Intro to Inflammation and Infection Part 2

Question 1

describe the specific inflammatory defense mechanisms/mediators of neutrophils

Answer 1

1. phagocytosis: fuse with lysosome to create phagolysosome; reactive oxygen species generated
2. degranulation
3. neutrophil extracellular traps: microbicidal, released in response to cytokines (IL-8) and stimuli (LPS); contain enzymes to break down microbes

Question 2

describe the specific inflammatory defense mechansims/mediators of eosinophils

Answer 2

eosinophils have hella products in their granules, but main one is major basic protein, which is cytotoxic to helminths!

Question 3

describe the specific inflammatory defense mechansims/mediators of NK cells

Answer 3

these are innate lymphoid cells with 2 types of receptors:
1. activation receptor: recognized viral proteins, altered surface glycoproteins, and antibody-coated cells
2. inhibitory receptor: recognizes self via MHC I expressed on all nucleated cells (stop signal)

if inhibitory signal is absent, NK cells release lytic granules perforin and granzyme; perforin inserts into membrane and granzyme enters that pore and triggers apoptosis; NK cells also secrete IFN-gamma, which activates macrophages

Question 4

recognize products of cell membrane damage and how they contribute to inflammation, identifying opportunities for pharmaceutical intervention

Answer 4

phospholipases break down cell membrane phospholipids and lead to downstream vasodilation: steroids inhibit these

phospholipases trigger arachidonic acid, which can trigger cyclooxygenase to release inflammatory prostaglandins, which can lead to inflammation, but COX-1 and COX-2 inhibitors, aspirin, and indomethacin inhibit cyclooxygenase

Question 5

briefly describe neutrophil clearance mechanisms that lead to resolution of inflammation

Answer 5

neutrophil apoptosis is programmed cell death, a quiet cleanup by macrophages, and release of anti-inflammatory mediators to assist with resolution of inflammation

Question 6

recognize that components of innate immune response can influence adaptive responses, and vice versa

Answer 6

1. helper T cells influence and drive responses and also play a role in cytokine release
2. cytotoxic T cells kill infected cells
3. B cells produce antibodies that have many functions, but bridge divide between innate and immune via opsonizing targets for innate cells to kill too

Question 7

describe clinical signs of inflammation, SIRS, and sepsis

Answer 7

inflammation: redness, heat, pain, swelling, loss of function

SIRS: two or more of: fever, increased heart rate, increased respiratory rate, increased WBC count

sepsis: SIRS plus a documented or highly suspected infection, can escalate to organ dysfunction, hypoperfusion, or hypotension, (severe sepsis) and then can escalate to multi organ dysfunction and unresponsive low BP (septic shock)