pain)

Answer 21

tissue stretching detected by free nerve endings

Question 22

leukocytosis

Answer 22

increase in the number of WBCs

Question 23

where do blood cells originate?

Answer 23

bone marrow

Question 24

what is the primary lineage of most innate immune cells?

Answer 24

myeloid lineage (w/ exception of the NK cell - lymphoid lineage)

Question 25

what are the innate immune cells?

Answer 25

macrophages, neutrophils. dendritic cells, NK cells, granulocytes

Question 26

macrophages

Answer 26

"sentinel cells" that phagocytose bacteria and dead cells, produce cytokines establishing the inflammatory response; more are recruited to sites of injury/infection when needed - they are also long-lived

Question 27

neutrophils

Answer 27

found in very high quantities in the blood (60-70%), migrate to tissues during inflammation, are recruited by chemokines incl. IL-8, contain toxic granules that can kill invaders and MUST be regulated to prevent immunopathology - also short-lived and replenished by bone marrow

Question 28

dendritic cells

Answer 28

antigen-presenting cells in the skin (Langerhans cells) that also differentiate from monocytes; bridge the gap b/w innate and adaptive immunity by activating T and B cells in lymph nodes and the splee

Question 29

natural killer (NK) cells

Answer 29

kill virus infected cells w/ dangerous mutations by releasing cytotoxic granules (perforin, granzymes) causing cytolysis or undergo apoptosis

Question 30

what are the types of granulocytes?

Answer 30

mast cells, eosinophils, basophils

Question 31

mast cells

Answer 31

important in allergic rxns via histamine release, help battle parasite infection, implicated in allergies and found primarily in tissues

Question 32

eosinophils

Answer 32

parasite infection and protection of mucosal surfaces (GI tract, lungs, genital tract)

Question 33

basophils

Answer 33

also important in allergic reaction via histamine release, release heparin to reduce blood clotting and found primarily in blood

Question 34

what is the innate response to extracellular bacteria?

Answer 34

phagocytosis by macrophages, releasing cytokines and chemokines to attract more monocytes and neutrophils; occurs in positive feedback until pathogen is cleared

Question 35

what is the innate response to intracellular viruses?

Answer 35

infected cells produce anti-viral cytokines (interferons) and the following happens: 1. temp. change (fever) 2. decreased protein synthesis 3. increased MHC expression 4. recruitment of NK cells 5. infected cells killed - phagocytes clean up released virus and dead cell material

Question 36

what happens if innate immunity fails?

Answer 36

the adaptive response will be activated

Question 37

TLR 1

Answer 37

Peptidoglycan

Question 38

TLR2

Answer 38

Peptidogylcan

Question 39

TLR 3

Answer 39

double stranded RNA

Question 40

TLR 4

Answer 40

LPS (NEG BACTERIA)

Question 41

TLR 5

Answer 41

FLAGELLIN

Question 42

TLR 9

Answer 42

Unmethylated CpG DNA

Question 43

Compliments are activated by

Answer 43

antibody pathogen binding lectin mannose binding pathogens themselves