Intro to Immune System

Question 1

conceptually the innate immune system is doing 2 thing.

Answer 1

1. keep microbes out of normally stable body sites.

2. target microbes that get in with PAMPS

Question 2

You need the innate immune system for the adaptive to work. what are some over arching roles of the innate immune system (2)?

Answer 2

1. activate complement cascade to opsonize microbes, activate cells and to promote clearance of dead cells or Ab complexes.
2. activates the adaptive immune system through antigen presentation (from APCs)

Question 3

where does a lysozyme exert

Answer 3

it snaps the NAG-NAM bond in gram positive. it can work on gram negative after damage to the Outer Membrane

Question 4

what are 4 defense mechanisms in the skin against microbes

Answer 4

1. epidermis/ water resistant barrier
2. dermal glands (sebum along hair, salt, pH)
3. b-defensins, cathelicidins
4. degradation of microbial nucleic acids (DNases, RNases)

Question 5

where is lysozyme secreted in the gut mucosa

Answer 5

paneth cells

Question 6

what are defensins

Answer 6

small, positvely-charged molecules that poke holes in microbes b/c microbial cell surfaces are negatively charged.. our cells tend to be negatively charged so defensins don’t really harm us

Question 7

alpha defensins

Answer 7

a class of defensins that protect babies

Question 8

beta defensins

Answer 8

found in the respiratory tract, kidneys, testes, and circulating

Question 9

what are three things that are resistant to MAC?

Answer 9

noneveloped viruses, gram positive, fungi with outside cell wall (mycolic acid)

Question 10

why doesn’t complement destroy out cells?

Answer 10

our cells are coated with molecules that diable MAC formation (Decay Accelerating Factor) DAF. some bacteria can do this too and enveloped viruses are using our cell membranes for their outer layer

Question 11

what two things in bacteria all protect from complement?

Answer 11

biofilms, capsule

Question 12

NK, B and T cells come from the lymphoid progenitor, what are it’s precursors

Answer 12

CD34 pluripotent stem cells which arise from myeloid progenitor

Question 13

what are dendritic cells and monocytes derived from?

Answer 13

monoblast

Question 14

what are the really good phagocytes

Answer 14

monocytes, neutrophils, and dendritic cells

Question 15

what is the differences b/w a monocyte and a macrophage

Answer 15

monocyte is an immature macrophage– it’s going through the blood.
A macrophage is a tissue resident macrophage and are named basted on their location, they express CD14. monocytes are 2-6% of circulating leukocytes

Question 16

tell me about dendritic cells

Answer 16

travel b/w tissue and regional lymph nodes as veiled cells.
capture antigen and bring it to consolidated T-cells
-present antigen for a long time
-express co-stimulatory molecules.

Question 17

what are some things about neutrophils (PMNs) granulocytes?

Answer 17

-60-70% of PBL
-90% of circulating granulocytes
-Short half life= 6 hours, but hardy
-maturation via csf and IL-3
NOT APCs

Question 18

primary granules of neutrophils

Answer 18

azurophilic- young neutrophils

Myeloperoxidase makes ROIs

Question 19

secondary granules of neutrophils

Answer 19

specific for mature neutrophils. contains lysozyme

NADPH oxidase components make ROIs

Question 20

mast cells enter the blood in precursor form and complete development in tissue under influence of local growth factors. what do their granules contain

Answer 20

histamine and heparin, but NOT hydrolytic enzymes.