1-25 Innate Immunity

Question 1

role of TLRs in recognition of pathogens

Answer 1

TLRs are found on macrophages and dendritic cells

recognize singals associated with invading pathogens (LPS, peptidoglycan, yeast, mycobacterium)

many types, all share common signaling pathways

binding of antigen to these receptors creates signaling pathways that result in the immune cell releasing cytokines (interferon, interleuken, etc..)

Question 2

explain the role of cytokines produced by the reaction to pathogens

Answer 2

At the site of infection, macrophages release inflammatory cytokines that collectively induce a state of inflammation.

TNF-alpha, IL1, IL6

Question 3

TNF-alpha

Answer 3

macrophage secreted cytokine - stimulates T and B cells, induces fever.

primary mediator of septic shock

Question 4

IL1

Answer 4

macrophage secreted cytokine - interleuken-1

released as a pro-cytokine, cleaved to mature form by the inflammasome which is assembled in response to inflammatory signals

Question 5

IL-6

Answer 5

macrophage secreted cytokine - induces fat/muscle cell to metabolize, make heat and raise temperature in infected tissue

Question 6

combined effect of IL1 and TNF-alpha

Answer 6

increase blood vessel permeability - enables effector cells and fluid containing molecules to enter tissue

Question 7

LPS segments

Answer 7

polysaccharide end - often antigenic and determinant of the O antigen

hydrophobic lipid rich end - contains Lipid A. the actual endotoxicity.

Question 8

LPS pathology

Answer 8

septic shock, disseminated intravascular coagulation, acute respiratory distress syndrome

Question 9

septic shock

Answer 9

endotoxin shock, associated with gram - bacteria

Question 10

CXCL8

Answer 10

macrophage secreted cytokine - receuirts neutrophils from blood and guides them to infected tissue

Question 11

IL-12

Answer 11

macrophage secreted cytokine - recruits/activates NK cells that also excrete cytokines to strengthen macrophage response

Question 12

cytokines in liver

Answer 12

activate complement opsonization

Question 13

cytokines in bone marrow

Answer 13

neurotrophil mobilization for phag

Question 14

cytokines in hypothalymus

Answer 14

increase body temp (decrease viral/bacterial replication)

Question 15

cytokines in fat/muscle

Answer 15

protein and energy mobilization to generate increased heat (decrease viral/bacterial replication)

Question 16

TLR-4

recognizes?
carried by?

Answer 16

recognizes and reponds to LPS.

macrophages, dendritic cells, mast cells, eosinophils

Question 17

Toll receptors are part of _______ of bacteria/viruses/fungi. Lead to production of____

Answer 17

innate recognition

of a bunch of molecules that are used by our body. High quantities activate lots of the toll receptor 4, leading to production of lots of tnf and IL1, which are potentially lethal at high concentrations.

Question 18

The answer to every tetanus question will likely be

Answer 18

administer tetanus toxoid (booster)

Question 19

inflammasome

Answer 19

assembles and reacts to inflammatory singals such as ATP. Resulting in activation of caspase which cleavse and releases the cytokine IL1

Question 20

superantigic toxins

Answer 20

Superantigen toxins bind to outside the variable region on the t-cell receptor. Bind outside of cleff of MHC. Bind to way more t-cells and most antigen presenting cells. Bring lots of t-cell and presenting cells together. Stimulate t-cells to be activated. t-cell populations get exhausted.

causes toxic shock

Question 21

why are the symptoms of toxic shock and septic shock similar?

Answer 21

toxic shock(superantigen) and septic shock(endotoxin shock from LOS) both arise from activation of the same cytokines (TNFalpha, IL1)