innate immunity

Question 1

endotoxin

Answer 1

heat stable, cell associated part of g- bacteria

• LPS is toxic part of bacteria
• lipid end and polysaccharide end
• polysaccharide end is antigenic and determines O antigen
• lipid A is endotoxic

Question 2

LPS

Answer 2

• causes acute inflammatory response
• binds TLR4 on surface of macrophages with help of CD14 and MD2
• stimulates active NFkB, which activates transcription of cytokines
• bad is becomes systemic: fever, and shock
• septic shock causes dec bp and cardiac output, DIC, necrosis, and ARDS

Question 3

cytokines

Answer 3

IL1B, IL6 and TNFa

• the mediators that make LPS toxic
• IL1B and TNF make blood vessels more permeable
• IL6 inc fat and muscle metabolism to raise body temp
• combined makes a site of inflammation at infection site, then travel:
• activate complement in liver (and thus T and B cells)
• neutrophil mobilization/phagocytosis in bone marrow
• inc body temp from hypothalamus, fat, muscle

Question 4

Toll like receptors

Answer 4

series of receptors that recognize diverse signals like LPS, peptidoglycan, yeast, mycobacterium
-induce cytokine production

Question 5

inflammasome

Answer 5

• assembles in response to inflammation. ATP is a signal
• signal causes activator to activate caspase
• active caspase cleaves pro-IL1B to active form
• IL1B does positve feedback and causes even more IL to be made

Question 6

super antigenic toxins

Answer 6

• caused by Staph Aureus
• TNF and IL1B role in toxic shock syndrome
• phage encodes staph enterotoxin F/pyrogenic exotoxinC
• produce many different cytokines